TY - JOUR A1 - Richter, Stefanie T1 - Integrated Care for People with Dementia BT - Results of a Social-Scientific Evaluation of an Established Dementia Care Model JF - Geriatrics N2 - This article presents results of the social-scientific evaluation of an established care model for people with dementia developed by the professionals as a result of acute problems in care in north-east Germany. In addition to the central elements of the model, the conditions of intersectoral and interprofessional cooperation as well as the qualification profile requirements of the professional groups involved are presented in detail. The results can give suggestions for the organization of integrated care for people with dementia in other countries. Further, the author would hereby like to highlight the gain from the scientific examination of solutions to problems in the field. KW - Demenz KW - Managed Care KW - Dementia KW - Integrated Care Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-22091 VL - 2 IS - 1 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Pangerl, Jonas A1 - Sukul, Pritam A1 - Rück, Thomas A1 - Fuchs, Patricia A1 - Weigl, Stefan A1 - Miekisch, Wolfram A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone JF - Photoacoustics N2 - n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field. KW - Photoacoustic spectroscopy KW - Real-time mass-spectrometry KW - Breath analysis KW - Acetone KW - UV-LED Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71279 SN - 2213-5979 N1 - Corresponding author der OTH Regensburg: Jonas Pangerl VL - 38 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 - TY - CHAP A1 - Ruiken, Axel A1 - Landmann, Philipp A1 - Zöller, Ralf A1 - Wolff, Thomas T1 - Untersuchungen zum Tragverhalten von Einfach- und Mehrfachverbundankern im Zuge des BA 2/2 der A281 in Bremen T2 - Vorträge der 38. Baugrundtagung, 25. bis 27. September 2024, Bremen N2 - Im Vorfeld zum Neubau der A281 BA2/2 in Bremen wurden u.a. 14 Eignungsanker hergestellt und das Lastabtragsverhalten in den anstehenden Wesersanden ermittelt. Die Verpresskörper wurden in Sanden mit mitteldichter und dichter Lagerung angeordnet und dabei die Länge und Anzahl der Verpresskörper systematisch variiert. Neben der Messung von Kraft und Verschiebung am Ankerkopf wurde mithilfe hochauflösender faseroptischer Instrumentierung von Verpresskörpern und Ankerlitzen der Lastabtrag über den reinen Verpresskörper hinaus über die gesamte Verbundlänge ermittelt. Anhand der Ergebnisse wird die sukzessive Aktivierung der Baugrundwiderstände sichtbar. Die Ergebnisse zeigen einen näherungsweise linearen Zusammenhang zwischen den untersuchten 6 m bis 12 m langen Verpresskörpern und den ermittelten Herausziehwiderständen im Sand und somit ein deutlich günstigeres Lastabtragsverhalten, als es bisherige Erfahrungen gezeigt haben. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77662 SN - 978-3-932653-57-5 SP - 129 EP - 135 PB - Aktiv Druck & Verlag GmbH CY - Ebelsbach ER - TY - JOUR A1 - Albrecht, Sophie Viktoria A1 - Hellerbrand, Stefan A1 - Weininger, Florian A1 - Thiel, Charlotte T1 - Strategies for Minimizing Environmental Impact in Construction: A Case Study of a Cementitious 3D Printed Lost Formwork for a Staircase JF - materials N2 - The construction industry faces significant challenges, including environmental sustainability, rising material costs, and a shortage of skilled labor. Digital fabrication technologies offer innovative solutions to address these issues by reducing raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an Environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, this study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and abiotic depletion potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low-clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities KW - permanent formwork KW - selective cement activation (SCA) KW - 3D concrete printing (3DCP) KW - life cycle assessment (LCA) KW - additive manufacturing in construction (AMC) Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79236 N1 - Corresponding author der OTHR: Sophie Viktoria Albrecht VL - 18 PB - MDPI ER - TY - JOUR A1 - Westner, Markus A1 - Reicheneder, Matthias A1 - Matschi, Markus T1 - From Captive Centers to Global Integration BT - Organizational Models and Good Practices in Information Technology Nearshoring and Offshoring JF - Information Resources Management Journal N2 - Contemporary developments in virtual work and global talent management are transforming information technology (IT) nearshoring and offshoring practices, yet research on organizational responses remains limited. Through expert interviews with 33 IT executives (76% chief information officers) from Germany's top 500 companies, this article examines organizational models, strategies, and good practices in IT nearshoring and offshoring. It reveals a shift from traditional captive centers toward fully integrated global teams, enabling high-value task delivery and reflecting increased workforce maturity. Companies are expanding their operations driven by talent needs rather than cost savings, with success factors including employee integration and robust on-site management. This study contributes to theory and practice by providing a framework for understanding organizational models in global IT delivery and offering actionable insights for executives, emphasizing workforce integration over geographical separation. KW - Offshoring KW - Informationstechnik KW - Internationale Arbeitsteilung KW - Organisationsstruktur KW - IT-Nearshoring KW - IT-Offshoring KW - Global IT-Teams KW - Organizational Models KW - Distributed Work Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-80406 SN - 1533-7979 N1 - Corresponding author der OTH Regensburg: Markus Westner VL - 38 IS - 1 PB - IGI Global ER - TY - JOUR A1 - Hausler, Peter A1 - Holzner, Lukas A1 - Ehrnsperger, Matthias A1 - Bierl, Rudolf T1 - Evaluation of the creep strength of samples produced by fused deposition modeling JF - Open Engineering N2 - Data sheets for 3D printing materials typically include softening temperature, impact strength, tensile strength, and stiffness. However, creep strength, an important parameter for components used over an extended period, is usually not included. Nevertheless, this parameter is of significant importance for components that are used over an extended period of time.This study compares the long-term creep behavior of a selection of materials that are commonly used in fused deposition modeling 3D printing. The materials under investigation are acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid, and polycarbonate. In addition, the influence of fiber reinforcements on these materials is also examined. A simple, reproducible test procedure is proposed for users to determine and compare creep resistance of materials. This enables developers to select materials suitable for their own requirements on creep resistance and allows 3D-printing users to compare different materials. Results suggest that fiber reinforcement generally improves creep stability in 3D-printing materials, with GreenTEC Pro Carbon and add:north PC Blend HT LCF showing the most promise in this study. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79760 N1 - Corresponding author der OTH Regensburg: Peter Hausler VL - 14 IS - 1 PB - de Gruyter ER - TY - CHAP A1 - Leinweber, Juliane ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Digitale Versorgung in der Logopädie/Sprachtherapie Von der Präsenz- und Videotherapie zur Teletherapie T2 - Digitale Technik für ambulante Pflege und Therapie II - Impulse für die Praxis T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 3 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-65039 SP - 145 EP - 152 PB - transcript CY - Bielefeld ER - TY - GEN ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Digitale Technik für ambulante Pflege und Therapie III BT - Nutzung, Akzeptanz, Wirkung und Lebensqualität N2 - Dieser Artikel untersucht die Machbarkeit und Wirksamkeit einer physiotherapeutischen Tele-Intervention bei Schlaganfallpatient*innen. Die prospektive, nicht kontrollierte Interventionsstudie basiert auf einem Mixed-Methods-Design und analysiert funktionelle Veränderungen sowie die Lebensqualität der Teilnehmenden vor und nach der Intervention. Eingeschlossen wurden postakute und chronische Schlaganfallpatient*innen mit stabilen Krankheitsbildern, die in ihrem häuslichen Umfeld lebten. Die Intervention bestand aus videobasierten Einzelsitzungen und einer optionalen Gruppenintervention, die Physiotherapie und Logopädie kombinierte. Die Ergebnisse zeigten signifikante Verbesserungen in der Arm-Hand-Funktion und der Teilhabefähigkeit. Die Teletherapie erwies sich als eine praktikable Ergänzung zur traditionellen Rehabilitation, insbesondere in ländlichen Regionen, und förderte die Autonomie und das aktive Engagement der Patient*innen in ihrem Genesungsprozess. Die Studie belegt das Potenzial teletherapeutischer Maßnahmen zur Überbrückung von Versorgungslücken und zur Sicherstellung einer kontinuierlichen, hochfrequenten Rehabilitation. T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 4 KW - AAL-Technik KW - Ambulanter Hilfs- und Pflegedienst Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-73914 SN - 978-3-8394-6728-2 N1 - Enthaltene Beiträge sind einzeln erfasst. PB - transcript CY - Bielefeld ET - 1. Aufl. ER - TY - JOUR A1 - Grad, Marius A1 - Zentgraf, Jan A1 - Schultheiss, Ulrich A1 - Esper, Lukas A1 - Diemar, Andreas A1 - Noster, Ulf A1 - Spiess, Lothar T1 - Effect of Carbon Content on the Phase Composition, Microstructure and Mechanical Properties of the TiC Layer Formed in Hot-Pressed Titanium-Steel Composites JF - Metals N2 - During the hot pressing of pure titanium and different carbon steels in a temperature range of ϑ = 950–1050 °C, a compound layer up to dL≈10 μm thick is formed at the titanium–steel interface. With a higher carbon content of the used steel, the layer thickness increases. The carbon concentration within the layer is in the range of stoichiometry for TiC. Apart from TiC, no other phases can be detected by X-ray diffraction (XRD) measurements inside the formed layer. The calculation of the activation energy for the TiC layer formation is Q = 126.5–136.7 kJ mol−1 and is independent of the carbon content of the steel. The resulting microstructure has a grain size gradient, wherein the mechanical properties, such as hardness and Young‘s modulus, are almost constant. Statistical analysis using Response Surface Methodology (RSM) indicates that the carbon content of the steel has the most significant influence on layer thickness, followed by annealing temperature and annealing time. By selecting the appropriate carbon steel and the subsequent removal of the steel, it is possible to produce targeted TiC layers on titanium substrates, which holds enormous potential for this material in wear-intensive applications. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-74617 SN - 2075-4701 N1 - Cooresponding author der OTH Regensburg: Marius Grad VL - 14 IS - 9 PB - MDPI AG ER - TY - JOUR A1 - Altmann, Matthias A1 - Schlegl, Peter A1 - Volbert, Klaus T1 - A low-power wireless system for energy consumption analysis at mains sockets JF - EURASIP Journal on Embedded Systems N2 - Introduction: Improving energy efficiency and reducing energy wastage is an important topic of our time. But it is quite difficult to figure out how much of our total electricity bill can be mapped to which device or at what time the device used it. We believe energy efficiency of normal households can be improved, if this kind of transparency would be available. In this article, we present a system for energy measurement at mains sockets to gain a transparent view of energy consumption for each device in a household. It consists of several smart energy measuring devices (SEMDs) that use a low-power radio protocol to dynamically build and connect to a radio network to transfer power usage date to a server. At the server, the data is stored and can be accessed via web interface. Results: Our primary goal was to build a back-end system for an energy metering platform with very low energy consumption. This platform can provide data for a variety of services that enables users (the consumers) to understand and improve their energy consumption behavior and increase overall energy efficiency of their households. KW - Low power KW - Smart grid KW - Smart home KW - Smart metering KW - Wireless system Y1 - 2017 U6 - https://doi.org/10.1186/s13639-016-0041-y N1 - Corresponding author: Peter Schlegl IS - 1 PB - Springer Nature ER - TY - JOUR A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Börner, Juliane A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Salgado, Josefina A1 - Han, Hong A1 - Böse, Holger A1 - Probst, Jörn A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Schlunck, Günther T1 - Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata JF - PLoS ONE N2 - Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young’s modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of α-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (≈40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0076196 VL - 8 IS - 10 PB - PLOS ER - TY - JOUR A1 - Reinker, Lukas A1 - Bläsing, Dominic A1 - Bierl, Rudolf A1 - Ulbricht, Sabina A1 - Dendorfer, Sebastian T1 - Correlation of Acceleration Curves in Gravitational Direction for Different Body Segments during High-Impact Jumping Exercises JF - sensors N2 - Osteoporosis is a common disease of old age. However, in many cases, it can be very well prevented and counteracted with physical activity, especially high-impact exercises. Wearables have the potential to provide data that can help with continuous monitoring of patients during therapy phases or preventive exercise programs in everyday life. This study aimed to determine the accuracy and reliability of measured acceleration data at different body positions compared to accelerations at the pelvis during different jumping exercises. Accelerations at the hips have been investigated in previous studies with regard to osteoporosis prevention. Data were collected using an IMU-based motion capture system (Xsens) consisting of 17 sensors. Forty-nine subjects were included in this study. The analysis shows the correlation between impacts and the corresponding drop height, which are dependent on the respective exercise. Very high correlations (0.83–0.94) were found between accelerations at the pelvis and the other measured segments at the upper body. The foot sensors provided very weak correlations (0.20–0.27). Accelerations measured at the pelvis during jumping exercises can be tracked very well on the upper body and upper extremities, including locations where smart devices are typically worn, which gives possibilities for remote and continuous monitoring of programs. KW - osteoporosis KW - inertial measurement units KW - wearable motion-tracking sensors KW - high-impact exercisess Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58217 N1 - Corresponding author: Lukas Reinker N1 - This work was supported by the Bavarian Academic Forum [BayWISS-Verbundkolleg Gesundheit] and the DHZK fond for behavioral cardiovascular diseases [Behaviorale kardiovaskuläre Erkrankungen; grand number: 81Z0400105]. VL - 23 IS - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Rusavy, Zdenek A1 - Cechova, Hana A1 - Dendorfer, Sebastian A1 - Kalis, Vladimir A1 - Ismail, Khaled M. T1 - Is the Finnish grip tight enough? A manometric study of two manual perineal protection techniques JF - Acta Obstetricia et Gynecologica Scandinavica Y1 - 2024 U6 - https://doi.org/10.1111/aogs.15033 PB - Wiley ET - Early view ER - TY - JOUR A1 - Schmitz, Paul A1 - Neumann, Christoph Cornelius A1 - Neumann, Carsten A1 - Nerlich, Michael A1 - Dendorfer, Sebastian T1 - Biomechanical analysis of iliac crest loading following cortico-cancellous bone harvesting JF - Journal of Orthopaedic Surgery and Research N2 - Background Iliac crest bone harvesting is a frequently performed surgical procedure widely used to treat bone defects. The objective of this study is to assess the biomechanical quantities related to risk for pelvic fracture after harvesting an autologous bone graft at the anterior iliac crest. Methods Finite element models with a simulated harvest site (sized 15 × 20 mm, 15 × 35 mm, 30 × 20 mm and 30 × 35 mm) in the iliac wing are created. The relevant loading case is when the ipsilateral leg is lifted off the ground. Musculoskeletal analysis is utilized to compute the muscle and joint forces involved in this motion. These forces are used as boundary conditions for the finite element analyses. Bone tissue stress is analyzed. Results Critical stress peaks are located between the anterior superior iliac spine (ASIS) and the anterior edge of the harvest site. Irrespective of the graft size, the iliac wing does not show any significant stress peaks with the harvest site being 20 to 25 mm posterior to the ASIS. The harvest area itself inhibits the distribution of the forces applied on the ASIS to extend to the posterior iliac wing. This leads to a lack of stress posterior to the harvest site. A balanced stress distribution with no stress peaks appears when the bone graft is taken below the iliac crest. Conclusion A harvest site located at least 20 to 25 mm posterior to the ASIS should be preferred to minimize the risk of iliac fatigue fracture. KW - Bone harvesting KW - Autologous bone graft KW - Iliac crest KW - Fatigue fracture KW - Pelvis KW - ASIS KW - FEA KW - Biomechanical investigation KW - Beckenkammknochen KW - Knochenentnahme KW - Spongiosa KW - Biomechanische Analyse Y1 - 2018 U6 - https://doi.org/10.1186/s13018-018-0822-1 VL - 13 IS - 108 SP - 1 EP - 8 PB - Springer Nature ER - TY - JOUR A1 - Völlner, Florian A1 - Weber, Tim A. A1 - Weber, Markus A1 - Renkawitz, Tobias A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Craiovan, Benjamin T1 - A simple method for determining ligament stiffness during total knee arthroplasty in vivo JF - Scientific Reports N2 - A key requirement in both native knee joints and total knee arthroplasty is a stable capsular ligament complex. However, knee stability is highly individual and ranges from clinically loose to tight. So far, hardly any in vivo data on the intrinsic mechanical of the knee are available. This study investigated if stiffness of the native ligament complex may be determined in vivo using a standard knee balancer. Measurements were obtained with a commercially available knee balancer, which was initially calibrated in vitro. 