@inproceedings{PijanowskaRemiszewskaPederzollietal.2006, author = {Pijanowska, Dorota G. and Remiszewska, Elzbieta and Pederzolli, Cecilia and Lunelli, Lorenzo and Vendano, Michele and Canteri, Roberto and Dudzinski, Konrad and Kruk, Jerzy and Torbicz, Wladyslaw}, title = {Surface modification for microreactor fabrication}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1480}, year = {2006}, abstract = {In this paper, methods of surface modification of different supports, i.e. glass and polymeric beads for enzyme immobilisation are described. The developed method of enzyme immobilisation is based on Schiff's base formation between the amino groups on the enzyme surface and the aldehyde groups on the chemically modified surface of the supports. The surface of silicon modified by APTS and GOPS with immobilised enzyme was characterised by atomic force microscopy (AFM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS) and infrared spectroscopy (FTIR). The supports with immobilised enzyme (urease) were also tested in combination with microreactors fabricated in silicon and Perspex, operating in a flow-through system. For microreactors filled with urease immobilised on glass beads (Sigma) and on polymeric beads (PAN), a very high and stable signal (pH change) was obtained. The developed method of urease immobilisation can be stated to be very effective.}, subject = {Biosensor}, language = {en} } @inproceedings{PijanowskaRemiszewska2006, author = {Pijanowska, Dorota G. and Remiszewska, Elzbieta}, title = {pH-based detection of phenylalnine by potentiometric and colorimetric methods}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1536}, year = {2006}, abstract = {In this paper, methods of sample preparation for potentiometric measurement of phenylalanine are presented. Basing on the spectrophotometric measurements of phenylalanine, the concentrations of reagents of the enzymatic reaction (10 mM L-Phe, 0,4 mM NAD+, 2U L-PheDH) were determined. Then, the absorption spectrum of the reaction product, NADH, was monitored (maximum peak at 340 nm). The results obtained by the spectrophotometric method were compared with the results obtained by the colourimetry, using pH indicators. The above-mentioned two methods will be used as references for potentiometric measurements of phenylalanine concentration.}, subject = {Biosensor}, language = {en} } @article{PfaffEnningSutter2022, author = {Pfaff, Raphael and Enning, Manfred and Sutter, Stefan}, title = {A risk‑based approach to automatic brake tests for rail freight service: incident analysis and realisation concept}, series = {SN Applied Sciences}, volume = {4}, journal = {SN Applied Sciences}, number = {4}, publisher = {Springer}, address = {Cham}, issn = {2523-3971}, doi = {10.1007/s42452-022-05007-x}, pages = {1 -- 14}, year = {2022}, abstract = {This study reviews the practice of brake tests in freight railways, which is time consuming and not suitable to detect certain failure types. Public incident reports are analysed to derive a reasonable brake test hardware and communication architecture, which aims to provide automatic brake tests at lower cost than current solutions. The proposed solutions relies exclusively on brake pipe and brake cylinder pressure sensors, a brake release position switch as well as radio communication via standard protocols. The approach is embedded in the Wagon 4.0 concept, which is a holistic approach to a smart freight wagon. The reduction of manual processes yields a strong incentive due to high savings in manual labour and increased productivity.}, language = {en} } @article{OliveiraMolinnusBegingetal.2021, author = {Oliveira, Danilo A. and Molinnus, Denise and Beging, Stefan and Siqueira Jr, Jos{\´e} R. and Sch{\"o}ning, Michael Josef}, title = {Biosensor Based on Self-Assembled Films of Graphene Oxide and Polyaniline Using a Field-Effect Device Platform}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000747}, pages = {1 -- 9}, year = {2021}, abstract = {A new functionalization method to modify capacitive electrolyte-insulator-semiconductor (EIS) structures with nanofilms is presented. Layers of polyallylamine hydrochloride (PAH) and graphene oxide (GO) with the compound polyaniline:poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PANI:PAAMPSA) are deposited onto a p-Si/SiO2 chip using the layer-by-layer technique (LbL). Two different enzymes (urease and penicillinase) are separately immobilized on top of a five-bilayer stack of the PAH:GO/PANI:PAAMPSA-modified EIS chip, forming a biosensor for detection of urea and penicillin, respectively. Electrochemical characterization is performed by constant capacitance (ConCap) measurements, and the film morphology is characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). An increase in the average sensitivity of the modified biosensors (EIS-nanofilm-enzyme) of around 15\% is found in relation to sensors, only carrying the enzyme but without the nanofilm (EIS-enzyme). In this sense, the nanofilm acts as a stable bioreceptor onto the EIS chip improving the output signal in terms of sensitivity and stability.