@article{HaugVetter, author = {Haug, Sonja and Vetter, Miriam}, title = {Altersgerechtes Wohnen im Quartier}, series = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, volume = {45}, journal = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, publisher = {Springer Nature}, issn = {1432-220X}, doi = {10.1007/s00548-020-00678-3}, pages = {11 -- 17}, abstract = {Im Alter nimmt das Quartier aufgrund geringerer Aktionsradien an Bedeutung zu. Der Beitrag befasst sich mit der Frage, welche Besonderheiten sich bei Senioren-Haushalten im Hinblick auf Wohnen und soziale Teilhabe zeigen. Aus dem Projekt MAGGIE werden Ergebnisse einer schriftlichen Haushaltsbefragung (N=195) in der Wohngenossenschaft Margaretenau Regensburg dargestellt. Hierbei wird auf die aktuelle und zuk{\"u}nftige Wohnsituation, den Ver{\"a}nderungsbedarf, den Wunsch nach Gemeinschaftsangeboten und die soziale Einbettung eingegangen. Es zeigt sich eine geringe Ver{\"a}nderungsbereitschaft und ein {\"u}berdurchschnittlich hohes Maß an lokalem Sozialkapital. Am Ende werden Schlussfolgerungen f{\"u}r das Sanierungs- und Quartiersmanagement gezogen.}, subject = {Alter}, language = {de} } @article{PalombaNowakDawoudetal., author = {Palomba, Valeria and Nowak, Sebastian and Dawoud, Belal and Frazzica, Andrea}, title = {Dynamic modelling of Adsorption systems: a comprehensive calibrated dataset for heat pump and storage applications}, series = {Journal of energy storage}, volume = {33}, journal = {Journal of energy storage}, publisher = {Elsevier}, doi = {10.1016/j.est.2020.102148}, abstract = {The growing efforts for the development of clean and efficient energy systems require the use of a multi-disciplinary approach and the integration of multiple generation appliances. Among the fields that can be considered enabling technologies, adsorption systems for air conditioning and thermal energy storages, are constantly increasing their maturity. However, for a proper design and integration of such systems, there is the need for a simulation framework that is reliable and computationally convenient. In the present paper, the implementation of a dynamic model for adsorption systems is presented, which includes different components (adsorber, phase changer, sorption materials) and is structured as a library. Modelica language and the commercial software Dymola (R) are used for the analysis. Data for different heat exchangers and working pairs are calibrated using experimental results and the calibrated model is subsequently used for the design of an adsorber based on a plate heat exchanger for thermal energy storage applications. The results proved that the model is fast and can reproduce experimental results with good accuracy, thus being a useful tool for the design and optimization of the different components of sorption systems.}, language = {en} } @article{SovacoolCabezaPiselloetal., author = {Sovacool, Benjamin K. and Cabeza, Luisa F. and Pisello, Anna Laura and Colladon, Andrea Fronzetti and Larijani, Hatef Madani and Dawoud, Belal and Martiskainen, Mari}, title = {Decarbonizing household heating: Reviewing demographics, geography and low-carbon practices and preferences in five European countries}, series = {Renewable \& Sustainable Energy Reviews}, journal = {Renewable \& Sustainable Energy Reviews}, number = {139}, publisher = {Elsevier}, doi = {10.1016/j.rser.2020.110703}, pages = {1 -- 28}, abstract = {What commonalities are there in sustainable or unsustainable heating practices in five high-income, high-emitting western European countries? What preferences do a nationally representative sample of the public in these countries hold towards low-carbon options? It is imperative that climate policy researchers and practitioners grapple with the difficulty of decarbonizing heat, which remains the largest single end-use service worldwide and which accounts about half of total final energy consumption. Based on a comparative assessment of five representative national surveys in Germany (N = 2009), Italy (N = 2039), Spain (N = 2038), Sweden (N = 2023), and the United Kingdom (N = 2000), this study explores the demographics and geography of household heat decarbonisation in Europe. By analyzing our country level data as well as our combined sample of 10,109 respondents, it investigates how people conceive of the purposes of low-carbon heat, their preferences for particular forms of heat supply, and their (at times odd) practices of heat consumption and temperature settings. Grounded in its original data, the study organizes its findings inductively across the five themes of literacy (heating knowledge, awareness and control), sustainability (heating practices, dynamics and conflicts), temperature (heating satisfaction and preferences), desirability of change (low-carbon heating priorities, business models and trust), and culture (country and national variation). The study also explores intersections between these dimensions, using multivariate analysis, as well as how preferences differ according to varying types of actors as well as geography and space.}, language = {en} } @article{MonkmanSindersbergerPremetal., author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina and Diermeier, Andreas and Szecsey, Tamara}, title = {Dielectric behaviour of magnetic hybrid materials}, series = {Physical Sciences Reviews}, volume = {7}, journal = {Physical Sciences Reviews}, number = {10}, publisher = {de Gruyter}, doi = {10.1515/psr-2019-0121}, pages = {1169 -- 1185}, abstract = {The objectives of this work include the analysis of electrical and magnetic properties of magneto-elastic hybrid materials with the intention of developing new techniques for sensor and actuator applications. This includes the investigation of dielectric properties at both low and high frequencies. The behaviour of capacitors whose dielectrics comprise magnetic hybrid materials is well known. Such interfacial magnetocapacitance can be varied according to magnetic content, magnetic flux density and the relative permittivity of the polymer matrix together with other dielectric content. The basic function of trapping electrical charges in polymers (electrets) is also established technology. However, the combination of magnetoactive polymers and electrets has led to the first electromagnetic device capable of adhering to almost any material, whether magnetically susceptible or not. During the course of this research, in addition to dielectrics, electrically conductive polymers based on (PDMS) matrices were developed in order to vary the electrical properties of the material in a targeted manner. In order to ensure repeatable results, this demanded new fabrication techniques hitherto unavailable. The 3D printing of silicones is far from being a mature technology and much pioneering work was necessary before extending the usual 3 d.o.f. to include orientation about and diffusion of particles in these three axes, thus leading to the concept of 6D printing. In 6D printing, the application of a magnetic field can be used during the curing process to control the particulate distribution and thus the spatial filler particle density as desired. Most of the devices (sensors and actuators) produced by such methods contain levels of carbonyl iron powder (CIP) embedded magnetic filler of up to 70 wt\%. Contrary to this, a hitherto neglected research area, namely magnetoactive polymers (MAPs) having significantly lower magnetic particle concentrations (1 to 3 wt\% CIP) were also investigated. With filler concentrations lower than 3 wt\%, structures are formed which are completely absent at higher filler levels. CIP concentrations in the range of 1wt\% demonstrate the formation of toroidal structures. Further development of coherent rings with a compact order results as filler concentrations increase towards 2 wt\%. Above 3 wt\% the structure eventually disintegrates to the usual random order found in traditional MAP with higher CIP content. Structured samples containing 1\%-3 wt\% CIP were investigated with the aid of X-ray tomography where solitary ring structures can be observed and eventually the formation of capillary doubles. Over wavelengths ranging from 1 to 25 µm, spectroscopic analysis of thin film MAP samples containing 2 wt\% CIP revealed measurable magnetic-field-dependent changes in IR absorption at a wavenumber 2350 (λ = 4.255 µm). This was found to be due to the diamagnetic susceptibility of atmospheric carbon dioxide (CO2). Consequently, the first potential application for sparse matrix MAPs was found.