@article{MathiasSchmiedGrossmann2020, author = {Mathias, Selvine George and Schmied, Sebastian and Großmann, Daniel}, title = {A framework for monitoring multiple databases in industries using OPC UA}, volume = {12}, journal = {Journal of Ambient Intelligence and Humanized Computing}, number = {1}, publisher = {Springer}, address = {Berlin}, issn = {1868-5145}, doi = {https://doi.org/10.1007/s12652-020-02850-x}, pages = {47 -- 56}, year = {2020}, abstract = {Database management and monitoring is an inseparable part of any industry. A uniform scheme of monitoring relational databases without explicit user access to database servers is not much explored outside the database environment. In this paper, we present an information distribution scheme related to databases using Open Platform Communication Unified Architecture (OPC UA) servers to clients when multiple databases are involved in a factory. The aim is for external, but relevant clients, to be able to monitor this information mesh independent of explicit access to user schemas. A methodology to dispense data from, as well as check changes in databases using SQL queries and events is outlined and implemented using OPC UA servers. The structure can be used as a remote viewing application for multiple databases in one address space of an OPC UA server.}, language = {en} } @article{LenkGleirscherNestleretal.2020, author = {Lenk, Kerstin and Gleirscher, Mario and Nestler, Simon and R{\"o}diger, Stefan and Petersen, Tom and Loebel, Jens-Martin}, title = {Lage und Zukunft des wissenschaftlichen Nachwuchses}, volume = {43}, journal = {Informatik Spektrum}, subtitle = {eine Stellungnahme des Beirats des Wissenschaftlichen Nachwuchses (WiN) der Gesellschaft f{\"u}r Informatik (GI e.V.)}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {1432-122X}, doi = {https://doi.org/10.1007/s00287-020-01250-x}, pages = {94 -- 102}, year = {2020}, abstract = {Der Beirat des Wissenschaftlichen Nachwuchses (GI-WiN) der Gesellschaft f{\"u}r Informatik (GI) fordert und empfiehlt Maßnahmen zur Verbesserung der Lage von Promovierenden sowie Postdoktoranden und Postdoktorandinnen in der Informatik und anderen Technikwissenschaften. Promovierende sowie Postdoktoranden und Postdoktorandinnen im Bereich der Informatik sind in zunehmendem Maß von den komplexen strukturellen und finanziellen Problematiken des Wissenschafts- und Lehrbetriebs betroffen. Der Flaschenhals auf dem Weg zur Professur f{\"u}hrt in der akademischen Karriere zu prek{\"a}ren Besch{\"a}ftigungsverh{\"a}ltnissen. Die schwierige Vereinbarkeit von Familie und akademischer Karriere erzeugt eine zus{\"a}tzliche Benachteiligung, insbesondere von Wissenschaftlerinnen. Mangelnde Qualit{\"a}tssicherung sowie fehlende zuverl{\"a}ssige und vertrauensw{\"u}rdige Prozesse erschweren die Aufdeckung und Aufarbeitung von Konflikten w{\"a}hrend der Promotionsphase und der Zeit des Postdoktorats. Fehlanreize im akademischen System beeintr{\"a}chtigen eine direkte, intensive und regelm{\"a}ßige Betreuung der jungen Akademiker durch Professorinnen und Professoren. Eine zeitnahe Bew{\"a}ltigung der in diesem Beitrag skizzierten Herausforderungen ist f{\"u}r den zuk{\"u}nftigen Fortbestand von Forschungseinrichtungen an Hochschulen sowie f{\"u}r eine erfolgreiche Fortf{\"u}hrung des Prinzips der Bestenauslese von zentraler Bedeutung. Vor dem Hintergrund von bereits geplanten und durchgef{\"u}hrten Maßnahmen zur St{\"a}rkung des wissenschaftlichen Nachwuchses skizziert dieser Beitrag konkrete Maßnahmen; einerseits zur Verbesserung der Betreuung w{\"a}hrend der Promotionsphase und andererseits zur Strukturierung und Schaffung weiterer Karrierewege.}, language = {de} } @article{LiuContiBhogarajuetal.2020, author = {Liu, E and Conti, Fosca and Bhogaraju, Sri Krishna and Signorini, Raffaella and Pedron, Danilo and Wunderle, Bernhard and Elger, Gordon}, title = {Thermomechanical stress in GaN-LEDs soldered onto Cu substrates studied using finite element method and Raman spectroscopy}, volume = {51}, journal = {Journal of Raman Spectroscopy}, number = {10}, publisher = {Wiley}, address = {Chichester}, issn = {1097-4555}, doi = {https://doi.org/10.1002/jrs.5947}, pages = {2083 -- 2094}, year = {2020}, abstract = {Local thermomechanical stress can cause failures in semiconductor packages during long-time operation under harsh environmental conditions. This study helps to explain the packaging-induced stress in blue GaN-LEDs soldered onto copper substrates using AuSn alloy as lead-free interconnect material. Based on the finite element method, a virtual prototype is developed to simulate the thermomechanical behavior and stress in the LED and in the complete LED/AuSn/Cu assembly considering plastic and viscoplastic strain. The investigations were performed by varying the temperature between -50°C and 180°C. To validate the model, the simulation results are compared to experimental data collected with Raman spectroscopy. Studies of the urn:x-wiley:03770486:media:jrs5947:jrs5947-math-0003 phonon mode of GaN semiconductor are elaborated to understand the induced thermomechanical stress. The model enables evaluation of the stress in the interfaces of the assembly, which otherwise cannot be accessed by measurements. It serves to predict how assemblies would perform, before committing resources to build a physical prototype.