TY - JOUR A1 - Eckert, Alexander A1 - Abbasi, Mozhdeh A1 - Mang, Thomas A1 - Saalwächter, Kay A1 - Walther, Andreas T1 - Structure, Mechanical Properties, and Dynamics of Polyethylenoxide/Nanoclay Nacre-Mimetic Nanocomposites JF - Macromolecules N2 - Nacre-mimetic nanocomposites based on high fractions of synthetic high-aspect-ratio nanoclays in combination with polymers are continuously pushing boundaries for advanced material properties, such as high barrier against oxygen, extraordinary mechanical behavior, fire shielding, and glass-like transparency. Additionally, they provide interesting model systems to study polymers under nanoconfinement due to the well-defined layered nanocomposite arrangement. Although the general behavior in terms of forming such layered nanocomposite materials using evaporative self-assembly and controlling the nanoclay gallery spacing by the nanoclay/polymer ratio is understood, some combinations of polymer matrices and nanoclay reinforcement do not comply with the established models. Here, we demonstrate a thorough characterization and analysis of such an unusual polymer/nanoclay pair that falls outside of the general behavior. Poly(ethylene oxide) (PEO) and sodium fluorohectorite form nacre-mimetic, lamellar nanocomposites that are completely transparent and show high mechanical stiffness and high gas barrier, but there is only limited expansion of the nanoclay gallery spacing when adding increasing amounts of polymer. This behavior is maintained for molecular weights of PEO varied over four orders of magnitude and can be traced back to depletion forces. By careful investigation via X-ray diffraction and proton low-resolution solid-state NMR, we are able to quantify the amount of mobile and immobilized polymer species in between the nanoclay galleries and around proposed tactoid stacks embedded in a PEO matrix. We further elucidate the unusual confined polymer dynamics, indicating a relevant role of specific surface interactions. Y1 - 2020 U6 - http://dx.doi.org/10.1021/acs.macromol.9b01931 SN - 1520-5835 VL - 53 IS - 5 SP - 1716 EP - 1725 PB - ACS Publications CY - Washington, DC ER - TY - CHAP A1 - Dümmler, Andreas A1 - Oetringer, Kerstin A1 - Göttsche, Joachim T1 - Auslegungstool zur energieeffizienten Kühlung von Gebäuden T2 - DKV-Tagung 2020, AA IV Y1 - 2020 N1 - Deutsche Kälte- und Klimatagung 2020 online SP - 1 EP - 12 ER - TY - CHAP A1 - Duran Paredes, Ludwin A1 - Mottaghy, Darius A1 - Herrmann, Ulf A1 - Groß, Rolf Fritz T1 - Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components T2 - EGU General Assembly 2020 N2 - We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation. Y1 - 2020 N1 - Online 4–8 May 2020 [Session ERE2.8] EGU2020-19052 ER - TY - JOUR A1 - Drumm, Christian A1 - Emhardt, Selina N. A1 - Kok, Ellen M. A1 - Jarodzka, Halzka A1 - Brand-Gruwel, Saskia A1 - van Gog, Tamara T1 - How Experts Adapt Their Gaze Behavior When Modeling a Task to Novices JF - Cognitive science N2 - Domain experts regularly teach novice students how to perform a task. This often requires them to adjust their behavior to the less knowledgeable audience and, hence, to behave in a more didactic manner. Eye movement modeling examples (EMMEs) are a contemporary educational tool for displaying experts’ (natural or didactic) problem-solving behavior as well as their eye movements to learners. While research on expert-novice communication mainly focused on experts’ changes in explicit, verbal communication behavior, it is as yet unclear whether and how exactly experts adjust their nonverbal behavior. This study first investigated whether and how experts change their eye movements and mouse clicks (that are displayed in EMMEs) when they perform a task naturally versus teach a task didactically. Programming experts and novices initially debugged short computer codes in a natural manner. We first characterized experts’ natural problem-solving behavior by contrasting it with that of novices. Then, we explored the changes in experts’ behavior when being subsequently instructed to model their task solution didactically. Experts became more similar to novices on measures associated with experts’ automatized processes (i.e., shorter