@article{LowisFergusonPaulssenetal.2021, author = {Lowis, Carsten and Ferguson, Simon and Paulßen, Elisabeth and Hoehr, Cornelia}, title = {Improved Sc-44 production in a siphon-style liquid target on a medical cyclotron}, series = {Applied Radiation and Isotopes}, volume = {172}, journal = {Applied Radiation and Isotopes}, number = {Art. 109675}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0969-8043}, doi = {10.1016/j.apradiso.2021.109675}, year = {2021}, language = {en} } @article{LeiseEsserEichenlaubetal.2021, author = {Leise, Philipp and Eßer, Arved and Eichenlaub, Tobias and Schleiffer, Jean-Eric and Altherr, Lena and Rinderknecht, Stephan and Pelz, Peter F.}, title = {Sustainable system design of electric powertrains - comparison of optimization methods}, series = {Engineering Optimization}, journal = {Engineering Optimization}, publisher = {Taylor \& Francis}, address = {London}, issn = {0305-215X}, doi = {10.1080/0305215X.2021.1928660}, year = {2021}, abstract = {The transition within transportation towards battery electric vehicles can lead to a more sustainable future. To account for the development goal 'climate action' stated by the United Nations, it is mandatory, within the conceptual design phase, to derive energy-efficient system designs. One barrier is the uncertainty of the driving behaviour within the usage phase. This uncertainty is often addressed by using a stochastic synthesis process to derive representative driving cycles and by using cycle-based optimization. To deal with this uncertainty, a new approach based on a stochastic optimization program is presented. This leads to an optimization model that is solved with an exact solver. It is compared to a system design approach based on driving cycles and a genetic algorithm solver. Both approaches are applied to find efficient electric powertrains with fixed-speed and multi-speed transmissions. Hence, the similarities, differences and respective advantages of each optimization procedure are discussed.}, language = {en} } @article{KoehlerRoepkeWolf2021, author = {K{\"o}hler, Klemens and R{\"o}pke, Ren{\´e} and Wolf, Martin R.}, title = {Through a mirror darkly - On the obscurity of teaching goals in game-based learning in IT security}, series = {ISAGA 2019: Simulation Gaming Through Times and Disciplines}, journal = {ISAGA 2019: Simulation Gaming Through Times and Disciplines}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-030-72132-9_6}, pages = {61 -- 73}, year = {2021}, abstract = {Teachers and instructors use very specific language communicating teaching goals. The most widely used frameworks of common reference are the Bloom's Taxonomy and the Revised Bloom's Taxonomy. The latter provides distinction of 209 different teaching goals which are connected to methods. In Competence Developing Games (CDGs - serious games to convey knowledge) and in IT security education, a two- or three level typology exists, reducing possible learning outcomes to awareness, training, and education. This study explores whether this much simpler framework succeeds in achieving the same range of learning outcomes. Method wise a keyword analysis was conducted. The results were threefold: 1. The words used to describe teaching goals in CDGs on IT security education do not reflect the whole range of learning outcomes. 2. The word choice is nevertheless different from common language, indicating an intentional use of language. 3. IT security CDGs use different sets of terms to describe learning outcomes, depending on whether they are awareness, training, or education games. The interpretation of the findings is that the reduction to just three types of CDGs reduces the capacity to communicate and think about learning outcomes and consequently reduces the outcomes that are intentionally achieved.}, language = {en} } @article{KuertenKotliarFuestetal.2021, author = {Kuerten, David and Kotliar, Konstantin and Fuest, Matthias and Walter, Peter and Hollstein, Muriel and Plange, Niklas}, title = {Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study}, series = {International Ophthalmology}, volume = {41}, journal = {International Ophthalmology}, number = {41}, editor = {Neri, Piergiorgio}, publisher = {Springer}, address = {Berlin}, isbn = {1573-2630}, doi = {10.1007/s10792-021-01876-0}, pages = {3109 -- 3119}, year = {2021}, abstract = {Purpose Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry. Methods 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 pro- found hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye. Results Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p \ 0.04 and p \ 0.02 respectively) in-between the hemispheres spheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance. Conclusion Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetri altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.}, language = {en} } @article{Kleefeld2021, author = {Kleefeld, Andreas}, title = {The hot spots conjecture can be false: some numerical examples}, series = {Advances in Computational Mathematics}, volume = {47}, journal = {Advances in Computational Mathematics}, publisher = {Springer}, address = {Dordrecht}, issn = {1019-7168}, doi = {10.1007/s10444-021-09911-5}, year = {2021}, abstract = {The hot spots conjecture is only known to be true for special geometries. This paper shows numerically that the hot spots conjecture can fail to be true for easy to construct bounded domains with one hole. The underlying eigenvalue problem for the Laplace equation with Neumann boundary condition is solved with boundary integral equations yielding a non-linear eigenvalue problem. Its discretization via the boundary element collocation method in combination with the algorithm by Beyn yields highly accurate results both for the first non-zero eigenvalue and its corresponding eigenfunction which is due to superconvergence. Additionally, it can be shown numerically that the ratio between the maximal/minimal value inside the domain and its maximal/minimal value on the boundary can be larger than 1 + 10- 3. Finally, numerical examples for easy to construct domains with up to five holes are provided which fail the hot spots conjecture as well.