}, language = {en} } @article{BorgmannRiessMeintrupetal.2020, author = {Borgmann, Stefan and Rieß, Beate and Meintrup, David and Klare, Ingo and Werner, Guido}, title = {Long-Lasting Decrease of the Acquisition of Enterococcus faecium and Gram-Negative Bacteria Producing Extended Spectrum Beta-Lactamase (ESBL) by Transient Application of Probiotics}, volume = {17}, pages = {6100}, journal = {International Journal of Environmental Research and Public Health (IJERPH)}, number = {17}, publisher = {MDPI}, address = {Basel}, issn = {1660-4601}, doi = {https://doi.org/10.3390/ijerph17176100}, year = {2020}, abstract = {Previously it was shown that application of probiotics stopped the acquisition of vancomycin-resistant Enterococcus faecium (VRE) by patients in an early rehabilitation ward. Once the application of probiotics ended, we examined whether acquisition of VRE reoccurred. Furthermore, we examined whether probiotics altered prevalence of vancomycin-susceptible E. faecium (VSE) and Gram-negative bacteria, which produce extended spectrum beta-lactamase (ESBL). Although probiotic application ceased in April 2018, VRE-colonized patients rarely presented on that ward until 2019. Probiotic treatment also resulted in a decreased number of patients with VSE and ESBL. While decreased incidence of VRE occurred immediately, decreased VSE and ESBL numbers occurred months later. A probiotic-mediated decrease of VSE and ESBL incidence cannot be explained when assuming bacterial transmission exclusively as a linear cause and effect event. The decrease is better understood by considering bacterial transmissions to be stochastic events, which depend on various driving forces similar to an electric current. We hypothesize that VRE, VSE and ESBL uptake by patients and by staff members mutually reinforced each other, leading staff members to form a bacterial reservoir, similar to a condenser that stores electrical energy. Probiotic treatment then inhibited regeneration of that store, resulting in a breakdown of the driving force.}, language = {en} } @article{CazaresGarciaContrerasPerezVelazquez2020, author = {Cazares, Adri{\´a}n and Garc{\´i}a-Contreras, Rodolfo and P{\´e}rez-Vel{\´a}zquez, Judith}, title = {Eco-evolutionary effects of bacterial cooperation on phage therapy}, volume = {11}, pages = {590294}, journal = {Frontiers in Microbiology}, subtitle = {an unknown risk?}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-302X}, doi = {https://doi.org/10.3389/fmicb.2020.590294}, year = {2020}, abstract = {If there is something we have learned from the antibiotic era, it is that indiscriminate use of a therapeutic agent without a clear understanding of its long-term evolutionary impact can have enormous health repercussions. This knowledge is particularly relevant when the therapeutic agents are remarkably adaptable and diverse biological entities capable of a plethora of interactions, most of which remain largely unexplored. Although phage therapy (PT) undoubtedly holds the potential to save lives, its current efficacy in case studies recalls the golden era of antibiotics, when these compounds were highly effective and the possibility of them becoming ineffective seemed remote. Safe PT schemes depend on our understanding of how phages interact with, and evolve in, highly complex environments. Here, we summarize and review emerging evidence in a commonly overlooked theme in PT: bacteria-phage interactions. In particular, we discuss the influence of quorum sensing (QS) on phage susceptibility, the consequent role of phages in modulating bacterial cooperation, and the potential implications of this relationship in PT, including how we can use this knowledge to inform PT strategies. We highlight that the influence of QS on phage susceptibility seems to be widespread but can have contrasting outcomes depending on the bacterial host, underscoring the need to thoroughly characterize this link in various bacterial models. Furthermore, we encourage researchers to exploit competition experiments, experimental evolution, and mathematical modeling to explore this relationship further in relevant infection models. Finally, we emphasize that long-term PT success requires research on phage ecology and evolution to inform the design of optimal therapeutic schemes.