TY - JOUR A1 - Akimbekov, Nuraly A1 - Digel, Ilya A1 - Abdieva, Gulzhamal A1 - Ualieva, Perizat A1 - Tastambek, Kuanysh T1 - Lignite biosolubilization and bioconversion by Bacillus sp.: the collation of analytical data JF - Biofuels N2 - The vast metabolic potential of microbes in brown coal (lignite) processing and utilization can greatly contribute to innovative approaches to sustainable production of high-value products from coal. In this study, the multi-faceted and complex coal biosolubilization process by Bacillus sp. RKB 7 isolate from the Kazakhstan coal-mining soil is reported, and the derived products are characterized. Lignite solubilization tests performed for surface and suspension cultures testify to the formation of numerous soluble lignite-derived substances. Almost 24% of crude lignite (5% w/v) was solubilized within 14 days under slightly alkaline conditions (pH 8.2). FTIR analysis revealed various functional groups in the obtained biosolubilization products. Analyses of the lignite-derived humic products by UV-Vis and fluorescence spectrometry as well as elemental analysis yielded compatible results indicating the emerging products had a lower molecular weight and degree of aromaticity. Furthermore, XRD and SEM analyses were used to evaluate the biosolubilization processes from mineralogical and microscopic points of view. The findings not only contribute to a deeper understanding of microbe–mineral interactions in coal environments, but also contribute to knowledge of coal biosolubilization and bioconversion with regard to sustainable production of humic substances. The detailed and comprehensive analyses demonstrate the huge biotechnological potential of Bacillus sp. for agricultural productivity and environmental health. KW - humic acid KW - Bacillus sp KW - lignite KW - Biosolubilization Y1 - 2021 SN - 1759-7277 VL - 12 IS - 3 SP - 247 EP - 258 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya A1 - Tastambek, Kuanysh T. A1 - Sherelkhan, Dinara K. A1 - Jussupova, Dariya B. A1 - Altynbay, Nazym P. T1 - Low-rank coal as a source of humic substances for soil amendment and fertility management JF - Agriculture N2 - Humic substances (HS), as important environmental components, are essential to soil health and agricultural sustainability. The usage of low-rank coal (LRC) for energy generation has declined considerably due to the growing popularity of renewable energy sources and gas. However, their potential as soil amendment aimed to maintain soil quality and productivity deserves more recognition. LRC, a highly heterogeneous material in nature, contains large quantities of HS and may effectively help to restore the physicochemical, biological, and ecological functionality of soil. Multiple emerging studies support the view that LRC and its derivatives can positively impact the soil microclimate, nutrient status, and organic matter turnover. Moreover, the phytotoxic effects of some pollutants can be reduced by subsequent LRC application. Broad geographical availability, relatively low cost, and good technical applicability of LRC offer the advantage of easy fulfilling soil amendment and conditioner requirements worldwide. This review analyzes and emphasizes the potential of LRC and its numerous forms/combinations for soil amelioration and crop production. A great benefit would be a systematic investment strategy implicating safe utilization and long-term application of LRC for sustainable agricultural production. KW - soil remediation KW - crop yield KW - soil health KW - soil amendment KW - low-rank coal Y1 - 2021 U6 - http://dx.doi.org/10.3390/agriculture11121261 SN - 2077-0472 N1 - This article belongs to the Special Issue "From Waste to Fertilizer in Sustainable Agriculture" VL - 11 IS - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Albanna, Walid A1 - Conzen, Catharina A1 - Weiss, Miriam A1 - Seyfried, Katharina A1 - Kotliar, Konstantin A1 - Schmidt, Tobias Philip A1 - Kuerten, David A1 - Hescheler, Jürgen A1 - Bruecken, Anne A1 - Schmidt-Trucksäss, Arno A1 - Neumaier, Felix A1 - Wiesmann, Martin A1 - Clusmann, Hans A1 - Schubert, Gerrit Alexander T1 - Non-invasive assessment of neurovascular coupling after aneurysmal subarachnoid hemorrhage: a prospective observational trial using retinal vessel analysis JF - Frontiers in Neurology N2 - Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus. Y1 - 2021 U6 - http://dx.doi.org/10.3389/fneur.2021.690183 SN - 1664-2295 VL - 12 IS - 12 SP - 1 EP - 15 ER - TY - JOUR A1 - Alexyuk, Madina A1 - Bogoyavlenskiy, Andrey A1 - Alexyuk, Pavel A1 - Moldakhanov, Yergali A1 - Berezin, Vladimir A1 - Digel, Ilya T1 - Epipelagic microbiome of the Small Aral Sea: Metagenomic structure and ecological diversity JF - MicrobiologyOpen N2 - Microbial diversity studies regarding the aquatic communities that experienced or are experiencing environmental problems are essential for the comprehension of the remediation dynamics. In this pilot study, we present data on the phylogenetic and ecological structure of microorganisms from epipelagic water samples collected in the Small Aral Sea (SAS). The raw data were generated by massive parallel sequencing using the shotgun approach. As expected, most of the identified DNA sequences belonged to Terrabacteria and Actinobacteria (40% and 37% of the total reads, respectively). The occurrence of Deinococcus-Thermus, Armatimonadetes, Chloroflexi in the epipelagic SAS waters was less anticipated. Surprising was also the detection of sequences, which are characteristic for strict anaerobes—Ignavibacteria, hydrogen-oxidizing bacteria, and archaeal methanogenic species. We suppose that the observed very broad range of phylogenetic and ecological features displayed by the SAS reads demonstrates a more intensive mixing of water masses originating from diverse ecological niches of the Aral-Syr Darya River basin than presumed before. KW - ecological structure KW - metagenomics KW - microbial diversity KW - shotgun sequencing KW - Small Aral Sea Y1 - 2021 U6 - http://dx.doi.org/10.1002/mbo3.1142 SN - 2045-8827 VL - 10 IS - 1 SP - 1 EP - 10 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Ball, Christopher Stephen A1 - Vögele, Stefan A1 - Grajewski, Matthias A1 - Kuckshinrichs, Wilhelm T1 - E-mobility from a multi-actor point of view: Uncertainties and their impacts JF - Technological Forecasting and Social Change Y1 - 2021 SN - 0040-1625 U6 - http://dx.doi.org/10.1016/j.techfore.2021.120925 VL - 170 IS - Art. 120925 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Becht, Alexander A1 - Schollmayer, Curd A1 - Monakhova, Yulia A1 - Holzgrabe, Ulrike T1 - Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis JF - Analytical and Bioanalytical Chemistry N2 - Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer. KW - IR KW - Manufacturer KW - Linear discriminant analysis KW - Principal component analysis Y1 - 2021 U6 - http://dx.doi.org/10.1007/s00216-021-03249-z SN - 1618-2650 VL - 413 SP - 3107 EP - 3118 PB - Springer Nature ER - TY - JOUR A1 - Bergs, Michel A1 - Monakhova, Yulia A1 - Diehl, Bernd W. A1 - Konow, Christopher A1 - Völkering, Georg A1 - Pude, Ralf A1 - Schulze, Margit T1 - Lignins isolated via catalyst-free organosolv pulping from Miscanthus x giganteus, M. sinensis, M. robustus and M. nagara: a comparative study JF - Molecules N2 - As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70% and significantly lower in stem and mixture lignins at around 60% and almost 65%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20% or more (maximum is M. sinensis Sin2 with over 30%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe. Y1 - 2021 U6 - http://dx.doi.org/10.3390/molecules26040842 SN - 1420-3049 N1 - Special Issue Lignin – A Natural Resource with Huge Potential https://www.mdpi.com/journal/molecules/special_issues/lignin_natural VL - 26 IS - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bernecker, Andreas A1 - Boyer, Pierre C. A1 - Gathmann, Christina T1 - The Role of Electoral Incentives for Policy Innovation: Evidence from the US Welfare Reform JF - American Economic Journal: Economic Policy Y1 - 2021 U6 - http://dx.doi.org/10.1257/pol.20190690 SN - 1945-774X VL - 13 IS - 2 SP - 26 EP - 57 PB - American Economic Association CY - Nashville, Tenn. ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics. Y1 - 2021 U6 - http://dx.doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER - TY - JOUR A1 - Bohndick, Carla A1 - Bosse, Elke A1 - Jänsch, Vanessa K. A1 - Barnat, Miriam T1 - How different diversity factors affect the perception of first-year requirements in higher education JF - Frontline Learning Research N2 - In the light of growing university entry rates, higher education institutions not only serve larger numbers of students, but also seek to meet first-year students’ ever more diverse needs. Yet to inform universities how to support the transition to higher education, research only offers limited insights. Current studies tend to either focus on the individual