}, language = {en} } @article{SchwanzerSchillingerMieslingeretal., author = {Schwanzer, Peter and Schillinger, Maximilian and Mieslinger, Johann and Walter, Stefanie and Hagen, Gunter and Maerkl, Susanne and Haft, Gerhard and Dietrich, Markus and Moos, Ralf and Gaderer, Matthias and Rabl, Hans-Peter}, title = {A Synthetic Ash-Loading Method for Gasoline Particulate Filters with Active Oil Injection}, series = {SAR International Journal of Engines}, volume = {14}, journal = {SAR International Journal of Engines}, number = {4}, publisher = {SAE International}, issn = {1946-3936}, doi = {10.4271/03-14-04-0029}, pages = {493 -- 506}, abstract = {To reduce particulate emissions, the use of particulate filters in diesel engines is meanwhile state of the art, while the integration of such systems in gasoline engines is now also necessary in order to comply with today's regulations. Over its lifetime, a gasoline particulate filter (GPF) collects ash components of fuel, lubrication oil, and materials originating from the catalytic coating and from engine abrasion. In the development and application process, synthetic ashing from GPFs is challenging. The ash of the lubrication oil can be increased in various ways, like oil-doped fuel, a separate oil burner, or changes in the piston-cylinder system of the engine. However, these methods show major disadvantages. For this reason, an improved approach is presented in this study, which allows a quick response to changes in combustion (e.g., engine knocking) and producing ash, which is more realistic due to its primary particle size and the density of ash plugs, in a shorter time. Therefore, an approach to accelerate ash loading by active oil injection using a multi-point injection (MPI) system is introduced. With the help of this methodology, an ashing capacity of 1.21 g/h is implemented, which is a high rate compared to other investigations. The primary particle size (evaluated by means of a transmission electron microscope), is in the same size range as those detected at the full-load curve during regular operation. A computer tomographic (CT) analysis of the incinerated particulate filter also shows that a very high density of ash plugs can be realized, which has also been found in the literature for real applications. In addition, with the help of a mass spectrometer (MS) and an intermediate weighing of the particulate filter, the current ash loading of the GPF could be determined with an accuracy of 1\%.}, language = {en} } @article{SchmidtStraubSindersbergeretal., author = {Schmidt, Henrik and Straub, Benedikt B. and Sindersberger, Dirk and Br{\"o}ckel, Ulrich and Monkman, Gareth J. and Auernhammer, G{\"u}nter}, title = {Collision and separation of nickel particles embedded in a Poly dimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function}, series = {Colloid and Polymer Science}, volume = {299}, journal = {Colloid and Polymer Science}, publisher = {Springer}, doi = {10.1007/s00396-020-04784-4}, pages = {955 -- 967}, abstract = {In order to function as soft actuators, depending on their field of use, magnetorheological elastomers (MREs) must fulfill certain criteria. To name just a few, these can include rapid response to external magnetic fields, mechanical durability, mechanical strength, and/or large deformation. Of particular interest are MREs which produce macroscopic deformation for small external magnetic field variations. This work demonstrates how this can be achieved by just a small change in magnetic field orientation. To achieve this, (super)paramagnetic nickel particles of size ≈ 160 μm were embedded in a non-magnetic polydimethylsiloxan (PDMS) (661-1301 Pa) and their displacement in a stepwise rotated magnetic field (170 mT) recorded using a video microscope. Changes in particle aggregation resulting from very small variations in magnetic field orientation led to the observation of a new strongly magneto-active effect. This configuration is characterized by an interparticle distance in relation to the angle difference between magnetic field and particle axis. This causes a strong matrix deformation which in turn demonstrates hysteresis on relaxation. It is shown that the occurrence strongly depends on the particle size, particle distance, and stiffness of the matrix. Choosing the correct parameter combination, the state can be suppressed and the particle-matrix system demonstrates no displacement or hysteresis. In addition, evidences of non-negligible higher order magnetization effects are experimentally ascertained which is qualitatively in agreement with similar, already theoretically described, particle systems. Even at larger particle geometries, the new strongly magneto-active configuration is preserved and could create macroscopic deformation changes.}, language = {en} } @inproceedings{RiegerOetjenvandeParetal., author = {Rieger, Anna and Oetjen, Arne and van de Par, Steven and Rabl, Hans-Peter}, title = {Geh{\"o}rbezogene Modellierung der Dissonanz}, series = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, volume = {47}, booktitle = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, pages = {1034 -- 1037}, language = {de} } @incollection{BauerGawlikSterneretal., author = {Bauer, Franz and Gawlik, Julia and Sterner, Michael and Hamacher, Thomas}, title = {{\"U}bergreifende Energiesystemmodellierung}, series = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, booktitle = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, editor = {Ausfelder, Florian and Dura, Hanna}, publisher = {DECHEMA Gesellschaft f{\"u}r Chemische Technik und Biotechnologie e.V.}, address = {Frankfurt a.M.}, isbn = {978-3-89746-236-6}, pages = {19 -- 33}, language = {de} } @article{LindnerPipaKarpenetal., author = {Lindner, Matthias and Pipa, Andrei V. and Karpen, Norbert and Hink, Ruediger and Berndt, Dominik and Foest, R{\"u}diger and Bonaccurso, Elmar and Weichwald, Robert and Friedberger, Alois and Caspari, Ralf and Brandenburg, Ronny and Schreiner, Rupert}, title = {Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {23}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app112311106}, pages = {1 -- 17}, abstract = {Avoiding ice accumulation on aerodynamic components is of enormous importance to flight safety. Novel approaches utilizing surface dielectric barrier discharges (SDBDs) are expected to be more efficient and effective than conventional solutions for preventing ice accretion on aerodynamic components. In this work, the realization of SDBDs based on thin-film substrates by means of micro-electro-mechanical-systems (MEMS) technology is presented. The anti-icing performance of the MEMS SDBDs is presented and compared to SDBDs manufactured by printed circuit board (PCB) technology. It was observed that the 35 mu m thick electrodes of the PCB SDBDs favor surface icing with an initial accumulation of supercooled water droplets at the electrode impact edges. This effect was not observed for 0.3 mu m thick MEMS-fabricated electrodes indicating a clear advantage for MEMS-technology SDBDs for anti-icing applications. Titanium was identified as the most suitable material for MEMS electrodes. In addition, an optimization of the MEMS-SDBDs with respect to the dielectric materials as well as SDBD design is discussed.