}, language = {en} } @inproceedings{O'HerasDigelTemizArtmann2009, author = {O\'Heras, Carlos and Digel, Ilya and Temiz Artmann, Ayseg{\"u}l}, title = {Nanostructured carbon-based column for LPS/protein adsorption : [abstract]}, year = {2009}, abstract = {The absence of a general method for endotoxin removal from liquid interfaces gives an opportunity to find new methods and materials to overcome this gap. Activated nanostructured carbon is a promising material that showed good adsorption properties due to its vast pore network and high surface area. The aim of this study is to find the adsorption rates for a carboneous material produced at different temperatures, as well as to reveal possible differences between the performance of the material for each of the adsorbates used during the study (hemoglobin, serum albumin and lipopolysaccharide, LPS).}, subject = {Kohlenstofffaser}, language = {en} } @inproceedings{NaetherJuarezEmmerichetal.2006, author = {N{\"a}ther, Niko and Ju{\´a}rez, Leon M. and Emmerich, R{\"u}diger and Berger, J{\"o}rg and Friedrich, Peter and Sch{\"o}ning, Michael Josef}, title = {Detection of hydrogen peroxide (H2O2) at exposed temperatures for industrial processes}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1418}, year = {2006}, abstract = {An H2O2 sensor for the application in industrial sterilisation processes has been developed. Therefore, automated sterilisation equipment at laboratory scale has been constructed using parts from industrial sterilisation facilities. In addition, a software tool has been developed for the control of the sterilisation equipment at laboratory scale. First measurements with the developed sensor set-up as part of the sterilisation equipment have been performed and the sensor has been physically characterised by optical microscopy and SEM.}, subject = {Biosensor}, language = {en} } @inproceedings{NiemuellerFerreinReuteretal.2015, author = {Niemueller, Tim and Ferrein, Alexander and Reuter, Sebastian and Jeschke, Sabina and Lakemeyer, Gerhard}, title = {The RoboCup Logistics League as a Holistic Multi-Robot Smart Factory Benchmark}, series = {Proceedings of the IROS 2015 Open forum on evaluation of results, replication of experiments and benchmarking in robotics research}, booktitle = {Proceedings of the IROS 2015 Open forum on evaluation of results, replication of experiments and benchmarking in robotics research}, pages = {3 S.}, year = {2015}, abstract = {With autonomous mobile robots receiving increased attention in industrial contexts, the need for benchmarks becomes more and more an urgent matter. The RoboCup Logistics League (RCLL) is one specific industry-inspired scenario focusing on production logistics within a Smart Factory. In this paper, we describe how the RCLL allows to assess the performance of a group of robots within the scenario as a whole, focusing specifically on the coordination and cooperation strategies and the methods and components to achieve them. We report on recent efforts to analyze performance of teams in 2014 to understand the implications of the current grading scheme, and derived criteria and metrics for performance assessment based on Key Performance Indicators (KPI) adapted from classic factory evaluation. We reflect on differences and compatibility towards RoCKIn, a recent major benchmarking European project.}, language = {en} } @inproceedings{NakagawaMichauxKallweitetal.2015, author = {Nakagawa, Masaki and Michaux, Frank and Kallweit, Stephan and Maeda, Kazuhiro}, title = {Unsteady flow measurements in the wake behind a wind-tunnel car model by using high-speed planar PIV}, series = {11TH International Symposium on Particle Image Velocimetry - PIV15 Santa Barbara, California, September 14-16, 2015}, booktitle = {11TH International Symposium on Particle Image Velocimetry - PIV15 Santa Barbara, California, September 14-16, 2015}, pages = {21 S.