5 patients underwent reconstruction of the force-displacement curves of the ligament complex. Stiffness of the medial and lateral compartments were calculated to measure the stability of the capsular ligament complex. All force-displacement curves consisted of a non-linear section at the beginning and of a linear section from about 80 N onwards. The medial compartment showed values of 28.4 ± 1.2 N/mm for minimum stiffness and of 39.9 ± 1.1 N/mm for maximum stiffness; the respective values for the lateral compartment were 19.9 ± 0.9 N/mm and 46.6 ± 0.8 N/mm. A commercially available knee balancer may be calibrated for measuring stiffness of knee ligament complex in vivo, which may contribute to a better understanding of the intrinsic mechanical behaviour of knee joints. KW - Biomechanische Analyse KW - Kniegelenkband KW - Steifigkeit Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-41732-x VL - 9 SP - 1 EP - 8 PB - Nature ER - TY - JOUR A1 - Putzer, Michael A1 - Auer, Stefan A1 - Malpica, William A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - A numerical study to determine the effect of ligament stiffness on kinematics of the lumbar spine during flexion JF - BMC Musculoskeletal Disorders N2 - Background There is a wide range of mechanical properties of spinal ligaments documented in literature. Due to the fact that ligaments contribute in stabilizing the spine by limiting excessive intersegmental motion, those properties are of particular interest for the implementation in musculoskeletal models. The aim of this study was to investigate the effect of varying ligament stiffness on the kinematic behaviour of the lumbar spine. Methods A musculoskeletal model with a detailed lumbar spine was modified according to fluoroscopic recordings and corresponding data files of three different subjects. For flexion, inverse dynamics analysis with a variation of the ligament stiffness matrix were conducted. The influence of several degrees of ligament stiffness on the lumbar spine model were investigated by tracking ligament forces, disc forces and resulting moments generated by the ligaments. Additionally, the kinematics of the motion segments were evaluated. Results An increase of ligament stiffness resulted in an increase of ligament and disc forces, whereas the relative change of disc force increased at a higher rate at the L4/L5 level (19 %) than at the L3/L4 (10 %) level in a fully flexed posture. The same behaviour applied to measured moments with 67 % and 45 %. As a consequence, the motion deflected to the lower levels of the lumbar spine and the lower discs had to resist an increase in loading. Conclusions Higher values of ligament stiffness over all lumbar levels could lead to a shift of the loading and the motion between segments to the lower lumbar levels. This could lead to an increased risk for the lower lumbar parts. KW - Lumbar spine KW - Ligament stiffness KW - Musculoskeletal Modeling KW - Biomechanics Y1 - 2016 U6 - https://doi.org/10.1186/s12891-016-0942-x VL - 17 IS - 95 ER - TY - JOUR A1 - Weber, Tim A. A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Verkerke, Gijsbertus Jacob A1 - Renkawitz, Tobias ED - Takagi, Michiaki T1 - Does Computer-Assisted Femur First THR Improve Musculoskeletal Loading Conditions? JF - BioMed Research International N2 - We have developed a novel, computer-assisted operation method for minimal-invasive total hip replacement (THR) following the concept of “femur first/combined anteversion,” which incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position (CAS FF). The purpose of this study is to assess whether the hip joint reaction forces and patient’s gait parameters are being improved by CAS FF in relation to conventional THR (CON). We enrolled 60 patients (28 CAS FF/32 CON) and invited them for gait analysis at three time points (preoperatively, postop six months, and postop 12 months). Data retrieved from gait analysis was processed using patient-specific musculoskeletal models. The target parameters were hip reaction force magnitude (hrf), symmetries, and orientation with respect to the cup. Hrf in the CAS FF group were closer to a young healthy normal. Phase-shift symmetry showed an increase in the CAS FF group. Hrf orientation in the CAS FF group was closer to optimum, though no edge or rim-loading occurred in the CON group as well. The CAS FF group showed an improved hrf orientation in an early stage and a trend to an improved long-term outcome. KW - Hüftgelenkprothese KW - Operationstechnik KW - Computerunterstütztes Verfahren KW - Bewegungsapparat KW - Mechanische Belastung Y1 - 2015 U6 - https://doi.org/10.1155/2015/625317 VL - 2015 SP - ID 625317 ER - TY - JOUR A1 - Weber, Markus A1 - Merle, Christian A1 - Nawabi, Danyal H. A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Renkawitz, Tobias T1 - Inaccurate offset restoration in total hip arthroplasty results in reduced range of motion JF - Scientific Reports N2 - Offset restoration in total hip arthroplasty (THA) is associated with postoperative range of motion (ROM) and gait kinematics. We aimed to research into the impact of high offset (HO) and standard stems on postoperative ROM. 121 patients received cementless THA through a minimally-invasive anterolateral approach. A 360° hip ROM analysis software calculated impingement-free hip movement based on postoperative 3D-CTs compared to ROM values necessary for activities of daily living (ADL). The same model was then run a second time after changing the stem geometry between standard and HO configuration with the implants in the same position. HO stems showed higher ROM for all directions between 4.6 and 8.9° (p < 0.001) compared with standard stems but with high interindividual variability. In the subgroup with HO stems for intraoperative offset restoration, the increase in ROM was even higher for all ROM directions with values between 6.1 and 14.4° (p < 0.001) compared to offset underrestoration with standard stems. Avoiding offset underrestoration resulted in a higher amount of patients of over 20% for each ROM direction that fulfilled the criteria for ADL (p < 0.001). In contrast, in patients with standard stems for offset restoration ROM did increase but not clinically relevant by offset overcorrection for all directions between 3.1 and 6.1° (p < 0.001). Offset overcorrection by replacing standard with HO stems improved ROM for ADL in a low number of patients below 10% (p > 0.03). Patient-individual restoration of offset is crucial for free ROM in THA. Both over and underrestoration of offset should be avoided. KW - Adaptive clinical trial KW - Bone imaging Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-70059-1 VL - 10 IS - 13208 SP - 9 PB - Nature ER - TY - JOUR A1 - Scheer, Clara A1 - Kubowitsch, Simone A1 - Dendorfer, Sebastian A1 - Jansen, Petra T1 - Happy Enough to Relax? How Positive and Negative Emotions Activate Different Muscular Regions in the Back - an Explorative Study JF - Frontiers in Psychology N2 - Embodiment theories have proposed a reciprocal relationship between emotional state and bodily reactions. Besides large body postures, recent studies have found emotions to affect rather subtle bodily expressions, such as slumped or upright sitting posture. This study investigated back muscle activity as an indication of an effect of positive and negative emotions on the sitting position. The electromyography (EMG) activity of six back muscles was recorded in 31 healthy subjects during exposure to positive and negative affective pictures. A resting period was used as a control condition. Increased muscle activity patterns in the back were found during the exposure to negative emotional stimuli, which was mainly measured in the lumbar and thorax regions. The positive emotion condition caused no elevated activity. The findings show that negative emotions lead to increased differential muscle activity in the back and thus corroborate those of previous research that emotion affects subtle bodily expressions. KW - electromyography KW - muscle activity KW - emotion KW - sadness KW - happiness KW - embodiment Y1 - 2021 U6 - https://doi.org/10.3389/fpsyg.2021.511746 SN - 1664-1078 VL - Volume 12 IS - May 2021 PB - Frontiers Media ER - TY - CHAP A1 - Greiner, Nina A1 - Lauer, Norina ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Meussling-Sentpali, Annette ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Informierte Einwilligung bei Aphasie T2 - Digitale Technik für ambulante Pflege und Therapie: Herausforderungen, Lösungen, Anwendungen und Forschungsperspektiven N2 - Nach einer Einführung in die Grundlagen der informierten Einwilligung werden Empfehlungen zur Durchführung zusammengefasst und Besonderheiten im Hinblick auf die Gestaltung des Einwilligungsprozesses bei Personen mit Aphasie herausgearbeitet. Zuletzt wird das aphasiefreundliche Vorgehen im Projekt DeinHaus 4.0 Oberpfalz kurz skizziert. KW - Informed consent KW - Aphasie KW - Versuchsperson KW - Logopädie KW - Digitalisierung KW - Informierte Einwilligung KW - Ethik KW - Forschung KW - Teletherapie Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-55107 SN - 978-3-8394-6235-5 SP - 137 EP - 154 PB - transcript CY - Bielefeld ET - 1. Aufl. ER - TY - JOUR A1 - Braun, Maximilian A1 - Kunkler, Jan A1 - Kellner, Florian T1 - Towards Sustainable Cities: Utilizing Floating Car Data to Support Location-Based Road Network Performance Measurements JF - Sustainability N2 - Road network performance (RNP) is a key element for urban sustainability as it has a significant impact on economy, environment, and society. Poor RNP can lead to traffic congestion, which can lead to higher transportation costs, more pollution and health issues regarding the urban population. To evaluate the effects of the RNP, the involved stakeholders need a real-world data base to work with. This paper develops a data collection approach to enable location-based RNP analysis using publicly available traffic information. Therefore, we use reachable range requests implemented by navigation service providers to retrieve travel times, travel speeds, and traffic conditions. To demonstrate the practicability of the proposed methodology, a comparison of four German cities is made, considering the network characteristics with respect to detours, infrastructure, and traffic congestion. The results are combined with cost rates to compare the economical dimension of sustainability of the chosen cities. Our results show that digitization eases the assessment of traffic data and that a combination of several indicators must be considered depending on the relevant sustainability dimension decisions are made from. Y1 - 2020 U6 - https://doi.org/10.3390/su12198145 VL - 12 IS - 19 PB - MDPI ER - TY - JOUR A1 - Kunkler, Jan A1 - Braun, Maximilian A1 - Kellner, Florian T1 - Speed Limit Induced CO2 Reduction on Motorways: Enhancing Discussion Transparency through Data Enrichment of Road Networks JF - Sustainability N2 - Considering climate change, recent political debates often focus on measures to reduce CO2 emissions. One key component is the reduction of emissions produced by motorized vehicles. Since the amount of emission directly correlates to the velocity of a vehicle via energy consumption factors, a general speed limit is often proposed. This article presents a methodology to combine openly available topology data of road networks from OpenStreetMap (OSM) with pay-per-use API traffic data from TomTom to evaluate such measures transparently by analyzing historical real-world circumstances. From our exemplary case study of the German motorway network, we derive that most parts of the motorway network on average do not reach their maximum allowed speed throughout the day due to traffic, construction sites and general road utilization by network participants. Nonetheless our findings prove that the introduction of a speed limit of 120 km per hour on the German autobahn would restrict 50.74% of network flow kilometers for a CO2 reduction of 7.43% compared to the unrestricted state. Y1 - 2021 U6 - https://doi.org/10.3390/su13010395 VL - 13 IS - 1 PB - MDPI ER - TY - JOUR A1 - Lienland, Bernhard A1 - Zeng, Li T1 - A Review and Comparison of Genetic Algorithms for the 0-1 Multidimensional Knapsack Problem JF - International Journal of Operations Research and Information Systems (IJORIS) N2 - The 0-1 multidimensional knapsack problem (MKP) is a well-known combinatorial optimization problem with several real-life applications, for example, in project selection. Genetic algorithms (GA) are effective heuristics for solving the 0-1 MKP. Multiple individual GAs with specific characteristics have been proposed in literature. However, so far, these approaches have only been partially compared in multiple studies with unequal conditions. Therefore, to identify the “best” genetic algorithm, this article reviews and compares 11 existing GAs. The authors' tests provide detailed information on the GAs themselves as well as their performance. The authors validated fitness values and required computation times in varying problem types and environments. Results demonstrate the superiority of one GA. Y1 - 2015 U6 - https://doi.org/10.4018/ijoris.2015040102 SN - 1947-9328 VL - 6 IS - 2 PB - IGI Global ER - TY - JOUR A1 - Kellner, Florian A1 - Otto, Andreas A1 - Brabänder, Christian T1 - Bringing infrastructure into pricing in road freight transportation – A measuring concept based on navigation service data JF - Transportation Research Procedia N2 - Differences in road infrastructure, such as capacity, congestion, speed limits affect the productivity and the costs of short-distance freight operations. This article introduces a novel methodology that is based on navigation service data to measure the effects in terms of cost per kilometer using navigation and shipment data. The methodology is applied to five terminals of a forwarding cooperation and has been able to document significant differences in cost per kilometer across the terminals. The research results can be used by logistics service providers to better understand how productivity and thus profitability is affected by the quality of the transportation infrastructure in the particular areas they operate in. Furthermore, the insights will help these companies for better, i.e. cost-based pricing and will allow to document why and where prices need to be adapted. Y1 - 2017 U6 - https://doi.org/10.1016/j.trpro.2017.05.458 VL - 25 SP - 794 EP - 805 PB - Elsevier ER - TY - JOUR A1 - Kellner, Florian T1 - Exploring the impact of traffic congestion on CO2 emissions in freight distribution networks JF - Logistics Research N2 - This research quantifies the impact that regular road traffic congestion has on the CO2 emissions of a real-world distribution network, and it studies the consequences when the number of distribution centers changes. For this purpose, this study makes use of a network model allowing for a detailed representation of all relevant transport operations, including production flows between factories and distribution centers, line haul shipments between distribution centers and customers, and round/delivery trips between transshipment points and retailer locations for the last mile. The processed trip and traffic information does not rely on standard traffic data collection approaches, such as interviews, in situ technologies, or floating car data, but the road traffic data are retrieved from an online navigation service, such as Bing Maps, Google Maps, Inrix, Here, and TomTom. This study proves that online navigation services may considerably contribute to future research projects analyzing CO2 sensitivities and greenhouse gas cutting opportunities in logistics networks. Y1 - 2016 U6 - https://doi.org/10.1007/s12159-016-0148-5 VL - 9 PB - Springer Nature ER - TY - JOUR A1 - Kraft, Sarah Katharina A1 - Quayson, Matthew A1 - Kellner, Florian T1 - Assessing the German Act on Corporate Due Diligence Obligations in Supply Chains: a perspective from the smallholder cocoa farmer JF - Frontiers in Sustainability N2 - This research examines the potential outputs, outcomes, and impacts of the German Act on Corporate Due Diligence Obligations in Supply Chains (LkSG) on the smallholder cocoa farmers in West Africa. The study primarily relies on a literature review and an impact pathway to conduct a systematic analysis to identify the potential effects of the LkSG on smallholder cocoa farmers. The findings indicate that some, but not