}, language = {en} } @misc{SchwanzerDietrichGadereretal., author = {Schwanzer, Peter and Dietrich, Markus and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Detektion unterschiedlicher Medien in Gasoline Particulate Filter (GPF) mit Hilfe eines Radio-Frequenz (RF-) Sensors}, series = {Bayerische Wissenschaftsforum - BayWISS 2020}, journal = {Bayerische Wissenschaftsforum - BayWISS 2020}, language = {de} } @book{AltmannGebhardEmbergeretal., author = {Altmann, Robert and Gebhard, J{\"u}rgen and Emberger, Peter and Thuneke, Klaus and Rabl, Hans-Peter and Remmele, Edgar}, title = {Z{\"u}nd- und Brennverhalten von Pflanzen{\"o}lkraftstoff und {\"U}bertragung auf einen Motor der Abgasstufe V}, volume = {69}, publisher = {Technologie- und F{\"o}rderzentrum im Kompetenzzentrum f{\"u}r Nachwachsende Rohstoffe}, address = {Straubing}, issn = {1614-1008}, pages = {188}, abstract = {Durch den Ersatz von Dieselkraftstoff durch Raps{\"o}lkraftstoff (R100) k{\"o}nnen Treibhausgasemissionen reduziert werden. F{\"u}r einen st{\"o}rungsfreien Betrieb eines Motors mit Raps{\"o}lkraftstoff sind jedoch Modifikationen an Motorkomponenten und Motorsteuerger{\"a}t notwendig, um eine effiziente Verbrennung im Motor zu erreichen. Ziel des Vorhabens ist die Erarbeitung von Grundlagen zur Auslegung der Motorsteuerung pflanzen{\"o}ltauglicher Offroad-Motoren mit moderner Abgasnachbehandlung mit anschließender entsprechender Abstimmung der Motorapplikation am Pr{\"u}fstand. Grundlegende Untersuchungen der physikalischen Prozessabl{\"a}ufe von R100 bei der Einspritzung werden an einem hydraulischen Druckanstiegsanalysator (HDA) und einer Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) durchgef{\"u}hrt. Unterschiede im Z{\"u}nd- und Brennverhalten werden in einer Konstantvolumenbrennkammer untersucht. Abschließend werden die Erkenntnisse am Motorenpr{\"u}fstand auf einen DEUTZ-Motor {\"u}bertragen, dessen Einspritzsystem auch bei den grundlegenden Untersuchungen verwendet wurde. Die Ergebnisse zeigen, dass das Einspritzverhalten von R100 eine h{\"o}here Sensitivit{\"a}t gegen{\"u}ber Kraftstofftemperaturvariationen aufweist als Dieselkraftstoff. Bei niedrigen raftstofftemperaturen sind mit R100 ein l{\"a}ngerer {\"O}ffnungsverzug und eine geringere Einspritzmenge festzustellen. Um diesen Einfluss bei der Einspritzstrategie zu kompensieren, ist die Kenntnis der Kraftstofftemperatur im Injektor notwendig. Eine weitere Herausforderung stellt die Gemischaufbereitung dar, hier f{\"u}hren unter anderem die h{\"o}here Viskosit{\"a}t und h{\"o}here Siedetemperaturen von R100 zu einem schm{\"a}leren Spritzwinkel und verz{\"o}gerter Verdampfung im Vergleich zum Dieselkraftstoff. Eine Erh{\"o}hung des Einspritzdrucks und h{\"o}here Temperaturen und Dr{\"u}cke in der Brennkammer verbessern die Gemischaufbereitung. Bei Bedingungen von mittlerer und hoher Last ist der Z{\"u}ndverzug von R100 k{\"u}rzer und das Verbrennungsverhalten {\"a}hnlich zum Dieselkraftstoff. Eine geringere W{\"a}rmefreisetzung von R100 wird durch den geringeren Heizwert verursacht. Unter Bedingungen von niedriger Last und Motorstart ist ein l{\"a}ngerer Z{\"u}ndverzug von R100 im Vergleich zum Dieselkraftstoff festzustellen. Eine Steigerung des Einspritzdrucks und h{\"o}here Brennkammerdr{\"u}cke und -temperaturen f{\"u}hren bei beiden Kraftstoffen zu k{\"u}rzeren Z{\"u}ndverz{\"u}gen, der Einfluss dieser Parameter ist jedoch f{\"u}r R100 st{\"a}rker als f{\"u}r Dieselkraftstoff. Voreinspritzungen f{\"u}hren bei beiden Kraftstoffen zu einer Verk{\"u}rzung des Z{\"u}ndverzugs der Haupteinspritzung und zu einer geringeren W{\"a}rmefreisetzungsrate. Am Motorpr{\"u}fstand ist bei gleicher Motorapplikation mit R100 eine geringere Leistung als mit Dieselkraftstoff festzustellen. Nach Angleichung der Motorleistung durch Anhebung der Einspritzmenge von R100 sind im Rohabgas Stickstoffoxid (NOX)- und Kohlenstoffmonoxidemissionen auf gleichem Niveau zu Dieselkraftstoff zu beobachten sowie geringere Partikelemissionen. Unter Verwendung eines DoE Vorgehens kann der Partikel-NOX - trade-off von R100 optimiert und Einstellparameter gefunden werden, in denen sowohl niedrigere NOX als auch niedrigere Partikelemissionen im Vergleich zum Dieselkraftstoff resultieren. Das installierte Abgasnachbehandlungssystem, bestehend aus einem Dieseloxidationskatalysator (DOC), Dieselpartikelfilter (DPF) und selektivem katalytischem Reduktionssystem (SCR), arbeitet f{\"u}r beide Kraftstoffe {\"a}hnlich und es scheint keine Anpassung der Dosierungsstrategie der w{\"a}ssrigen Harnstoffl{\"o}sung notwendig zu sein. Eine Regeneration des Partikelfilters mit R100 war nach Optimierung der Einstellparameter der Drosselklappe m{\"o}glich. Motorkaltstart und Leerlauf sind herausfordernde Betriebsphasen, die f{\"u}r R100 einer weiteren Optimierung bed{\"u}rfen. Eine Temperierung von R100 im Injektor auf 50-60 °C sowie eine Kompensation der Einspritzmenge in Abh{\"a}ngigkeit von der Kraftstofftemperatur sind m{\"o}gliche Verbesserungsmaßnahmen. Zudem kann durch einen fr{\"u}heren Einspritzbeginn von R100 das Verbrennungsverhalten angepasst werden. Die Motorpr{\"u}fstandsuntersuchungen best{\"a}tigen qualitativ die Erkenntnisse die mit dem hydraulischen Druckanstiegsanalysator (HDA), der Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) und der Konstantvolumenbrennkammer gewonnen wurden. Weitere Untersuchungen sind notwendig, um die Ergebnisse auf einen baugleichen, in einer mobilen Arbeitsmaschine eingebauten Motor zu transferieren, damit Informationen zur Dauerhaltbarkeit unter realen Bedingungen erhalten werden k{\"o}nnen. Weiterf{\"u}hrende Forschungsarbeiten sind im Bereich der Betriebsphasen des Motorkaltstarts und Leerlaufs mit Raps{\"o}lkraftstoff n{\"o}tig, um einen dauerhaft st{\"o}rungsfreien Betrieb in diesen Betriebsphasen zu erreichen. Die erzielten Erkenntnisse deuten darauf hin, dass hier noch viel Verbesserungspotenzial vorhanden ist.}, subject = {Biokraftstoff}, language = {de} } @misc{OetjenRiegerRabletal., author = {Oetjen, Arne and Rieger, Anna and Rabl, Hans-Peter and van de Par, Steven}, title = {The role of dissonance in the sound quality perception for electric vehicles}, series = {The Journal of the Acoustical Society of America}, volume = {148}, journal = {The Journal of the Acoustical Society of America}, number = {4}, publisher = {Acoustical Society of America}, doi = {10.1121/1.5147356}, abstract = {Tonal components can be regarded as one of the most relevant components for interior sound quality of electric vehicles, especially at low speeds. Sources for these tones are for example the vehicles' drivetrains but also other technical components. Depending on the driving conditions, due to the interaction of various dominant sources, audible tone complexes can occur. Similar to musical intervals, the different frequency ratios within these complexes can result in consonant or dissonant sensations. The strength of this sensation does not only depend on the frequency relation of the tones but also on their relative levels. In this study, different musical intervals were subjectively rated in terms of their specific consonant or dissonant character. Using an adaptive procedure, sound pairs, each consisting of a two-tone signal, where adjusted to equal dissonance by varying the level of the second tone of one of the two-tone signals. Using the same paradigm, also pairs of equal vehicle sound quality were obtained. With these results, it is possible to quantify dissonance, and theinfluence of dissonance on sound quality expressed in terms of level differences of two-tone signals. These results can help to make the concept of dissonance more useful for sound-engineering applications.