}, year = {2015}, abstract = {This study investigates unsteady characteristics of the wake behind a 28\%-scale car model in a wind tunnel using highspeed planar particle image velocimetry (PIV). The car model is based on a hatchback passenger car that is known to have relatively high fluctuations in its aerodynamic loads. This study primarily focuses on the lateral motion of the flow on the horizontal plane to determine the effect of the flow motion on the straight-line stability and the initial steering response of the actual car on a track. This paper first compares the flow fields in the wake behind the above mentioned model obtained using conventional and high-speed planar PIV, with sampling frequencies of 8 Hz and 1 kHz, respectively. Large asymmetrically coherent flow structures, which fluctuate at frequencies below 2 Hz, are observed in the results of highspeed PIV measurements, whereas conventional PIV is unable to capture these features of the flow owing to aliasing. This flow pattern with a laterally swaying motion is represented by opposite signs of cross-correlation coefficients of streamwise velocity fluctuations for the two sides of the car model. Effects of two aerodynamic devices that are known to reduce the fluctuation levels of the aerodynamic loads are then extensively investigated. The correlation analyses reveal that these devices indeed reduce the fluctuation levels of the flow and the correlation values around the rear combination-lamp, but it is found that the effects of these devices are different around the c-pillar.}, language = {en} } @article{MoehrenBergmannJanseretal.2024, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {Assessment of structural mechanical effects related to torsional deformations of propellers}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (eISSN)}, doi = {10.1007/s13272-024-00737-7}, pages = {22 Seiten}, year = {2024}, abstract = {Lifting propellers are of increasing interest for Advanced Air Mobility. All propellers and rotors are initially twisted beams, showing significant extension-twist coupling and centrifugal twisting. Torsional deformations severely impact aerodynamic performance. This paper presents a novel approach to assess different reasons for torsional deformations. A reduced-order model runs large parameter sweeps with algebraic formulations and numerical solution procedures. Generic beams represent three different propeller types for General Aviation, Commercial Aviation, and Advanced Air Mobility. Simulations include solid and hollow cross-sections made of aluminum, steel, and carbon fiber-reinforced polymer. The investigation shows that centrifugal twisting moments depend on both the elastic and initial twist. The determination of the centrifugal twisting moment solely based on the initial twist suffers from errors exceeding 5\% in some cases. The nonlinear parts of the torsional rigidity do not significantly impact the overall torsional rigidity for the investigated propeller types. The extension-twist coupling related to the initial and elastic twist in combination with tension forces significantly impacts the net cross-sectional torsional loads. While the increase in torsional stiffness due to initial twist contributes to the overall stiffness for General and Commercial Aviation propellers, its contribution to the lift propeller's stiffness is limited. The paper closes with the presentation of approximations for each effect identified as significant. Numerical evaluations are necessary to determine each effect for inhomogeneous cross-sections made of anisotropic material.}, language = {en} } @article{MoehrenBergmannJanseretal.2023, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {On the influence of elasticity on propeller performance: a parametric study}, series = {CEAS Aeronautical Journal}, volume = {14}, journal = {CEAS Aeronautical Journal}, publisher = {Springer Nature}, address = {Berlin}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-023-00649-y}, pages = {311 -- 323}, year = {2023}, abstract = {The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings.}, language = {en} } @article{MonakhovaDiehl2021, author = {Monakhova, Yulia and Diehl, Bernd W. K.