}, language = {en} } @article{HechelmannSeeversOtteetal.2020, author = {Hechelmann, Ron-Hendrik and Seevers, Jan-Peter and Otte, Alexander and Sponer, Jan and Stark, Matthias}, title = {Renewable Energy Integration for Steam Supply of Industrial Processes: A Food Processing Case Study}, volume = {13}, pages = {2532}, journal = {Energies}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en13102532}, year = {2020}, abstract = {This study highlights the CO2,e -emission reduction potentials and related economic consequences for changing steam generation from fossil to renewable. Seven different utility concepts are developed, including a steam accumulator for load management. Peculiarities for the integration of biogas boilers, biomass-fuelled boilers, electrode steam boilers, biomethane-fuelled solid oxide fuel cells, micro gas turbine, solar energy systems, heat pumps and steam accumulators into a steam system with fluctuating steam demand are explained and the energy balance based models for the simulation study are described. The characteristics of batch processes, start up times and part load efficiency are considered via an annual dynamic simulation. Based on a detailed process analysis and dimensioning of the utilities and the accumulator a comprehensive simulation study is conducted for a pet food processing company having an average steam demand of 18,000 MWh at around 9 bar and 3 t/h. The results show that the highest CO2,e -emissions reduction of up to 63\% is achieved by the transition to a solid biomass-fuelled boiler system. This leads to an increase of the operating costs by 27.8\%}, language = {en} } @article{BaerWagenederSolkaetal.2020, author = {B{\"a}r, Katharina and Wageneder, Stefanie and Solka, Felix and Saidi, Abdessamad and Z{\"o}rner, Wilfried}, title = {Flexibility Potential of Photovoltaic Power Plant and Biogas Plant Hybrid Systems in the Distribution Grid}, volume = {43}, journal = {Chemical Engineering \& Technology}, number = {8}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.202000025}, pages = {1571 -- 1577}, year = {2020}, abstract = {The potential of combining biogas and photovoltaic (PV) power plants in hybrid systems in the German distribution grid is analyzed. The focus of the present research is on balancing the intermittent power supply from PV power plants with the controllable power production of combined heat and power (CHP) units of biogas plants within a period of seconds. To achieve an increase of the total energy feed-in of biogas and PV power plants to the electricity grid, a biogas plant energy management system is described. System parameters, such as the variable feed-in of PV power plants or power ramps of the start-up process of controllable biogas plant CHP unit, are described and adapted to the global installed capacity of PV power plant and biogas plants in the German distribution grid.}, language = {en} } @article{ContiSaidiGoldbrunner2020, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Numeric Simulation-Based Analysis of the Mixing Process in Anaerobic Digesters of Biogas Plants}, volume = {43}, journal = {Chemical Engineering \& Technology}, number = {8}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201900650}, pages = {1522 -- 1529}, year = {2020}, abstract = {Stirring systems with two rotational three-bladed propellers were analyzed using computational fluid dynamics. The propellers are located at three heights and seven angles in a tank with 9 m radius. The fluid was characterized by non-Newtonian rheology and simulated by applying the k-ε turbulence model and the standard k-ω model. Reynolds numbers were estimated. High fluid speeds were obtained with the propellers located at a height of 2 m and oriented at 90° with respect to the tank radius. In the top regions of the tank, the fluid velocity was generally less intense and less affected by the angle setting. The configurations identified as good mixing systems showed power consumptions broadly distributed around 30 kW.}, language = {en} } @article{FrisonForsterWintersbergeretal.2020, author = {Frison, Anna-Katharina and Forster, Yannick and Wintersberger, Philipp and Geisel, Viktoria and Riener, Andreas}, title = {Where We Come from and Where We Are Going: A Systematic Review of Human Factors Research in Driving Automation}, volume = {10}, pages = {8914}, journal = {Applied Sciences}, number = {24}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {https://doi.org/10.3390/app10248914}, year = {2020}, abstract = {During the last decade, research has brought forth a large amount of studies that investigated driving automation from a human factor perspective. Due to the multitude of possibilities for the study design with regard to the investigated constructs, data collection methods, and evaluated parameters, at present, the pool of findings is heterogeneous and nontransparent. This literature review applied a structured approach, where five reviewers investigated n = 161 scientific papers of relevant journals and conferences focusing on driving automation