}, language = {en} } @incollection{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Haft, Gerhard and Dietrich, Markus and Rabl, Hans-Peter and Moos, Ralf}, title = {Hochfrequenzsensorik zur direkten Beladungserkennung von Benzinpartikelfiltern}, series = {Automobil-Sensorik 3}, booktitle = {Automobil-Sensorik 3}, editor = {Tille, Thomas}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-61259-0}, doi = {10.1007/978-3-662-61260-6_7}, pages = {185 -- 208}, abstract = {In Folge der Versch{\"a}rfung der gesetzlichen Abgasnormen wurden f{\"u}r direkt-einspritzende Benzinmotoren Partikelfilter notwendig. Zur Beladungs{\"u}berwachung k{\"o}nnen aufgrund stark unterschiedlicher Rahmenbedingungen die aus Dieselmotoren bekannten Systeme, wie dem Differenzdrucksensor, nur eingeschr{\"a}nkt {\"u}bernommen werden. Ein hochfrequenzbasiertes Verfahren koppelt mittels Antennen elektromagnetische Wellen in das Filtergeh{\"a}use ein, deren Ausbreitungsverhalten durch die dielektrischen Eigenschaften des eingelagerten Rußes beeinflusst wird. Hierdurch kann bei Auswertung von Transmissionsd{\"a}mpfung oder Resonanzfrequenzen die Rußbeladung direkt detektiert werden.}, language = {en} } @misc{SchwanzerMieslingerRabletal., author = {Schwanzer, Peter and Mieslinger, Johann and Rabl, Hans-Peter and Dietrich, Markus and Haft, Gerhard and Walter, Stefanie and Hagen, Gunter and Moos, Ralf and Gaderer, Matthias}, title = {Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor}, series = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, journal = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, abstract = {In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor.}, language = {en} } @article{Briem, author = {Briem, Ulrich}, title = {Die neue VDI 2500 : Faserseilwissen kompakt}, series = {Logistik f{\"u}r Unternehmen}, journal = {Logistik f{\"u}r Unternehmen}, number = {11-12}, pages = {36 -- 37}, abstract = {Die Richtlinie VDI 2500 „Faserseile" hat 1990 erstmals zusammenfassend den Stand der Technik auf dem Gebiet der Faserseile dargestellt und wertvolle Infor-mationen {\"u}ber Aufbau, Auswahl, Konfek-tionierung und {\"U}berwachung von Faser-seilen gegeben. Die jetzt erscheinende zweite Auflage enth{\"a}lt eine Vielzahl wichtiger technischer Neuerungen f{\"u}r die Praxis. Zu nennen sind hier die hochfesten Fasern und deren Beschichtung sowie die erstmals systematisch aufgef{\"u}hrten Sei-lendverbindungen und ein Ausblick auf die zuk{\"u}nftig bedeutsamen sogenannten Hybridseile. Eine Checkliste hilft bei der richtigen Auswahl und Bemessung von Faserseilen. Bei den Normen wurde - soweit m{\"o}glich - auf europ{\"a}ische Normen verwiesen.}, language = {de} } @article{Briem, author = {Briem, Ulrich}, title = {Umlaufbiegewechselzahl von verdichteten Seildr{\"a}hten}, series = {Draht}, journal = {Draht}, number = {6}, pages = {14 -- 15}, language = {de} } @misc{SchrollDecker, author = {Schroll-Decker, Irmgard}, title = {Rezension zu: Ethik des Wissens. Freiheit und Verantwortung der Wissenschaft in Zeiten des Klimawandels. oekom Verlag (M{\"u}nchen) 2019. ISBN 978-3-96238-163-9}, series = {socialnet Rezensionen}, journal = {socialnet Rezensionen}, issn = {2190-9245}, language = {de} } @article{RomeisKostrovKramarenkoetal., author = {Romeis, Dirk and Kostrov, Sergei A. and Kramarenko, Elena Yu and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail and Saphiannikova, M.}, title = {Magnetic-field-induced stress in confined magnetoactive elastomers}, series = {Soft Matter}, volume = {16}, journal = {Soft Matter}, number = {39}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, doi = {10.1039/D0SM01337D}, pages = {9047 -- 9058}, abstract = {We present a theoretical approach for calculating the state of stress induced by a uniform magnetic field in confined magnetoactive elastomers of arbitrary shape. The theory explicitly includes the magnetic field generated by magnetizable spherical inclusions in the sample interior assuming a non-linear magnetization behavior. The initial spatial distribution of particles and its change in an external magnetic field are considered. This is achieved by the introduction of an effective demagnetizing factor where both the sample shape and the material microstructure are taken into account. Theoretical predictions are fitted to the stress data measured using a specifically designed experimental setup. It is shown that the theory enables the quantification of the effect of material microstructure upon introducing a specific microstructural factor and its derivative with respect to the extensional strain in the undeformed state. The experimentally observed differences between isotropic and anisotropic samples, compliant and stiff elastomer matrices are explained.}, language = {en} } @article{GeilfussDawoud, author = {Geilfuß, Kristina and Dawoud, Belal}, title = {Analytical investigation of a zeolite-NaY-water adsorption heat and cold storage and its integration into a steam power process}, series = {Energy}, volume = {195}, journal = {Energy}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.energy.2020.116977}, abstract = {tabilizing the effects of greenhouse gas emissions on the atmosphere is a key step towards solving the global climate change problems. Storage technologies play an essential role in compensating the discrepancy between surplus energy and peak times. Sorption processes, in particular, offer an environment friendly way for almost loss-free heat (of adsorption or absorption) and cold storage. This work is dedicated first to analytically investigate the potential of applying NaY-Water/Zeolite as a working pair for heat and cold storage upon utilizing high temperature heat. It turned out that, the mass of the adsorber heat exchanger increases the useful specific heat stored from 229 kWh/tzeolite for the ideal storage to 538 kWh/tzeolite or even higher depending on the thermal capacity of the adsorber heat exchanger (AdsHX). Contrary to that trend, COP will decrease with increasing the thermal capacity of the AdsHX. Sensible heat losses between charging and discharging phases do have a negative effect on both stored heating capacity and COP. In addition, an innovative hybrid steam power cum adsorption storage process is introduced and analytically investigated at different ambient conditions and time scenarios for on-peak and off-peak durations over the day. The introduced hybrid process seems quite promising in achieving electrical power production and efficiency enhancements during peak load durations. The extent of enhancing both performance indicators increases with increasing the ambient temperature difference between peak and off-peak times.}, language = {en} } @article{SnarskiiShamoninChamonineYuskevich, author = {Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Yuskevich, Pavel}, title = {Effective medium theory for the elastic properties of composite materials with various percolation thresholds}, series = {Materials}, volume = {13}, journal = {Materials}, number = {5}, publisher = {MPDI}, address = {Basel}, doi = {10.3390/ma13051243}, pages = {1 -- 19}, abstract = {It is discussed that the classical effective medium theory for the elastic properties of random heterogeneous materials is not congruous with the effective medium theory for the electrical conductivity. In particular, when describing the elastic and electro-conductive properties of a strongly inhomogeneous two-phase composite material, the steep rise of effective parameters occurs at different concentrations. To achieve the logical concordance between the cross-property relations, a modification of the effective medium theory of the elastic properties is introduced. It is shown that the qualitative conclusions of the theory do not change, while a possibility of describing a broader class of composite materials with various percolation thresholds arises. It is determined under what conditions there is an elasticity theory analogue of the Dykhne formula for the effective conductivity. The theoretical results are supported by known experiments and show improvement over the existing approach. The introduction of the theory with the variable percolation threshold paves the way for describing the magnetorheological properties of magnetoactive elastomers. A similar approach has been recently used for the description of magneto-dielectric and magnetic properties.}, language = {en} } @article{SnarskiiShamoninChamonineYuskevichetal., author = {Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Yuskevich, Pavel and Saveliev, Dmitry V. and Belyaeva, Inna A.