all of the risks addressed by the LkSG align with those faced by smallholder cocoa farmers and their families. Additionally, the research also reveals weaknesses, particularly in managing environmental risks, which the LkSG does not adequately cover. Our findings show that in the short- and medium-term, the LkSG has no potential effects on smallholder cocoa farmers. Furthermore, the potential positive impacts of the law on smallholder cocoa farmers will take a long time to realize, as the LkSG considers primarily tier-1 suppliers. Companies in Germany might reassess their supply chains to strive for an LkSG-risk-free supply chain, which could in the long term have sustained impacts on smallholder cocoa farmers. However, we recommend a comprehensive risk analysis of the cocoa supply chain to enhance the human rights of cocoa farmers. Y1 - 2024 U6 - https://doi.org/10.3389/frsus.2024.1376619 VL - 5 PB - frontiers ER - TY - JOUR A1 - Kraft, Sarah Katharina A1 - Kellner, Florian T1 - Can Blockchain Be a Basis to Ensure Transparency in an Agricultural Supply Chain? JF - Sustainability N2 - Many supply chains within developing countries lack transparency and are fraught with fraud, corruption, and a substantial number of intermediaries. For several decades, the cocoa sector has faced multiple social, economic, and environmental challenges, some of which include the issue of child labor and very low incomes for farmers, leading to poor living conditions. Blockchain technology has a high potential to reduce—or completely eradicate—some of these hurdles. In this article, we present a blockchain-based solution based on the open-source framework Hyperledger Fabric for the cocoa supply chain to promote transparency and reduce fraud. In doing so, we explicitly describe how farmers can be directly integrated into the whole blockchain solution considering the limited infrastructure, knowledge, and technologies available to them. Since about 70% of all cocoa worldwide is produced in West Africa, this case study uses the cocoa sector in Ghana as an example. Y1 - 2022 U6 - https://doi.org/10.3390/su14138044 VL - 14 IS - 13 PB - MDPI ER - TY - JOUR A1 - Kunkler, Jan A1 - Kellner, Florian T1 - Sustainable City Evaluation Using the Database for Estimation of Road Network Performance JF - Sustainability N2 - This article introduces the Database for Estimation of Road Network Performance (DERNP) to enable wide-scale estimation of relevant Road Network Performance (RNP) factors for major German cities. The methodology behind DERNP is based on a randomized route sampling procedure that utilizes the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) in combination with the tile-based HERE Maps Traffic API v7 and a digital elevation model provided by the European Union’s Earth Observation Programme Copernicus to generate a large set of independent and realistic routes throughout OpenStreetMap road networks. By evaluating these routes using the PHEMLight5 framework, a comprehensive list of RNP parameters is estimated and translated into polynomial regression models for general usage. The applicability of these estimations is demonstrated based on a case study of four major German cities. This case study considers network characteristics in terms of detours, infrastructure, traffic congestion, fuel consumption, and CO2 emissions. Our results show that DERNP and its underlying randomized route sampling methodology overcomes major limitations of previous wide-scale RNP approaches, enabling efficient, easy-to-use, and region-specific RNP comparisons. Y1 - 2023 U6 - https://doi.org/10.3390/su15010733 VL - 15 IS - 1 PB - MDPI ER - TY - JOUR A1 - Philipp, Alois A1 - de Somer, Filip A1 - Foltan, Maik A1 - Bredthauer, Andre A1 - Krenkel, Lars A1 - Zeman, Florian A1 - Lehle, Karla T1 - Life span of different extracorporeal membrane systems for severe respiratory failure in the clinical practice JF - PLOS ONE N2 - Over the past decade, veno-venous extracorporeal membrane oxygenation (vvECMO) has been increasingly utilized in respiratory failure in patients. This study presents our institution´s experience focusing on the life span of ECMO systems reflecting the performance of a particular system. A retrospective review of our ECMO database identified 461 adult patients undergoing vvECMO (2010-2017). Patients that required more than one system and survived the first exchange >24 hours (n = 139) were included. Life span until the first exchange and exchange criteria were analyzed for all systems (PLS, Cardiohelp HLS-set, both Maquet Cardiopulmonary, Rastatt, Germany; Deltastream/Hilite7000LT, iLA-activve, Xenios/NovaLung, Heilbronn, Germany; ECC.O5, LivaNova, Mirandola, Italy). At our ECMO center, the frequency of a system exchange was 30%. The median (IQR) life span was 9 (6-12) days. There was no difference regarding the different systems (p = 0.145 and p = 0.108, respectively). However, the Deltastream systems were exchanged more frequently due to elective technical complications (e. g. worsened gas transfer, development of coagulation disorder, increased bleedings complications) compared to the other exchanged systems (p = 0.013). In summary, the used ECMO systems are safe and effective for acute respiratory failure. There is no evidence for the usage of a specific system. Only the increased predictability of an imminent exchange preferred the usage of a Deltastream system. However, the decision to use a particular system should not depend solely on the possible criteria for an exchange. KW - Equipment Failure Analysis/statistics & numerical data KW - Extracorporeal Membrane Oxygenation/instrumentation KW - Membrane/classification/standards/statistics & numerical data KW - Primary Health Care/statistics & numerical data KW - Respiratory Distress Syndrome/therapy KW - Retrospective Studies KW - Severity of Illness Index KW - Time factors KW - MULTIDETECTOR COMPUTED-TOMOGRAPHY KW - THROMBOTIC DEPOSITS KW - ECMO SYSTEMS KW - Flow KW - OXYGENATION Y1 - 2018 U6 - https://doi.org/10.1371/journal.pone.0198392 VL - 13 IS - 6 SP - 1 EP - 10 PB - PLOS ER - TY - JOUR A1 - Diermeier, Andreas A1 - Sindersberger, Dirk A1 - Krenkel, Lars A1 - Rosell, X. C. A1 - Monkman, Gareth J. T1 - Controllable Magnetoactive Polymer Conduit JF - The Open Mechanical Engineering Journal N2 - Objective: Magneto-active Polymers (MAP) are smart materials whose mechanical characteristics, such as elastic and shear moduli, may be controllable by means of an externally applied magnetic field. Methods: Various additives may be used to influence the characteristics of the polymer matrix whilst a suspension of soft and/or hard magnetic particles determine the magnetic properties of the composite. Both pre-cure and post-cure magnetization is possible. Results: A range of control strategies have been investigated for evaluation of the system using fluids of differing kinematic viscosity. Conclusion: Depending on the degree of magnetic field homogeneity, magneto-deformation and magnetostriction contribute to MAP actuation. This paper presents a novel application in the form of a peristaltic MAP tube system, applicable to flow control and pumping of hemorheological fluids in blood circulatory systems for biomedical research purposes. Y1 - 2018 UR - https://www.benthamopen.com/ABSTRACT/TOMEJ-12-192 N1 - Corresponding authro: Gareth J. Monkman VL - 12 IS - 1 SP - 192 EP - 200 PB - Bentham ER - TY - JOUR A1 - Köck, Hannah A1 - Striegl, Birgit A1 - Kraus, Annalena A1 - Zborilova, Magdalena A1 - Christiansen, Silke H. A1 - Schäfer, Nicole A1 - Grässel, Susanne A1 - Hornberger, Helga T1 - In Vitro Analysis of Human Cartilage Infiltrated by Hydrogels and Hydrogel-Encapsulated Chondrocytes JF - Bioengineering N2 - Osteoarthritis (OA) is a degenerative joint disease causing loss of articular cartilage and structural damage in all joint tissues. Given the limited regenerative capacity of articular cartilage, methods to support the native structural properties of articular cartilage are highly anticipated. The aim of this study was to infiltrate zwitterionic monomer solutions into human OA-cartilage explants to replace lost proteoglycans. The study included polymerization and deposition of methacryloyloxyethyl-phosphorylcholine- and a novel sulfobetaine-methacrylate-based monomer solution within ex vivo human OA-cartilage explants and the encapsulation of isolated chondrocytes within hydrogels and the corresponding effects on chondrocyte viability. The results demonstrated that zwitterionic cartilage–hydrogel networks are formed by infiltration. In general, cytotoxic effects of the monomer solutions were observed, as was a time-dependent infiltration behavior into the tissue accompanied by increasing cell death and penetration depth. The successful deposition of zwitterionic hydrogels within OA cartilage identifies the infiltration method as a potential future therapeutic option for the repair/replacement of OA-cartilage extracellular suprastructure. Due to the toxic effects of the monomer solutions, the focus should be on sealing the OA-cartilage surface, instead of complete infiltration. An alternative treatment option for focal cartilage defects could be the usage of monomer solutions, especially the novel generated sulfobetaine-methacrylate-based monomer solution, as bionic for cell-based 3D bioprintable hydrogels. KW - osteoarthritis KW - human articular cartilage KW - chondrocytes KW - hydrogels KW - zwitterionic monomers KW - infiltration Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-61235 N1 - Corresponding author: Helga Hornberger VL - 10 SP - 1 EP - 21 PB - MDPI ER - TY - JOUR A1 - Müller, Wolf-Dieter A1 - Hornberger, Helga T1 - The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys JF - International Journal of Molecular Science N2 - Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg2+ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE) is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg+ intermediate state, the stability of MgH2 and the role of hydrogen overpotential. Finally, the impact of MgH2 formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys. KW - magnesium KW - magnesium alloys KW - magnesium hydride KW - corrosion Y1 - 2014 U6 - https://doi.org/10.3390/ijms150711456 VL - 15 SP - 11456 EP - 11472 ER - TY - JOUR A1 - Hornberger, Helga A1 - Striegl, Birgit A1 - Trahanofsky, M. A1 - Kneissl, F. A1 - Kronseder, Matthias T1 - Degradation and bioactivity studies of Mg membranes for dental surgery JF - Materials Letter X N2 - Bioresorbable materials are under investigation due to their promising properties for applications as implant material. This study is about the degradation and bioactivity behaviour of magnesium foils, which allegorize dental membranes. The degradation behaviour including pitting corrosion during immersion tests can be precisely observed using micro-computed tomography. Using the bioactivity test according to Kokubo, it is shown that magnesium has strong Ca-phosphate layer formation correlated with high degradation. Therefore, magnesium foils appear to hold a great potential for bone implant application. KW - Magnesium KW - Dental membrane KW - Bioactivity KW - Corrosion rate Y1 - 2019 U6 - https://doi.org/10.1016/j.mlblux.2019.100007 VL - 2 IS - June SP - 1 EP - 5 PB - Elsevier ER - TY - JOUR A1 - Steinhauser, Stefanie A1 - Raptis, Georgios T1 - Design propositions for nudging in healthcare: Adoption of national electronic health recordsystems JF - Digital Health N2 - Objectives: Electronic health records (EHRs) are considered important for improving efficiency and reducing costs of ahealthcare system. However, the adoption of EHR systems differs among countries and so does the way the decision to par-ticipate in EHRs is presented. Nudging is a concept that deals with influencing human behaviour within the research streamof behavioural economics. In this paper, we focus on the effects of the choice architecture on the decision for the adoption ofnational EHRs. Our study aims to link influences on human behaviour through nudging with the adoption of EHRs to inves-tigate how choice architects can facilitate the adoption of national information systems. Methods: We employ a qualitative explorative research design, namely the case study method. Using theoretical sampling,we selected four cases (i.e., countries) for our study: Estonia, Austria, the Netherlands, and Germany. We collected and ana-lyzed data from various primary and secondary sources: ethnographic observation, interviews, scientific papers, homepages,press releases, newspaper articles, technical specifications, publications from governmental bodies, and formal studies. Results: The findings from our European case studies show that designing for EHR adoption should encompass choice archi-tecture elements (i.e., defaults), technical elements (i.e., choice granularity and access transparency), and institutional ele-ments (i.e., regulations for data protection, information campaigns, and financial incentives) in combination. Conclusions: Our findings provide insights on the design of the adoption environments of large-scale, national EHR systems.Future research could estimate the magnitude of effects of the determinants. KW - Health policies KW - national KW - information system KW - multihospital KW - electronic health records KW - doption KW - ealthcare systems Y1 - 2023 U6 - https://doi.org/10.1177/20552076231181208 SN - 2055-2076 VL - 9 SP - 1 EP - 12 PB - Sage ER - TY - JOUR A1 - Tauwald, Sandra Melina A1 - Michel, Johanna A1 - Brandt, Marie A1 - Vielsmeier, Veronika A1 - Stemmer, Christian A1 - Krenkel, Lars T1 - Experimental studies and mathematical modeling of the viscoelastic rheology of tracheobronchial mucus from respiratory healthy patients JF - Multidisciplinary Respiratory Medicine N2 - BACKGROUND: Tracheobronchial mucus plays a crucial role in pulmonary function by providing protection against inhaled pathogens. Due to its composition of water, mucins, and other biomolecules, it has a complex viscoelastic rheological behavior. This interplay of both viscous and elastic properties has not been fully described yet. In this study, we characterize the rheology of human mucus using oscillatory and transient tests. Based on the transient tests, we describe the material behavior of mucus under stress and strain loading by mathematical models. METHODS: Mucus samples were collected from clinically used endotracheal tubes. For rheological characterization, oscillatory amplitude-sweep and frequency-sweep tests, and transient creep-recovery and stress-relaxation tests were performed. The results of the transient test were approximated using the Burgers model, the Weibull distribution, and the six-element Maxwell model. The three-dimensional microstructure of the tracheobronchial mucus was visualized using scanning electron microscope imaging. RESULTS: Amplitude-sweep tests showed storage moduli ranging from 0.1 Pa to 10000 Pa and a median critical strain of 4 %. In frequency-sweep tests, storage and loss moduli increased with frequency, with the median of the storage modulus ranging from 10 Pa to 30 Pa, and the median of the loss modulus from 5 Pa to 14 Pa. The Burgers model approximates the viscoelastic behavior of tracheobronchial mucus during a constant load of stress appropriately (R2 of 0.99), and the Weibull distribution is suitable to predict the recovery of the sample after the removal of this stress (R2 of 0.99). The approximation of the stress-relaxation test data by a six-element Maxwell model shows a larger fit error (R2 of 0.91). CONCLUSIONS: This study provides a detailed description of all process steps of characterizing the rheology of tracheobronchial mucus, including sample collection, microstructure visualization, and rheological investigation. Based on this characterization, we provide mathematical models of the rheological behavior of tracheobronchial mucus. These can now be used to simulate mucus flow in the respiratory system through numerical approaches. KW - tracheobronchial mucus KW - rheological model KW - viscoelasticity Y1 - 2023 U6 - https://doi.org/10.4081/mrm.2023.923 SN - 2049-6958 N1 - Corresponding author: Sandra Melina Tauwald VL - 18 IS - 1 PB - PAGEPress CY - Pavia, Italy ER - TY - JOUR A1 - Loo, Xuyan A1 - Nagaraju, Bhavana A1 - Pathivada, Sai A1 - Bartsch, Alexander A1 - Schratzenstaller, Thomas A1 - Sattler, Robert A1 - Monkman, Gareth J. T1 - Electrical properties of bisphenol-A-free magnetoactive borosilicate polymers JF - AIP Advances N2 - The recent REACH regulations require the elimination of bisphenol-A and titanium dioxide from commercially available boron-based polymers. This has led to changes in some of the mechanical characteristics, which strongly influence the properties of magnetoactive borosilicate polymers. This work delivers results on the electrical properties and discusses some implications for future research using bisphenol-A and titanium-dioxide-free substitutes. KW - Electrical components KW - Electrical properties and parameters KW - Dielectric properties KW - Electrical resistivity KW - Magnetic materials KW - Viscoelasticity KW - Polymers KW - Non Newtonian fluids KW - Magnetic fluids Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-72936 SN - 2158-3226 N1 - Corresponding author der OTH Regensburg: Gareth J. Monkman VL - 14 IS - 5 PB - AIP Publishing ER - TY - JOUR A1 - Eigenberger, Andreas A1 - Felthaus, Oliver A1 - Schratzenstaller, Thomas A1 - Haerteis, Silke A1 - Utpatel, Kirsten A1 - Prantl, Lukas T1 - The Effects of Shear