}, language = {en} } @article{KezerashviliDachwald2021, author = {Kezerashvili, Roman Ya and Dachwald, Bernd}, title = {Preface: Solar sailing: Concepts, technology, and missions II}, series = {Advances in Space Research}, volume = {67}, journal = {Advances in Space Research}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2021.01.037}, pages = {2559 -- 2560}, year = {2021}, language = {en} } @article{KaschSchmidtJahnetal.2021, author = {Kasch, Susanne and Schmidt, Thomas and Jahn, Simon and Eichler, Fabian and Thurn, Laura and Bremen, Sebastian}, title = {L{\"o}sungsans{\"a}tze und Verfahrenskonzepte zum Laserstrahlschmelzen von Glas}, series = {Schweissen und Schneiden}, volume = {73}, journal = {Schweissen und Schneiden}, number = {Heft 1-2}, publisher = {DVS Verlag}, address = {D{\"u}sseldorf}, isbn = {0036-7184}, pages = {32 -- 39}, year = {2021}, language = {de} } @article{KarschuckKaulenPoghossianetal.2021, author = {Karschuck, Tobias and Kaulen, Corinna and Poghossian, Arshak and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef}, title = {Gold nanoparticle-modified capacitive field-effect sensors: Studying the surface density of nanoparticles and coupling of charged polyelectrolyte macromolecules}, series = {Electrochemical Science Advances}, volume = {2}, journal = {Electrochemical Science Advances}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0938-5193}, doi = {10.1002/elsa.202100179}, pages = {10 Seiten}, year = {2021}, abstract = {The coupling of ligand-stabilized gold nanoparticles with field-effect devices offers new possibilities for label-free biosensing. In this work, we study the immobilization of aminooctanethiol-stabilized gold nanoparticles (AuAOTs) on the silicon dioxide surface of a capacitive field-effect sensor. The terminal amino group of the AuAOT is well suited for the functionalization with biomolecules. The attachment of the positively-charged AuAOTs on a capacitive field-effect sensor was detected by direct electrical readout using capacitance-voltage and constant capacitance measurements. With a higher particle density on the sensor surface, the measured signal change was correspondingly more pronounced. The results demonstrate the ability of capacitive field-effect sensors for the non-destructive quantitative validation of nanoparticle immobilization. In addition, the electrostatic binding of the polyanion polystyrene sulfonate to the AuAOT-modified sensor surface was studied as a model system for the label-free detection of charged macromolecules. Most likely, this approach can be transferred to the label-free detection of other charged molecules such as enzymes or antibodies.}, language = {en} } @article{JildehWagnerSchoening2021, author = {Jildeh, Zaid B. and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef}, title = {Sterilization of Objects, Products, and Packaging Surfaces and Their Characterization in Different Fields of Industry: The Status in 2020}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000732}, pages = {27 Seiten}, year = {2021}, abstract = {The treatment method to deactivate viable microorganisms from objects or products is termed sterilization. There are multiple forms of sterilization, each intended to be applied for a specific target, which depends on—but not limited to—the thermal, physical, and chemical stability of that target. Herein, an overview on the currently used sterilization processes in the global market is provided. Different sterilization techniques are grouped under a category that describes the method of treatment: radiation (gamma, electron beam, X-ray, and ultraviolet), thermal (dry and moist heat), and chemical (ethylene oxide, ozone, chlorine dioxide, and hydrogen peroxide). For each sterilization process, the typical process parameters as defined by regulations and the mode of antimicrobial activity are summarized. Finally, the recommended microorganisms that are used as biological indicators to validate sterilization processes in accordance with the rules that are established by various regulatory agencies are summarized.}, language = {en} } @article{JablonskiPoghossianSeverinetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Severin, Robin and Keusgen, Michael and Wege, Christian and Sch{\"o}ning, Michael Josef}, title = {Capacitive Field-Effect Biosensor Studying Adsorption of Tobacco Mosaic Virus Particles}, series = {Micromachines}, volume = {12}, journal = {Micromachines}, number = {1}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/mi12010057}, pages = {Artikel 57}, year = {2021}, abstract = {Plant virus-like particles, and in particular, tobacco mosaic virus (TMV) particles, are increasingly being used in nano- and biotechnology as well as for biochemical sensing purposes as nanoscaffolds for the high-density immobilization of receptor molecules. The sensitive parameters of TMV-assisted biosensors depend, among others, on the density of adsorbed TMV particles on the sensor surface, which is affected by both the adsorption conditions and surface properties of the sensor. In this work, Ta₂O₅-gate field-effect capacitive sensors have been applied for the label-free electrical detection of TMV adsorption. The impact of the TMV concentration on both the sensor signal and the density of TMV particles adsorbed onto the Ta₂O₅-gate surface has been studied systematically by means of field-effect and scanning electron microscopy methods. In addition, the surface density of TMV particles loaded under different incubation times has been investigated. Finally, the field-effect sensor also demonstrates the label-free detection of penicillinase immobilization as model bioreceptor on TMV particles.}, language = {en} } @article{JablonskiPoghossianKeusgenetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Detection of plant virus particles with a capacitive field-effect sensor}, series = {Analytical and Bioanalytical Chemistry}, volume = {413}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer Nature}, address = {Cham}, issn = {1618-2650}, doi = {10.1007/s00216-021-03448-8}, pages = {5669 -- 5678}, year = {2021}, abstract = {Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.