}, title = {Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold}, series = {Physica A: Statistical Mechanics and its Applications}, volume = {560}, journal = {Physica A: Statistical Mechanics and its Applications}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.physa.2020.125170}, abstract = {In composite materials, with field-dependent restructuring of the filler material (changes in the mutual arrangement of inclusions), the presence of an external magnetic field induces anisotropy of the dielectric properties, even if the composite is isotropic in the absence of an external field. A modified effective medium approximation is proposed for the calculation of the components of effective permittivity within a class of composites with reconfigurable microstructure, where both phases (the filler and the matrix) are isotropic and the inclusions have spherical shape. The effective physical properties are calculated in the parallel and perpendicular directions to an applied field. The appearance of the anisotropy of the permittivity is simulated by the introduction of two not-equal, possibly variable (field-dependent) percolation thresholds. The implications, of the proposed theoretical approach, are demonstrated for the case of the dielectric properties of magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of micrometer-sized magnetic inclusions can significantly change in an applied magnetic field. A reasonable agreement between theory and experiment at a measurement frequency of 1 kHz is found, and is improved in comparison to the previous models. The components of the effective permittivity tensor, characterizing the dielectric properties along the direction of the applied magnetic field and in the orthogonal direction, grow with an increasing field. This growth is more pronounced for the permittivity component in the field direction. The possible extensions of the theoretical model and future directions of research are discussed. The presented theoretical approach can be useful for the application-driven development of a number of smart materials, in particular electro- and magnetorheological gels, elastomers and fluids.}, language = {en} } @article{SavelievBelyaevaChashinetal., author = {Saveliev, Dmitry V. and Belyaeva, Inna A. and Chashin, Dmitri V. and Fetisov, Leonid Y. and Romeis, Dirk and Kettl, Wolfgang and Kramarenko, Elena Yu and Saphiannikova, M. and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail}, title = {Giant extensional strain of magnetoactive elastomeric cylinders in uniform magnetic fields}, series = {Materials}, volume = {13}, journal = {Materials}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma13153297}, pages = {1 -- 17}, abstract = {Elongations of magnetoactive elastomers (MAEs) under ascending-descending uniform magnetic fields were studied experimentally using a laboratory apparatus specifically designed to measure large extensional strains (up to 20\%) in compliant MAEs. In the literature, such a phenomenon is usually denoted as giant magnetostriction. The synthesized cylindrical MAE samples were based on polydimethylsiloxane matrices filled with micrometer-sized particles of carbonyl iron. The impact of both the macroscopic shape factor of the samples and their magneto-mechanical characteristics were evaluated. For this purpose, the aspect ratio of the MAE cylindrical samples, the concentration of magnetic particles in MAEs and the effective shear modulus were systematically varied. It was shown that the magnetically induced elongation of MAE cylinders in the maximum magnetic field of about 400 kA/m, applied along the cylinder axis, grew with the increasing aspect ratio. The effect of the sample composition is discussed in terms of magnetic filler rearrangements in magnetic fields and the observed experimental tendencies are rationalized by simple theoretical estimates. The obtained results can be used for the design of new smart materials with magnetic-field-controlled deformation properties, e.g., for soft robotics.}, language = {en} } @article{SavelievBelyaevaChashinetal., author = {Saveliev, Dmitry V. and Belyaeva, Inna A. and Chashin, Dmitri V. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Large Wiedemann effect in a magnetoactive elastomer}, series = {Journal of Magnetism and Magnetic Materials}, volume = {511}, journal = {Journal of Magnetism and Magnetic Materials}, number = {October}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2020.166969}, abstract = {Large twists of a soft tube (hollow cylinder) in helical magnetic fields are presented for the first time. Such a phenomenon is usually denoted as the Wiedemann effect. The tube is fabricated from a soft magnetoactive elastomer material with the shear modulus of about 56 kPa. The composite material comprises 80 mass\% of micrometer-sized iron particles embedded into a polydimethylsiloxane matrix. The circular magnetic field is generated by an electric current in a straight wire passing through the inner hole of the tube. The maximum value of approximately 350″/cm is observed in a longitudinal magnetic field of a few kA/m overlapped with a circumferential magnetic field of about 1.4 kA/m on the surface of the inner hole. A pronounced hysteresis in the dependence of the Wiedemann effect on the circular magnetic field is found. The ways to enhance the Wiedemann twist in magnetoactive elastomers are discussed. The observed large effect is promising for application in magnetic-field controlled torsional actuators, in particular for soft robotics.}, language = {en} } @article{AndersBriemNovaketal., author = {Anders, M. and Briem, Ulrich and Novak, G. and Steinbach, G.}, title = {Inspektionsintervalle im Blick}, series = {Technische Logistik}, journal = {Technische Logistik}, publisher = {Huss-Medien}, address = {Berlin}, pages = {14 -- 17}, language = {de} } @article{BrockKoderRabletal., author = {Brock, Damian and Koder, Alexander and Rabl, Hans-Peter and Touraud, Didier and Kunz, Werner}, title = {Optimising the biodiesel production process: Implementation of glycerol derivatives into biofuel formulations and their potential to form hydrofuels}, series = {Fuel}, volume = {264}, journal = {Fuel}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2019.116695}, abstract = {A new biofuel concept is developed, enabling the usage of vegetable oils and glycerol derivatives in mixtures with biodiesel. This concept significantly enhances the biodiesel production's profitability and thus strongly contributes to the sustainability of future biofuels. After simple addition reactions with building block chemicals, less hydrophilic glycerol derivatives are obtained, which are compatible with biofuels. Even more, the products of the reactions of glycerol with acetone or butyric acid, referred to as solketal and tributyrin, respectively, lead to promising biofuels in mixtures with rapeseed oil and its biodiesel. Due to their low freezing points, they act as cloud and freezing point depressants, when added to vegetable oil/biodiesel blends. Further, since their viscosity is close to common biodiesel, biofuels containing high amounts of vegetable oil and even more glycerol derivatives than they arise during the biodiesel production can be obtained. Thus, this new class of biofuels enables adaptable compositions depending on the application and also the usage as drop-in fuel without any or just few percent of further additives. After optimising the formulations, ignition delay, exhaust gas recirculation, fuel consumption and combustion process measurements were performed in an unmodified upto-date diesel engine. The experiments showed that the properties of the formulated biofuels are either similar to or even better than diesel. The hydrotropy of the glycerol derivatives in these mixtures enables the potential to implement water into biofuels, so-called hydrofuels, reducing nitrogen oxide emissions and leading to further optimised dropin fuels.