Force-Based Processing of Lipoaspirates on White Adipose Tissue and the Differentiation Potential of Adipose Derived Stem Cells JF - cells N2 - Autologous lipotransfer is a promising method for tissue regeneration, because white adipose tissue contains a heterogeneous cell population, including mesenchymal stem cells, endothelial cells, immune cells, and adipocytes. In order to improve the outcome, adipose tissue can be processed before application. In this study, we investigated changes caused by mechanical processing. Lipoaspirates were processed using sedimentation, first-time centrifugation, shear-force homogenization, and second-time centrifugation. The average adipocyte size, stromal vascular cell count, and adipocyte depot size were examined histologically at every processing step. In addition, the adipose derived stem cells (ADSCs) were isolated and differentiated osteogenically and adipogenically. While homogenization causes a disruption of adipocyte depots, the shape of the remaining adipocytes is not changed. On average, these adipocytes are smaller than the depot adipocytes, they are surrounded by the ECM, and therefore mechanically more stable. The volume loss of adipocyte depots leads to a significant enrichment of stromal vascular cells such as ADSCs. However, the mechanical processing does not change the potential of the ADSCs to differentiate adipogenically or steogenically. It thus appears that mechanically processed lipoaspirates are promising for the reparation of even mechanically stressed tissue as that found in nasolabial folds. The changes resulting from the processing correspond more to a filtration of mechanically less stable components than to a manipulation of the tissue. KW - white adipose tissue KW - lipograft KW - stem cells KW - fat grafting KW - surgery KW - cell-enriched lipotransfer KW - CELT KW - lipoaspirate Y1 - 2022 U6 - https://doi.org/10.3390/cells11162543 VL - 11 IS - 16 PB - MDPI CY - Basel ER - TY - JOUR A1 - Wiesent, Lisa A1 - Schultheiss, Ulrich A1 - Schmid, Christof A1 - Schratzenstaller, Thomas A1 - Nonn, Aida T1 - Experimentally validated simulation of coronary stents considering different dogboning ratios and asymmetric stent positioning JF - PlOS One N2 - In-stent restenosis remains a major problem of arteriosclerosis treatment by stenting. Expansion-optimized stents could reduce this problem. With numerical simulations, stent designs/ expansion behaviours can be effectively analyzed. For reasons of efficiency, simplified models of balloon-expandable stents are often used, but their accuracy must be challenged due to insufficient experimental validation. In this work, a realistic stent life-cycle simulation has been performed including balloon folding, stent crimping and free expansion of the balloon-stent-system. The successful simulation and validation of two stent designs with homogenous and heterogeneous stent stiffness and an asymmetrically positioned stent on the balloon catheter confirm the universal applicability of the simulation approach. Dogboning ratio, as well as the final dimensions of the folded balloon, the crimped and expanded stent, correspond well to the experimental dimensions with only slight deviations. In contrast to the detailed stent life-cycle simulation, a displacement-controlled simulation can not predict the transient stent expansion, but is suitable to reproduce the final expanded stent shape and the associated stress states. The detailed stent life-cycle simulation is thus essential for stent expansion analysis/optimization, whereas for reasons of computational efficiency, the displacement-controlled approach can be considered in the context of pure stress analysis. KW - Catheters KW - Coronary stenting KW - Deformation KW - Stent implantation KW - Stiffness KW - Stent KW - Ballondilatation KW - Numerische Strömungssimulation Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0224026 VL - 14 IS - 10 SP - 1 EP - 25 PB - PLOS ER - TY - JOUR A1 - Geith, Markus A. A1 - Swidergal, Krzysztof A1 - Hochholdinger, Bernd A1 - Schratzenstaller, Thomas A1 - Wagner, Marcus A1 - Holzapfel, Gerhard A. T1 - On the importance of modeling balloon folding, pleating, and stent crimping: An FE study comparing experimental inflation tests JF - International Journal for Numerical Methods in Biomedical Engineering N2 - Finite element (FE)–based studies of preoperative processes such as folding,pleating, and stent crimping with a comparison with experimental inflation tests are not yet available. Therefore, a novel workflow is presented in which residual stresses of balloon folding and pleating, as well as stent crimping, and the geometries of all contact partners were ultimately implemented in an FE code to simulate stent expansion by using an implicit solver. The numerical results demonstrate that the incorporation of residual stresses and strains experienced during the production step significantly increased the accuracy of the subsequent simulations, especially of the stent expansion model. During the preoperative processes, stresses inside the membrane and the stent material also reached a rather high level. Hence, there can be no presumption that balloon catheters or stents are undamaged before the actual surgery. The implementation of the realistic geometry, in particular the balloon tapers, and the blades of the process devices improved the simulation of the expansion mech-anisms, such as dogboning, concave bending, or overexpansion of stent cells. This study shows that implicit solvers are able to precisely simulate the mentioned preoperative processes and the stent expansion procedure without a preceding manipulation of the simulation time or physical mass. KW - Catheter KW - Coronary KW - Crimping KW - Finite element KW - Stent KW - Stent KW - Implantation KW - Simulation KW - Finite-Elemente-Methode Y1 - 2019 U6 - https://doi.org/10.1002/cnm.3249 N1 - This study was funded by the Bavarian Research Foundation within the project “PIZ‐225‐18” VL - 35 IS - 11 PB - Wiley ER - TY - JOUR A1 - Geith, Markus A. A1 - Sommer, Gerhard A1 - Schratzenstaller, Thomas A1 - Holzapfel, Gerhard A. T1 - Biomechanical and structural quantification of vascular damage: A unique investigation of stent implantation JF - Artery Research Y1 - 2017 U6 - https://doi.org/10.1016/j.artres.2017.10.025 VL - 20 IS - Issue C SP - 50 ER - TY - JOUR A1 - Zentgraf, Jan A1 - Nützel, Florian A1 - Mühlbauer, Nico A1 - Schultheiss, Ulrich A1 - Grad, Marius A1 - Schratzenstaller, Thomas T1 - Surface Treatment of Additively Manufactured Polyetheretherketone (PEEK) by Centrifugal Disc Finishing Process: Identification of the Key Parameters JF - Polymers N2 - Polyetheretherketone is a promising material for implants due to its good mechanical properties and excellent biocompatibility. Its accessibility to a wide range of applications is facilitated by the ability to process it with an easy-to-use manufacturing process such as fused filament fabrication. The elimination of disadvantages associated with the manufacturing process, such as a poor surface quality, is a main challenge to deal with. As part of the mass finishing process, centrifugal disc finishing has demonstrated good results in surface optimization, making it a promising candidate for the post-processing of additively manufactured parts. The objective of this study is to identify the key parameters of the centrifugal disc finishing process on the waviness of additively manufactured PEEK specimens, which has not been investigated previously. The waviness of the specimen was investigated by means of confocal laser scanning microscopy (CLSM), while weight loss was additionally tracked. Six parameters were investigated: type, amount and speed of media, use of compound, amount of water and time. Type of media, time and speed were found to significantly influence waviness reduction and weight loss. Surface electron microscopy images demonstrated the additional effects of deburring and corner rounding. Results on previous studies with specimens made of metal showed similar results. Further investigation is required to optimize waviness reduction and polish parts in a second post-processing step. KW - PEEK KW - fused deposition modeling KW - fused filament fabrication KW - centrifugal disc finishing KW - mass finishing KW - 3D printing KW - post-processing of 3D printed parts KW - surface treatment KW - high-performance polymers KW - additive manufacturing Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-73959 SN - 2073-4360 N1 - Corresponding author der OTH Regensburg: Jan Zentgraf VL - 16 PB - MDPI CY - Basel ER - TY - JOUR A1 - Wiesent, Lisa A1 - Schultheiß, Ulrich A1 - Lulla, Philipp A1 - Noster, Ulf A1 - Schratzenstaller, Thomas A1 - Schmid, Christof A1 - Nonn, Aida A1 - Spear, Ashley T1 - Computational analysis of the effects of geometric irregularities and post-processing steps on the mechanical behavior of additively manufactured 316L stainless steel stents JF - PLoS ONE N2 - Advances in additive manufacturing enable the production of tailored lattice structures and thus, in principle, coronary stents. This study investigates the effects of process-related irregularities, heat and surface treatment on the morphology, mechanical response, and expansion behavior of 316L stainless steel stents produced by laser powder bed fusion and provides a methodological approach for their numerical evaluation. A combined experimental and computational framework is used, based on both actual and computationally reconstructed laser powder bed fused stents. Process-related morphological deviations between the as-designed and actual laser powder bed fused stents were observed, resulting in a diameter increase by a factor of 2-2.6 for the stents without surface treatment and 1.3-2 for the electropolished stent compared to the as-designed stent. Thus, due to the increased geometrically induced stiffness, the laser powder bed fused stents in the as-built (7.11 ± 0.63 N) or the heat treated condition (5.87 ± 0.49 N) showed increased radial forces when compressed between two plates. After electropolishing, the heat treated stents exhibited radial forces (2.38 ± 0.23 N) comparable to conventional metallic stents. The laser powder bed fused stents were further affected by the size effect, resulting in a reduced yield strength by 41% in the as-built and by 59% in the heat treated condition compared to the bulk material obtained from tensile tests. The presented numerical approach was successful in predicting the macroscopic mechanical response of the stents under compression. During deformation, increased stiffness and local stress concentration were observed within the laser powder bed fused stents. Subsequent numerical expansion analysis of the derived stent models within a previously verified numerical model of stent expansion showed that electropolished and heat treated laser powder bed fused stents can exhibit comparable expansion behavior to conventional stents. The findings from this work motivate future experimental/numerical studies to quantify threshold values of critical geometric irregularities, which could be used to establish design guidelines for laser powder bed fused stents/lattice structures. KW - Heat treatment KW - Lasers KW - Surface treatments KW - Specimen preparation and treatment KW - Material properties KW - Stiffness KW - Deformation KW - Powders KW - Koronarendoprothese KW - Rapid prototyping KW - Numerische Methode Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0244463 N1 - Corresponding author: Lisa Wiesent VL - 15 IS - 12 SP - 1 EP - 30 PB - PLOS ER - TY - JOUR A1 - Geith, Markus A. A1 - Eckmann, Jakob D. A1 - Haspinger, Daniel Ch. A1 - Agrafiotis, Emmanouil A1 - Maier, Dominik A1 - Szabo, Patrick A1 - Sommer, Gerhard A1 - Schratzenstaller, Thomas A1 - Holzapfel, Gerhard A. T1 - Experimental and mathematical characterization of coronary polyamide-12 balloon catheter membranes JF - PLoS One N2 - The experimental quantification and modeling of the multiaxial mechanical response of polymer membranes of coronary balloon catheters have not yet been carried out. Due to the lack of insights, it is not shown whether isotropic material models can describe the material response of balloon catheter membranes expanded with nominal or higher, supra-nominal pressures. Therefore, for the first time, specimens of commercial polyamide-12 balloon catheters membranes were investigated during uniaxial and biaxial loading scenarios. Furthermore, the influence of kinematic effects on the material response was observed by comparing results from quasi-static and dynamic biaxial extension tests. Novel clamping techniques are described, which allow to test even tiny specimens taken from the balloon membranes. The results of this study reveal the semi-compliant, nonlinear, and viscoelastic character of polyamide-12 balloon catheter membranes. Above nominal pressure, the membranes show a pronounced anisotropic mechanical behavior with a stiffer response in the circumferential direction. The anisotropic feature intensifies with an increasing strain-rate. A modified polynomial model was applied to represent the realistic mechanical response of the balloon catheter membranes during dynamic biaxial extension tests. This study also includes a compact set of constitutive model parameters for the use of the proposed model in future finite element analyses to perform more accurate simulations of expanding balloon catheters. KW - Catheters KW - Anisotropy KW - Polymers KW - Viscoelasticity KW - Coronary stenting KW - Finite element analysis KW - Deformation KW - Adhesives Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0234340 VL - 15 IS - 6 SP - 1 EP - 22 PB - PLOS ER - TY - JOUR A1 - Görtler, Michael T1 - Politische Erwachsenenbildung und Zeit JF - Zeitschrift für Weiterbildungsforschung (ZfW) N2 - Der Beitrag fokussiert die Bedeutung von Zeit für die politische Erwachsenenbildung. Angesichts aktueller soziokultureller und sozioökonomischer Herausforderungen - besonders: der Ökonomisierung und Beschleunigung im Kontext von Bildung und Lernen - ergeben sich eine ganze Reihe von drängenden Zeitfragen. Der Bedeutung von Zeit wird in der Erwachsenenbildung und der Politischen Bildung jedoch bisher wenig Aufmerksamkeit geschenkt. Aus diesem Grund wird diese Fragestellung im Beitrag vertieft. Erstens werden die Situation der politischen Erwachsenenbildung und zweitens der Forschungsstand untersucht. Ausgehend von den Befunden werden drittens drei Zugänge herausgearbeitet, welche die Bedeutung von Zeit für die politische Erwachsenenbildung sichtbar machen: Politische Bildung als Prozess und Verzögerung sowie Zeit als Gegenstand, um die Zeitlichkeit von Gesellschaft und Politik zu verstehen und zu beurteilen, um sich an der Gestaltung der Zeitstrukturen zu beteiligen. Der Beitrag endet mit einem Ausblick und offenen Fragen, die sich an die zeittheoretischen Überlegungen anschließen. The article focusses on the importance of time for the political adult education. Current socio-cultural and socio-economic challenges – in particular: the commodification and acceleration in the context of education and learning – results in a wide range of pressing time issues. However the adult education und the political education pay little attention to the importance of time. For this reason, this issue will be deepened in the article. First, the situation of the political adult education and secondly, the state of research are examined. On the base of the findings, three approaches are pointed out, which emphasize the importance of time for the political adult education: political education as a process and as a deceleration and also as a subject to understand and judge the temporality of politics and society as a necessary condition to participate in shaping the time structures. The paper ends with an outlook and open-ended questions, which adjoin the time theoretical considerations. KW - Acceleration KW - Adult education KW - Forschungsbericht KW - Lernen KW - Political education KW - Politische Erwachsenenbildung KW - Time Y1 - 2016 U6 - https://doi.org/10.1007/s40955-016-0052-2 IS - 1 SP - 9 EP - 25 PB - Springer ER - TY - JOUR A1 - Görtler, Michael T1 - Soziale Arbeit, Zeit und Nachhaltigkeit : Zeitpolitische Perspektiven JF - ZPM - Zeitpolitisches Magazin N2 - In diesem Beitrag sollen in der gebotenen Kürze zeitpolitische Perspektiven auf die Bedeutung von Zeit und Nachhaltigkeit im Kontext der Sozialen Arbeit reflektiert werden. Dafür werden die Begriffsfelder um Nachhaltigkeit und Zeit diskutiert und zeitpolitische Implikationen formuliert. Y1 - 2022 UR - https://zeitpolitik.org/wp-content/uploads/2022/08/ZPM40_nachhaltigleben.pdf SN - 2196-0356 VL - 19 IS - 40 SP - 24 EP - 26 PB - DGfZP (Deutsche Gesellschaft für Zeitpolitik) ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Steiner, Carsten A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Mixing Rules for an Exact Determination of the Dielectric Properties of Engine Soot Using the Microwave Cavity Perturbation Method and Its Application in Gasoline Particulate Filters JF - Sensors N2 - In recent years, particulate filters have become mandatory in almost all gasoline-powered vehicles to comply with emission standards regarding particulate number. In contrast to diesel applications, monitoring gasoline particulate filters (GPFs) by differential pressure sensors is challenging due to lower soot masses to be deposited in the GPFs. A different approach to determine the soot loading of GPFs is a radio frequency-based sensor (RF