}, title = {A step towards optimization of the qNMR workflow: proficiency testing exercise at an GxP-accredited laboratory}, series = {Applied Magnetic Resonance}, volume = {52}, journal = {Applied Magnetic Resonance}, publisher = {Springer Nature}, address = {Wien}, issn = {1613-7507}, doi = {10.1007/s00723-021-01324-3}, pages = {581 -- 593}, year = {2021}, abstract = {Quantitative nuclear magnetic resonance (qNMR) is considered as a powerful tool for multicomponent mixture analysis as well as for the purity determination of single compounds. Special attention is currently paid to the training of operators and study directors involved in qNMR testing. To assure that only qualified personnel are used for sample preparation at our GxP-accredited laboratory, weighing test was proposed. Sixteen participants performed six-fold weighing of the binary mixture of dibutylated hydroxytoluene (BHT) and 1,2,4,5-tetrachloro-3-nitrobenzene (TCNB). To evaluate the quality of data analysis, all spectra were evaluated manually by a qNMR expert and using in-house developed automated routine. The results revealed that mean values are comparable and both evaluation approaches are free of systematic error. However, automated evaluation resulted in an approximately 20\% increase in precision. The same findings were revealed for qNMR analysis of 32 compounds used in pharmaceutical industry. Weighing test by six-fold determination in binary mixtures and automated qNMR methodology can be recommended as efficient tools for evaluating staff proficiency. The automated qNMR method significantly increases throughput and precision of qNMR for routine measurements and extends application scope of qNMR.}, language = {en} } @article{MolinnusJanusFangetal.2022, author = {Molinnus, Denise and Janus, Kevin Alexander and Fang, Anyelina C. and Drinic, Aleksander and Achtsnicht, Stefan and K{\"o}pf, Marius and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Thick-film carbon electrode deposited onto a biodegradable fibroin substrate for biosensing applications}, series = {Physica status solidi (a)}, volume = {219}, journal = {Physica status solidi (a)}, number = {23}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202200100}, pages = {1 -- 9}, year = {2022}, abstract = {This study addresses a proof-of-concept experiment with a biocompatible screen-printed carbon electrode deposited onto a biocompatible and biodegradable substrate, which is made of fibroin, a protein derived from silk of the Bombyx mori silkworm. To demonstrate the sensor performance, the carbon electrode is functionalized as a glucose biosensor with the enzyme glucose oxidase and encapsulated with a silicone rubber to ensure biocompatibility of the contact wires. The carbon electrode is fabricated by means of thick-film technology including a curing step to solidify the carbon paste. The influence of the curing temperature and curing time on the electrode morphology is analyzed via scanning electron microscopy. The electrochemical characterization of the glucose biosensor is performed by amperometric/voltammetric measurements of different glucose concentrations in phosphate buffer. Herein, systematic studies at applied potentials from 500 to 1200 mV to the carbon working electrode (vs the Ag/AgCl reference electrode) allow to determine the optimal working potential. Additionally, the influence of the curing parameters on the glucose sensitivity is examined over a time period of up to 361 days. The sensor shows a negligible cross-sensitivity toward ascorbic acid, noradrenaline, and adrenaline. The developed biocompatible biosensor is highly promising for future in vivo and epidermal applications.}, language = {en} } @article{MolinnusIkenJohnenetal.2022, author = {Molinnus, Denise and Iken, Heiko and Johnen, Anna Lynn and Richstein, Benjamin and Hellmich, Lena and Poghossian, Arshak and Knoch, Joachim and Sch{\"o}ning, Michael Josef}, title = {Miniaturized pH-Sensitive Field-Effect Capacitors with Ultrathin Ta₂O₅ Films Prepared by Atomic Layer Deposition}, series = {physica status solidi (a) applications and materials science}, volume = {219}, journal = {physica status solidi (a) applications and materials science}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202100660}, pages = {7 Seiten}, year = {2022}, abstract = {Miniaturized electrolyte-insulator-semiconductor capacitors (EISCAPs) with ultrathin gate insulators have been studied in terms of their pH-sensitive sensor characteristics: three different EISCAP systems consisting of Al-p-Si-Ta2O5(5 nm), Al-p-Si-Si3N4(1 or 2 nm)-Ta2O5 (5 nm), and Al-p-Si-SiO2(3.6 nm)-Ta2O5(5 nm) layer structures are characterized in buffer solution with different pH values by means of capacitance-voltage and constant capacitance method. The SiO2 and Si3N4 gate insulators are deposited by rapid thermal oxidation and rapid thermal nitridation, respectively, whereas the Ta2O5 film is prepared by atomic layer deposition. All EISCAP systems have a clear pH response, favoring the stacked gate insulators SiO2-Ta2O5 when considering the overall sensor characteristics, while the Si3N4(1 nm)-Ta2O5 stack delivers the largest accumulation capacitance (due to the lower equivalent oxide thickness) and a higher steepness in the slope of the capacitance-voltage curve among the studied stacked gate insulator systems.