}, language = {en} } @article{JablonskiMuenstermannNorketal.2021, author = {Jablonski, Melanie and M{\"u}nstermann, Felix and Nork, Jasmina and Molinnus, Denise and Muschallik, Lukas and Bongaerts, Johannes and Wagner, Torsten and Keusgen, Michael and Siegert, Petra and Sch{\"o}ning, Michael Josef}, title = {Capacitive field-effect biosensor applied for the detection of acetoin in alcoholic beverages and fermentation broths}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000765}, pages = {7 Seiten}, year = {2021}, abstract = {An acetoin biosensor based on a capacitive electrolyte-insulator-semiconductor (EIS) structure modified with the enzyme acetoin reductase, also known as butane-2,3-diol dehydrogenase (Bacillus clausii DSM 8716ᵀ), is applied for acetoin detection in beer, red wine, and fermentation broth samples for the first time. The EIS sensor consists of an Al/p-Si/SiO₂/Ta₂O₅ layer structure with immobilized acetoin reductase on top of the Ta₂O₅ transducer layer by means of crosslinking via glutaraldehyde. The unmodified and enzyme-modified sensors are electrochemically characterized by means of leakage current, capacitance-voltage, and constant capacitance methods, respectively.}, language = {en} } @article{HunkerGossmannRamanetal.2021, author = {Hunker, Jan L. and Gossmann, Matthias and Raman, Aravind Hariharan and Linder, Peter}, title = {Artificial neural networks in cardiac safety assessment: Classification of chemotherapeutic compound effects on hiPSC-derived cardiomyocyte contractility}, series = {Journal of Pharmacological and Toxicological Methods}, volume = {111}, journal = {Journal of Pharmacological and Toxicological Methods}, number = {Article number 107044}, publisher = {Elsevier}, address = {New York}, issn = {1056-8719}, doi = {10.1016/j.vascn.2021.107044}, year = {2021}, language = {en} } @article{HugenrothNeidlinEngelmannetal.2021, author = {Hugenroth, Kristin and Neidlin, Michael and Engelmann, Ulrich M. and Kaufmann, Tim A. S. and Steinseifer, Ulrich and Heilmann, Torsten}, title = {Tipless Transseptal Cannula Concept Combines Improved Hemodynamic Properties and Risk-Reduced Placement: an In Silico Proof-of-Concept}, series = {Artificial Organs}, journal = {Artificial Organs}, number = {Accepted Article}, publisher = {Wiley}, address = {Weinheim}, issn = {1525-1594}, doi = {10.1111/aor.13964}, year = {2021}, language = {en} } @article{HugenrothBorchardtRitteretal.2021, author = {Hugenroth, Kristin and Borchardt, Ralf and Ritter, Philine and Groß‑Hardt, Sascha and Meyns, Bart and Verbelen, Tom and Steinseifer, Ulrich and Kaufmann, Tim A. S. and Engelmann, Ulrich M.}, title = {Optimizing cerebral perfusion and hemodynamics during cardiopulmonary bypass through cannula design combining in silico, in vitro and in vivo input}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {Art. No. 16800}, publisher = {Springer}, address = {Berlin}, issn = {2045-2322}, doi = {10.1038/s41598-021-96397-2}, pages = {1 -- 12}, year = {2021}, abstract = {Cardiopulmonary bypass (CPB) is a standard technique for cardiac surgery, but comes with the risk of severe neurological complications (e.g. stroke) caused by embolisms and/or reduced cerebral perfusion. We report on an aortic cannula prototype design (optiCAN) with helical outflow and jet-splitting dispersion tip that could reduce the risk of embolic events and restores cerebral perfusion to 97.5\% of physiological flow during CPB in vivo, whereas a commercial curved-tip cannula yields 74.6\%. In further in vitro comparison, pressure loss and hemolysis parameters of optiCAN remain unaffected. Results are reproducibly confirmed in silico for an exemplary human aortic anatomy via computational fluid dynamics (CFD) simulations. Based on CFD simulations, we firstly show that optiCAN design improves aortic root washout, which reduces the risk of thromboembolism. Secondly, we identify regions of the aortic intima with increased risk of plaque release by correlating areas of enhanced plaque growth and high wall shear stresses (WSS). From this we propose another easy-to-manufacture cannula design (opti2CAN) that decreases areas burdened by high WSS, while preserving physiological cerebral flow and favorable hemodynamics. With this novel cannula design, we propose a cannulation option to reduce neurological complications and the prevalence of stroke in high-risk patients after CPB.}, language = {en} } @article{HeuermannHarzheimCronenbroeck2021, author = {Heuermann, Holger and Harzheim, Thomas and Cronenbroeck, Tobias}, title = {First SIMO harmonic radar based on the SFCW concept and the HR transfer function}, series = {Remote sensing}, volume = {13}, journal = {Remote sensing}, number = {24}, publisher = {MDPI}, address = {Basel}, issn = {2072-4292}, doi = {10.3390/rs13245088}, pages = {23 Seiten}, year = {2021}, abstract = {This paper presents a new SIMO radar system based on a harmonic radar (HR) stepped frequency continuous wave (SFCW) architecture. Simple tags that can be electronically individually activated and deactivated via a DC control voltage were developed and combined to form an MO array field. This HR operates in the entire 2.45 GHz ISM band for transmitting the illumination signal and receives at twice the stimulus frequency and bandwidth centered around 4.9 GHz. This paper presents the development, the basic theory of a HR system for the characterization of objects placed into the propagation path in-between the radar and the reflectors (similar to a free-space measurement with a network analyzer) as well as first measurements performed by the system. Further detailed measurement series will be made available later on to other researchers to develop AI and machine learning based signal processing routines or synthetic aperture radar algorithms for imaging, object recognition, and feature extraction. For this purpose, the necessary information is published in this paper. It is explained in detail why this SIMO-HR can be an attractive solution augmenting or replacing existing systems for radar measurements in production technology for material under test measurements and as a simplified MIMO system. The novel HR transfer function, which is a basis for researchers and developers for material characterization or imaging algorithms, is introduced and metrologically verified in a well traceable coaxial setup.