}, language = {en} } @article{FrazzicaBrancatoDawoud, author = {Frazzica, Andrea and Brancato, Vincenza and Dawoud, Belal}, title = {Unified Methodology to Identify the Potential Application of Seasonal Sorption Storage Technology}, series = {Energies}, volume = {13}, journal = {Energies}, number = {5}, publisher = {MPDI}, address = {Basel}, doi = {10.3390/en13051037}, pages = {1 -- 17}, abstract = {In this study, the definition of a new methodology for a preliminary evaluation of the working boundary conditions under which a seasonal thermal energy storage (STES) system operates is described. The approach starts by considering the building features as well as the reference heating system in terms of solar thermal collectors' technology, ambient heat sinks/source, and space heating distribution systems employed. Furthermore, it is based on a deep climatic analysis of the place where the STES needs to be installed, to identify both winter and summer operating conditions. In particular, the STES energy density is evaluated considering different space heating demands covered by the STES (ranging from 10\% up to 60\%). The obtained results demonstrate that this approach allows for the careful estimation of the achievable STES density, which is varies significantly both with the space heating coverage guaranteed by the STES as well as with the ambient heat source/sink that is employed in the system. This confirms the need for careful preliminary analysis to avoid the overestimation of the STES material volume. The proposed approach was then applied for different climatic conditions (e.g., Germany and Sweden) and the volume of one of the most attractive composite sorbent materials reported in the literature, i.e., multi-wall carbon nanotubes (MWCNT)-LiCl, using water as the working fluid, needed for covering the variable space heating demand in a Nearly Zero Energy Building (NZEB) was calculated. In the case of Swedish buildings, it ranges from about 3.5 m3 when 10\% of the space heating demand is provided by the STES, up to 11.1 m3 when 30\% of the space heating demand is provided by the STES.}, language = {en} } @inproceedings{SchiedermeierRettnerSteineretal., author = {Schiedermeier, Maximilian and Rettner, Cornelius and Steiner, Marcel and M{\"a}rz, Martin}, title = {Dual-inverter control synchronization strategy to minimize the DC-link capacitor current}, series = {2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain}, booktitle = {2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain}, publisher = {IEEE}, doi = {10.1109/VPPC49601.2020.9330921}, pages = {1 -- 6}, abstract = {This paper proposes the possible switching synchronization strategies of an automotive dual-inverter against the background of minimizing the RMS DC-link capacitor current. The publication mainly focuses on the straight-ahead motion of a rear axle with one electric drive per wheel. In addition to it, a dual-inverter consisting of two subinverters with a common DC-link capacitor is taken into consideration. These sub-inverters each have three phases and are based on a 2-level voltage-source-topology. To control the electrical machines, the continuous Space-Vector-Modulation strategy is used. For this application, different control signal synchronization strategies of the two sub-inverters of the dualinverter are presented. Apart from the existing strategies, this paper proposes a new method, which inherits a compromise between low complexity and high effectiveness. In contrast to previous publications, the resulting capacitor currents are quantified and subsequentlyevaluated. This novel quantification, which is dependent on the dual-inverter's operating point, provides a base for targeted dimensioning of the capacitor. Moreover, this forms the foundation for further investigations of vehicle's cornering, as well as for the possible synchronization of stand-alone inverters. In the context of this publication, the presented results are verified by experimentally determined data of a motor-inverter system.}, language = {en} } @article{ChatzitakisSafarovOpferkuchetal., author = {Chatzitakis, Paris and Safarov, Javid and Opferkuch, Frank and Dawoud, Belal and Hassel, Egon}, title = {Vapor pressures and activity coefficients of 2,2,2-trifluoroethanol in binary mixtures with 1,3-dimethyl-2-imidazolidinone and 2-pyrrolidone}, series = {Journal of Molecular Liquids}, volume = {305}, journal = {Journal of Molecular Liquids}, number = {May}, publisher = {Elsevier}, issn = {0167-7322}, doi = {10.1016/j.molliq.2020.112828}, abstract = {The vapor pressures of two binary mixtures containing 2-trifluoroethanol (TFE) + 1,3-dimethyl-2-imidazolidinone (DMI) and TFE + 2-pyrrolidone (PYR), were investigated at temperatures T = (274.15 to 423.15) K using two different static method installations. Both combinations were modelled using an extended Clausius-Clapeyron equation with concentration dependent parameters and the NRTL equation with temperature dependent parameters. The best fit was obtained using the NRTL equation.}, language = {en} } @article{HaslbeckBrueckl, author = {Haslbeck, Matthias and Br{\"u}ckl, Oliver}, title = {Netzplanung Mittelspannungsnetze: Abbildung eines innovativen Blindleistungsmanagements, Teil 1 und 2}, series = {ew - Magazin f{\"u}r die Energiewirtschaft}, journal = {ew - Magazin f{\"u}r die Energiewirtschaft}, number = {7-8 und 9}, pages = {36 -- 39}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Ohne Speicher, Wasserstoff und Power-to-X keine Dekarbonisierung von Verkehr und Industrie - M{\"o}glichkeiten und Notwendigkeit der integrierten Sektorenkopplung}, series = {CIGRE/CIRED Informationsveranstaltung 2020, Leipzig, 13.10.2020}, journal = {CIGRE/CIRED Informationsveranstaltung 2020, Leipzig, 13.10.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Power-to-Gas technologies in the energy sector and their role in the fight against climate change}, series = {Hungarian Power-to-Gas REKK Forum, Budapest Corvinus University, 12.02.2020}, journal = {Hungarian Power-to-Gas REKK Forum, Budapest Corvinus University, 12.02.2020}, language = {en} } @misc{Sterner, author = {Sterner, Michael}, title = {Die Rolle von Wasserstoff in allen Sektoren}, series = {Sektoren{\"u}bergreifende Erkenntnisse zu PtX Fachforum "Wasserstoff Technologie, Prozesssicherheit und Regionalentwicklung", Kurt-Schwabe-Institut f{\"u}r Mess- und Sensortechnik Meinsberg e.V.) Meinsberg, 23.9.2020}, journal = {Sektoren{\"u}bergreifende Erkenntnisse zu PtX Fachforum "Wasserstoff Technologie, Prozesssicherheit und Regionalentwicklung", Kurt-Schwabe-Institut f{\"u}r Mess- und Sensortechnik Meinsberg e.V.) Meinsberg, 23.9.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Power-to-X im Kontext der Energiewende und des Klimaschutzes in Deutschland}, series = {Hydrogen Dialogue H2.Bayern, 18.11.2020, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t}, journal = {Hydrogen Dialogue H2.Bayern, 18.11.2020, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Bedeutung des Klimaschutzes f{\"u}r die Wirtschaft in Ostbayern}, series = {Veranstaltungsreihe der Freunde der OTH Regensburg e. V., Regensburg, Regensburg 25.11.2020}, journal = {Veranstaltungsreihe der Freunde der OTH Regensburg e. V., Regensburg, Regensburg 25.11.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Vom Klimaschutz zum Wasserstoff in Verkehr und Industrie - jetzt regional handeln}, series = {Kick-Off Workshop: HyExpert Wasserstoffmodellregion Fichtelgebirge, Wunsiedel, 22.09.2020}, journal = {Kick-Off Workshop: HyExpert Wasserstoffmodellregion Fichtelgebirge, Wunsiedel, 22.09.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Wasserstoff als zentraler Baustein der Energiewende in S{\"u}ddeutschland: Powerto- Gas und der rechtliche Rahmen}, series = {1. Wasserstofftag S{\"u}ddeutschland, Um 29.10.2020}, journal = {1. Wasserstofftag S{\"u}ddeutschland, Um 29.10.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Warum wir Power-to-X f{\"u}r die Klimaneutralit{\"a}t und Mobilit{\"a}tswende brauchen}, series = {DECHEMA Fachforum Diesel: Mobilit{\"a}tswende durch alternative Antriebe und Kraftstoffe:, Frankfurt 02.12.2020}, journal = {DECHEMA Fachforum Diesel: Mobilit{\"a}tswende durch alternative Antriebe und Kraftstoffe:, Frankfurt 02.12.