}, language = {en} } @inproceedings{MirmohseniRostamizadeh2006, author = {Mirmohseni, Abdolreza and Rostamizadeh, Kobra}, title = {Quartz crystal nanobalance in conjunction with principal component analysis for identification of volatile organic compounds}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1434}, year = {2006}, abstract = {Quartz crystal nanobalance (QCN) sensors are considered as powerful masssensitive sensors to determine materials in the sub-nanogram level. In this study, a single piezoelectric quartz crystal nanobalance modified with polystyrene was employed to detect benzene, toluene, ethylbenzene and xylene (BTEX compounds). The frequency shift of the QCN sensor was found to be linear against the BTEX compound concentrations in the range about 1-45 mg l-1. The correlation coefficients for benzene, toluene, ethylbenzene, and xylene were 0.991, 0.9977, 0.9946 and 0.9971, respectively. The principal component analysis was also utilized to process the frequency response data of the single piezoelectric crystal at different times, considering to the different adsorption-desorption dynamics of BTEX compounds. Using principal component analysis, it was found that over 90\% of the data variance could still be explained by use of two principal components (PC1 and PC2). Subsequently, the successful identification of benzene and toluene was possible through the principal component analysis of the transient responses of the polystyrene modified QCN sensor. The results showed that the polystyrene-modified QCN had favorable identification and quantification performances for the BTEX compounds.}, subject = {Biosensor}, language = {en} } @inproceedings{Mertens2000, author = {Mertens, Josef}, title = {Laminar leading edges: manufacturing, contamination, and operational aspects - results from the German RaWid programme}, year = {2000}, abstract = {RaWid was the German national technology programme on transonic aerodynamics and supporting technologies, lasting from 1995 to 1998. One of the main topics was laminar wing development. Besides aerodynamic design work, many operational aspects were investigated. A manufacturing concept was developed to be applied to operational laminar wings and empennages. It was built in a large scale manufacturing demonstrator with the aerodynamic shape of a 1,5 m section of the A320 fin nose. Tolerances in shape and roughness fulfilled all requirements. The construction can easily be adapted to varying stiffness and strength requirements. Weight and manufacturing costs are comparable to common nose designs. The mock-up to be designed in ALTTA is based on this manufacturing principle. Another critical point is contamination of suction surfaces. Several tests were performed to investigate perforated titanium suction surfaces at realistic operational conditions: - a one year flight test with a suction plate in the stagnation area of the Airbus "Beluga" - a one year test of several suction plates in a ground test near the airport - a one year test of a working suction ground test installation at all weather conditions. No critical results were found. There is no long term suction degradation visible. Icing conditions and ground de-icing fluids used on airports did not pose severe problems. Some problems detected require only respection of weak design constraints.}, subject = {Laminare Str{\"o}mung}, language = {en} } @inproceedings{MertenConradKaemperetal.2006, author = {Merten, Sabine and Conrad, Thorsten and K{\"a}mper, Klaus-Peter and Picard, Antoni and Sch{\"u}tze, Andreas}, title = {Virtual Technology Labs - an efficient tool for the preparation of hands-on-MEMS-courses in training foundries}, year = {2006}, abstract = {Hands-on-training in high technology areas is usually limited due to the high cost for lab infrastructure and equipment. One specific example is the field of MEMS, where investment and upkeep of clean rooms with microtechnology equipment is either financed by production or R\&D projects greatly reducing the availability for education purposes. For efficient hands-on-courses a MEMS training foundry, currently used jointly by six higher education institutions, was established at FH Kaiserslautern. In a typical one week course, students manufacture a micromachined pressure sensor including all lithography, thin film and packaging steps. This compact and yet complete program is only possible because participants learn to use the different complex machines in advance via a Virtual Training Lab (VTL). In this paper we present the concept of the MEMS training foundry and the VTL preparation together with results from a scientific evaluation of the VTL over the last three years.