}, language = {en} } @article{HennesLaumann2021, author = {Hennes, Philipp and Laumann, J{\"o}rg}, title = {Ansatz der Drehbehinderung aus Koppelpfetten mit d{\"u}nnwandigen kaltgeformten Z-Profilen}, series = {Stahlbau}, volume = {90}, journal = {Stahlbau}, number = {3}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.202000104}, pages = {158 -- 168}, year = {2021}, language = {de} } @article{HeinkeKnickerAlbracht2021, author = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten}, title = {Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men}, series = {Journal of Electromyography and Kinesiology}, volume = {62}, journal = {Journal of Electromyography and Kinesiology}, number = {Article 102611}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2021.102611}, year = {2021}, abstract = {Until now the reproducibility of the short latency stretch reflex of the internal rotator muscles of the glenohumeral joint has not been identified. Twenty-three healthy male participants performed three sets of external shoulder rotation stretches with various pre-activation levels on two different dates of measurement to assess test-retest reliability. All stretches were applied with a dynamometer acceleration of 104°/s2 and a velocity of 150°/s. Electromyographical response was measured via surface EMG. Reflex latencies showed a pre-activation effect (ƞ2 = 0,355). ICC ranged from 0,735 to 0,909 indicating an overall "good" relative reliability. SRD 95\% lay between ±7,0 to ±12,3 ms.. The reflex gain showed overall poor test-retest reproducibility. The chosen methodological approach presented a suitable test protocol for shoulder muscles stretch reflex latency evaluation. A proof-of-concept study to validate the presented methodical approach in shoulder involvement including subjects with clinically relevant conditions is recommended.}, language = {en} } @article{HeiligersSchoutetensDachwald2021, author = {Heiligers, Jeannette and Schoutetens, Frederic and Dachwald, Bernd}, title = {Photon-sail equilibria in the alpha centauri system}, series = {Journal of Guidance, Control, and Dynamics}, volume = {44}, journal = {Journal of Guidance, Control, and Dynamics}, number = {5}, issn = {1533-3884}, doi = {10.2514/1.G005446}, pages = {1053 -- 1061}, year = {2021}, language = {en} } @article{HeelDiktaBraekers2021, author = {Heel, Mareike van and Dikta, Gerhard and Braekers, Roel}, title = {Bootstrap based goodness‑of‑fit tests for binary multivariate regression models}, series = {Journal of the Korean Statistical Society}, volume = {51}, journal = {Journal of the Korean Statistical Society}, publisher = {Springer Nature}, address = {Singapur}, issn = {2005-2863 (Online)}, doi = {10.1007/s42952-021-00142-4}, pages = {28 Seiten}, year = {2021}, abstract = {We consider a binary multivariate regression model where the conditional expectation of a binary variable given a higher-dimensional input variable belongs to a parametric family. Based on this, we introduce a model-based bootstrap (MBB) for higher-dimensional input variables. This test can be used to check whether a sequence of independent and identically distributed observations belongs to such a parametric family. The approach is based on the empirical residual process introduced by Stute (Ann Statist 25:613-641, 1997). In contrast to Stute and Zhu's approach (2002) Stute \& Zhu (Scandinavian J Statist 29:535-545, 2002), a transformation is not required. Thus, any problems associated with non-parametric regression estimation are avoided. As a result, the MBB method is much easier for users to implement. To illustrate the power of the MBB based tests, a small simulation study is performed. Compared to the approach of Stute \& Zhu (Scandinavian J Statist 29:535-545, 2002), the simulations indicate a slightly improved power of the MBB based method. Finally, both methods are applied to a real data set.}, language = {en} } @article{HarzheimMuehmelHeuermann2021, author = {Harzheim, Thomas and M{\"u}hmel, Marc and Heuermann, Holger}, title = {A SFCW harmonic radar system for maritime search and rescue using passive and active tags}, series = {International Journal of Microwave and Wireless Technologies}, volume = {13}, journal = {International Journal of Microwave and Wireless Technologies}, number = {Special Issue 7}, publisher = {Cambridge University Press}, address = {Cambridge}, doi = {10.1017/S1759078721000520}, pages = {691 -- 707}, year = {2021}, abstract = {This paper introduces a new maritime search and rescue system based on S-band illumination harmonic radar (HR). Passive and active tags have been developed and tested while attached to life jackets and a small boat. In this demonstration test carried out on the Baltic Sea, the system was able to detect and range the active tags up to a distance of 5800 m using an illumination signal transmit-power of 100 W. Special attention is given to the development, performance, and conceptual differences between passive and active tags used in the system. Guidelines for achieving a high HR dynamic range, including a system components description, are given and a comparison with other HR systems is performed. System integration with a commercial maritime X-band navigation radar is shown to demonstrate a solution for rapid search and rescue response and quick localization.}, language = {en} } @article{HagenkampBlankeDoering2021, author = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Thermoelectric building temperature control: a potential assessment}, series = {International Journal of Energy and Environmental Engineering}, volume = {13}, journal = {International Journal of Energy and Environmental Engineering}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s40095-021-00424-x}, pages = {241 -- 254}, year = {2021}, abstract = {This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.