factors that affect student success or they highlight students’ social background and their educational biography in order to examine the achievement of selected, non-traditional groups of students. Both lines of research appear to lack integration and often fail to take organisational diversity into account, such as different types of higher education institutions or degree programmes. For a more comprehensive understanding of student diversity, the present study includes individual, social and organisational factors. To gain insights into their role for the transition to higher education, we examine how the different factors affect the students’ perception of the formal and informal requirements of the first year as more or less difficult to cope with. As the perceived requirements result from both the characteristics of the students and the institutional context, they allow to investigate transition at the interface of the micro and the meso level of higher education. Latent profile analyses revealed that there are no profiles with complex patterns of perception of the first-year requirements, but the identified groups rather differ in the overall level of perceived challenges. Moreover, SEM indicates that the differences in the perception largely depend on the individual factors self-efficacy and volition. Y1 - 2021 U6 - http://dx.doi.org/10.14786/flr.v9i2.667 SN - 2295-3159 VL - 9 IS - 2 SP - 78 EP - 95 PB - EARLI ER - TY - JOUR A1 - Braun, Sebastian A1 - Cheng, Chi-Tsun A1 - Dowey, Steve A1 - Wollert, Jörg T1 - Performance evaluation of skill-based order-assignment in production environments with multi-agent systems JF - IEEE Journal of Emerging and Selected Topics in Industrial Electronics N2 - The fourth industrial revolution introduces disruptive technologies to production environments. One of these technologies are multi-agent systems (MASs), where agents virtualize machines. However, the agent's actual performances in production environments can hardly be estimated as most research has been focusing on isolated projects and specific scenarios. We address this gap by implementing a highly connected and configurable reference model with quantifiable key performance indicators (KPIs) for production scheduling and routing in single-piece workflows. Furthermore, we propose an algorithm to optimize the search of extrema in highly connected distributed systems. The benefits, limits, and drawbacks of MASs and their performances are evaluated extensively by event-based simulations against the introduced model, which acts as a benchmark. Even though the performance of the proposed MAS is, on average, slightly lower than the reference system, the increased flexibility allows it to find new solutions and deliver improved factory-planning outcomes. Our MAS shows an emerging behavior by using flexible production techniques to correct errors and compensate for bottlenecks. This increased flexibility offers substantial improvement potential. The general model in this paper allows the transfer of the results to estimate real systems or other models. KW - cyber-physical production systems KW - event-based simulation KW - multi-agent systems KW - digital factory KW - industrial agents Y1 - 2021 U6 - http://dx.doi.org/10.1109/JESTIE.2021.3108524 SN - 2687-9735 IS - Early Access PB - IEEE CY - New York ER - TY - JOUR A1 - Brockhaus, Moritz K. A1 - Behbahani, Mehdi A1 - Muris, Farina A1 - Jansen, Sebastian V. A1 - Schmitz- Rode, Thomas A1 - Steinseifer, Ulrich A1 - Clauser, Johanna C. T1 - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept JF - Artificial Organs N2 - Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential. Y1 - 2021 U6 - http://dx.doi.org/10.1111/aor.14046 SN - 1525-1594 VL - 45 IS - 12 SP - 1513 EP - 1521 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Burger, René A1 - Rumpf, Jessica A1 - Do, Xuan Tung A1 - Monakhova, Yulia A1 - Diehl, Bernd W. K. A1 - Rehahn, Matthias A1 - Schulze, Margit T1 - Is NMR combined with multivariate regression applicable for the molecular weight determination of randomly cross-linked polymers such as lignin? JF - ACS Omega N2 - The molecular weight properties of lignins are one of the key elements that need to be analyzed for a successful industrial application of these promising biopolymers. In this study, the use of 1H NMR as well as diffusion-ordered spectroscopy (DOSY NMR), combined with multivariate regression methods, was investigated for the determination of the molecular weight (Mw and