sensor). To facilitate sensor development, in previous work, a simulation model was created to determine the RF signal at arbitrary engine operating points. To ensure accuracy, the exact dielectric properties of the soot need to be known. This work has shown how small samples of soot-loaded filter are sufficient to determine the dielectric properties of soot itself using the microwave cavity perturbation method. For this purpose, mixing rules were determined through simulation and measurement, allowing the air and substrate fraction of the sample to be considered. Due to the different geometry of filter substrates compared to crushed soot samples, a different mixing rule had to be derived to calculate the effective filter properties required for the simulation model. The accuracy of the determined mixing rules and the underlying simulation model could be verified by comparative measurements on an engine test bench. KW - mixing rule KW - dielectric properties KW - microwave cavity perturbation KW - finite element method (FEM) KW - soot mass determination KW - radio-frequency (RF) KW - gasoline particulate filter (GPF) Y1 - 2022 U6 - https://doi.org/10.3390/s22093311 VL - 22 IS - 9 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Thema, Martin A1 - Sterner, Michael A1 - Lenck, Thorsten A1 - Götz, Philipp T1 - Necessity and Impact of Power-to-gas on Energy Transition in Germany JF - Energy Procedia N2 - The present paper gives an outlook on a bandwidth of required installed power-to-gas capacity in the German power sector fed by 100% renewable generation until 2050. Two scenarios were simulated to quantify cost effects of power-to-gas on the electricity system: once with, once without additional short-term flexibility options to a system using fossil natural gas as sole flexibility option instead. As a result, at latest in 2035, power-to-gas capacity expansion has to take place to reach required installed capacities of up to 89-134 GW in 2050. Application of power-to-gas as long-term flexibility leads to cost savings of up to 11,7-19 bn Euro enabling a fully renewable system in 2050. KW - decarbonization KW - energy storage KW - energy transition KW - Power-to-Gas KW - renewable energy KW - supply security KW - surplus energy KW - system costs Y1 - 2016 U6 - https://doi.org/10.1016/j.egypro.2016.10.129 VL - 99 SP - 392 EP - 400 PB - Elsevier ER - TY - JOUR A1 - Thema, Martin A1 - Weidlich, Tobias A1 - Hörl, Manuel A1 - Bellack, Annett A1 - Mörs, Friedemann A1 - Hackl, Florian A1 - Kohlmayer, Matthias A1 - Gleich, Jasmin A1 - Stabenau, Carsten A1 - Trabold, Thomas A1 - Neubert, Michael A1 - Ortloff, Felix A1 - Brotsack, Raimund A1 - Schmack, Doris A1 - Huber, Harald A1 - Hafenbradl, Doris A1 - Karl, Jürgen A1 - Sterner, Michael T1 - Biological CO2-Methanation: An Approach to Standardization JF - Energies N2 - Power-to-Methane as one part of Power-to-Gas has been recognized globally as one of the key elements for the transition towards a sustainable energy system. While plants that produce methane catalytically have been in operation for a long time, biological methanation has just reached industrial pilot scale and near-term commercial application. The growing importance of the biological method is reflected by an increasing number of scientific articles describing novel approaches to improve this technology. However, these studies are difficult to compare because they lack a coherent nomenclature. In this article, we present a comprehensive set of parameters allowing the characterization and comparison of various biological methanation processes. To identify relevant parameters needed for a proper description of this technology, we summarized existing literature and defined system boundaries for Power-to-Methane process steps. On this basis, we derive system parameters providing information on the methanation system, its performance, the biology and cost aspects. As a result, three different standards are provided as a blueprint matrix for use in academia and industry applicable to both, biological and catalytic methanation. Hence, this review attempts to set the standards for a comprehensive description of biological and chemical methanation processes. KW - Biological methanation KW - bubble column reactor KW - CO2-methanation KW - CSTR KW - membrane reactor KW - methanation KW - Power-to-Gas KW - Power-to-Methane KW - standardization KW - Trickle-bed reactor Y1 - 2019 U6 - https://doi.org/10.3390/en12091670 N1 - Corresponding author: Martin Thema VL - 12 IS - 9 SP - 1 EP - 32 PB - MDPI ER - TY - CHAP A1 - Vitzthum, Thorsten A1 - Claus, Thorsten A1 - Herrmann, Frank T1 - Can Aggregate Production Planning (APP) be modified to be as good as Master Production Scheduling (MPS) T2 - ACC Journal N2 - In diesem Beitrag wird anhand einer Fallstudie die Bedeutung der Hauptproduktionsprogrammplanung (HPPLAN) für die hierarchische Produktionsplanung herausgearbeitet werden. Dazu wird versucht das Ergebnis der aggregierten Gesamtplanung (AGGRPLAN) durch Veränderung einzelner Paramater so zu verbessern, dass es dem Ergebnis der HPPLAN entspricht. Im Rahmen der Untersuchungen konnten dabei Verbesserungen für einzelne Planungssituationen erzielt werden, eine generelle Lösung konnte jedoch nicht gefunden werden. Insbesondere der Einsatz eines geeigneten Kapazitätsreduktionsfaktors in Verbindung mit der Berücksichtigung der Durchlaufzeit führt zu einer Verbesserung der Lösung. Bei der Planung von mehr als einem Produkt ist allerdings schwierig einen geeigneten Kapazitätsreduktionsfaktor zu finden, da dieser abhängig von der Nachfrage ist. KW - Hierarchische Produktionsplanung KW - Fertigungsprogrammplanung KW - Fallstudie KW - Hierarchical production planning KW - Aggregate production planning (APP) KW - Master production scheduling (MPS) KW - Material requirement planning KW - Resource profiles Y1 - 2017 U6 - https://doi.org/10.15240/tul/004/2017-2-012 VL - 23 IS - 2 SP - 155 EP - 162 ER - TY - CHAP A1 - Trost, Marco A1 - Teich, Enrico A1 - Claus, Thorsten A1 - Herrmann, Frank T1 - Master Production Scheduling and the relevance of included social criteria T2 - ACC Journal N2 - Folgender Beitrag untersucht die Notwendigkeit einer Berücksichtigung von Mitarbeiterauslastungen und davon abhängiger Bearbeitungszeiten in der Hauptproduktionsprogrammplanung. Zudem wird aufgezeigt, dass dieses Themengebiet aktuell eine Forschungslücke darstellt. Aus diesem Grund wird ein selbst entwickeltes lineares Optimierungsmodell für die Hauptproduktionsprogrammplanung vorgestellt, welches soziale Kriterien und eine geeignete Fallstudie enthält. Die Ergebnisse verdeutlichen, dass erhebliche Abweichungen durch eine Ignoranz von Mitarbeiterauslastungen und davon abhängiger Bearbeitungszeiten entstehen. Deshalb ist eine Integration zu empfehlen. Allerdings wird auch deutlich, dass weitere Forschungen notwendig sind, speziell für die Bestimmung geeigneter Erschöpfungsfunktionen, so wie beispielsweise Funktionen für Lerneffekte existieren. KW - Fertigungsprogrammplanung KW - Personaleinsatz KW - Lineare Optimierung KW - Sustainability KW - Production planning and control KW - Master production scheduling KW - Linear optimization KW - Human fatigue Y1 - 2017 U6 - https://doi.org/10.15240/tul/004/2017-2-011 VL - 23 IS - 3 SP - 146 EP - 154 ER - TY - JOUR A1 - Herrmann, Frank T1 - Scheduling a flow shop with simultaneously loaded stations: A real world application JF - Journal of Control Science and Engineering N2 - Companies use special designed flow shops, in order to satisfy specific demands. Products need to be transported (from one station to the next station) by a crane and the way of working of this crane excludes the intermediate storage (of a work piece). In addition, the way of working restricts the set of feasible schedules even more than the no-buffer restriction discussed in the literature in the case of limited storage. Since this scheduling problem is integrated in the usual hierarchical planning, the tardiness is minimised. A linear optimisation model is presented to provide a formal description of this NP-hard problem. It is also used to explain the performance of priority rule based heuristic solutions on small test problems. In detail, priority rules as well as a priority rule based branch and bound procedure are analysed; priority rules are regarded, because a priority rule is still the standard procedure for on-line scheduling in industrial practise. Out of successful priority rules in the literature the best one is identified by an extensive simulative investigation. An improved look-ahead is realised by a restricted search over all possible schedules. KW - Fließfertigung KW - Flow-shop-Problem KW - Scheduling KW - Real world flow shop with restrictions KW - No buffer and no wait KW - Minimising tardiness KW - Optimisation model KW - Priority rules KW - Priority rule based branch and bound procedure Y1 - 2015 U6 - https://doi.org/10.17265/2328-2231/2015.03.004 VL - 3 SP - 147 EP - 163 ER - TY - CHAP A1 - Schmailzl, Anton A1 - Hierl, Stefan A1 - Schmidt, Michael ED - Schmidt, Michael T1 - Gap-Bridging during Quasi-Simultaneous Laser Transmission Welding T2 - Physics Procedia N2 - Tightness is often the main requirement for quasi-simultaneous laser transmission welds. However, remaining gaps cannot be detected by the used set-path monitoring. By using a pyrometer in combination with a 3D-scanner, weld seam interruptions can be localized precisely while welding, due to temperature deviations along the weld contour. To analyze the temperature signal in correlation to the progress of gap-bridging, T-joint samples with predefined gaps are welded. The set-path is measured synchronously. Additionally, the temperature distribution and the influence of the thermal expansion of the polymers are studied by a thermo-mechanical FEM-process simulation. On top of that, the melt blow-out of the welded samples is analyzed using μCT-measurements. The experiments have shown that closing of a gap can be identified reliably by the temperature signal and that the squeezed melt flow into the gap and the thermal expansion in the gap zone accelerates gap-bridging. Furthermore the inserted heat can be adapted in the fault zone, in order to avoid thermal damage. Y1 - 2016 U6 - https://doi.org/10.1016/j.phpro.2016.08.113 SN - 1875-3892 SN - 1875-3884 VL - 83 SP - 1073 EP - 1082 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - CHAP A1 - Schmailzl, Anton A1 - Quandt, Benjamin A1 - Schmidt, Michael A1 - Hierl, Stefan T1 - In-Situ Process Monitoring during Laser Transmission Welding of PA6-GF30 T2 - Procedia CIRP N2 - Quasi-simultaneous laser transmission welding is preferably used for packaging sensors and electronics. In order to protect the components from moisture, a hermetic encapsulation is needed. However, local weld seam interruptions cannot be identified with the commonly used set-path monitoring. By using a pyrometer, coaxially integrated into a 3D-scanner, gaps between the joining partners can be allocated on basis of the measured temperature. However, the scattering of the heat radiation, especially caused by the fiber reinforcement of the plastics, leads to a reduction of the accessible heat radiation, which makes the identification of gaps considerably more difficult. The herein used experimental setup is characterized by a small detection spot and only by a slight weakening of the heat radiation inside the scanner. Hence, for welding PA6-GF30, the detection of small sized gaps is possible, even if a glass fiber content of 30 percent (wt.) and a weld seam width with approximately 1 mm are given. Y1 - 2018 U6 - https://doi.org/10.1016/j.procir.2018.08.131 VL - 74 SP - 524 EP - 527 ER - TY - CHAP A1 - Meussling-Sentpali, Annette ED - Schöpf, Nicolas T1 - Berufsbegleitend Pflegemanagement studieren: Aus der Pflegepraxis ins Management T2 - Akademische Weiterbildung für soziale Berufe N2 - In diesem Beitrag werden am Beispiel des berufsbegleitenden Bachelorstudiengangs Pflegemanagement der OTH Regensburg die Charakteristika dieses Studiums sowie die Merkmale der Studierenden und die daraus resultierenden methodischen, didaktischen und organisatorischen Spezifika dargestellt. Um Hintergrund und Relevanz aufzuzeigen, soll zunächst ein Blick auf die Akademisierung der Pflege geworfen und eine Standortbestimmung von Pflegemanagementstudiengängen innerhalb der verschiedenen inzwischen etablierten Pflegestudiengänge vorgenommen werden. Im zweiten Kapitel wird der Studiengang der OTH Regensburg vorgestellt und im dritten Kapitel werden die Erfahrungen, Herausforderungen und Lösungsstrategien beschrieben, die aus dem berufsbegleitenden Format mit „nicht-traditionell“ Studierenden resultieren. Abschließend finden sich eine kurze Zusammenfassung und ein Ausblick. Y1 - 2022 UR - https://nbn-resolving.org/urn:nbn:de:bvb:898-opus4-55292 SN - 9783763966479 SP - 193 EP - 207 PB - wbv CY - Bielefeld ER - TY - CHAP A1 - Ettl, Katrin A1 - Mohr, Christa ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa T1 - »Mein Selbstvertrauen ist wieder ein bisschen mehr geworden« - Bewertung der häuslichen Telenursinginterventionen durch Schlaganfallbetroffene und pflegende Angehörige T2 - Digitale Technik für ambulante Pflege und Therapie III: Nutzung Akzeptanz Wirkung und Lebensqualität T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 4 Y1 - 2024 SN - 978-3-8376-6728-8 U6 - https://doi.org/10.14361/9783839467282-006 SP - 89 EP - 124 PB - transcript CY - Bielefeld ER - TY - CHAP A1 - Altenbuchner, Amelie A1 - Haug, Sonja A1 - Kretschmer, Rainer A1 - Weber, Karsten T1 - How to Measure Physical Motion and the Impact of Individualized Feedback in the Field of Rehabilitation of Geriatric Trauma Patients T2 - Health Informatics Meets eHealth N2 - Background: This preparatory study accelerates an implementation of individualized monitoring and feedback of physical motion using conventional motion trackers in the rehabilitation process of geriatric trauma patients. Regaining mobility is accompanied with improved quality of life in persons of very advanced age recovering from fragility fractures. Objectives: Quantitative survey of regaining physical mobility provides recommendations for action on how to use motion trackers effectively in a clinical geriatric setting. Methods: Method mix of quantitative and qualitative interdisciplinary and mutual complementary research approaches (sociology, health research, philosophy/ethics, medical informatics, nursing science, gerontology and physical therapy). While validating motion tracker use in geriatric traumatology preliminary data are used to develop a target group oriented motion feedback. In addition measurement accuracy of a questionnaire about quality of life of multimorbid geriatric patients (FLQM) is tested. Conclusion: Implementing a new technology in a complex clinical setting needs to be based on a strong theoretical background but will not succeed without careful field testing. KW - Health monitoring KW - motion tracker KW - quality of life KW - geriatric assessment Y1 - 2018 U6 - https://doi.org/10.3233/978-1-61499-858-7-226 SP - 226 EP - 232 ER - TY - JOUR A1 - Weber, Karsten A1 - Kleine, Nadine A1 - Pallas, Frank A1 - Ulbricht, Max-R. T1 - Technik zur Unterstützung von Citizen Science und Open Science BT - Technische und organisatorische Herausforderungen und mögliche Lösungsansätze JF - TATuP - Zeitschrift für Technikfolgenabschätzung in Theorie und Praxis N2 - If citizens actively participate in the process of collecting empirical data, as a key element of empirically oriented scientific projects, this can be seen as a contribution to an open and citizen-oriented science. Such participation can be supported by providing technical tools. The paper therefore presents examples of participatory sensing as the provision of affordable sensors for measuring environmental parameters as well as wearable technologies for recording quantified vital data and physiological states. Conceptually, the provision of data collected with these tools can be understood as a commons – with all opportunities and risks associated with such goods. After describing examples of participatory sensing and wearable technologies, the authors identify potential challenges and outline technical and organizational approaches to solve them. Y1 - 2017 U6 - https://doi.org/10.14512/tatup.26.1-2.25 VL - 26 IS - 1/2 SP - 25 EP - 30 ER - TY - CHAP A1 - Altenbuchner, Amelie A1 - Weber, Karsten ED - Haltaufderheide, Joschka ED - Hovemann, Johanna ED - Vollmann, Jochen T1 - Geriatric trauma patients as research subjects in a technology-driven research project BT - A preliminary field report T2 - Aging between Participation and Simulation N2 - This article highlights methodological and ethical challenges in research with adults of older and oldest age, by presenting field experiences of the current research project “Motion Monitoring of Geriatric Trauma Patients - Explorative Study on the Rehabilitation Process after Hip Fracture Using Sensor-based Data”. Depiction of the survey situation, with regard to the subjects in particular, can serve as practical examples for designing future research projects. The group of older adults is a rather large and growing group for which research is required, especially concerning their heterogeneity, their individual autonomy and quality of life. It is assumed, that research designs of studies on the target group must be specifically adjusted, in particular when considering the attribution of vulnerability of the group members. At the same time, it