}, language = {en} } @article{HacklNacovKammerlohretal.2021, author = {Hackl, Michael and Nacov, Julia and Kammerlohr, Sandra and Staat, Manfred and Buess, Eduard and Leschinger, Tim and M{\"u}ller, Lars P. and Wegmann, Kilian}, title = {Intratendinous Strain Variations of the Supraspinatus Tendon Depending on Repair Technique: A Biomechanical Analysis Regarding the Cause of Medial Cuff Failure}, series = {The American Journal of Sports Medicine}, volume = {49}, journal = {The American Journal of Sports Medicine}, number = {7}, publisher = {Sage}, address = {London}, issn = {1552-3365}, doi = {10.1177/03635465211006138}, pages = {1847 -- 1853}, year = {2021}, language = {en} } @article{HacklBuessKammerlohretal.2021, author = {Hackl, Michael and Buess, Eduard and Kammerlohr, Sandra and Nacov, Julia and Staat, Manfred and Leschinger, Tim and M{\"u}ller, Lars P. and Wegmann, Kilian}, title = {A "comma sign"-directed subscapularis repair in anterosuperior rotator cuff tears yields biomechanical advantages in a cadaveric model}, series = {The american journal of sports medicine}, volume = {49}, journal = {The american journal of sports medicine}, number = {12}, publisher = {Sage}, address = {London}, issn = {1552-3365}, doi = {10.1177/03635465211031506}, pages = {3212 -- 3217}, year = {2021}, abstract = {Background: Additional stabilization of the "comma sign" in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair. Purpose: This in vitro investigation aimed to investigate the influence of a comma sign-directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair. Study Design: Controlled laboratory study. Methods: A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups. Results: The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred (P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared (P = .596). Conclusion: The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading. Clinical Relevance: The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.}, language = {en} } @article{GoettenHavermannBraunetal.2021, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach}, series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, journal = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2021-1535}, pages = {1 -- 12}, year = {2021}, language = {en} } @article{GoettenFingerHavermannetal.2021, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, M. and Bil, C.}, title = {Full configuration drag estimation of short-to-medium range fixed-wing UAVs and its impact on initial sizing optimization}, series = {CEAS Aeronautical Journal}, volume = {12}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Berlin}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-021-00522-w}, pages = {589 -- 603}, year = {2021}, abstract = {The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used for surveillance, reconnaissance, and search and rescue missions. The aircraft is simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.}, language = {en} } @article{GrundlachBaumannEngelmann2021, author = {Grundlach, Michael and Baumann, Martin and Engelmann, Ulrich M.}, title = {How Multimodal Examinations Can Increase Sustainable Student Gain by Aligning Teaching and Assessment}, series = {Current Directions in Biomedical Engineering}, volume = {7}, journal = {Current Directions in Biomedical Engineering}, number = {7/2}, editor = {D{\"o}ssel, Olaf}, publisher = {De Gruyter}, address = {Berlin}, isbn = {2364-5504}, doi = {10.1515/cdbme-2021-2019}, pages = {73 -- 76}, year = {2021}, abstract = {Modern industry and multi-discipline projects require highly trained individuals with resilient science and engineering back-grounds. Graduates must be able to agilely apply excellent theoretical knowledge in their subject matter as well as essential practical "hands-on" knowledge of diverse working processes to solve complex problems. To meet these demands, university education follows the concept of Constructive Alignment and thus increasingly adopts the teaching of necessary practical skills to the actual industry requirements and assessment routines. However, a systematic approach to coherently align these three central teaching demands is strangely absent from current university curricula. We demonstrate the feasibility of implementing practical assessments in a regular theory-based examination, thus defining the term "blended assessment". We assessed a course for natural science and engineering students pursuing a career in biomedical engineering, and evaluated the benefit of blended assessment exams for students and lecturers. Our controlled study assessed the physiological background of electrocardiograms (ECGs), the practical measurement of ECG curves, and their interpretation of basic pathologic alterations. To study on long time effects, students have been assessed on the topic twice with a time lag of 6 months. Our findings suggest a significant improvement in student gain with respect to practical skills and theoretical knowledge. The results of the reassessments support these outcomes. From the lecturers' point of view, blended assessment complements practical training courses while keeping organizational effort manageable. We consider blended assessment a viable tool for providing an improved student gain, industry-ready education format that should be evaluated and established further to prepare university graduates optimally for their future careers.}, language = {en} } @article{GriegerSchwabedalWendeletal.2021, author = {Grieger, Niklas and Schwabedal, Justus T. C. and Wendel, Stefanie and Ritze, Yvonne and Bialonski, Stephan}, title = {Automated scoring of pre-REM sleep in mice with deep learning}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {Art. 12245}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-021-91286-0}, year = {2021}, abstract = {Reliable automation of the labor-intensive manual task of scoring animal sleep can facilitate the analysis of long-term sleep studies. In recent years, deep-learning-based systems, which learn optimal features from the data, increased scoring accuracies for the classical sleep stages of Wake, REM, and Non-REM. Meanwhile, it has been recognized that the statistics of transitional stages such as pre-REM, found between Non-REM and REM, may hold additional insight into the physiology of sleep and are now under vivid investigation. We propose a classification system based on a simple neural network architecture that scores the classical stages as well as pre-REM sleep in mice. When restricted to the classical stages, the optimized network showed state-of-the-art classification performance with an out-of-sample F1 score of 0.95 in male C57BL/6J mice. When unrestricted, the network showed lower F1 scores on pre-REM (0.5) compared to the classical stages. The result is comparable to previous attempts to score transitional stages in other species such as transition sleep in rats or N1 sleep in humans. Nevertheless, we observed that the sequence of predictions including pre-REM typically transitioned from Non-REM to REM reflecting sleep dynamics observed by human scorers. Our findings provide further evidence for the difficulty of scoring transitional sleep stages, likely because such stages of sleep are under-represented in typical data sets or show large inter-scorer variability. We further provide our source code and an online platform to run predictions with our trained network.