Mn) and the polydispersity of organosolv lignins (n = 53, Miscanthus x giganteus, Paulownia tomentosa, and Silphium perfoliatum). The suitability of the models was demonstrated by cross validation (CV) as well as by an independent validation set of samples from different biomass origins (beech wood and wheat straw). CV errors of ca. 7–9 and 14–16% were achieved for all parameters with the models from the 1H NMR spectra and the DOSY NMR data, respectively. The prediction errors for the validation samples were in a similar range for the partial least squares model from the 1H NMR data and for a multiple linear regression using the DOSY NMR data. The results indicate the usefulness of NMR measurements combined with multivariate regression methods as a potential alternative to more time-consuming methods such as gel permeation chromatography. Y1 - 2021 U6 - http://dx.doi.org/10.1021/acsomega.1c03574 SN - 2470-1343 VL - 6 IS - 44 SP - 29516 EP - 29524 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Burmistrova, Natalia A. A1 - Soboleva, Polina M. A1 - Monakhova, Yulia T1 - Is infrared spectroscopy combined with multivariate analysis a promising tool for heparin authentication? JF - Journal of Pharmaceutical and Biomedical Analysis N2 - The investigation of the possibility to determine various characteristics of powder heparin (n = 115) was carried out with infrared spectroscopy. The evaluation of heparin samples included several parameters such as purity grade, distributing company, animal source as well as heparin species (i.e. Na-heparin, Ca-heparin, and heparinoids). Multivariate analysis using principal component analysis (PCA), soft independent modelling of class analogy (SIMCA), and partial least squares – discriminant analysis (PLS-DA) were applied for the modelling of spectral data. Different pre-processing methods were applied to IR spectral data; multiplicative scatter correction (MSC) was chosen as the most relevant. Obtained results were confirmed by nuclear magnetic resonance (NMR) spectroscopy. Good predictive ability of this approach demonstrates the potential of IR spectroscopy and chemometrics for screening of heparin quality. This approach, however, is designed as a screening tool and is not considered as a replacement for either of the methods required by USP and FDA. KW - IR spectroscopy KW - Heparin KW - Authenticity KW - Principal component analysis KW - Soft independent modeling of class analogy Y1 - 2021 SN - 0731-7085 U6 - http://dx.doi.org/10.1016/j.jpba.2020.113811 VL - 194 IS - Article number: 113811 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Butenweg, Christoph A1 - Bursi, Oreste S. A1 - Paolacci, Fabrizio A1 - Marinković, Marko A1 - Lanese, Igor A1 - Nardin, Chiara A1 - Quinci, Gianluca ED - Yang, J. T1 - Seismic performance of an industrial multi-storey frame structure with process equipment subjected to shake table testing JF - Engineering Structures N2 - Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of process equipment and multiple and simultaneous release of hazardous substances. Nonetheless, current standards for seismic design of industrial facilities are considered inadequate to guarantee proper safety conditions against exceptional events entailing loss of containment and related consequences. On these premises, the SPIF project -Seismic Performance of Multi-Component Systems in Special Risk Industrial Facilities- was proposed within the framework of the European H2020 SERA funding scheme. In detail, the objective of the SPIF project is the investigation of the seismic behaviour of a representative industrial multi-storey frame structure equipped with complex process components by means of shaking table tests. Along this main vein and in a performance-based design perspective, the issues investigated in depth are the interaction between a primary moment resisting frame (MRF) steel structure and secondary process components that influence the performance of the whole system; and a proper check of floor spectra predictions. The evaluation of experimental data clearly shows a favourable performance of the MRF structure, some weaknesses of local details due to the interaction between floor crossbeams and process components and, finally, the overconservatism of current design standards w.r.t. floor spectra predictions. KW - Multi-storey KW - Frame structure KW - Earthquake KW - Tank KW - Piping Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.engstruct.2021.112681 SN - 0141-0296 VL - 243 IS - 15 