is not clear yet what exact specifics of the subjects and target group must be considered in research designs, as surprisingly little is known about the target group as subjects and corresponding theories have been insufficiently tested. The exploratory long-term design of the research project presented in the second section of this chapter has a positive evaluation of an ethics committee. Still ethical challenges occurred in the field situation, that are illustrated in the third section of this chapter, by providing information on the patients, their role as research subjects, how they were recruited, how an informed consensus was reached, and in some cases how participation was rejected or abandoned. After a summary, the end of the paper is marked by recommendations on how to design future research projects. Cumulatively it must always be expected that interaction between researchers and research subjects of this target group can become very intensive, what requires to follow clearly defined procedures and at the same time to be prepared to act flexibly. Y1 - 2020 SN - 9783110677485 U6 - https://doi.org/10.1515/9783110677485-006 SP - 87 EP - 104 PB - De Gruyter CY - Berlin u.a. ER - TY - CHAP A1 - Weber, Karsten A1 - Kleine, Nadine ED - Christen, Markus ED - Gordijn, Bert ED - Loi, Michele T1 - Cybersecurity in Health Care T2 - The Ethics of Cybersecurity N2 - Ethical questions have always been crucial in health care; the rapid dissemination of ICT makes some of those questions even more pressing and also raises new ones. One of these new questions is cybersecurity in relation to ethics in health care. In order to more closely examine this issue, this chapter introduces Beauchamp and Childress’ four principles of biomedical ethics as well as additional ethical values and technical aims of relevance for health care. Based on this, two case studies—implantable medical devices and electronic Health Card—are presented, which illustrate potential conflicts between ethical values and technical aims as well as between ethical values themselves. It becomes apparent that these conflicts cannot be eliminated in general but must be reconsidered on a case-by-case basis. An ethical debate on cybersecurity regarding the design and implementation of new (digital) technologies in health care is essential. Y1 - 2020 UR - https://www.springer.com/de/book/9783030290528 SN - 978-3-030-29053-5 U6 - https://doi.org/10.1007/978-3-030-29053-5_7 VL - 21 SP - 139 EP - 156 PB - Springer Nature CY - Cham, Switzerland ER - TY - JOUR A1 - Weber, Karsten T1 - Computers as omnipotent instruments of power BT - Hopes, fears and actual change in administration, politics, and society from the 1960s to 1980s JF - The ORBIT Journal - An Online Journal for Responsible Research and Innovation in ICT N2 - With examples concerning the development and dissemination of computer technology in the Soviet Union, the U.S., and other Western countries it shall be demonstrated that computer development on the one hand and social change as well as changes in policy making and administration on the other hand are mingled with each other without a clear direction of causation being discernible.It also shall be shown that perceived social and political threats imposed by early computer technology sometimes actually helped to stop or at least slow down social change. One conclusion that can be drawn from the case studies described for RRI is that the conscious steering of innovations fails because of diffuse and uncoordinated resistance from very different stakeholders. The case studies also suggest that the effectiveness of RRI might be rather limited. Y1 - 2018 U6 - https://doi.org/10.29297/orbit.v2i1.97 VL - 2 IS - 1 SP - 1 EP - 19 PB - Elsevier ER - TY - JOUR A1 - Weber, Karsten A1 - Haug, Sonja T1 - Ist automatisiertes Fahren nachhaltig? BT - Entwicklungstendenzen und Forschungsüberlegungen angesichts geringer Akzeptanz JF - TATuP - Zeitschrift für Technikfolgenabschätzung in Theorie und Praxis N2 - Automatisiertes Fahren stößt derzeit noch auf große Skepsis. Eine disruptive Strategie bei der Einführung (voll-)automatisierten Fahrens könnte daher auf fehlende Akzeptanz treffen. Um dem zu entgehen, laufen evolutionäre Strategien darauf hinaus, durch die Entwicklung adaptiver Fahrassistenzsysteme Vertrautheit, Vertrauen und damit Akzeptanz bei den prospektiven NutzerInnen zu schaffen. Erste Ergebnisse einer Pilotstudie lassen jedoch Zweifel an der Nachhaltigkeit dieser Strategie aufkommen. KW - driver assistance systems KW - automated driving KW - acceptance KW - sustainability Y1 - 2018 U6 - https://doi.org/10.14512/tatup.27.2.16 VL - 27 IS - 2 SP - 16 EP - 22 PB - Karlsruhe Institute of Technology (KIT) ER - TY - CHAP A1 - Berndt, Dominik A1 - Lindner, Matthias A1 - Tschurtschenthaler, Karl A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Miniaturized Plasma Actuator Flow Measurements by MEMS-Based Thermal Conductivity Sensors T2 - MDPI Proceedings of Eurosensors 2018, 9-12 September, Graz N2 - The gasflow created by a minaturized dielectric barrier discharge (DBD) plasma actuator is measured by a MEMS-based thermal conductivity gas sensor giving an indication of flow velocity and flow direction. The possiblity of several sensors in a small area gives a far better accuracy of local flow phenomena compared to conventional sensors. This is important for a better understanding of plasma- induced flow characteristics. KW - thermal conductivity sensors; plasma actuators; surface hotfilms; sensors for aerospace Y1 - 2018 U6 - https://doi.org/10.3390/proceedings2130939 VL - Vol.13 IS - 2 ER - TY - CHAP A1 - Frommeld, Debora A1 - Weber, Karsten ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa T1 - Aufklärung, Risiko, Datennutzung: Ergebnisse einer MEESTAR-Befragung zu Telepräsenzrobotern T2 - Digitale Technik für ambulante Pflege und Therapie III - Nutzung Akzeptanz Wirkung und Lebensqualität T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 4 Y1 - 2024 SN - 978-3-8376-6728-8 U6 - https://doi.org/10.14361/9783839467282-011 SP - 241 EP - 272 PB - transcript CY - Bielefeld ER - TY - CHAP A1 - Frommeld, Debora A1 - Weber, Karsten ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa T1 - Telepräsenzroboter zur Unterstützung von Pflege und Therapie BT - Eine qualitative Interviewstudie zu Nutzung und Ablehnung T2 - Digitale Technik für ambulante Pflege und Therapie III: Nutzung Akzeptanz Wirkung und Lebensqualität T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 4 Y1 - 2024 SN - 978-3-8376-6728-8 U6 - https://doi.org/10.14361/9783839467282-013 SP - 307 EP - 328 PB - transcript CY - Bielefeld ER - TY - JOUR A1 - Hellwig, Michael A1 - Schroll-Decker, Irmgard T1 - Wirksamkeit wissenschaftlicher Weiterbildung aus Sicht von Stakeholdern BT - Kriterien zur Erfolgsbestimmung und den wahrgenommenen Bedingungsfaktoren JF - ZHWB - Zeitschrift Hochschule und Weiterbildung N2 - Die Weiterbildung an Hochschulen ist an evidenzbasierten Daten interessiert, um Aussagen über die Wirksamkeit von eigenen Angeboten treffen zu können. Oftmals unklar ist, was unter Wirksamkeit verstanden werden kann und welche Voraussetzungen gegeben sein müssen, damit die Weiterbildungen Wirkung entfalten. Der Beitrag stellt eine Studie vor, die beide Aspekte adressiert und Aussagen unterschiedlicher Beteiligter am Weiterbildungsgeschehen wiedergibt. Angebotsseitig wurden Weiterbildungsverantwortliche sowie Lehrpersonen der Hochschule befragt. Nachfrageseitig wurden Teilnehmende berufsbegleitender Studiengänge und Unternehmensvertreter*innen aus ausgewählten Branchen einbezogen. Die erhobenen qualitativen Daten wurden inhaltsanalytisch analysiert und induktiv zu Kategorien zusammengefasst. Die Ergebnisse zeigen insgesamt fünf Oberkategorien auf, die die Wirksamkeit abbilden: (1) Erfolgreicher Praxistransfer; (2) Erwerb von Kenntnissen, Fähigkeiten und Kompetenzen; (3) Strategischer Nutzen; (4) Sozialer/kultureller Nutzen und (5) Resonanz der Teilnehmenden auf die wissenschaftliche Weiterbildung. Die Voraussetzungen lassen sich ebenfalls in fünf Kategorien abbilden: (a) teilnehmenden-, (b) unternehmens-, (c) angebots-, (d) hochschul- und (e) markt-/umfeldbezogene Faktoren. Im Beitrag werden nach der Darstellung der Studienergebnisse Schlussfolgerungen für die Weiterbildungspraxis in Hinblick auf die Themen Evaluation, Theorie-Praxis-Transfer und Marketing/Zielgruppenspezifische Kommunikation diskutiert. KW - Wissenschaftliche Weiterbildung KW - Nachhaltigkeit KW - Stakeholder Y1 - 2019 U6 - https://doi.org/10.4119/zhwb-2369 IS - 2 SP - 22 EP - 31 ER - TY - JOUR A1 - Maiwald, Frederik A1 - Englmaier, Stephan A1 - Hierl, Stefan T1 - Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers JF - Journal of Laser Micro/Nanoengineering N2 - Production of optical and medical devices makes high demands on cleanliness, precision, visual appearance and reliability. Advantages of laser transmission welding – contactless input of energy, high precision, no adhesives and no particle formation – can be fully exploited for this use. For absorber-free welding, lasers emitting in the polymers’ intrinsic absorption spectrum between 1.6 μm and 2 μm are used. Focusing the laser beam with high NA provides large intensity gradients inside the specimen and enables selective fusing of the joining zone without affecting the surface. Since a molten upper surface leads to visible and palpable irregularities and causes warpage, the verticalexpansion of the weld seam is crucial. To meet the high quality and reliability required in the medical and optical industry, online monitoring of the seam is necessary. The aim of this work is the localization and evaluation of the weld seam using pyrometry. First, the emitted thermal radiation is computed, enabling signal analysis regarding origin and spectrum. Thus, assessment of measurement spectrum and forecast of the signal in dependence on seam shape and position is possible. Finally, welding tests with Topas 8007-04 are performed at 200 mm/s feed rate and monitored with 100 kHz. The comparison of tracked data with thin-cuts demonstrates that weld seam localization by pyrometry is possible, enabling online assessment of the process. KW - Laserdurchstrahlschweissen KW - Kunststoff KW - Transparenz KW - Schweißnaht KW - Wärmestrahlung KW - Pyrometrie KW - Prozessüberwachung Y1 - 2021 U6 - https://doi.org/10.2961/jlmn.2021.01.2002 SN - 1880-0688 VL - Vol. 16 IS - 1 SP - 8 EP - 13 PB - Japan Laser Processing Society ER - TY - CHAP A1 - Käsbauer, Johannes A1 - Schmailzl, Anton A1 - Prehm, Jens A1 - Loose, Tobias A1 - Hierl, Stefan T1 - Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics BT - Optimization of Material Parameters in Broad Temperature Range T2 - Procedia CIRP N2 - Thermo-mechanical simulation offers great opportunities to optimize welding processes of plastics. For realistic simulation, the temperature dependent mechanical properties need to be implemented from ambient temperature to temperatures above the flow temperature. Standard test methods are insufficient for characterization in the entire temperature range because close to the flow temperature the material is too soft for tensile tests and too stiff for rheometry. Therefore, an optimization strategy is developed, that determines unknown material parameters by testing in welding simulations. The unknown parameters are iteratively adjusted to minimize the mismatch between computed and measured set-paths. Thus, important process characteristics are calculated realistically, enabling the computer aided assessment of the weld quality. KW - plastics welding KW - simulation KW - material modelling KW - optimization KW - parameterization KW - Kunststoffschweißen KW - Thermomechanische Eigenschaft KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.procir.2020.09.136 VL - 94 SP - 737 EP - 741 PB - Elsevier ER - TY - CHAP A1 - Maiwald, Frederik A1 - Englmaier, Stephan A1 - Hierl, Stefan T1 - Absorber-free Laser Transmission Welding of Transparent Polymers using Fixed Focus Optics and 3D Laser Scanner T2 - Procedia CIRP N2 - Laser transmission welding is a well-known joining technology for thermoplastics, providing reliable and hermetical sealing without adhesives or particle formation. The main advantages of laser-based energy input - high precision, no additional adhesive and no particle emission - are essential for medical and optical applications. To obtain sufficient absorption in visually transparent polymers, thulium fibre lasers emitting in the polymers’ intrinsic absorption spectrum are used. Optics with high numerical aperture provide large intensity gradients inside the specimen, enabling selective fusing in the joining zone. Although the basic feasibility has already been demonstrated, the welding process lacks stability and productivity. Aim of this work is the determination of optimized settings for a fast and reliable welding process. Thus, the interplay of process parameters as well as their impact on the seam are analysed by thermal simulations. Calculated settings are verified by welding tests with COC, PA6 and PETG, using a fixed-focus optics and a 3D laser scanner with up to 200 mm/s feed rate. Y1 - 2020 U6 - https://doi.org/10.1016/j.procir.2020.09.117 VL - 94 SP - 686 EP - 690 PB - Elsevier ER - TY - CHAP A1 - Haug, Sonja A1 - Vetter, Miriam ED - Teti, Andrea T1 - Ältere Menschen im Wohnquartier Margaretenau in Regensburg – aktuelle Situation und zukünftiger Bedarf T2 - Wohnen und Gesundheit im Alter T2 - Vechtaer Beiträge zur Gerontologie N2 - Der Beitrag zeigt Ergebnisse einer Begleitstudie zur Restaurierung und energetischen Modernisierung des historischen genossenschaftlichen Wohnquartiers Margaretenau in Regensburg im Projekt MAGGIE. Bei der Gestaltung von Wohnungen und Gelegenheiten für die soziale Einbettung im Quartier wird eine altersgerechte Perspektive eingenommen. Die Darstellung der schriftlichen standardisierten Haushaltsbefragung (n = 195) nimmt die Lebenssituation älterer Menschen ab 65 Jahren in den Fokus. Dazu werden die Themenbereiche Haushaltsstruktur, altersgerechtes Wohnen und Gemeinschaftseinrichtungen präsentiert. Neben der aktuellen Wohnsituation wurden Pläne und Wünsche für das zukünftige Wohnen abgefragt. Im Alter schwindet die Bereitschaft für Veränderungen, was sich am Wunsch zum Altern in der bisherigen Wohnung und Verbleib im Wohnquartier zeigt. Das Interesse am barrierereduzierten Wohnen ist bei älteren Haushalten geringer als bei jüngeren. Es zeigt sich ein überdurchschnittlich hohes Maß an lokalem Sozialkapital, wobei kein signifikanter Unterschied zwischen jüngeren und älteren Haushalten besteht. Y1 - 2022 SN - 978-3-658-34385-9 U6 - https://doi.org/10.1007/978-3-658-34386-6_14 N1 - Corresponding author: Sonja Haug SP - 215 EP - 227 PB - Springer VS CY - Wiesbaden ER - TY - CHAP A1 - Weber, Karsten ED - Frommeld, Debora ED - Scorna, Ulrike ED - Haug, Sonja ED - Weber, Karsten T1 - Altersgerechte Assistenzsysteme. Ein Überblick T2 - Gute Technik für ein gutes Leben im Alter? Akzeptanz, Chancen und Herausforderungen altersgerechter Assistenzsysteme KW - Altenpflege KW - Assistenzsystem KW - AAL-Technik Y1 - 2021 SN - 978-3-8376-5469-1 U6 - https://doi.org/10.1515/9783839454695-002 SP - 27 EP - 62 PB - transcript CY - Bielefeld ER - TY - CHAP A1 - Haug, Sonja A1 - Scharf, Anna ED - Schöpf, Nicolas T1 - Berufsbegleitend Studieren aus der Perspektive von Studieninteressierten, Dozierenden und Beratungsstellen: Bedarf im Bereich virtuelle Lehre und Diversität der Studierenden BT - Bedarf im Bereich virtuelle Lehre und Diversität der Studierenden T2 - Akademische Weiterbildung für soziale Berufe. Theoretische, empirische und praktische Aspekte N2 - Die sozialwissenschaftliche Begleitforschung zum Projekt WANTED (Wissens-management, Aktualität, Netzwerk,Transfer, Entwicklung, Diversität) an der OTH Regensburg zielte auf die inhaltlichen Schwerpunkte Flexibilisierung bzw. Digitalisie-rung und Diversität der Zielgruppen, insbesondere im Hinblick auf Personen mit Migrationshintergrund. Zur Erhebung und Bewertung des Bedarfs und der Passgenauigkeit der geplanten Angebote wurden vier Erhebungen mit verschiedenen Stake-holdern durchgeführt: Weiterbildungsinteressierte, Dozierende berufsbegleitender Bachelorstudiengänge sowie Beratungsstellen für (Weiter-)Bildung. Bei der quantitativen und qualitativen Analyse zeigt sich ein Bedarf nach Vereinbarkeit von Familie, Beruf und Studium sowie eine Erweiterung des Angebots an Auswahlmöglichkeiten, digitaler Lehre, Modularisierung und verbesserter Informationsverbreitung. KW - Weiterbildung KW - Studierende KW - Motivation KW - Migrationshintergrund KW - Digitalisierung Y1 - 2022 SN - 978-3-7639-6646-2 N1 - Gefördert durch wbv Open-Library 2021 SP - 107 EP - 126 PB - WBV Media CY - Bielefeld ER - TY - CHAP A1 - Haug, Sonja A1 - Currle, Edda A1 - Frommeld, Debora A1 - Weber, Karsten ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Meussling-Sentpali, Annette ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Telepräsenzroboter für die Pflege und Unterstützung von Schlaganfallpatientinnen und -patienten: Das Forschungsdesign für die sozialwissenschaftliche Begleitforschung BT - Das Forschungsdesign für die sozialwissenschaftliche Begleitforschung T2 - Digitale Technik für ambulante Pflege und Therapie: Herausforderungen, Lösungen, Anwendungen und Forschungsperspektiven Y1 - 2022 SN - 978-3-8376-6235-1 U6 - https://doi.org/10.14361/9783839462355-009 SP - 175 EP - 193 PB - Transcript CY - Bielefeld ER - TY - CHAP A1 - Currle, Edda A1 - Haug, Sonja