fixation durations, fewer transitions between code and output per click on the run button when behaving didactically). This adaptation might make it easier for novices to follow or imitate the expert behavior. In contrast, experts became less similar to novices for measures associated with more strategic behavior (i.e., code reading linearity, clicks on run button) when behaving didactically. Y1 - 2020 U6 - http://dx.doi.org/10.1111/cogs.12893 SN - 1551-6709 VL - 44 IS - 9 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Dinghofer, Kai A1 - Hartung, Frank T1 - Analysis of Criteria for the Selection of Machine Learning Frameworks T2 - 2020 International Conference on Computing, Networking and Communications (ICNC) Y1 - 2020 U6 - http://dx.doi.org/10.1109/ICNC47757.2020.9049650 SP - 373 EP - 377 ER - TY - JOUR A1 - Digel, Ilya A1 - Kern, Inna A1 - Geenen, Eva-Maria A1 - Akimbekov, Nuraly T1 - Dental plaque removal by ultrasonic toothbrushes JF - dentistry journal N2 - With the variety of toothbrushes on the market, the question arises, which toothbrush is best suited to maintain oral health? This thematic review focuses first on plaque formation mechanisms and then on the plaque removal effectiveness of ultrasonic toothbrushes and their potential in preventing oral diseases like periodontitis, gingivitis, and caries. We overviewed the physical effects that occurred during brushing and tried to address the question of whether ultrasonic toothbrushes effectively reduced the microbial burden by increasing the hydrodynamic forces. The results of published studies show that electric toothbrushes, which combine ultrasonic and sonic (or acoustic and mechanic) actions, may have the most promising effect on good oral health. Existing ultrasonic/sonic toothbrush models do not significantly differ regarding the removal of dental biofilm and the reduction of gingival inflammation compared with other electrically powered toothbrushes, whereas the manual toothbrushes show a lower effectiveness. Y1 - 2020 U6 - http://dx.doi.org/10.3390/dj8010028 SN - 2304-6767 VL - 8 IS - 28 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Dantism, Shahriar A1 - Röhlen, Desiree A1 - Dahmen, Markus A1 - Wagner, Torsten A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - LAPS-based monitoring of metabolic responses of bacterial cultures in a paper fermentation broth JF - Sensors and Actuators B: Chemical N2 - As an alternative renewable energy source, methane production in biogas plants is gaining more and more attention. Biomass in a bioreactor contains different types of microorganisms, which should be considered in terms of process-stability control. Metabolically inactive microorganisms within the fermentation process can lead to undesirable, time-consuming and cost-intensive interventions. Hence, monitoring of the cellular metabolism of bacterial populations in a fermentation broth is crucial to improve the biogas production, operation efficiency, and sustainability. In this work, the extracellular acidification of bacteria in a paper-fermentation broth is monitored after glucose uptake, utilizing a differential light-addressable potentiometric sensor (LAPS) system. The LAPS system is loaded with three different model microorganisms (Escherichia coli, Corynebacterium glutamicum, and Lactobacillus brevis) and the effect of the fermentation broth at different process stages on the metabolism of these bacteria is studied. In this way, different signal patterns related to the metabolic response of microorganisms can be identified. By means of calibration curves after glucose uptake, the overall extracellular acidification of bacterial populations within the fermentation process can be evaluated. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.snb.2020.128232 SN - 0925-4005 VL - 320 IS - Art. 128232 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dadfar, Dryed Mohammadali A1 - Camozzi, Denise A1 - Darguzyte, Milita A1 - Roemhild, Karolin A1 - Varvarà, Paola A1 - Metselaar, Josbert A1 - Banala, Srinivas A1 - Straub, Marcel A1 - Güver, Nihan A1 - Engelmann, Ulrich M. A1 - Slabu, Ioana A1 - Buhl, Miriam A1 - Leusen, Jan van A1 - Kögerler, Paul A1 - Hermanns-Sachweh, Benita A1 - Schulz, Volkmar A1 - Kiessling, Fabian A1 - Lammers, Twan T1 - Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance JF - Journal of Nanobiotechnology N2 - Superparamagnetic iron oxide nanoparticles (SPION) are extensively used for magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), as well as for magnetic fluid hyperthermia (MFH). We here describe a sequential centrifugation protocol to obtain SPION with well-defined sizes from a polydisperse SPION starting formulation, synthesized using the routinely employed co-precipitation technique. Transmission electron microscopy, dynamic light scattering and nanoparticle tracking analyses show that the SPION fractions obtained upon size-isolation are well-defined and almost monodisperse. MRI, MPI and MFH analyses demonstrate improved imaging and hyperthermia performance for size-isolated SPION as compared to the polydisperse starting mixture, as well as to commercial and clinically used iron oxide nanoparticle formulations, such as Resovist® and Sinerem®. The size-isolation protocol presented here may help to identify SPION with optimal properties for diagnostic, therapeutic and theranostic applications. Y1 - 2020 U6 - http://dx.doi.org/10.1186/s12951-020-0580-1 SN - 1477-3155 VL - 18 IS - Article number 22 SP - 1 EP - 13 PB - Nature Portfolio ER - TY - JOUR A1 - Dachwald, Bernd A1 - Ulamec, Stephan A1 - Postberg, Frank A1 - Sohl, Frank A1 - Vera, Jean-Pierre de A1 - Christoph, Waldmann A1 - Lorenz, Ralph D. A1 - Hellard, Hugo A1 - Biele, Jens A1 - Rettberg, Petra T1 - Key technologies and instrumentation for subsurface exploration of ocean worlds JF - Space Science Reviews N2 - In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter’s moon Europa and Saturn’s moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find life, if it exists. Technologically, such missions are extremely challenging. The required key technologies include power generation, communications, pressure resistance, radiation hardness, corrosion protection, navigation, miniaturization, autonomy, and sterilization and cleaning. Simpler mission concepts involve impactors and penetrators or – in the case of Enceladus – plume-fly-through missions. Y1 - 2020 U6 - http://dx.doi.org/10.1007/s11214-020-00707-5 SN - 1572-9672 N1 - Corresponding author: Bernd Dachwald VL - 216 IS - Art. 83 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Czarnecki, Christian A1 - Dietze, Christian T1 - Gestaltungsorientierte Forschung am Beispiel der Referenzmodellierung in der Telekommunikationsindustrie JF - HMD Praxis der Wirtschaftsinformatik N2 - Am Beispiel der Telekommunikationsindustrie zeigt der Beitrag eine konkrete Ausgestaltung anwendungsorientierter Forschung, die sowohl für die Praxis als auch für die Wissenschaft nutzen- und erkenntnisbringend ist. Forschungsgegenstand sind die Referenzmodelle des Industriegremiums TM Forum, die von vielen Telekommunikationsunternehmen zur Transformation ihrer Strukturen und Systeme genutzt werden. Es wird die langjährige Forschungstätigkeit bei der Weiterentwicklung und Anwendung dieser Referenzmodelle beschrieben. Dabei wird ein konsequent gestaltungsorientierter Forschungsansatz verfolgt. Das Zusammenspiel aus kontinuierlicher Weiterentwicklung in Zusammenarbeit mit einem Industriegremium und der Anwendung in vielfältigen Praxisprojekten führt zu einer erfolgreichen Symbiose aus praktischer Nutzengenerierung sowie wissenschaftlichem Erkenntnisgewinn. Der Beitrag stellt den gewählten Forschungsansatz anhand konkreter Beispiele vor. Darauf basierend werden Empfehlungen und Herausforderungen für eine gestaltungs- und praxisorientierte Forschung diskutiert. KW - Design Science Research KW - Anwendungsorientierter Forschungsansatz KW - Praxisprojekte KW - Referenzmodellierung KW - Enhanced Telecom Operations Map Y1 - 2020 U6 - http://dx.doi.org/10.1365/s40702-020-00594-y SN - 2198-2775 VL - 57 IS - 2 SP - 310 EP - 323 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Czarnecki, Christian T1 - Buchbesprechung : Anwendungsorientierte Wirtschaftsinformatik - Strategische Planung, Entwicklung und Nutzung von Informationssystemen JF - Anwendungen und Konzepte der Wirtschaftsinformatik (AKWI-Journal) Y1 - 2020 U6 - http://dx.doi.org/10.26034/lu.akwi.2020.3264 SN - 2296-4592 N1 - Das besprochene Buch ist im Katalog Plus als E-Book zu finden. Eine ältere Auflage steht im Regal unter der Grundsignatur 21 QGT 55 SP - 101 EP - 101 PB - Technische Hochschule Wildau CY - Wildau ER - TY - JOUR A1 - Cosma, Cosmin A1 - Kessler, Julia A1 - Gebhardt, Andreas A1 - Campbell, Ian A1 - Balc, Nicolae T1 - Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed JF - Materials N2 - To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 μm and just 10% of them hold a diameter less than 21.18 μm. SLM parameters under consideration include laser power up to 200 W, 250–1500 mm/s scanning speed, 80 μm hatch spacing, 35 μm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L. Y1 - 2020 U6 - http://dx.doi.org/10.3390/ma13040905 SN - 1996-1944 VL - 13 IS - 4 SP - 1 EP - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Choi, Chang-Hoon A1 - Felder, Tim A1 - Felder, Jörg A1 - Tellmann, Lutz A1 - Hong, Suk-Min A1 - Wegener, Hans-Peter A1 - Shah, N Jon A1 - Ziemons, Karl T1 - Design, evaluation and comparison of endorectal coils for hybrid MR-PET imaging of the prostate JF - Physics in Medicine & Biology N2 - Prostate cancer is one of the most common cancers among men and its early detection is critical for its successful treatment. The use of multimodal imaging, such as MR-PET, is most advantageous as it is able to provide detailed information about the prostate. However, as the human prostate is flexible and can move into different positions under external conditions, it is important to localise the focused region-of-interest using both MRI and PET under identical circumstances. In this work, we designed five commonly used linear and quadrature radiofrequency surface coils suitable for hybrid MR-PET use in endorectal applications. Due to the endorectal design and the shielded PET insert, the outer face of the coils investigated was curved and the region to be imaged was outside the volume of the coil. The tilting angles of the coils were varied with respect to the main magnetic field direction. This was done to approximate the various positions from which the prostate could be imaged. The transmit efficiencies and safety excitation efficiencies from simulations, together with the signal-to-noise ratios from the MR images were calculated and analysed. Overall, it was found that the overlapped loops driven in quadrature were superior to the other types of coils we tested. In order to determine the effect of the different coil designs on PET, transmission scans were carried out, and it was observed that the differences between attenuation maps with and without the coils were negligible. The findings of this work can provide useful guidance for the integration of such coil designs into MR-PET hybrid systems in the future. Y1 - 2020 U6 - http://dx.doi.org/10.1088/1361-6560/ab87f8 SN - 0031-9155 VL - 65 IS - 11 PB - IOP CY - Bristol ER - TY - CHAP A1 - Chavez Bermudez, Victor Francisco A1 - Wollert, Jörg T1 - Arduino based Framework for Rapid Application Development of a Generic IO-Link interface T2 - Kommunikation und Bildverarbeitung in der Automation N2 - The implementation of IO-Link in the automation industry has increased over the years. Its main advantage is it offers a digital point-to-point plugand-play interface for any type of device or application. This simplifies the communication between devices and increases productivity with its different features like self-parametrization and maintenance. However, its complete potential is not always used. The aim of this paper is to create an Arduino based framework for the development of generic IO-Link devices and increase its implementation for rapid prototyping. By generating the IO device description file (IODD) from a graphical user interface, and further customizable options for the device application, the end-user can intuitively develop generic IO-Link devices. The peculiarity of this framework relies on its simplicity and abstraction which allows to implement any sensor functionality and virtually connect any type of device to an IO-Link master. This work consists of the general overview of the