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Capitain, Charlotte A1 - Wagner, Sebastian A1 - Hummel, Joana A1 - Tippkötter, Nils T1 - Investigation of C–N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion JF - Waste and Biomass Valorization Y1 - 2021 U6 - http://dx.doi.org/10.1007/s12649-020-01110-5 SN - 1877-265X N1 - Corresponding author: Nils Tippkötter VL - 12 SP - 1761 EP - 1779 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Dickhoff, Jens A1 - Horikawa, Atsushi A1 - Funke, Harald T1 - Hydrogen Combustion - new DLE Combustor Addresses NOx Emissions and Flashback JF - Turbomachinery international : the global journal of energy equipment Y1 - 2021 SN - 2767-2328 SN - 0149-4147 VL - 62 IS - 4 SP - 26 EP - 27 PB - MJH Life Sciences CY - Cranbury ER - TY - JOUR A1 - Engelmann, Ulrich M. A1 - Shalaby, Ahmed A1 - Shasha, Carolyn A1 - Krishnan, Kannan M. A1 - Krause, Hans-Joachim T1 - Comparative modeling of frequency mixing measurements of magnetic nanoparticles using micromagnetic simulations and Langevin theory JF - Nanomaterials N2 - 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. KW - Magnetic nanoparticles KW - Frequency mixing magnetic detection KW - Langevin theory KW - Micromagnetic simulation KW - Nonequilibrium dynamics Y1 - 2021 SN - 2079-4991 U6 - http://dx.doi.org/10.3390/nano11051257 N1 - This article belongs to the Special Issue Applications and Properties of Magnetic Nanoparticles VL - 11 IS - 5 SP - 1 EP - 16 PB - MDPI CY - Basel ER - TY - JOUR A1 - Engemann, Heiko A1 - Cönen, Patrick A1 - Dawar, Harshal A1 - Du, Shengzhi A1 - Kallweit, Stephan T1 - A robot-assisted large-scale inspection of wind turbine blades in manufacturing using an autonomous mobile manipulator JF - Applied Sciences N2 - 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. KW - mobile manipulation KW - large-scale inspection KW - wind turbine production KW - autonomous navigation KW - surface-orthogonal path planning Y1 - 2021 U6 - http://dx.doi.org/10.3390/app11199271 SN - 2076-3417 N1 - Belongs to the Special Issue "Advances in Industrial Robotics and Intelligent Systems" VL - 11 IS - 19 SP - 1 EP - 22 PB - MDPI CY - Basel ER - TY - JOUR A1 - Erpicum, Sebastien A1 - Crookston, Brian M. A1 - Bombardelli, Fabian A1 - Bung, Daniel B. A1 - Felder, Stefan A1 - Mulligan, Sean A1 - Oertel, Mario A1 - Palermo, Michele T1 - Hydraulic structures engineering: An evolving science in a changing world JF - Wires Water Y1 - 2021 U6 - http://dx.doi.org/10.1002/wat2.1505 SN - 2049-1948 VL - 8 IS - 2 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Fagan, Andrew J. A1 - Bitz, Andreas A1 - Björkman-Burtscher, Isabella M. A1 - Collins, Christopher M. A1 - Kimbrell, Vera A1 - Raaijmakers, Alexander J. E. T1 - 7T MR Safety JF - Journal of Magnetic Resonance Imaging (JMRI) Y1 - 2021 U6 - http://dx.doi.org/10.1002/jmri.27319 SN - 1522-2586 VL - 53 IS - 2 SP - 333 EP - 346 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Gaigall, Daniel T1 - Test for Changes in the Modeled Solvency Capital Requirement of an Internal Risk Model JF - ASTIN Bulletin N2 - 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. KW - Bootstrap KW - Empirical process KW - Functional Delta Method KW - Hadamard differentiability KW - Paired sample Y1 - 2021 U6 - http://dx.doi.org/10.1017/asb.2021.20 SN - 1783-1350 VL - 51 IS - 3 SP - 813 EP - 837 PB - Cambridge Univ. Press CY - Cambridge ER - TY - JOUR A1 - German, Laura A1 - Mikucki, Jill A. A1 - Welch, Susan A. A1 - Welch, Kathleen A. A1 - Lutton, Anthony A1 - Dachwald, Bernd A1 - Kowalski, Julia A1 - Heinen, Dirk A1 - Feldmann, Marco A1 - Francke, Gero A1 - Espe, Clemens A1 - Lyons, W. Berry T1 - Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry JF - International Journal of Environmental Analytical Chemistry N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1080/03067319.2019.1704750 SN - 0306-7319 VL - 101 IS - 15 SP - 2654 EP - 2667 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Givanoudi, Stella A1 - Cornelis, Peter A1 - Rasschaert, Geertrui A1 - Wackers, Gideon A1 - Iken, Heiko A1 - Rolka, David A1 - Yongabi, Derick A1 - Robbens, Johan A1 - Schöning, Michael Josef A1 - Heyndrickx, Marc A1 - Wagner, Patrick T1 - Selective Campylobacter detection and quantification in poultry: A sensor tool for detecting the cause of a common zoonosis at its source JF - Sensors and Actuators B: Chemical Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.snb.2021.129484 SN - 0925-4005 IS - In Press, Journal Pre-proof