T1 - Acceptance of Telepresence Robotics, Telecare and Teletherapy Among Stroke Patients, Relatives and Therapy Staff T2 - dHealth 2024: proceedings of the 18th annual conference on Health Informatics meets Digital Health conference N2 - Background: Stroke as a cause of disability in adulthood causes an increasing demand for therapy and care services, including telecare and teletherapy. Objectives: Aim of the study is to analyse the acceptance of telepresence robotics and digital therapy applications. Methods: Longitudinal study with a before and after survey of patients, relatives and care and therapy staff. Results: Acceptance of the technology analysed is high in all three groups. Although acceptance among patients declined in parts of the cases in the second survey after having used telerobotics, all in all approval ratings remained high. With regard to patients no significant correlation was found between the general technology acceptance and the acceptance of use of telerobotics. Conclusion: Accepted new telecare and teletherapies can be offered with the help of telepresence robotics. This requires knowledge of and experience with the technology. Y1 - 2024 SN - 978-1-64368-517-5 U6 - https://doi.org/10.3233/SHTI240005 SN - 0926-9630 N1 - Corresponding Author: Edda Currle SP - 15 EP - 21 PB - IOS Press ER - TY - CHAP A1 - Haug, Sonja ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Digitale Technik für ambulante Pflege und Therapie II – zukunftsweisende Wege BT - Vorwort T2 - Digitale Technik für ambulante Pflege und Therapie II – Impulse für die Praxis T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 3 KW - Digitalisierung KW - Gesundheit KW - Gesundheitswesen KW - Pflege KW - Therapie Y1 - 2023 SN - 978-3-8394-6727-5 U6 - https://doi.org/10.14361/9783839467275-002 SP - 11 EP - 19 PB - transcript CY - Bielefeld ER - TY - CHAP A1 - Weber, Karsten ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Meussling-Sentpali, Annette ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Der Einsatz von Telepräsenzrobotern als normatives Gebot: Ein Plädoyer für mehr Technikoffenheit und Technikeinsatz in Pflege und Gesundheit T2 - Digitale Technik für ambulante Pflege und Therapie: Herausforderungen, Lösungen, Anwendungen und Forschungsperspektiven Y1 - 2022 UR - https://www.transcript-verlag.de/978-3-8376-6235-1 SN - 978-3-8376-6235-1 U6 - https://doi.org/10.14361/9783839462355-014 SP - 317 EP - 334 PB - Transcript CY - Bielefeld ER - TY - CHAP A1 - Weber, Karsten ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Meussling-Sentpali, Annette ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - DeinHaus 4.0 Oberpfalz – Feldstudie, Schaufenster und Stolpersteine BT - Ein Vorwort T2 - Digitale Technik für ambulante Pflege und Therapie Y1 - 2022 SN - 978-3-8376-6235-1 U6 - https://doi.org/10.14361/9783839462355 SP - 9 EP - 17 PB - Transcript CY - Bielefeld ER - TY - CHAP A1 - Altenbuchner, Amelie A1 - Mücke, Vanessa A1 - Haug, Sonja ED - Schreier, Günter T1 - Comparing monitoring results of two motion trackers for geriatric patients T2 - dHealth 2020: biomedical informatics for health and care, proceedings of the 14th Health Informatics Meets Digital Health Conference N2 - Background: Fitbit and Garmin motion tracker devices are highly used in research. The validity and reliability of these devices is proven for healthy adults between 18 and 64. Objectives: Comparing data output of two devices. Methods: Observational case study on a test track and in the domestic environment of a 80- year-old female multimorbide geriatric patient. Results: High significant correlation of the devices on the test track [r=.776, p≤.001, Bca-CI-95% (.618;.874), N=33], but significant different in the domestic environment over time (z=4.840, p≤.001). Conclusion: The dominant/non-dominant body side and further sources of error may play a role in monitoring steps with these devices. KW - physical activity KW - steps KW - geriatric patients KW - health monitoring KW - motion tracker KW - wearables KW - parallel test reliability KW - concurrent validity Y1 - 2020 SN - 978-1-64368-085-9 U6 - https://doi.org/10.3233/SHTI200078 SP - 77 EP - 84 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Haug, Sonja A1 - Vetter, Miriam A1 - Weber, Karsten T1 - Gebäudesanierung zwischen Energieeffizienz und Sozialverträglichkeit BT - Zwei empirische Fallstudien JF - TATuP - Zeitschrift für Technikfolgenabschätzung in Theorie und Praxis N2 - Die Akzeptanz unter Bewohnern und Bewohnerinnen gewinnt bei hoch komplexen, technisch anspruchsvollen energetischen Sanierungen als „Innovationsmotor“ zunehmend an Relevanz. Der Beitrag basiert auf zwei Fallstudien zur partizipativen Nutzereinbindung bei energetischen Sanierungen im genossenschaftlichen Wohnbau historischer Stadtquartiere in Regensburg. Neben einer sozialverträglichen Sanierung wurde jeweils ein hohes Maß an Energieeffizienz bei den technischen Lösungen ange-strebt. Haushaltsbefragungen und qualitative Interviews zeigen die hohe Akzeptanz von Sanierungsmaßnahmen, sofern die Senkung der Energiekosten die erhöhte Miete kompensiert. Abschließend werden Akzeptanzfaktoren wie Partizipation, Vertrauen, Sozialverträglichkeit und Autarkie erörtert. T2 - Building restoration between energy efficiency and user acceptance KW - Altbaumodernisierung KW - Energieeinsparung KW - Sozialverträglichkeit KW - Fallstudie KW - energy-efficient building restoration KW - user acceptance KW - household survey KW - historic quarter KW - renewable energy Y1 - 2020 U6 - https://doi.org/10.14512/tatup.29.3.56 SN - 2567-8833 VL - 29 IS - 3 SP - 56 EP - 63 PB - oekom-Verlag ER - TY - JOUR A1 - Haug, Sonja A1 - Milewski, Nadja T1 - Women’s attitudes towards assisted reproductive technologies BT - a pilot study among migrant minorities and non-migrants in Germany JF - Comparative Population Studies. Special Collection on "New aspects in fertility of migrant and minority populations in Europe: The role of attitudes and intentions in family planning" N2 - This study examines attitudes toward assisted reproductive technologies (ART) among immigrant women and non-migrants in Germany. The social relevance of ART is increasing in Western countries due to overall low birth rates, a high rate of childlessness, and a gap between the desired and the actual numbers of children. Previous literature has been scarce, however, on attitudes toward ART, and immigrant minorities have rarely been included in studies on ART. Our working hypotheses are drawn from theoretical considerations on political socialisation and cultural integration. The analysis is based on data collected in a pilot study in 2014 and 2015. The sample includes 960 women aged 18 to 50 living in Germany. About 81 percent of the sample are immigrants who originate from Turkey, Poland, the Balkan countries, or countries of the (Russian) Commonwealth of Independent States (CIS). We study the social norm to use ART to have a child, the personal attitude of whether a woman would use ART herself, and the methods that they would consider for their own use. Our results show that ART is overall socially acceptable, and the majority of women said that they would use it if necessary. There is significant variation between the origin groups, however. Non-migrants show the lowest acceptance rates and migrants from Poland and Turkey the highest approval. There is also variation in the ART procedures considered for use with the migrants more approving of heterologous methods than non-migrants. The differences between the origin groups diminish only partly when controlling for further explanatory variables, i.e. gender-role attitudes, religiosity, and socio-demographic characteristics of the respondents. We conclude that attitudes toward ART are shaped less by socio-demographic characteristics, but rather by cultural factors and the socialization in the migrants’ countries of origin. The diversity in attitudes toward ART by cultural background should be acknowledged in research and public discourses on ART as well as in regulating policies. KW - ART KW - Family norms KW - Women’s social status KW - Migrant women KW - Germany Y1 - 2018 U6 - https://doi.org/10.12765/CPoS-2019-06 VL - Vol. 43 SP - 343 EP - 370 ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Kalita, Viktor M. A1 - Shamonin (Chamonine), Mikhail T1 - Renormalization of the critical exponent for the shear modulus of magnetoactive elastomers JF - Scientific Reports N2 - It is shown that the critical exponent for the effective shear modulus of a composite medium where a compliant polymer matrix is filled with ferromagnetic particles may significantly depend on the external magnetic field. The physical consequence of this dependence is the critical behavior of the relative magnetorheological effect. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-22333-6 N1 - Corresponding author: Mikhail Shamonin VL - 8 SP - 1 EP - 8 PB - Nature ER - TY - JOUR A1 - Prantl, Lukas A1 - Eigenberger, Andreas A1 - Reinhard, Ruben A1 - Siegmund, Andreas A1 - Heumann, Kerstin A1 - Felthaus, Oliver T1 - Cell-Enriched Lipotransfer (CELT) Improves Tissue Regeneration and Rejuvenation without Substantial Manipulation of the Adipose Tissue Graft JF - Cells N2 - The good availability and the large content of adult stem cells in adipose tissue has made it one of the most interesting tissues in regenerative medicine. Although lipofilling is one of the most frequent procedures in plastic surgery, the method still struggles with high absorption rates and volume losses of up to 70%. Therefore, many efforts have been made to optimize liposuction and to process the harvested tissue in order to increase fat graft retention. Because of their immunomodulatory properties, their cytokine secretory activity, and their differentiation potential, enrichment with adipose tissue-derived stem cells was identified as a promising tool to promote transplant survival. Here, we review the important parameters for lipofilling optimization. Finally, we present a new method for the enrichment of lipoaspirate with adipose tissue-derived stem cells and discuss the parameters that contribute to fat graft survival. Y1 - 2022 U6 - https://doi.org/10.3390/cells11193159 VL - 11 IS - 19 SP - 1 EP - 11 PB - MDPI ER - TY - JOUR A1 - Laumer, Tobias A1 - Karg, Michael Cornelius Hermann A1 - Schmidt, Michael T1 - Laser Beam Melting of Multi-Material Components JF - Physics Procedia N2 - First results regarding the realisation of multi-material components manufactured by Laser Beam Melting of polymers and metals are published. For realising composite structures from polymer powders by additive manufacturing, at first relevant material properties regarding compatibility have to be analysed. The paper shows the main requirements for compatibility between different materials and offers first results in form of a compatibility matrix of possible combinations for composite structures.For achieving gradient properties of additively manufactured metal parts by using composite materials the composition of alloying components in the powder and adapted process strategies are varied. As an alternative to atomizing pre-alloyed materials, mixtures of different powders are investigated. KW - additive manufacturing KW - laser beam melting Y1 - 2012 U6 - https://doi.org/10.1016/j.phpro.2012.10.068 SN - 1875-3892 SN - 1875-3884 VL - 39 SP - 518 EP - 525 PB - Elsevier ER - TY - JOUR A1 - Widbiller, Matthias A1 - Keim, Lukas A1 - Schlichting, Ralf A1 - Striegl, Birgit A1 - Hiller, Karl-Anton A1 - Jungbauer, Rebecca A1 - Buchalla, Wolfgang A1 - Galler, Kerstin M. T1 - Debris Removal by Activation of Endodontic Irrigants in Complex Root Canal Systems BT - A Standardized In-Vitro-Study JF - Applied Sciences N2 - Aim of the study was to develop a standardized model system to investigate endodontic irrigation techniques and assess the efficiency of different activation methods on the removal of hard tissue debris in complex root canal systems. Mesial roots of mandibular molars were firstly scanned by micro-computed tomography (µCT) and allocated to three groups of irrigant activation: sonic activation (EDDY, VDW, Munich, Germany), laser activation (AutoSWEEPS, FOTONA, Ljubljana, Slovenia) and conventional needle irrigation (control). Roots were fixed in individual 3D-printed holders to facilitate root canal enlargement under constant irrigation with NaOCl (5%). To enable standardized quantification of remaining debris, BaSO4-enriched dentine powder was compacted into the canals, followed by another µCT-scan. The final irrigation was performed using 17% ethylenediaminetetraacetic acid (EDTA) and 5% sodium hypochlorite (NaOCl) with the respective activation method, and the volume of remaining artificial debris was quantified after a final µCT-scan. The newly developed model system allowed for reliable, reproducible and standardized assessment of irrigation methods. Activation of the irrigant proved to be significantly more effective than conventional needle irrigation regarding the removal of debris, which persisted particularly in the apical third of the root canal in the control group. The efficiency of irrigation was significantly enhanced with laser- and sonic-based activation, especially in the apical third. Y1 - 2021 U6 - https://doi.org/10.3390/app11167331 VL - 11 IS - 16 SP - 1 EP - 14 PB - MDPI CY - Basel ER - TY - CHAP A1 - Giese, Constanze ED - Weber, Karsten ED - Haug, Sonja ED - Mohr, Christa ED - Lauer, Norina ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Roboter als Hoffnungsträger in der Pflege: Pflegeethische Zugänge zur Einschätzung künftiger Einsatzmöglichkeiten T2 - Digitale Technik für ambulante Pflege und Therapie II - Impulse für die Praxis T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 3 Y1 - 2023 U6 - https://doi.org/10.14361/9783839467275-010 SP - 115 EP - 130 PB - transcript CY - Bielefeld ER - TY - JOUR A1 - Osmanlic, Fuad A1 - Wudy, Katrin A1 - Laumer, Tobias A1 - Schmidt, Michael A1 - Drummer, Dietmar A1 - Körner, Carolin T1 - Modeling of Laser Beam Absorption in a Polymer Powder Bed JF - Polymers N2 - In order to understand the absorption characteristic, a ray trace model is developed by taking into account the reflection, absorption and refraction. The ray paths are resolved on a sub-powder grid. For validation, the simulation results are compared to analytic solutions of the irradiation of the laser beam onto a plain surface. In addition, the absorptance, reflectance and transmittance of PA12 powder layers measured by an integration sphere setup are compared with the numerical results of our model. It is shown that the effective penetration depth can be lower than the penetration depth in bulk material for polymer powders and, therefore, can increase the energy density at the powder bed surface. The implications for modeling of the selective laser sintering (SLS) process and the processability of fine powder distributions and high powder bed densities are discussed. KW - additive manufacturing KW - laser absorption KW - PA12 KW - polyamide 12 KW - powder bed Y1 - 2018 U6 - https://doi.org/10.3390/polym10070784 VL - 10 IS - 7 SP - 1 EP - 11 PB - MDPI ER - TY - GEN A1 - Roller, Katrin A1 - Rudolph, Clarissa A1 - Eck, Sandra A1 - Schneider, Kyra A1 - Vischer, Nina T1 - Wohnen, Care, Geschlecht - Theorie und Praxis kollektiven Wohnens aus Geschlechterperspektive Y1 - 2024 SN - 978-3-98634-175-6 U6 - https://doi.org/10.56715/398634175 PB - Westfälisches Dampfboot CY - Münster ER - TY - JOUR A1 - Haynack, Alexander A1 - Sekandar, Zadran A1 - Jithender, J. Timothy A1 - Gambarelli, Serena A1 - Kränkel, Thomas A1 - Thiel, Charlotte A1 - Ozbolt, Josko A1 - Gehlen, Christoph T1 - Can a Hend-Held 3D Scanner Capture Temperature-Induced Strain of Mortar Samples? Comparison between Experimental Measurements and Numerical Simulations JF - mathematics N2 - The expected lifespan of cement-based materials, particularly concrete, is at least 50 years. Changes in the pore structure of the material need to be considered due to external influences and associated transport processes. The expansion behaviour of concrete and mortar during freeze–thaw attacks, combined with de-icing salt agents, is crucial for both internal and external damage. It is essential to determine and simulate the expansion behaviour of these materials in the laboratory, as well as detect the slow, long-term expansion in real structures. This study measures the expansion of mortar samples during freeze–thaw loading using a high-resolution hand-held 3D laser scanner. The specimens are prepared with fully or partially saturated pore structures through water storage or drying. During freeze–thaw experiments, the specimens are exposed to pure water or a 3% sodium chloride solution (NaCl). Results show contraction during freezing and subsequent expansion during thawing. Both test solutions exhibit similar expansion behaviour, with differences primarily due to saturation levels. Further investigations are required to explore the changing expansion behaviour caused by increasing microcracking resulting from continuous freeze–thaw cycles. A numerical analysis using a 3D coupled hygro-thermo-mechanical (HTM) model is conducted to examine the freeze–thaw behaviour of the mortar. The model accurately represents the freezing deformation during the freeze–thaw cycle. KW - concrete KW - mortar KW - durability KW - freeze–thaw and de-icing salt resistance KW - strain KW - 3D laser scanning KW - numerical simulation KW - 3D FE numerical model KW - hygro-thermo-mechanical coupling Y1 - 2023 U6 - https://doi.org/10.3390/math11173672 VL - 11 IS - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Krüger, Norbert A1 - Fischer, Kerstin A1 - Manoonpong, Poramate A1 - Palinko, Oskar A1 - Bodenhagen, Leon A1 - Baumann, Timo A1 - Kjærum, Jens A1 - Rano, Ignacio A1 - Naik, Lakshadeep A1 - Juel, William Kristian A1 - Haarslev, Frederik A1 - Ignasov, Jevgeni A1 - Marchetti, Emanuela A1 - Langedijk, Rosalyn Melissa A1 - Kollakidou, Avgi A1 - Jeppesen, Kasper Camillus A1 - Heidtmann, Conny A1 - Dalgaard, Lars T1 - The SMOOTH-Robot: A Modular, Interactive Service Robot JF - Frontiers in Robotics and AI N2 - The SMOOTH-robot is a mobile robot that-due to its modularity-combines a relatively low price with the possibility to be used for a large variety of tasks in a wide range of domains. In this article, we demonstrate the potential of the SMOOTH-robot through three use cases, two of which were performed in elderly care homes. The robot is designed so that it can either make itself ready or be quickly changed by staff to perform different tasks. We carefully considered important design parameters such as the appearance, intended and unintended interactions with users, and the technical complexity, in order to achieve high acceptability and a sufficient degree of utilization of the robot. Three demonstrated use cases indicate that such a robot could contribute to an improved work environment, having the potential to free resources of care staff which could be allocated to actual care-giving tasks. Moreover, the SMOOTH-robot can be used in many other domains, as we will also exemplify in this article. KW - human–robot interaction KW - mobile robots KW - proactive control KW - service robots KW - socially aware navigation Y1 - 2021 U6 - https://doi.org/10.3389/frobt.2021.645639 VL - 8 PB - Frontiers ER - TY - JOUR A1 - Alvarez Moret, Judit A1 - Obermeier, Tina A1 - Pohl, Fabian A1 - Löschel, Rainer A1 - Kölbl, Oliver A1 - Dobler, Barbara T1 - Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator JF - Journal of Applied Clinical Medical Physics N2 - Pediatric patients suffering from ependymoma are usually treated with cranial or craniospinal three-dimensional (3D) conformal radiotherapy (3DCRT). Intensity-modulated techniques spare dose to the surrounding tissue, but the risk for second malignancies may be increased due to the increase in low-dose volume. The aim of this study is to investigate if the flattening filter free (FFF) mode allows reducing the risk for second malignancies compared to the mode with flattening filter (FF) for intensity-modulated techniques and to 3DCRT. A reduction of the risk would be advantageous for treating pediatric ependymoma. 3DCRT was compared to intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) with and without flattening filter. Dose-volume histograms (DVHs) were compared to evaluate the plan quality and used to calculate the excess absolute risk (EAR) to develop second cancer in the brain. Dose verification was performed with a two-dimensional (2D) ionization chamber array and the out-of-field dose was measured with an ionization chamber to determine the EAR in peripheral organs. Delivery times were measured. Both VMAT and IMRT achieved similar plan quality in terms of dose sparing in the OAR and higher PTV coverage as compared to 3DCRT. Peripheral dose in low-dose region, which is proportional to the EAR in organs located in this region, for example, gonads, bladder, or bowel, could be significantly reduced using FFF. The lowest peripheral EAR and lowest delivery times were hereby achieved with VMATFFF . The EAR calculated based on DVH in the brain could not be reduced using FFF mode. VMATFFF improved the target coverage and homogeneity and kept the dose in the OAR similar compared to 3DCRT. In addition, delivery times were significantly reduced using VMATFFF . Therefore, for radiotherapy of ependymoma patients, VMATFFF may be considered advantageous for the combination of Elekta Synergy linac and Oncentra External Beam planning system used in this study. KW - Adolescent KW - Child KW - Child, Preschool KW - Ependymoma/radiotherapy KW - Humans KW - Infant KW - Neoplasms, Radiation-Induced KW - Neoplasms, Second Primary KW - Particle Accelerators KW - Radiotherapy Dosage KW - Radiotherapy Planning, Computer-Assisted KW - Radiotherapy, Intensity-Modulated KW - Retrospective Studies Y1 - 2018 U6 - https://doi.org/10.1002/acm2.12438 VL - 19 IS - 5 SP - 632 EP - 639 PB - Wiley ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results JF - Frontiers in Energy Research N2 - This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1%. Y1 - 2022 U6 - https://doi.org/10.3389/fenrg.2022.818486 N1 - Corresponding author: Belal Dawoud VL - 10 SP - 1 EP - 15 PB - Frontiers ER - TY - JOUR A1 - Curbach, Janina A1 - Lander, Jonas A1 - Dierks, Marie-Luise A1 - Grepmeier, Eva-Maria A1 - von Sommoggy, Julia T1 - How do health professionals translate evidence on early childhood allergy prevention into health literacy-responsive practice? BT - A protocol for a mixed-method study on the views of German health professionals JF - BMJ OPEN N2 - Introduction Paediatricians, general practitioners (GPs) and midwives in primary care are important sources of information for parents on early childhood allergy prevention (ECAP). Research has shown that preventive counselling by health professionals can be effective in improving patients' health literacy (HL) and health behaviour. Providing effective advice relies on two factors. First, health professionals need be up-to-date with research evidence on ECAP, to consider popular misconceptions and fears and to translate this knowledge into clear recommendations for parents (knowledge translation). Second, they need to know and apply counselling techniques and create a practice setting which accommodates parental HL needs (health literacy-responsive care). The objective of this study is to explore and assess how German health professionals take up and translate ECAP evidence into appropriate recommendations for parents, how they consider HL in counselling and practice organisation and what barriers and enablers they find in their performance of HL-responsive ECAP. Methods and analysis The study has a sequential mixed-method design, in two phases. In the first phase, qualitative semi-structured expert interviews will be conducted with health professionals (paediatricians, GPs and midwives) at primary care level and professional policy level. Data collection is ongoing until January 2022. In the second phase, based on the qualitative results, a standardised questionnaire will be developed, and pilot-tested in a wider population of German health professionals. The findings of both phases will be integrated. Ethics and dissemination The study has received ethical approval from the Ethics Committee of the University of Regensburg (18-1205-101). The results will be published in international peer-reviewed open access journals and via presentations at scientific conferences. The results will also be shared with German health professionals, decision-makers and potential funders of interventions. KW - FOOD ALLERGY KW - INTERVENTION KW - MINDLINES KW - PERCEPTIONS KW - PERSPECTIVES KW - PHYSICAL-ACTIVITY KW - preventive medicine KW - PRIMARY-CARE KW - public health KW - qualitative research KW - social medicine Y1 - 2021 U6 - https://doi.org/10.1136/bmjopen-2020-047733 N1 - Corresponding author: Janina Curbach VL - 11 SP - 1 EP - 8 PB - BMJ ER - TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Heckel, Robert A1 - Rahiman, Mohd Fuad A1 - Lindner, Matthias A1 - Heinrich, Stephan A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - A Robust Miniaturized Gas Sensor for H₂ and CO₂ Detection Based on the 3ω Method JF - Sensors N2 - Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62% in the case of CO2, and only 0.062% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors. KW - 3ω-method KW - CO2 sensor KW - H2 sensor KW - thermal gas sensor Y1 - 2022 U6 - https://doi.org/10.3390/s22020485 N1 - Corresponding author: Dominik J. Berndt VL - 22 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Steffens, Oliver A1 - Dawoud, Belal T1 - Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System JF - Buildings N2 - A newly-developed solar active thermal insulation system (SATIS) is introduced with the main objective to accomplish a highly-dependent total solar transmittance on the irradiation angle. SATIS is also designed to obtain the maximum transmittance at a prescribed design irradiation angle and to reduce it remarkably at higher irradiation angles. A purely mineral thermal insulation plaster with micro hollow glass spheres is applied to manufacture the investigated SATIS prototype. Light-conducting elements (LCEs) have been introduced into SATIS and suitable closing elements have been applied. The SATIS prototype has been investigated both experimentally and numerically. It turned out that the contributions of conduction, radiation and convection to the effective thermal conductivity of SATIS, without the closing elements (49 mWmK), amount to 86.2%, 13.2% and 0.6%, respectively. The angle-dependent short-wave radiation exchange within the LCE has been investigated via ray tracing. At the incidence angle of 19% (design angle), 27% of the radiation within the LCE is absorbed by the absorber plate, resulting in measured and computed total solar energy transmittances of 11.2%/11.7%, respectively. For a typical summer irradiation angle of 60%, 98% of the incident radiation is absorbed by the surfaces at the entrance of the LCE. The corresponding total solar energy transmittance amounts to 2.9%. KW - angle-dependent total solar energy transmittance KW - effective thermal conductivity KW - experimental investigation KW - numerical simulation KW - ray tracing KW - solar active thermal insulation system (SATIS) Y1 - 2021 U6 - https://doi.org/10.3390/buildings11030123 N1 - Corresponding author: Belal Dawoud VL - 11 IS - 3 SP - 1 EP - 22 PB - MDPI ER - TY - JOUR A1 - Gamisch, Bernd A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions JF - Applied Sciences N2 - This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90% Fe2O3, 10% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen. KW - hydrogen storage KW - iron/iron oxide KW - reaction kinetics KW - redox reactions Y1 - 2021 U6 - https://doi.org/10.3390/app11041623 N1 - Corresponding author: Belal Dawoud VL - 11 IS - 4 SP - 1 EP - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. T1 - Mini-Extruder for 3D Magnetoactive Polymer Printing JF - Advances in Materials Science and Engineering N2 - This work describes the development of a new miniature extruder, essential to cavity-free 3D printing of silicone-based smart materials. This makes the 3D printing of magnetoactive and electroactive polymer soft robotic components and devices directly from CAD data possible. The special feature of such an extruder is that it is designed for use with addition-crosslinking RTV-2 silicones, including solid particulate additives. The extruder merges the respective components automatically during extrusion which obviates the need for premixing and vacuum evacuation. Problems associated with inhomogeneities and unwanted cavity production are consequently eliminated. Rheological details necessary to the design, together with some preliminary performance results, are presented. Y1 - 2019 U6 - https://doi.org/10.1155/2019/8715718 N1 - Corresponding author: Gareth J. Monkman SP - 1 EP - 8 PB - HINDAWI ER - TY - JOUR A1 - Dechant, Eduard A1 - Fedulov, Feodor A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Bandwidth Widening of Piezoelectric Cantilever Beam Arrays by Mass-Tip Tuning for Low-Frequency Vibration Energy Harvesting JF - Applied Science N2 - Wireless sensor networks usually rely on internal permanent or rechargeable batteries as a power supply, causing high maintenance efforts. An alternative solution is to supply the entire system by harvesting the ambient energy, for example, by transducing ambient vibrations into electric energy by virtue of the piezoelectric effect. The purpose of this paper is to present a simple engineering approach for the bandwidth optimization of vibration energy harvesting systems comprising multiple piezoelectric cantilevers (PECs). The frequency tuning of a particular cantilever is achieved by changing the tip mass. It is shown that the bandwidth enhancement by mass tuning is limited and requires several PECs with close resonance frequencies. At a fixed frequency detuning between subsequent PECs, the achievable bandwidth shows a saturation behavior as a function of the number of cantilevers used. Since the resonance frequency of each PEC is different, the output voltages at a particular excitation frequency have different amplitudes and phases. A simple power-transfer circuit where several PECs with an individual full wave bridge rectifier are connected in parallel allows one to extract the electrical power close to the theoretical maximum excluding the diode losses. The experiments performed on two- and three-PEC arrays show reasonable agreement with simulations and demonstrate that this power-transfer circuit additionally influences the frequency dependence of the harvested electrical power. KW - array KW - BAND-PASS FILTERS KW - bandwidth KW - BIMORPH KW - Optimization KW - OUTPUT KW - PERFORMANCE KW - piezoelectric cantilever KW - POWER KW - vibration energy harvesting Y1 - 2017 U6 - https://doi.org/10.3390/app7121324 N1 - Corresponding Author: Mikhail Shamonin VL - 7 IS - 12 PB - MDPI ER - TY - JOUR A1 - Diamantidis, Dimitris T1 - A Critical View on Environmental and Human Risk Acceptance Criteria JF - International Journal of Environmental Science and Development N2 - Natural and technological hazards have a major impact on environmental and human safety. Risk assessment plays an essential role in the risk management of the effects of such hazards. This contribution summarizes first the general formulation of risk depending on two parameters: hazard probability and associated consequences. Problems faced in industrial applications based on the experience of the author are discussed. Risk acceptance criteria for the contributors to risk i.e. human, economic and environment are critically reviewed. Resilience based criteria are also included and conclusions for future developments are provided. KW - Environmental risk KW - human risk KW - Risk acceptance KW - Risk analysis KW - safety measures Y1 - 2017 U6 - https://doi.org/10.18178/ijesd.2017.8.1.921 N1 - Corresponding author: Dimitris Diamantidis VL - 8 IS - 1 SP - 62 EP - 66 ER - TY - JOUR A1 - Kreitmeier, Florian A1 - Chashin, Dmitri V. A1 - Fetisov, Yuri K. A1 - Fetisov, Leonid Y. A1 - Schulz, Irene A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Nonlinear Magnetoelectric Response of Planar Ferromagnetic-Piezoelectric Structures to Sub-Millisecond Magnetic Pulses JF - Sensors N2 - The magnetoelectric response of bi- and symmetric trilayer composite structures to pulsed magnetic fields is experimentally investigated in detail. The structures comprise layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 µs and amplitudes ranging from 500 Oe to 38 kOe. The time dependence of the resulting voltage is presented and explained by theoretical estimations. Appearance of voltage oscillations with frequencies much larger than the reciprocal pulse length is observed for sufficiently large amplitudes (~1-10 kOe) of the magnetic-field pulse. The origin of these oscillations is the excitation of bending and planar acoustic oscillations in the structures. Dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated by digital signal processing and compared with those obtained by the method of harmonic field modulation. The results are of interest for developing magnetoelectric sensors of pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures. Y1 - 2012 U6 - https://doi.org/10.3390/s121114821 N1 - Corresponding author: Mikhail Shamonin VL - 12 IS - 11 SP - 14821 EP - 14837 PB - MDPI CY - Basel ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Gleixner, Ramona A1 - Mayer, Matthias A1 - Shamonin (Chamonine), Mikhail A1 - Schmauss, Bernhard T1 - Intensity referencing in an extrinsic optical fiber temperature sensor JF - Procedia Engineering N2 - Optical fiber sensors based on intensity measurement require some form of intensity referencing to avoid errors arising from parasitic losses. Known techniques of referencing such as balanced bridge, divided beam systems or two-wavelength referencing are not suitable for low-cost applications since they use relatively complicated optical components such as multiple LED sources, couplers, filters etc. In this work a novel method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of absorption edge in a semiconductor crystal is described. The sensor system comprises a single LED source and no optical fiber junctions. The emission spectrum of an LED depends on its temperature. The reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. The entire process is controlled by a microprocessor unit. Performance of a sensor system is investigated and it is shown that the losses in connectors may be compensated for. KW - Extrinsic optical fiber sensor KW - Intensity referencing KW - Temperature measurement KW - Absorption edge KW - Semiconductor KW - Hot-spot measurement Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.301 VL - 5 SP - 1095 EP - 1098 PB - Elsevier ER -