}, language = {en} } @article{GorzalkaSchmiedtSchorn2021, author = {Gorzalka, Philip and Schmiedt, Jacob Estevam and Schorn, Christian}, title = {Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery}, series = {Buildings}, volume = {11}, journal = {Buildings}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2075-5309}, doi = {10.3390/buildings11090380}, pages = {15 Seiten}, year = {2021}, abstract = {An approach to automatically generate a dynamic energy simulation model in Modelica for a single existing building is presented. It aims at collecting data about the status quo in the preparation of energy retrofits with low effort and costs. The proposed method starts from a polygon model of the outer building envelope obtained from photogrammetrically generated point clouds. The open-source tools TEASER and AixLib are used for data enrichment and model generation. A case study was conducted on a single-family house. The resulting model can accurately reproduce the internal air temperatures during synthetical heating up and cooling down. Modelled and measured whole building heat transfer coefficients (HTC) agree within a 12\% range. A sensitivity analysis emphasises the importance of accurate window characterisations and justifies the use of a very simplified interior geometry. Uncertainties arising from the use of archetype U-values are estimated by comparing different typologies, with best- and worst-case estimates showing differences in pre-retrofit heat demand of about ±20\% to the average; however, as the assumptions made are permitted by some national standards, the method is already close to practical applicability and opens up a path to quickly estimate possible financial and energy savings after refurbishment.}, language = {en} } @article{Golland2021, author = {Golland, Alexander}, title = {Cookies \& Co. - trotz neuem Gesetz alte Probleme f{\"u}r Website-Betreiber. Anpassung des deutschen Rechts durch das TTDSG an unionsrechtliche Vorgaben zum 1.12.2021}, series = {NWB Steuer- und Wirtschaftsrecht}, volume = {2021}, journal = {NWB Steuer- und Wirtschaftsrecht}, number = {25}, publisher = {NWB-Verlag}, address = {Herne}, issn = {0028-3460}, pages = {1818 -- 1825}, year = {2021}, language = {de} } @article{Golland2021, author = {Golland, Alexander}, title = {Neuregelungen zum Datenschutz: Ein Update f{\"u}r Website-Betreiber. Reform des Telekommunikations- und Telemedienrechts verabschiedet}, series = {NWB Rechnungswesen - BBK}, journal = {NWB Rechnungswesen - BBK}, number = {14}, isbn = {0340-9848}, pages = {672 -- 674}, year = {2021}, language = {de} } @article{Golland2021, author = {Golland, Alexander}, title = {Bußgelder wegen Datenschutzverst{\"o}ßen - Vermeidung und Verteidigung. Deutsche Aufsichtsbeh{\"o}rden setzen seit vergangenem Jahr zunehmend auf Sanktion}, series = {NWB Steuer- und Wirtschaftsrecht}, volume = {36}, journal = {NWB Steuer- und Wirtschaftsrecht}, publisher = {NWB-Verlag}, address = {Herne}, isbn = {0028-3460}, pages = {2678 -- 2687}, year = {2021}, language = {de} } @article{Golland2021, author = {Golland, Alexander}, title = {Das Telekommunikation-Telemedien-Datenschutzgesetz. Cookies und PIMS als Herausforderungen f{\"u}r Website-Betreiber}, series = {NJW Neue Juristische Wochenschrift}, journal = {NJW Neue Juristische Wochenschrift}, number = {31}, editor = {Ewer, Wolfgang and Hamm, Rainer and Karpenstein, Ulrich and Oberth{\"u}r, Nathalie and Herchen, Hilke and Br{\"a}utigam, Peter}, publisher = {Beck}, address = {M{\"u}nchen}, issn = {0341-1915}, pages = {2238 -- 2243}, year = {2021}, language = {de} } @article{Golland2021, author = {Golland, Alexander}, title = {Anforderungen an Transfer Impact Assessments bei Datentransfers in unsichere Drittl{\"a}nder}, series = {DSB Datenschutz-Berater}, volume = {45}, journal = {DSB Datenschutz-Berater}, number = {7-8}, publisher = {DFV Mediengruppe}, address = {Frankfurt a.M.}, isbn = {0170-7256}, pages = {229 -- 231}, year = {2021}, language = {de} } @article{Golland2021, author = {Golland, Alexander}, title = {Datenschutzkonforme Test-, Impf- und Genesungskontrollen in Betrieben der Privatwirtschaft}, series = {DSB Datenschutz-Berater}, volume = {45}, journal = {DSB Datenschutz-Berater}, number = {5}, publisher = {DFV Mediengruppe}, address = {Frankfurt a.M.}, issn = {0170-7256}, pages = {158 -- 160}, year = {2021}, language = {de} } @article{GivanoudiCornelisRasschaertetal.2021, author = {Givanoudi, Stella and Cornelis, Peter and Rasschaert, Geertrui and Wackers, Gideon and Iken, Heiko and Rolka, David and Yongabi, Derick and Robbens, Johan and Sch{\"o}ning, Michael Josef and Heyndrickx, Marc and Wagner, Patrick}, title = {Selective Campylobacter detection and quantification in poultry: A sensor tool for detecting the cause of a common zoonosis at its source}, series = {Sensors and Actuators B: Chemical}, journal = {Sensors and Actuators B: Chemical}, number = {In Press, Journal Pre-proof}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2021.129484}, pages = {Article 129484}, year = {2021}, language = {en} } @article{GermanMikuckiWelchetal.2021, author = {German, Laura and Mikucki, Jill A. and Welch, Susan A. and Welch, Kathleen A. and Lutton, Anthony and Dachwald, Bernd and Kowalski, Julia and Heinen, Dirk and Feldmann, Marco and Francke, Gero and Espe, Clemens and Lyons, W. Berry}, title = {Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry}, series = {International Journal of Environmental Analytical Chemistry}, volume = {101}, journal = {International Journal of Environmental Analytical Chemistry}, number = {15}, publisher = {Taylor \& Francis}, address = {London}, issn = {0306-7319}, doi = {10.1080/03067319.2019.1704750}, pages = {2654 -- 2667}, year = {2021}, abstract = {Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe's sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2-+NO3- from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.