SP - Article 129484 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gorzalka, Philip A1 - Schmiedt, Jacob Estevam A1 - Schorn, Christian T1 - Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery JF - Buildings N2 - 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. KW - Modelica KW - heat transfer coefficient KW - heat demand KW - building energy modelling KW - building energy simulation Y1 - 2021 U6 - http://dx.doi.org/10.3390/buildings11090380 SN - 2075-5309 N1 - This article belongs to the Special Issue "Application of Computer Technology in Buildings" VL - 11 IS - 9 PB - MDPI CY - Basel ER - TY - JOUR A1 - Grieger, Niklas A1 - Schwabedal, Justus T. C. A1 - Wendel, Stefanie A1 - Ritze, Yvonne A1 - Bialonski, Stephan T1 - Automated scoring of pre-REM sleep in mice with deep learning JF - Scientific Reports N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1038/s41598-021-91286-0 SN - 2045-2322 N1 - Corresponding author: Stephan Bialonski VL - 11 IS - Art. 12245 PB - Springer Nature CY - London ER - TY - JOUR A1 - Grundlach, Michael A1 - Baumann, Martin A1 - Engelmann, Ulrich M. ED - Dössel, Olaf T1 - How Multimodal Examinations Can Increase Sustainable Student Gain by Aligning Teaching and Assessment JF - Current Directions in Biomedical Engineering N2 - 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. KW - constructive alignment KW - examination KW - long-term retention KW - multimodal KW - practical learning Y1 - 2021 SN - 2364-5504 U6 - http://dx.doi.org/10.1515/cdbme-2021-2019 VL - 7 IS - 7/2 SP - 73 EP - 76 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Götten, Falk A1 - Finger, Felix A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, M. A1 - Bil, C. T1 - Full configuration drag estimation of short-to-medium range fixed-wing UAVs and its impact on initial sizing optimization JF - CEAS Aeronautical Journal N2 - 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. KW - Parasitic drag KW - UAV KW - CFD KW - Aircraft sizing Y1 - 2021 U6 - http://dx.doi.org/10.1007/s13272-021-00522-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Falk Götten VL - 12 SP - 589 EP - 603 PB - Springer CY - Berlin ER - TY - JOUR A1 - Götten, Falk A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, Matthew A1 - Bil, Cees T1 - Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach JF - SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021 Y1 - 2021 U6 - http://dx.doi.org/10.2514/6.2021-1535 SP - 1 EP - 12 PB - AIAA CY - Reston, Va. ER - TY - JOUR A1 - Hackl, Michael A1 - Buess, Eduard A1 - Kammerlohr, Sandra A1 - Nacov, Julia A1 - Staat, Manfred A1 - Leschinger, Tim A1 - Müller, Lars P. A1 - Wegmann, Kilian T1 - A "comma sign"-directed subscapularis repair in anterosuperior rotator cuff tears yields biomechanical advantages in a cadaveric model JF - The american journal of sports medicine N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1177/03635465211031506 SN - 1552-3365 SN - 0363-5465 VL - 49 IS - 12 SP - 3212 EP - 3217 PB - Sage CY - London ER - TY - JOUR A1 - Hackl, Michael A1 - Nacov, Julia A1 - Kammerlohr, Sandra A1 - Staat, Manfred A1 - Buess, Eduard A1 - Leschinger, Tim A1 - Müller, Lars P. A1 - Wegmann, Kilian T1 - Intratendinous Strain Variations of the Supraspinatus Tendon Depending on Repair Technique: A Biomechanical Analysis Regarding the Cause of Medial Cuff Failure JF - The American Journal of Sports Medicine Y1 - 2021 U6 - http://dx.doi.org/10.1177/03635465211006138 SN - 1552-3365 SN - 0363-5465 VL - 49 IS - 7 SP - 1847 EP - 1853 PB - Sage CY - London ER - TY - JOUR A1 - Hagenkamp, Markus A1 - Blanke, Tobias A1 - Döring, Bernd T1 - Thermoelectric building temperature control: a potential assessment JF - International Journal of Energy and Environmental Engineering N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1007/s40095-021-00424-x N1 - Corresponding author: Markus Hagenkamp VL - 13 SP - 241 EP - 254 PB - Springer CY - Berlin ER - TY - JOUR A1 - Harzheim, Thomas A1 - Mühmel, Marc A1 - Heuermann, Holger T1 - A SFCW harmonic radar system for maritime search and rescue using passive and active tags JF - International Journal of Microwave and Wireless Technologies N2 - 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. KW - Radar KW - microwave measurements KW - harmonic radar KW - harmonic radar tags KW - nonlinear VNA measurements Y1 - 2021 U6 - http://dx.doi.org/10.1017/S1759078721000520 VL - 13 IS - Special Issue 7 SP - 691 EP - 707 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Heel, Mareike