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Wasserstoff - Energietr{\"a}ger der Zukunft}, series = {BBA Forum, Passau 24.11.2020}, journal = {BBA Forum, Passau 24.11.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Megathema Wasserstoff: Power-to-X im Kontext der Energiewende und des Klimaschutzes in Deutschland}, series = {IRES Symposium, Berlin 18.11.2020}, journal = {IRES Symposium, Berlin 18.11.2020}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {The role of green H 2 + Power-to-X in the German Energy Transition}, series = {First Brazilian-German Green Hydrogen Congress, Brasilia 06.10.2020}, journal = {First Brazilian-German Green Hydrogen Congress, Brasilia 06.10.2020}, language = {en} } @inproceedings{HaenninenNiemetzSchoepe, author = {H{\"a}nninen, Risto and Niemetz, Michael and Schoepe, Wilfried}, title = {Transition to turbulence in oscillatory superflows}, series = {ETC 2013 - 14th European Turbulence Conference 2020: 2 September 2013 - 4 September 2013, Lyon, France}, booktitle = {ETC 2013 - 14th European Turbulence Conference 2020: 2 September 2013 - 4 September 2013, Lyon, France}, abstract = {The flow of superfluid helium-4 at very low temperatures around an oscillating microsphere has been studied in detail. At small oscillation amplitudes the drag force is linear in velocity amplitude. Above a critical velocity amplitude vc a transition from potential flow to turbulent flow is signaled by a large and nonlinear drag force that scales as (v2 - v2 c ), where vc is found to be independent of temperature (below 1 K) and of driving force. Interestingly, the critical velocity is found to scale as vc ~ √κω, where κ = h/m ≈ 10-7 m2/s (h is Planck's constant and m is the mass of a helium-4 atom) is the circulation quantum of the superfluid vortices and ω/2π is the oscillation frequency ranging from about 120 Hz to 700 Hz. We also observe slightly above vc that the flow pattern is unstable and switches intermittently between potential flow and turbulence. From time series recorded at constant drive and temperature we have investigated the statistical properties of this switching phenomenon. In this talk the universal law vc ~ √κω will be discussed in detail. It can be derived theoretically in various ways: firstly, from a qualitative but very general argument based on the "superfluid Reynolds number" Rs = vl/κ where v is the flow velocity and l is a characteristic length scale, secondly, and in more detail, from Kopnin's equation of the time dependence of the vortex line density, and, finally, we have obtained this law rigorously by dynamical scaling of the equations of motion of vortex dynamics.}, language = {en} } @inproceedings{RiegerMuehlbauerRabletal., author = {Rieger, Anna and M{\"u}hlbauer, Christian and Rabl, Hans-Peter and Weber, Rainer}, title = {Dissonanz als Bewertungskriterium multi-tonalen Schalls}, series = {Fortschritte der Akustik - DAGA 2020: 46. Deutsche Jahrestagung f{\"u}r Akustik}, booktitle = {Fortschritte der Akustik - DAGA 2020: 46. Deutsche Jahrestagung f{\"u}r Akustik}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, pages = {788 -- 791}, language = {de} } @inproceedings{MuehlbauerRablRottengruber, author = {M{\"u}hlbauer, Christian and Rabl, Hans-Peter and Rottengruber, Herrmann}, title = {Development of a Methodology for Acoustic Analysis and Optimization of Mechatronic Fuel Injection Systems}, series = {Automotive Acoustics Conference 2019: Proceedings, 5. Internationale ATZ-Fachtagung Fahrzeugakustik}, booktitle = {Automotive Acoustics Conference 2019: Proceedings, 5. Internationale ATZ-Fachtagung Fahrzeugakustik}, editor = {Siebenpfeiffer, Wolfgang}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-27668-3}, doi = {10.1007/978-3-658-27669-0_15}, pages = {211 -- 225}, abstract = {To identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed that simulates the structure and airborne noise emission. The setup of the system test bench includes an assembly of the acoustical relevant engine parts and an encapsulated drive for the high-pressure pump. A specific control unit enables a high variability for the operation strategy of the injection system. The focus of this study is on the development of a methodology to analyze and optimize the sound quality of gasoline direct injectors in critical operation points by suitable active means. For this, the injection parameters in engine idle have been identified and subsequently transferred to the system test bench. Additionally, the injection parameters have been optimized acoustically and the impacts on the key functions regarding injection rating and shot-to-shot scattering of the injected fuel mass are discussed.}, language = {en} } @inproceedings{ReindlMeierNiemetz, author = {Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Scalable, Decentralized Battery Management System Based on Self-organizing Nodes}, series = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, volume = {12155}, booktitle = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, editor = {Brinkmann, Andr{\´e} and Karl, Wolfgang and Lankes, Stefan and Tomforde, Sven and Pionteck, Thilo and Trinitis, Carsten}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-52793-8}, doi = {10.1007/978-3-030-52794-5_13}, pages = {171 -- 184}, abstract = {Due to the transition to renewable energy sources and the increasing share of electric vehicles and smart grids, batteries are gaining in importance. Battery management systems (BMSs) are required for optimal, reliable operation. In this paper, existing BMS topologies are presented and evaluated in terms of reliability, scalability and flexibility. The decentralisation of BMSs and associated advantages are shown. A scalable, reconfigurable BMS based on a distributed architecture of self-organized, locally controlled nodes is proposed. For distributed system control, producers, batteries and consumers each are equipped with a local microcontroller based control unit, which monitors and controls the local parameters with its own computing and communication resources. Features, advantages and challenges to overcome of the proposed approach are described.}, language = {en} } @inproceedings{AndersBriemNovaketal., author = {Anders, M. and Briem, Ulrich and Novak, G. and Steinbach, G.}, title = {Neue VDI-Richtlinie f{\"u}r die Seiltriebauslegung}, series = {28. Internationale Kranfachtagung 2020 "Kran 4.0: Potenziale der Digitalisierung", 4. und 5. M{\"a}rz 2020, Magdeburg}, booktitle = {28. Internationale Kranfachtagung 2020 "Kran 4.0: Potenziale der Digitalisierung", 4. und 5. M{\"a}rz 2020, Magdeburg}, editor = {Katterfeld, Andr{\´e} and Krause, Friedrich and Pfeiffer, Dagmar and Richter, Klaus}, publisher = {LOGiSCH GmbH}, address = {Magdeburg}, isbn = {978-3-947068-08-1}, pages = {59 -- 72}, language = {de} } @inproceedings{DiamantidisSykora, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Reliability Differentiation and Uniform Risk in Standards}, series = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, booktitle = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, doi = {10.5592/CO/FTCE.2019.11}, pages = {241 -- 260}, abstract = {Reliability of structures and infrastructures is a major issue in structural engineering. Structural standards have traditionally been mainly concerned with public safety preventing loss of life or injury; this view has been shifting in recent years towards minimisation of economic loss. This contribution discusses the reliability differentiation principle in modern standards. Its aim is to achieve uniform risk levels for the various classes of structures. Codified criteria for reliability differentiation and risk informed decisions inherent in standards and especially in the Eurocodes are critically reviewed. It is shown that the classification of structures based on consequences of failure is an approach that has not been widely implemented in everyday design. Practical rules for the classification and implementation in design are needed and related proposals are presented.