framework, the technical background of its development and a proof of concept which demonstrates the workflow for its implementation. Y1 - 2020 SN - 978-3-662-59895-5 SN - 978-3-662-59894-8 U6 - http://dx.doi.org/10.1007/978-3-662-59895-5_2 N1 - Teil der Buchserie "Technologien für die intelligente Automation" (TIA,volume 12) SP - 21 EP - 33 PB - Springer Vieweg CY - Berlin ER - TY - JOUR A1 - Capitain, Charlotte A1 - Ross-Jones, Jesse A1 - Möhring, Sophie A1 - Tippkötter, Nils T1 - Differential scanning calorimetry for quantification of polymer biodegradability in compost JF - International Biodeterioration & Biodegradation N2 - The objective of this study is the establishment of a differential scanning calorimetry (DSC) based method for online analysis of the biodegradation of polymers in complex environments. Structural changes during biodegradation, such as an increase in brittleness or crystallinity, can be detected by carefully observing characteristic changes in DSC profiles. Until now, DSC profiles have not been used to draw quantitative conclusions about biodegradation. A new method is presented for quantifying the biodegradation using DSC data, whereby the results were validated using two reference methods. The proposed method is applied to evaluate the biodegradation of three polymeric biomaterials: polyhydroxybutyrate (PHB), cellulose acetate (CA) and Organosolv lignin. The method is suitable for the precise quantification of the biodegradability of PHB. For CA and lignin, conclusions regarding their biodegradation can be drawn with lower resolutions. The proposed method is also able to quantify the biodegradation of blends or composite materials, which differentiates it from commonly used degradation detection methods. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.ibiod.2020.104914 SN - 0964-8305 VL - 149 SP - In Press, Article number 104914 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Cacciatore, Pamela A1 - Butenweg, Christoph T1 - Seismic safety of cylindrical granular material steel silos under seismic loading T2 - Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference) Y1 - 2020 SN - 978-3-86359-729-0 SP - 231 EP - 244 ER - TY - JOUR A1 - Butenweg, Christoph A1 - Rosin, Julia T1 - Seismischer Nachweis von Mauerwerksbauten in deutschen Erdbebengebieten JF - Mauerwerk N2 - Mit finanzieller Unterstützung der Deutschen Gesellschaft für Mauerwerks- und Wohnungsbau e.V. (DGfM) und des Deutschen Instituts für Bautechnik in Berlin (DIBt) wurden zwei aufeinander aufbauende Forschungsvorhaben zur Verbesserung der seismischen Nachweise von Mauerwerksbauten in deutschen Erdbebengebieten durchgeführt. Zunächst wurde das seismische Verhalten von drei modernen unbewehrten Mauerwerksgebäuden in der Region Emilia Romagna in Italien während der Erdbebenserie im Jahr 2012 in Kooperation mit der Universität Pavia eingehend untersucht. Aufbauend auf den Erkenntnissen dieser Untersuchungen wurde ein verbessertes seismisches Bemessungskonzept für unbewehrte Mauerwerksbauten erarbeitet. Der Beitrag stellt die wesentlichen Ergebnisse dieser Forschungsarbeiten und deren Eingang in die Normung vor. Y1 - 2020 U6 - http://dx.doi.org/10.1002/dama.202000006 SN - 1437-1022 VL - 24 IS - 2 SP - 108 EP - 113 PB - Wiley CY - Weinheim ER - TY - BOOK A1 - Butenweg, Christoph A1 - Hoffmeister, Benno A1 - Holtschoppen, Britta A1 - Klinkel, Sven A1 - Rosin, Julia A1 - Schmitt, Timo T1 - Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference) Y1 - 2020 SN - 978-3-86359-729-0 PB - Apprimus Verlag CY - Aachen ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Erpicum, Sébastien A1 - Tullis, Blanke P. T1 - Advances in hydraulic structures engineering JF - Journal of Hydraulic Engineering Y1 - 2020 U6 - http://dx.doi.org/10.1061/(ASCE)HY.1943-7900.0001851 SN - 0733-9429 (Druckausgabe) SN - 1943-7900 (Online-Ausgabe) VL - 147 IS - 1 PB - ASCE CY - Reston, Va. ER - TY - JOUR A1 - Bung, Daniel B. A1 - Crookston, Brian M. A1 - Valero, Daniel T1 - Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case JF - Journal of Hydraulic Research Y1 - 2020 U6 - http://dx.doi.org/10.1080/00221686.2020.1844810 SN - 1814-2079 PB - Taylor & Francis CY - London ER -