van A1 - Dikta, Gerhard A1 - Braekers, Roel T1 - Bootstrap based goodness‑of‑fit tests for binary multivariate regression models JF - Journal of the Korean Statistical Society N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1007/s42952-021-00142-4 SN - 2005-2863 (Online) SN - 1226-3192 (Print) N1 - Corresponding author: Mareike van Heel VL - 51 PB - Springer Nature CY - Singapur ER - TY - JOUR A1 - Heiligers, Jeannette A1 - Schoutetens, Frederic A1 - Dachwald, Bernd T1 - Photon-sail equilibria in the alpha centauri system JF - Journal of Guidance, Control, and Dynamics Y1 - 2021 U6 - http://dx.doi.org/10.2514/1.G005446 SN - 1533-3884 SN - 0731-5090 SN - 0162-3192 VL - 44 IS - 5 SP - 1053 EP - 1061 ER - TY - JOUR A1 - Heinke, Lars N. A1 - Knicker, Axel J. A1 - Albracht, Kirsten T1 - Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men JF - Journal of Electromyography and Kinesiology N2 - 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. KW - stretch reflex KW - shoulder KW - test-retest reliability KW - intraclass correlation coefficient KW - standard error of measurement Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.jelekin.2021.102611 SN - 1050-6411 VL - 62 IS - Article 102611 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Heuermann, Holger A1 - Harzheim, Thomas A1 - Cronenbroeck, Tobias T1 - First SIMO harmonic radar based on the SFCW concept and the HR transfer function JF - Remote sensing N2 - 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. KW - MUT measurement; scanner KW - transponder KW - SFCW KW - harmonic radar KW - nonlinear radar Y1 - 2021 U6 - http://dx.doi.org/10.3390/rs13245088 SN - 2072-4292 N1 - This article belongs to the Special Issue "Nonlinear Junction Detection and Harmonic Radar" VL - 13 IS - 24 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hugenroth, Kristin A1 - Borchardt, Ralf A1 - Ritter, Philine A1 - Groß‑Hardt, Sascha A1 - Meyns, Bart A1 - Verbelen, Tom A1 - Steinseifer, Ulrich A1 - Kaufmann, Tim A. S. A1 - Engelmann, Ulrich M. T1 - Optimizing cerebral perfusion and hemodynamics during cardiopulmonary bypass through cannula design combining in silico, in vitro and in vivo input JF - Scientific Reports N2 - 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. Y1 - 2021 U6 - http://dx.doi.org/10.1038/s41598-021-96397-2 SN - 2045-2322 VL - 11 IS - Art. No. 16800 SP - 1 EP - 12 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hugenroth, Kristin A1 - Neidlin, Michael A1 - Engelmann, Ulrich M. A1 - Kaufmann, Tim A. S. A1 - Steinseifer, Ulrich A1 - Heilmann, Torsten T1 - Tipless Transseptal Cannula Concept Combines Improved Hemodynamic Properties and Risk‐Reduced Placement: an In Silico Proof‐of‐Concept JF - Artificial Organs Y1 - 2021 U6 - http://dx.doi.org/10.1111/aor.13964 SN - 1525-1594 IS - Accepted Article PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Hunker, Jan L. A1 - Gossmann, Matthias A1 - Raman, Aravind Hariharan A1 - Linder, Peter T1 - Artificial neural networks in cardiac safety assessment: Classification of chemotherapeutic compound effects on hiPSC-derived cardiomyocyte contractility JF - Journal of Pharmacological and Toxicological Methods Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.vascn.2021.107044 SN - 1056-8719 VL - 111 IS - Article number 107044 PB - Elsevier CY - New York ER - TY - JOUR A1 - Jablonski, Melanie A1 - Münstermann, Felix A1 - Nork, Jasmina A1 - Molinnus, Denise A1 - Muschallik, Lukas A1 - Bongaerts, Johannes A1 - Wagner, Torsten A1 - Keusgen, Michael A1 - Siegert, Petra A1 - Schöning, Michael Josef T1 - Capacitive field‐effect biosensor applied for the detection of acetoin in alcoholic beverages and fermentation broths JF - physica status solidi (a) applications and materials science N2 - 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. KW - acetoin KW - acetoin reductase KW - alcoholic beverages KW - biosensors KW - capacitive field-effect sensors Y1 - 2021 U6 - http://dx.doi.org/10.1002/pssa.202000765 SN - 1862-6319 VL - 218 IS - 13 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jablonski, Melanie A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Detection of plant virus particles with a capacitive field-effect sensor JF - Analytical and Bioanalytical Chemistry N2 - 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. KW - Plant virus KW - Capacitive field-effect sensor KW - Tobacco mosaic virus (TMV) KW - Label-free detection KW - Zeta potential Y1 - 2021 U6 - http://dx.doi.org/10.1007/s00216-021-03448-8 