}, subject = {Virtuelles Laboratorium}, language = {en} } @article{MaurerRiekeSchemmetal.2023, author = {Maurer, Florian and Rieke, Christian and Schemm, Ralf and Stollenwerk, Dominik}, title = {Analysis of an urban grid with high photovoltaic and e-mobility penetration}, series = {Energies}, volume = {16}, journal = {Energies}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en16083380}, pages = {18 Seiten}, year = {2023}, abstract = {This study analyses the expected utilization of an urban distribution grid under high penetration of photovoltaic and e-mobility with charging infrastructure on a residential level. The grid utilization and the corresponding power flow are evaluated, while varying the control strategies and photovoltaic installed capacity in different scenarios. Four scenarios are used to analyze the impact of e-mobility. The individual mobility demand is modelled based on the largest German studies on mobility "Mobilit{\"a}t in Deutschland", which is carried out every 5 years. To estimate the ramp-up of photovoltaic generation, a potential analysis of the roof surfaces in the supply area is carried out via an evaluation of an open solar potential study. The photovoltaic feed-in time series is derived individually for each installed system in a resolution of 15 min. The residential consumption is estimated using historical smart meter data, which are collected in London between 2012 and 2014. For a realistic charging demand, each residential household decides daily on the state of charge if their vehicle requires to be charged. The resulting charging time series depends on the underlying behavior scenario. Market prices and mobility demand are therefore used as scenario input parameters for a utility function based on the current state of charge to model individual behavior. The aggregated electricity demand is the starting point of the power flow calculation. The evaluation is carried out for an urban region with approximately 3100 residents. The analysis shows that increased penetration of photovoltaics combined with a flexible and adaptive charging strategy can maximize PV usage and reduce the need for congestion-related intervention by the grid operator by reducing the amount of kWh charged from the grid by 30\% which reduces the average price of a charged kWh by 35\% to 14 ct/kWh from 21.8 ct/kWh without PV optimization. The resulting grid congestions are managed by implementing an intelligent price or control signal. The analysis took place using data from a real German grid with 10 subgrids. The entire software can be adapted for the analysis of different distribution grids and is publicly available as an open-source software library on GitHub.}, language = {en} } @inproceedings{MansurovZhubanovaDigeletal.2008, author = {Mansurov, Zulkhair and Zhubanova, Azhar A. and Digel, Ilya and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Savitskaja, Irina S. and Kozhalakova, A. A. and Kistaubaeva, Aida S.}, title = {The sorption of LPS toxic shock by nanoparticles on base of carbonized vegetable raw materials}, year = {2008}, abstract = {Immobilization of lactobacillus on high temperature carbonizated vegetable raw material (rice husk, grape stones) increases their physiological activity and the quantity of the antibacterial metabolits, that consequently lead to increase of the antagonistic activity of lactobacillus. It is implies that the use of the nanosorbents for the attachment of the probiotical microorganisms are highly perspective for decision the important problems, such as the probiotical preparations delivery to the right address and their attachment to intestines mucosa with the following detoxication of gastro-intestinal tract and the normalization of it's microecology. Besides that, thus, the received carbonizated nanoparticles have peculiar properties - ability to sorption of LPS toxical shock and, hence, to the detoxication of LPS.