TY - JOUR A1 - Burdin, Dmitrii A. A1 - Ekonomov, Nikolai A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Fetisov, Yuri K. A1 - Shamonin (Chamonine), Mikhail T1 - Temperature Dependence of the Resonant Magnetoelectric Effect in Layered Heterostructures JF - Materials N2 - The dependence of the resonant direct magnetoelectric effect on temperature is studied experimentally in planar composite structures. Samples of rectangular shapes with dimensions of 5 mm x 20 mm employed ferromagnetic layers of either an amorphous (metallic glass) alloy or nickel with a thickness of 20-200 m and piezoelectric layers of single crystalline langatate material or lead zirconate titanate piezoelectric ceramics with a thickness of 500 m. The temperature of the samples was varied in a range between 120 and 390 K by blowing a gaseous nitrogen stream around them. It is shown that the effective characteristics of the magnetoelectric effectsuch as the mechanical resonance frequency f(r), the quality factor Q and the magnitude of the magnetoelectric coefficient (E) at the resonance frequencyare contingent on temperature. The interrelations between the temperature changes of the characteristics of the magnetoelectric effect and the temperature variations of the following material parametersYoung's modulus Y, the acoustic quality factor of individual layers, the dielectric constant epsilon, the piezoelectric modulus d of the piezoelectric layer as well as the piezomagnetic coefficients ((n)) of the ferromagnetic layerare established. The effect of temperature on the characteristics of the nonlinear magnetoelectric effect is observed for the first time. The results can be useful for designing magnetoelectric heterostructures with specified temperature characteristics, in particular, for the development of thermally stabilized magnetoelectric devices. KW - acoustic quality factor KW - composite structure KW - linear KW - magnetoelectric effect KW - magnetoelectric heterostructure KW - magnetostriction KW - nonlinear KW - piezoelectric KW - temperature dependence Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-32185 N1 - corresponding author: Mikhail Shamonin VL - 10 IS - 10 PB - MDPI ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Prem, Nina T1 - Magnetically enhanced photoconductive high voltage control JF - ISSS Journal of Micro and Smart Systems N2 - The recent surge of interest in electrostatic actuators, particularly for soft robotic applications, has placed increasing demands on high voltage control technology. In this respect, optoelectronic bidirectional switching and analogue regulation of high voltages is becoming increasingly important. One common problem is the leakage current due to dark resistance of the material or device used. Another is the physical size of such elements. However, their ability to provide galvanic separation makes them a very attractive alternative to conventional (wired) semiconductor elements. This paper gives an overview of available methods and devices before introducing a concept based on the combination of photoresistive and magnetoresistive effects in Gallium Arsenide that are potentially applicable to other semiconductor materials. KW - GaAs KW - High voltage actuators KW - Magnetoresistance KW - Opto-sensors KW - Photoconduction KW - Soft robotics Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-30606 N1 - Corresponding author: Gareth J. Monkman VL - 11 SP - 317 EP - 328 PB - Springer Nature ER - TY - CHAP A1 - Diehl, Andreas A1 - Wolff, Lilli A1 - Fuhrmann, Thomas A1 - Niemetz, Michael A1 - Mörtlbauer, Stefanie A1 - Dirnberger, Sandra T1 - Compact Freshmen Welcome Seminar for Engineering Students T2 - Procedia - Social and Behavioral Sciences N2 - The Faculty of Electrical Engineering and Information Technology of the OTH Regensburg developed and implemented a compact freshmen seminar for the afternoon of the first day of study. The intention of this seminar is to help the freshmen during their transition between school and study without losing lecture time in the first semester. The concept was tested with one small study group at the beginning of the summer semester 2015. To rate the impact of the seminar and to find aspects for continuous improvement an evaluation method was developed and used. Due to the good student resonance during the first run, this introduction seminar was held again in the winter semester 2015/16. It is planned to integrate this seminar as a regular session for all freshmen of the faculty curriculum and monitor the long-term effects of student motivation and success. KW - Engineering Education KW - Freshmen Seminar Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-31034 N1 - Corresponding author: Thomas Fuhrmann IS - 228 SP - 45 EP - 52 PB - Elsevier ER - TY - JOUR A1 - Sterner, Michael A1 - Specht, Michael T1 - Power-to-Gas and Power-to-X-The History and Results of Developing a New Storage Concept JF - Energies N2 - Germany's energy transition, known as 