}, language = {en} } @inproceedings{Roesel, author = {R{\"o}sel, Birgit}, title = {A concept of a mainly digitalized course on control theory including problembased practical units and digital supported exams}, series = {HEAd'20: Sixth International Conference on Higher Education Advances, June 2 - June 5 2020, Valencia (Spain)}, booktitle = {HEAd'20: Sixth International Conference on Higher Education Advances, June 2 - June 5 2020, Valencia (Spain)}, doi = {10.4995/HEAd20.2020.11112}, abstract = {This paper decribes the concept of a course on control theory as a minor subject in the department of electrical engineering at the OTH Regensburg. The basis for a new concept is the idea of contructive alignment. The whole teaching module is devided in two blocks. The first block contains the teaching of the knowledge about control theory with an integrated approach for lectures, exercises and practical sessions. In the second block the students attent a practical work package to have the possibility to applicate and deepen their knowledge. To foster active participation the students are asked to document and reflect their work with the course context in an electronic portfolio. The exam of this module consists of three parts with respect to the different competencies obtained during the module. This concept develops not only the knowledge on control theory but personal and social competencies which are of growing interest. The aim of the paper is to present the idea of the concept. Following papers will illustrate the development process and the results obtained later on.}, language = {en} } @article{MalzKrenkelSteffens, author = {Malz, Sebastian and Krenkel, Walter and Steffens, Oliver}, title = {Infrared Reflective Wall Paint in Buildings: Energy Saving Potentials and Thermal Comfort}, series = {Energy and Buildings}, volume = {224}, journal = {Energy and Buildings}, number = {October}, publisher = {Elsevier}, issn = {0378-7788}, doi = {10.1016/j.enbuild.2020.110212}, abstract = {The reduction of the energy demand of existing buildings is the main objective of building refurbishment. Managing the heat radiation properties of the wall construction is a possible way to develop highly effective and resource efficient insulation materials and concepts. The application of infrared reflective wall paints and coatings has been studied since the latter half of the 20th century. A brief review of the literature gives an account of the current research status. One has to realise that the conclusions are not uniformly consistent but depend strongly on the specific boundary conditions and investigated parameters. The study presented here discusses the usage of infrared reflective wall paint in conjunction with heat insulation for historic brick masonry. The possible energy savings are linked to the resulting thermal comfort. We identify critical parameters that must be taken into account when using infrared reflective wall paint and derive recommended design rules for the refurbishment of such building types. The findings prove that infrared reflective wall paint can decrease heat losses by 18\% and up to 22\% if comfort conditions are considered. Increasing energy savings can also cause the negative effect of high radiative asymmetry. Thus, each configuration must be observed in detail.}, language = {en} } @article{SchulzSchwarz, author = {Schulz, Carsten and Schwarz, Colin}, title = {Drivetrain fatigue strength characteristics of model-predictive control for wind turbines}, series = {Wind Energy}, volume = {23}, journal = {Wind Energy}, number = {12}, publisher = {Wiley}, doi = {10.1002/we.2520}, pages = {2137 -- 2149}, abstract = {Wind turbines play a crucial role in the revolution towards renewable resources. They need to be economically competitive to be sustainable. This still requires to lower the cost of energy (COE). To this end, nonlinear model predictive control (NMPC) is used within this paper. As known from literature, NMPC significantly improves the energy extracting performance as well as the mitigation of tower loads of wind turbines. As it is shown in this paper, the drivetrain fatigue strength drops disproportionally in parallel, which either increases the demands on the turbine design or decreases the lifetime of drivetrain components. Without additional boundary conditions to the underlying optimal control problems (OCPs), the application of energy-maximizing NMPC might so even raise the COE. Only penalizing axial torque oscillations by quadratic terms decreases energy-extracting performance below the level of classical wind turbine controllers. This makes more sophisticated conditions necessary. In this paper, the increase of the drivetrain damage by NMPC is analyzed, and appropriate boundary conditions are derived, to balance the two contradicting objectives of energy maximization and drivetrain load mitigation. An NMPC approach based on indirect methods is used, to obtain a solution of the OCPs very efficiently. It applies the Hamilton equations and Pontryagin's maximum principle. Its accuracy and efficiency to solve OCPs was presented over the last decades.}, language = {en} } @inproceedings{SippenauerBrueckl, author = {Sippenauer, Thomas and Br{\"u}ckl, Oliver}, title = {Verankerung von Flexibilit{\"a}t in der Netzplanung}, series = {ScienceLab (begleitender Workshop zur Konferenz Zuk{\"u}nftige Stromnetze: 29.-30. Januar 2020, Berlin)}, booktitle = {ScienceLab (begleitender Workshop zur Konferenz Zuk{\"u}nftige Stromnetze: 29.-30. Januar 2020, Berlin)}, publisher = {Conexio GmbH}, address = {Pforzheim}, isbn = {978-3-948176-07-5}, doi = {10.35096/othr/pub-5559}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-55592}, pages = {77 -- 81}, abstract = {Im Rahmen des Projektes C/sells wurden mehrere Mittelspannungsnetze modelliert, um die aktuellen Spannungsverh{\"a}ltnisse und Leitungsauslastungen nachbilden zu k{\"o}nnen. Zudem wurden, angelehnt an den Netzentwicklungsplan, Szenarien f{\"u}r den zuk{\"u}nftigen PV-Zubau und die potenzielle Entwicklung der Elektromobilit{\"a}t entworfen. Auf Basis der Ergebnisse l{\"a}sst sich eine Netzanalyse hinsichtlich Spannungs- und Stromgrenzwert{\"u}berschreitungen sowie zu deren potenziellen Auftrittszeitpunkten und Auftrittsdauern durchf{\"u}hren. Parallel wurde anhand von Sensitivit{\"a}tsanalysen untersucht, welche Wirksamkeit Flexibilit{\"a}tseins{\"a}tze an den verschiedenen Netzknoten auf den Engpass haben. Dadurch kann bestimmt werden, wie effektiv die verf{\"u}gbaren, in der Regel {\"o}rtlich gebundenen Flexibilit{\"a}tsanbieter eingesetzt werden k{\"o}nnen. Da die Sensitivit{\"a}ten arbeitspunktabh{\"a}ngig sind, wurden verschiedene Zeitpunkte im Jahresverlauf berechnet und die jeweilige {\"A}nderungen der Wirksamkeit ausgewertet. Neben der H{\"o}he der Leistungsabweichung wurde die Flexibilit{\"a}tsanforderung auch anhand der Einsatzzeitpunkte und Einsatzdauer sowie anhand der H{\"a}ufigkeit der n{\"o}tigen Flexibilit{\"a}tseins{\"a}tze charakterisiert. Aus den gewonnenen Erkenntnissen soll abgeleitet werden, inwiefern sich der flexible Einsatz der Verbrauchsanlagen in der Netzplanung verankern l{\"a}sst. Besonders relevant ist deshalb, mit welcher Verl{\"a}sslichkeit die Flexibilit{\"a}t abgerufen werden kann. Eine sehr hohe Verl{\"a}sslichkeit l{\"a}sst sich je nach Flexibilit{\"a}tsanbieter m{\"o}glicherweise nicht oder nur zu sehr hohen Preisen gew{\"a}hrleisten. Die Eignung der Flexibilit{\"a}tseins{\"a}tze wird somit sowohl aus technischer als auch aus wirtschaftlicher Sicht bewertet. Da eine vollst{\"a}ndige Verl{\"a}sslichkeit ohnehin nicht sichergestellt werden kann (technische St{\"o}rungen einer Anlage, Wettereinfl{\"u}sse, etc.), werden auch Fallback-Strategien, z. B. Einspeisespitzenkappung, in die Analyse einbezogen.}, language = {de} }