SN - 1618-2650 N1 - Corresponding authors: Arshak Poghossian & Michael J. Schöning VL - 413 SP - 5669 EP - 5678 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Jablonski, Melanie A1 - Poghossian, Arshak A1 - Severin, Robin A1 - Keusgen, Michael A1 - Wege, Christian A1 - Schöning, Michael Josef T1 - Capacitive Field-Effect Biosensor Studying Adsorption of Tobacco Mosaic Virus Particles JF - Micromachines N2 - 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. KW - capacitive field-effect sensor KW - plant virus detection KW - tobacco mosaic virus (TMV) KW - TMV adsorption KW - Ta₂O₅ gate Y1 - 2021 U6 - http://dx.doi.org/10.3390/mi12010057 VL - 12 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Jildeh, Zaid B. A1 - Wagner, Patrick H. A1 - Schöning, Michael Josef T1 - Sterilization of Objects, Products, and Packaging Surfaces and Their Characterization in Different Fields of Industry: The Status in 2020 JF - physica status solidi (a) applications and materials science N2 - 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. KW - bioburdens KW - sterility tests KW - sterilization efficacy KW - sterilization methods KW - validation methods Y1 - 2021 U6 - http://dx.doi.org/10.1002/pssa.202000732 SN - 1862-6319 N1 - Corresponding author: Michael J. Schöning VL - 218 IS - 13 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Karschuck, Tobias A1 - Kaulen, Corinna A1 - Poghossian, Arshak A1 - Wagner, Patrick H. A1 - Schöning, Michael Josef T1 - Gold nanoparticle-modified capacitive field-effect sensors: Studying the surface density of nanoparticles and coupling of charged polyelectrolyte macromolecules JF - Electrochemical Science Advances N2 - 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. KW - polystyrene sulfonate KW - gold nanoparticles KW - field-effect sensor KW - detection of charged macromolecules KW - capacitive EIS sensor Y1 - 2021 U6 - http://dx.doi.org/10.1002/elsa.202100179 SN - 0938-5193 VL - 2 IS - 5 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kezerashvili, Roman Ya A1 - Dachwald, Bernd T1 - Preface: Solar sailing: Concepts, technology, and missions II JF - Advances in Space Research Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.asr.2021.01.037 SN - 0273-1177 VL - 67 IS - 9 SP - 2559 EP - 2560 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kuerten, David A1 - Kotliar, Konstantin A1 - Fuest, Matthias A1 - Walter, Peter A1 - Hollstein, Muriel A1 - Plange, Niklas ED - Neri, Piergiorgio T1 - Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study JF - International Ophthalmology N2 - 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. KW - Glaucoma KW - Visual field asymmetry KW - Ocular blood flow KW - RVA KW - Vascular response Y1 - 2021 SN - 1573-2630 U6 - http://dx.doi.org/10.1007/s10792-021-01876-0 VL - 41 IS - 41 SP - 3109 EP - 3119 PB - Springer CY - Berlin ER - TY - JOUR A1 - Köhler, Klemens A1 - Röpke, René A1 - Wolf, Martin T1 - Through a mirror darkly – On the obscurity of teaching goals in game-based learning in IT security JF - ISAGA 2019: Simulation Gaming Through Times and Disciplines N2 - 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. KW - IT security education KW - Competence Developing Games KW - Game-based learning KW - Keyword analysis KW - Bloom’s Taxonomy Y1 - 2021 U6 - http://dx.doi.org/10.1007/978-3-030-72132-9_6 N1 - ISAGA 2019 - International Simulation and Gaming Association Conference. 26-30 August 2019. Warsaw, Poland. Part of the Lecture Notes in Computer Science book series (LNCS, volume 11988) SP - 61 EP - 73 PB - Springer CY - Cham ER - TY - JOUR A1 - Leise, Philipp A1 - Eßer, Arved A1 - Eichenlaub, Tobias A1 - Schleiffer, Jean-Eric A1 - Altherr, Lena A1 - Rinderknecht, Stephan A1 - Pelz, Peter F. T1 - Sustainable system design of electric powertrains - comparison of optimization methods JF - Engineering Optimization N2 - 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. KW - Powertrain KW - stochastic optimization KW - global optimization KW - genetic algorithm Y1 - 2021 U6 - http://dx.doi.org/10.1080/0305215X.2021.1928660 SN - 0305-215X PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Lowis, Carsten A1 - Ferguson, Simon A1 - Paulßen, Elisabeth A1 - Hoehr, Cornelia T1 - Improved Sc-44 production in a siphon-style liquid target on a medical cyclotron JF - Applied Radiation and Isotopes Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.apradiso.2021.109675 SN - 0969-8043 VL - 172 IS - Art. 109675 PB - Elsevier CY - Amsterdam ER -