}, subject = {Kohlenstofffaser}, language = {en} } @article{LuftBremenLuft2023, author = {Luft, Angela and Bremen, Sebastian and Luft, Nils}, title = {A cost/benefit and flexibility evaluation framework for additive technologies in strategic factory planning}, series = {Processes}, volume = {11}, journal = {Processes}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {2227-9717}, doi = {10.3390/pr11071968}, pages = {Artikel 1968}, year = {2023}, abstract = {There is a growing demand for more flexibility in manufacturing to counter the volatility and unpredictability of the markets and provide more individualization for customers. However, the design and implementation of flexibility within manufacturing systems are costly and only economically viable if applicable to actual demand fluctuations. To this end, companies are considering additive manufacturing (AM) to make production more flexible. This paper develops a conceptual model for the impact quantification of AM on volume and mix flexibility within production systems in the early stages of the factory-planning process. Together with the model, an application guideline is presented to help planners with the flexibility quantification and the factory design process. Following the development of the model and guideline, a case study is presented to indicate the potential impact additive technologies can have on manufacturing flexibility Within the case study, various scenarios with different production system configurations and production programs are analyzed, and the impact of the additive technologies on volume and mix flexibility is calculated. This work will allow factory planners to determine the potential impacts of AM on manufacturing flexibility in an early planning stage and design their production systems accordingly.}, language = {en} } @inproceedings{LeiMulchandaniChenetal.2006, author = {Lei, Yu and Mulchandani, Priti and Chen, Wilfred and Mulchandani, Ashok}, title = {Biosensor for direct determination of fenitrothion and EPN using recombinant Pseudomonas putida JS444 with surface expressed organophosphorus hydrolase. 1. modified clark oxygen electrode}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1573}, year = {2006}, abstract = {This paper reports a first microbial biosensor for rapid and cost-effective determination of organophosphorus pesticides fenitrothion and EPN. The biosensor consisted of recombinant PNP-degrading/oxidizing bacteria Pseudomonas putida JS444 anchoring and displaying organophosphorus hydrolase (OPH) on its cell surface as biological sensing element and a dissolved oxygen electrode as the transducer. Surfaceexpressed OPH catalyzed the hydrolysis of fenitrothion and EPN to release 3-methyl-4-nitrophenol and p-nitrophenol, respectively, which were oxidized by the enzymatic machinery of Pseudomonas putida JS444 to carbon dioxide while consuming oxygen, which was measured and correlated to the concentration of organophosphates. Under the optimum operating conditions, the biosensor was able to measure as low as 277 ppb of fenitrothion and 1.6 ppm of EPN without interference from phenolic compounds and other commonly used pesticides such as carbamate pesticides, triazine herbicides and organophosphate pesticides without nitrophenyl substituent. The applicability of the biosensor to lake water was also demonstrated.}, subject = {Biosensor}, language = {en} } @article{LaarmannThomaMischetal.2023, author = {Laarmann, Lukas and Thoma, Andreas and Misch, Philipp and R{\"o}th, Thilo and Braun, Carsten and Watkins, Simon and Fard, Mohammad}, title = {Automotive safety approach for future eVTOL vehicles}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer Nature}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-023-00655-0}, pages = {11 Seiten}, year = {2023}, abstract = {The eVTOL industry is a rapidly growing mass market expected to start in 2024. eVTOL compete, caused by their predicted missions, with ground-based transportation modes, including mainly passenger cars. Therefore, the automotive and classical aircraft design process is reviewed and compared to highlight advantages for eVTOL development. A special focus is on ergonomic comfort and safety. The need for further investigation of eVTOL's crashworthiness is outlined by, first, specifying the relevance of passive safety via accident statistics and customer perception analysis; second, comparing the current state of regulation and certification; and third, discussing the advantages of integral safety and applying the automotive safety approach for eVTOL development. Integral safety links active and passive safety, while the automotive safety approach means implementing standardized mandatory full-vehicle crash tests for future eVTOL. Subsequently, possible crash impact conditions are analyzed, and three full-vehicle crash load cases are presented.