'Energiewende', was always very progressive. However, it came technically to a halt at the question of large-scale, seasonal energy storage for wind and solar, which was not available. At the end of the 2000s, we combined our knowledge of both electrical and process engineering, imitated nature by copying photosynthesis and developed Power-to-Gas by combining water electrolysis with CO2-methanation to convert water and CO2 together with wind and solar power to synthetic natural gas. Storing green energy by coupling the electricity with the gas sector using its vast TWh-scale storage facility was the solution for the biggest energy problem of our time. This was the first concept that created the term 'sector coupling' or 'sectoral integration'. We first implemented demo sites, presented our work in research, industry and ministries, and applied it in many macroeconomic studies. It was an initial idea that inspired others to rethink electricity as well as eFuels as an energy source and energy carrier. We developed the concept further to include Power-to-Liquid, Power-to-Chemicals and other ways to 'convert' electricity into molecules and climate-neutral feedstocks, and named it 'Power-to-X'at the beginning of the 2010s. KW - 100% renewable energy scenarios KW - CARBON RECYCLING SYSTEM KW - CO2 KW - eFuels KW - electric fuels KW - energy transition KW - hydrogen KW - methanation KW - METHANOL KW - Power-to-Gas KW - Power-to-Hydrogen KW - Power-to-Methane KW - Power-to-X KW - sector coupling KW - sectoral integration KW - TRANSPORTATION Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-26202 N1 - Corresponding author: Michael Sterner VL - 14 IS - 20 PB - MDPI ER - TY - JOUR A1 - Schiek, Roland T1 - Excitation of nonlinear beams: from the linear Talbot effect through modulation instability to Akhmediev breathers JF - Optics express N2 - The smooth transition between stable, Talbot-effect-dominated and modulationally unstable nonlinear optical beam propagation is described as the superposition of oscillating, growing and decaying eigenmodes of the common linearized theory of modulation instability. The saturation of the instability in form of breather maxima is embedded between eigenmode growth and decay. This explains well the changes of beam characteristics when the input intensity increases in experiments on modulation instability and breather excitation in spatial-spatial experimental platforms. An increased accuracy of instability gain measurements, a variety of interesting nonlinear beam scenarios and a more selective and well-directed breather excitation are demonstrated experimentally. KW - DYNAMICS KW - FIBER KW - GENERATION KW - PEREGRINE SOLITON KW - SPATIAL SOLITONS KW - WAVE-GUIDE Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-26049 N1 - Corresponding author: Roland Schiek VL - 29 IS - 10 SP - 15830 EP - 15851 PB - Optica Publishing Group CY - Washington, DC, USA ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Striegl, Birgit A1 - Prem, Nina A1 - Sindersberger, Dirk T1 - Electrical Properties of Magnetoactive Boron‐Organo‐Silicon Oxide Polymers JF - Macromolecular Chemistry and Physics N2 - The electrical properties of rheopectic magnetoactive composites comprising boron-organo-silicon oxide dielectric matrices containing carbonyl iron microparticles are presented for the first time. The increase in interfacial magnetocapacitance is seen to greatly exceed that experienced when using conventional elastomeric matrices such as polydimethylsiloxane. In addition to the increase in capacitance, a simultaneous and sharp decrease in the parallel electrical resistance over several orders of magnitude is also observed. The effects are time dependent but repeatable. Potential applications include magnetically controlled frequency dependent devices, magnetic sensor systems, weighting elements for neural networks, etc. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-26488 N1 - Corresponding author: Gareth J. Monkman VL - 221 IS - 4 SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. T1 - Infrared spectral analysis of low concentration magnetoactive polymers JF - Journal of Applied Polymer Science N2 - This work concerns an area of magnetoactive polymer (MAP) research seldom considered. Traditionally only MAP with high concentrations of magnetic filler (typically between 10 and 90 wt%) have been investigated. This article deals with a hitherto neglected aspect of research, namely MAP containing lower magnetic filler concentrations (1 to 3 wt%). This article utilizes a range of spectroscopic analysis methods (Raman and FTIR) and their applicability to MAP characterization at wavelengths ranging from 2.5 to 25 mu m. Particular attention is paid to low carbonyl iron particle (CIP) concentrations in MAP for which the emergence of capillary doublets at a critical 2 wt% concentration is revealed. This results in measurable magnetic field-dependent changes in IR absorption at a wavelength of 4.255 mu m together with a detectable CO2 susceptibility. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48366. KW - ELASTOMERS KW - magnetism and magnetic properties KW - sensors and actuators KW - spectroscopy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-25913 SN - 1097-4628 N1 - Corresponding author: Nina Prem VL - 137 IS - 7 SP - 1 EP - 7 PB - Wiley ER - TY - JOUR A1 - Gärtner, Sebastian A1 - Marx-Schubach, Thomas A1 - Gaderer, Matthias A1 - Schmitz, Gerhard A1 - Sterner, Michael T1 - Techno-Economic Analysis of Carbon Dioxide Separation for an Innovative Energy Concept towards Low-Emission Glass Melting JF - energies N2 - The currently still high fossil energy demand is forcing the glass industry to search for innovative approaches for the reduction in CO2 emissions and the integration of renewable energy sources. In this paper, a novel power-to-methane concept is presented and discussed for this purpose. A special focus is on methods for the required CO2 capture from typical flue gases in the glass industry, which have hardly been explored to date. To close this research gap, process simulation models are developed to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Due to reduced flue gas volume, the designed CO2 capture plant is found to be much smaller (40 m3 absorber column volume) than absorption-based CO2 separation processes for power plants (12,560 m3 absorber column volume). As there are many options for waste heat utilization in the glass industry, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 separation costs range between 41 and 42 EUR/t CO2, depending on waste heat utilization for desorption. These costs are below the values of 50–65 EUR/t CO2 for comparable industrial applications. Despite these promising economic results, there are still some technical restrictions in terms of solvent degradation due to the high oxygen content in flue gas compositions. The results of this study point towards parametric studies for approaching these issues, such as the use of secondary and tertiary amines as solvents, or the optimization of operating conditions such as stripper pressure for further cost reductions potential. KW - economic evaluation KW - CO2-separation KW - glass industry KW - oxyfuel KW - methanation KW - power-to-gas Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-53627 N1 - Corresponding author: Sebastian Gärtner VL - 16 IS - 5 SP - 1 EP - 25 PB - MDPI CY - Basel ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Meier, Alexander A1 - Böse, Holger A1 - Baumann, Michael A1 - Ermert, Helmut A1 - Kahled, W. A1 - Freimuth, Herbert T1 - Technologies for Haptic Displays in Teleoperation JF - Industrial Robot N2 - Since the 1960s many alphanumeric to tactile data conversion methods have been investigated, mainly with the ultimate aim of assisting the blind. More recently, interest has been directed toward the display of pictures on haptically explorable surfaces – tactile imaging – for a range of medical, remote sensing and entertainment purposes. This paper examines the technologies which have been utilised for haptically explorable tactile displays over the past three decades, focussing on those which appear commercially viable in the immediate future. Y1 - 2003 U6 - https://doi.org/10.1108/01439910310506792 SN - 0143-991x VL - 30 IS - 6 SP - 525 EP - 530 PB - Emerald ER - TY - JOUR A1 - Fuhrmann, Thomas A1 - Mandl, Roland A1 - Shamonin (Chamonine), Mikhail T1 - Analysis of learning improvement on changing lab course from single experiments to projects JF - International Journal of Electrical Engineering Education N2 - During recent years, there has been a trend to replace traditional lab courses by project-based learning activities. However, there is currently little scientific evidence for educational improvements through such changes. Some years ago, a lab course on electrical measurements in our bachelor Electrical Engineering and Information Technology was modified from single experiments to projects. This change led to a significant increase in the necessary manpower and lab costs. To justify these higher efforts, it is important to investigate if the learning success increased. We carried out the surveys and collected the statistical data from the students who attended this course. In order to see if the students appreciated this lab course and if there was an objective increase of the students' knowledge, these results were evaluated. Evaluation of the grades in the lecture and lab courses shows that the increase of the students' theoretical and practical knowledge is statistically significant. KW - Electrical engineering education KW - project-based learning KW - student experiments Y1 - 2015 U6 - https://doi.org/10.1177/0020720915583863 VL - 52 IS - 4 SP - 287 EP - 297 PB - SAGE ER - TY - JOUR A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Striegl, Birgit A1 - Böhm, Valter A1 - Monkman, Gareth J. T1 - Shape memory effects using magnetoactive Boron-organo-silicon oxide polymers JF - Macromolecular Chemistry and Physics N2 - Thermomechanical shape memory materials have certain disadvantages when it comes to 3D volumetric reproduction intended for rapid prototyping or robotic prehension. The need to constantly supply energy to counteract elastic retraction forces in order to maintain the required geometry, together with the inability to achieve conformal stability at elevated temperatures, limits the application of thermal shape memory polymers. Form removal also presents problems as most viscoelastic materials do not ensure demolding stability. This work demonstrates how magnetoactive boron−organo−silicon oxide polymers under the influence of an applied magnetic field can be used to achieve energy free sustainable volumetric shape memory effects over extended periods. The rheopectic properties of boron−organo−silicon oxide materials sustain form removal without mold distortion. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-23205 N1 - Corresponding Author: Gareth J. Monkman VL - 221 IS - 15 SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Maier, Robert A1 - Schlattl, Andreas A1 - Guess, Thomas A1 - Mottok, Jürgen T1 - CausalOps - Towards an industrial lifecycle for causal probabilistic graphical models JF - Information and Software Technology N2 - Context: Causal probabilistic graph-based models have gained widespread utility, enabling the modeling of cause-and-effect relationships across diverse domains. With their rising adoption in new areas, such as safety analysis of complex systems, software engineering, and machine learning, the need for an integrated lifecycle framework akin to DevOps and MLOps has emerged. Currently, such a reference for organizations interested in employing causal engineering is missing. This lack of guidance hinders the incorporation and maturation of causal methods in the context of real-life applications. Objective: This work contextualizes causal model usage across different stages and stakeholders and outlines a holistic view of creating and maintaining them within the process landscape of an organization. Method: A novel lifecycle framework for causal model development and application called CausalOps is proposed. By defining key entities, dependencies, and intermediate artifacts generated during causal engineering, a consistent vocabulary and workflow model to guide organizations in adopting causal methods are established. Results: Based on the early adoption of the discussed methodology to a real-life problem within the automotive domain, an experience report underlining the practicability and challenges of the proposed approach is discussed. Conclusion: It is concluded that besides current technical advancements in various aspects of causal engineering, an overarching lifecycle framework that integrates these methods into organizational practices is missing. Although diverse skills from adjacent disciplines are widely available, guidance on how to transfer these assets into causality-driven practices still need to be addressed in the published literature. CausalOps’ aim is to set a baseline for the adoption of causal methods in practical applications within interested organizations and the causality community. KW - Causal engineering KW - Model lifecycle KW - MLOps KW - Causal graphical models Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-73350 SN - 0950-5849 N1 - Corresponding author der OTH Regensburg: Robert Maier PB - Elsevier ER - TY - JOUR A1 - Bauer, Franz A1 - Sterner, Michael T1 - Impacts of lifestyle changes on energy demand and greenhouse gas emissions in Germany JF - Renewable and Sustainable Energy Reviews N2 - Most energy scenario studies typically focus on technological options and fuel substitution for decarbonising future energy systems. Lifestyle changes are rarely considered, although they can significantly reduce energy demand and climate change mitigation efforts. By using an energy system model, this study shows that it is possible to reduce final energy demand in Germany by 61 % in 2050 relative to 2019 levels, resulting in an annual per capita energy demand of 44 GJ for a representative country of the Global North. This goal can be achieved through a combination of technological measures and lifestyle changes without sacrificing a decent standard of living. Societal chances can eliminate reliance on not-yet-established negative emission technologies, reduce energy dependency, and reduce the need for energy-intensive hydrogen and e-fuels. Downsizing the energy system provides an opportunity for strengthening climate change mitigation, decrease material demand and reduce land use. KW - Climate change mitigation KW - Energy system modelling KW - Sufficiency KW - Lifestyle changes KW - Climate neutrality KW - Low energy demand KW - German climate targets Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77682 SN - 1364-0321 N1 - Corresponding author der OTH Regensburg: Franz Bauer VL - 207 PB - Elsevier CY - Amsterdam ER -