}, language = {en} } @article{GeorgStollenwerkReinkensmeieretal.2021, author = {Georg, J{\"o}rg Heiner and Stollenwerk, Dominik and Reinkensmeier, Sebastian and Jungbluth, Christian}, title = {„Smartes" Laden an {\"o}ffentlich zug{\"a}nglichen Lades{\"a}ulen - Teil 1: Quo vadis, Marktdesign?}, series = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, volume = {71}, journal = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, number = {1/2}, publisher = {ETV Energieverlag}, address = {Essen}, isbn = {0720-6240}, issn = {0013-743X}, pages = {64 -- 69}, year = {2021}, language = {de} } @article{Gaigall2021, author = {Gaigall, Daniel}, title = {Test for Changes in the Modeled Solvency Capital Requirement of an Internal Risk Model}, series = {ASTIN Bulletin}, volume = {51}, journal = {ASTIN Bulletin}, number = {3}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, issn = {1783-1350}, doi = {10.1017/asb.2021.20}, pages = {813 -- 837}, year = {2021}, abstract = {In the context of the Solvency II directive, the operation of an internal risk model is a possible way for risk assessment and for the determination of the solvency capital requirement of an insurance company in the European Union. A Monte Carlo procedure is customary to generate a model output. To be compliant with the directive, validation of the internal risk model is conducted on the basis of the model output. For this purpose, we suggest a new test for checking whether there is a significant change in the modeled solvency capital requirement. Asymptotic properties of the test statistic are investigated and a bootstrap approximation is justified. A simulation study investigates the performance of the test in the finite sample case and confirms the theoretical results. The internal risk model and the application of the test is illustrated in a simplified example. The method has more general usage for inference of a broad class of law-invariant and coherent risk measures on the basis of a paired sample.}, language = {en} } @article{Fissabre2021, author = {Fissabre, Anke}, title = {Ein pazifistisches Kriegerdenkmal der Moderne. Das Totenkreuz von Rudolf Schwarz}, series = {In situ: Zeitschrift f{\"u}r Architekturgeschichte}, journal = {In situ: Zeitschrift f{\"u}r Architekturgeschichte}, number = {1}, publisher = {Wernersche Verlagsgesellschaft}, address = {Worms}, issn = {1866-959X}, pages = {127 -- 138}, year = {2021}, language = {de} } @article{Finkenberger2021, author = {Finkenberger, Isabel Maria}, title = {Wohnen als Produktionsgemeinschaftsaufgabe}, series = {Jahrbuch f{\"u}r Christliche Sozialwissenschaften}, journal = {Jahrbuch f{\"u}r Christliche Sozialwissenschaften}, number = {62}, publisher = {Aschendorff}, address = {M{\"u}nster}, issn = {0075-2584}, doi = {10.17879/jcsw-2021-3537}, pages = {31 -- 42}, year = {2021}, abstract = {Wohnen als neue soziale Frage ist mehr als die Produktion neuer Formen von Wohnen und deren architektonischer Gestalt, und auch mehr als nur die Umsetzung sich ver{\"a}ndernder, jedoch individuell formulierter Wohnw{\"u}nsche. Sie spannt sich auf zwischen gesellschafts- und nachhaltigkeitspolitischen, hardcore-kapitalistischen und globalen Rahmenbedingungen, Hardware und Software, Individuum und Gemeinwohl, Konsum und Mitgestaltung. Entscheidend sind die Akteure und die Art und Weise, wie und nach welchen Maßst{\"a}ben sie handeln. Entscheidend ist aber auch, Wohnen sowohl kontextuell wie auch programmatisch neu zu denken und dadurch zu neuen Mischungen, Nachbarschaften und Bewertungskriterien einer Projekt- und Stadtentwicklung zu kommen, die mehr als die Summe seiner Einzelteile wollen - ein gutes Leben f{\"u}r Alle abseits der Frage des Geldbeutels und der sozialen Zugeh{\"o}rigkeit.}, language = {de} } @article{FiedlerOrzadaFloeseretal.2021, author = {Fiedler, Thomas M. and Orzada, Stephan and Fl{\"o}ser, Martina and Rietsch, Stefan H. G. and Quick, Harald H. and Ladd, Mark E. and Bitz, Andreas}, title = {Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T}, series = {NMR in Biomedicine}, volume = {34}, journal = {NMR in Biomedicine}, number = {7}, publisher = {Wiley}, address = {Weinheim}, issn = {0952-3480 (ISSN)}, doi = {10.1002/nbm.4515}, pages = {18 SeitenWiley}, year = {2021}, abstract = {The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit ele- ments. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual obser- vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the devia- tion from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe- cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homoge- neous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study.}, language = {en} } @article{FaganBitzBjoerkmanBurtscheretal.2021, author = {Fagan, Andrew J. and Bitz, Andreas and Bj{\"o}rkman-Burtscher, Isabella M. and Collins, Christopher M. and Kimbrell, Vera and Raaijmakers, Alexander J. E.}, title = {7T MR Safety}, series = {Journal of Magnetic Resonance Imaging (JMRI)}, volume = {53}, journal = {Journal of Magnetic Resonance Imaging (JMRI)}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2586}, doi = {10.1002/jmri.27319}, pages = {333 -- 346}, year = {2021}, language = {en} } @article{ErpicumCrookstonBombardellietal.2021, author = {Erpicum, Sebastien and Crookston, Brian M. and Bombardelli, Fabian and Bung, Daniel Bernhard and Felder, Stefan and Mulligan, Sean and Oertel, Mario and Palermo, Michele}, title = {Hydraulic structures engineering: An evolving science in a changing world}, series = {Wires Water}, volume = {8}, journal = {Wires Water}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {2049-1948}, doi = {10.1002/wat2.1505}, year = {2021}, language = {en} } @article{EngemannCoenenDawaretal.2021, author = {Engemann, Heiko and C{\"o}nen, Patrick and Dawar, Harshal and Du, Shengzhi and Kallweit, Stephan}, title = {A robot-assisted large-scale inspection of wind turbine blades in manufacturing using an autonomous mobile manipulator}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {19}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app11199271}, pages = {1 -- 22}, year = {2021}, abstract = {Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human-robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.