between 2010 and 2018. The aim was to present an overview of the status quo of existing methodological approaches and investigated constructs to help scientists in conducting research with established methods and advanced study setups. Results show that most studies focused on safety aspects, followed by trust and acceptance, which were mainly collected through self-report measures. Driving/Take-Over performance also marked a significant portion of the published papers; however, a wide range of different parameters were investigated by researchers. Based on our insights, we propose a set of recommendations for future studies. Amongst others, this includes validation of existing results on real roads, studying long-term effects on trust and acceptance (and of course other constructs), or triangulation of self-reported and behavioral data. We furthermore emphasize the need to establish a standardized set of parameters for recurring use cases to increase comparability. To assure a holistic contemplation of automated driving, we moreover encourage researchers to investigate other constructs that go beyond safety.}, language = {en} } @article{BanoHegnerHeinrichetal.2020, author = {Bano, Tayyaba and Hegner, Franziska and Heinrich, Martin and Schwarze, R{\"u}diger}, title = {Investigation of Fluid-Structure Interaction Induced Bending for Elastic Flaps in a Cross Flow}, volume = {10}, pages = {6177}, journal = {Applied Sciences}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {https://doi.org/10.3390/app10186177}, year = {2020}, abstract = {With the recent increase in the design of light and flexible structures, numerical investigations of fluid and structure together play a significant role in most engineering applications. Therefore, the current study presents an examination of fluid-structure interaction involving flexible structures. The problem is numerically solved by a commercial software ANSYS-Workbench. Two-way coupled three-dimensional transient simulations are carried out for the flexible flaps of different thicknesses in glycerin for a laminar flow and Reynolds number ranging from 3 < Re < 12. The bending line of the flaps is compared with experimental data for different alignments of the flaps relative to the fluid flow. The study reports the computation of the maximum tip-deflection and deformation of flaps fixed at the bottom and mounted normal to the flow. Additionally, drag coefficients for flexible flaps are computed and flow regimes in the wake of the flaps are presented. As well, the study gives an understanding on how the fluid response changes as the structure deforms and the model is appropriate to predict the behavior of thick and comparatively thinner flaps. The results are sufficiently encouraging to consider the present model for analyzing turbulent flow processes against flexible objects.}, language = {en} } @article{ContiSaidiGoldbrunner2020, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Evaluation Criteria and Benefit Analysis of Mixing Process in Anaerobic Digesters of Biogas Plants}, volume = {24}, journal = {Environmental and Climate Technologies}, number = {3}, publisher = {De Gruyter Poland}, address = {Warsaw}, issn = {2255-8837}, doi = {https://doi.org/10.2478/rtuect-2020-0105}, pages = {305 -- 317}, year = {2020}, abstract = {A valid method to evaluate decisions of a project proposal is the so-called cost-benefit analysis. Criteria are selected and properly weighted to determine if the project is effective and feasible. The present research study is focused on methodical selection of design parameters to install two propeller mixers inside anaerobic digesters of biogas plants. A cylindrical tank of 1400 m3 was considered. For the model-based optimisation, the substrate was considered as a non-Newtonian fluid with a density of 1090 kg/m3. The Oswald-de Waele power-law model was selected to account for the rheological behaviour of the fluid. Installation parameters of the mixers were rotational angles and heights of the shafts of the two propellers. A computational model was developed to simulate the fluid dynamics depending on the mixing process inside the tank. Several configurations were analysed according to evaluating criteria such as the value of the fluid velocity, its distribution along the three spatial dimensions, and the power consumption to rotate the mixers. The maximum fluid velocity and minimum power consumption were observed when the propellers are located at intermediate height inside the tank and with the shafts perpendicular to the tank radius. With this configuration, the fluid reaches a maximum velocity of 0.28 m/s. According to the investigation, it is evident that mixing systems with propeller shafts deep-seated and parallel to the tank radius should be avoided, both in term of efficiency of the fluid mixing distribution and in term of power consumption.}, language = {en} }