}, language = {en} } @article{EngelmannShalabyShashaetal.2021, author = {Engelmann, Ulrich M. and Shalaby, Ahmed and Shasha, Carolyn and Krishnan, Kannan M. and Krause, Hans-Joachim}, title = {Comparative modeling of frequency mixing measurements of magnetic nanoparticles using micromagnetic simulations and Langevin theory}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {5}, publisher = {MDPI}, address = {Basel}, isbn = {2079-4991}, doi = {10.3390/nano11051257}, pages = {1 -- 16}, year = {2021}, abstract = {Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90\% of the frequency mixing magnetic response signal is generated by the largest 10\% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory.}, language = {en} } @article{ElDeibButenwegKlinkel2021, author = {El-Deib, Khaled and Butenweg, Christoph and Klinkel, Sven}, title = {Erdbebennachweis von Mauerwerksbauten mit realistischen Modellen und erh{\"o}hten Verhaltensbeiwerten}, series = {Mauerwerk}, volume = {2021}, journal = {Mauerwerk}, number = {3}, editor = {Jesse, Dirk}, publisher = {Wiley}, address = {Weinheim}, issn = {1437-1022}, doi = {10.1002/dama.202110014}, pages = {110 -- 119}, year = {2021}, abstract = {Die Anwendung des linearen Nachweiskonzepts auf Mauerwerksbauten f{\"u}hrt dazu, dass bereits heute Standsicherheitsnachweise f{\"u}r Geb{\"a}ude mit {\"u}blichen Grundrissen in Gebieten mit moderaten Erdbebeneinwirkungen nicht mehr gef{\"u}hrt werden k{\"o}nnen. Diese Problematik wird sich in Deutschland mit der Einf{\"u}hrung kontinuierlicher probabilistischer Erdbebenkarten weiter versch{\"a}rfen. Aufgrund der Erh{\"o}hung der seismischen Einwirkungen, die sich vielerorts ergibt, ist es erforderlich, die vorhandenen, bislang nicht ber{\"u}cksichtigten Tragf{\"a}higkeitsreserven in nachvollziehbaren Nachweiskonzepten in der Baupraxis verf{\"u}gbar zu machen. Der vorliegende Beitrag stellt ein Konzept f{\"u}r die geb{\"a}udespezifische Ermittlung von erh{\"o}hten Verhaltensbeiwerten vor. Die Verhaltensbeiwerte setzen sich aus drei Anteilen zusammen, mit denen die Lastumverteilung im Grundriss, die Verformungsf{\"a}higkeit und Energiedissipation sowie die {\"U}berfestigkeiten ber{\"u}cksichtigt werden. F{\"u}r die rechnerische Ermittlung dieser drei Anteile wird ein nichtlineares Nachweiskonzept auf Grundlage von Pushover-Analysen vorgeschlagen, in denen die Interaktionen von W{\"a}nden und Geschossdecken durch einen Einspanngrad beschrieben werden. F{\"u}r die Bestimmung der Einspanngrade wird ein nichtlinearer Modellierungsansatz eingef{\"u}hrt, mit dem die Interaktion von W{\"a}nden und Decken abgebildet werden kann. Die Anwendung des Konzepts mit erh{\"o}hten geb{\"a}udespezifischen Verhaltensbeiwerten wird am Beispiel eines Mehrfamilienhauses aus Kalksandsteinen demonstriert. Die Ergebnisse der linearen Nachweise mit erh{\"o}hten Verhaltensbeiwerten f{\"u}r dieses Geb{\"a}ude liegen deutlich n{\"a}her an den Ergebnissen nichtlinearer Nachweise und somit bleiben {\"u}bliche Grundrisse in Erdbebengebieten mit den traditionellen linearen Rechenans{\"a}tzen nachweisbar.}, language = {de} } @article{DickhoffHorikawaFunke2021, author = {Dickhoff, Jens and Horikawa, Atsushi and Funke, Harald}, title = {Hydrogen Combustion - new DLE Combustor Addresses NOx Emissions and Flashback}, series = {Turbomachinery international : the global journal of energy equipment}, volume = {62}, journal = {Turbomachinery international : the global journal of energy equipment}, number = {4}, publisher = {MJH Life Sciences}, address = {Cranbury}, issn = {2767-2328}, pages = {26 -- 27}, year = {2021}, language = {en} } @article{CapitainWagnerHummeletal.2021, author = {Capitain, Charlotte and Wagner, Sebastian and Hummel, Joana and Tippk{\"o}tter, Nils}, title = {Investigation of C-N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion}, series = {Waste and Biomass Valorization}, volume = {12}, journal = {Waste and Biomass Valorization}, publisher = {Springer Nature}, address = {Cham}, issn = {1877-265X}, doi = {10.1007/s12649-020-01110-5}, pages = {1761 -- 1779}, year = {2021}, language = {en} } @article{ButenwegKubalskiElDeibetal.2021, author = {Butenweg, Christoph and Kubalski, Thomas and El-Deib, Khaled and Gellert, Christoph}, title = {Erdbebennachweis von Mauerwerksbauten nach DIN EN 1998-1/NA-2021}, series = {Bautechnik : Zeitschrift f{\"u}r den gesamten Ingenieurbau}, volume = {98}, journal = {Bautechnik : Zeitschrift f{\"u}r den gesamten Ingenieurbau}, number = {11}, editor = {Jesse, Dirk}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-0999}, doi = {10.1002/bate.202100064}, pages = {852 -- 863}, year = {2021}, abstract = {Mauerwerksbauten in Deutschland sind mit Einf{\"u}hrung des nationalen Anwendungsdokuments DIN EN 1998-1/NA auf Grundlage einer neuen probabilistischen Erdbebenkarte nachzuweisen. F{\"u}r erfolgreiche Erdbebennachweise {\"u}blicher Grundrissformen von Mauerwerksbauten stehen in dem zuk{\"u}nftigen Anwendungsdokument neue rechnerische Nachweism{\"o}glichkeiten zur Verf{\"u}gung, mit denen die Tragf{\"a}higkeitsreserven von Mauerwerksbauten in der Baupraxis mit einem {\"u}berschaubaren Aufwand besser in Ansatz gebracht werden k{\"o}nnen. Das Standardrechenverfahren ist weiterhin der kraftbasierte Nachweis, der nun mit h{\"o}heren Verhaltensbeiwerten im Vergleich zur DIN 4149 durchgef{\"u}hrt werden kann. Die h{\"o}heren Verhaltensbeiwerte basieren auf der besseren Ausnutzung der geb{\"a}udespezifischen Verformungsf{\"a}higkeit und Energiedissipation sowie der Lastumverteilung der Schubkr{\"a}fte im Grundriss mit Ansatz von Rahmentragwirkung durch Wand-Deckeninteraktionen. Alternativ dazu kann ein nichtlinearer Nachweis auf Grundlage von Pushover-Analysen zur Anwendung kommen. Vervollst{\"a}ndigt werden die Regelungen f{\"u}r Mauerwerksbauten durch neue Regelungen f{\"u}r nichttragende Innenw{\"a}nde und Außenmauerschalen. Der vorliegende Beitrag stellt die Grundlagen und Hintergr{\"u}nde der neuen rechnerischen Nachweise in DIN EN 1998-1/NA vor und demonstriert deren Anwendung an einem Beispiel aus der Praxis.}, language = {de} }