}, language = {en} } @article{KuehnHaugnerStaatetal.2004, author = {K{\"u}hn, Raoul-Roman and Haugner, Werner and Staat, Manfred and Sponagel, Stefan}, title = {A Two Phase Mixture Model based on Bone Observation}, year = {2004}, abstract = {An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff's law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency.}, subject = {Knochen}, language = {en} } @article{KaemperPicardBrilletal.2003, author = {K{\"a}mper, Klaus-Peter and Picard, Antoni and Brill, Manfred and Cassel, Detlev and Jentsch, Andreas and Merten, Sabine and Rollwa, Markus}, title = {The Virtual Clean Room - a new tool in teaching MST process technologies}, year = {2003}, abstract = {The Virtual Clean Room - a new tool in teaching MST process technologies University education in high-technology fields like MST is not complete without intensive laboratory sessions. Students cannot fully grasp the complexity and the special problems related to the manufacturing of microsystems without a thorough hands-on experience in a MST clean room.}, subject = {Virtuelle Maschine}, language = {en} } @misc{Kaemper2007, author = {K{\"a}mper, Klaus-Peter}, title = {Lecture notes Sensors and Actuators}, year = {2007}, abstract = {Kennwortgesch{\"u}tzter Zugang nur f{\"u}r Studierende bei Prof. Dr. Klaus-Peter K{\"a}mper. Wintersemester 2007/2008. Version vom 30.08.2007. 472 Seiten (pdf-Format)}, subject = {Sensor}, language = {en} } @misc{Kaemper2008, author = {K{\"a}mper, Klaus-Peter}, title = {Lecture notes Sensors and Actuators WS 2008/2009}, year = {2008}, abstract = {Password necessarily. Access only for Students by Prof. Dr. Klaus-Peter K{\"a}mper. Winter semester 2008/2009. 488 pages (pdf) Contents 1. Introduction 2. Introduction to Sensors 3. Introduction to Microfabrication 4. Pressure Sensors 5. Acceleration Sensors 6. Angular Rate Sensors 7. Position Sensors 8. Flow Sensors 9. Piezoelectric Actuators 10. Magnetostrictive Actuators 11. Actuators based on Shape Memory Alloys 12. Actuators based on Electrorheological Fluids 13. Actuators based on Magnetorheological Fluids 14. Index}, subject = {Sensor}, language = {en} } @inproceedings{KurulganDemirciLinderDemircietal.2010, author = {Kurulgan Demirci, Eylem and Linder, Peter and Demirci, Taylan and Gierkowski, Jessica R. and Digel, Ilya and Gossmann, Matthias and Temiz Artmann, Ayseg{\"u}l}, title = {rhAPC reduces the endothelial cell permeability via a decrease of cellular mechanical contractile tensions : [abstract]}, year = {2010}, abstract = {In this study, the CellDrum technology quanitfying cellular mechanical tension on a pico-scale was used to investigate the effect of LPS (lipopolysaccharide) on HAoEC (Human Aortic Endothelial Cell) tension.}, subject = {Endothelzelle}, language = {en} } @inproceedings{KronhardtAlexopoulosReisseletal.2015, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Latzke, Markus and Rendon, C. and Sattler, Johannes Christoph and Herrmann, Ulf}, title = {Simulation of operational management for the Solar Thermal Test and Demonstration Power Plant J{\"u}lich using optimized control strategies of the storage system}, series = {Energy procedia}, booktitle = {Energy procedia}, issn = {1876-6102}, pages = {1 -- 6}, year = {2015}, language = {en} } @inproceedings{KreutzLoergenGraeweetal.2006, author = {Kreutz, Christian and L{\"o}rgen, J{\"u}rgen and Graewe, Boris and Bargon, Joachim and Yoshida, Mayumi and Freso, Zachary M. and Fr{\`e}chet, Jean M. J.}, title = {High frequency quartz micro balances: a promising path to enhanced sensitivity of gravimetric sensors}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1445}, year = {2006}, abstract = {An array of 50 MHz quartz microbalances (QMBs) coated with a dendronized polymer was used to detect small amounts of volatile organic compounds (VOCs) in the gas phase. The results were compared to those obtained with the commonly used 10 MHz QMBs. The 50 MHz QMBs proved to be a powerful tool for the detection of VOCs in the gas phase; therefore, they represent a promising alternative to the much more delicate surface acoustic wave devices (SAWs).}, subject = {Biosensor}, language = {en} } @inproceedings{KraftWilhelms2005, author = {Kraft, Bodo and Wilhelms, Nils}, title = {Visual Knowledge Specification for Conceptual Design}, year = {2005}, abstract = {Proc. of the 2005 ASCE Intl. Conf. on Computing in Civil Engineering (ICCC 2005) eds. L. Soibelman und F. Pena-Mora, Seite 1-14, ASCE (CD-ROM), Cancun, Mexico, 2005 Current CAD tools are not able to support the fundamental conceptual design phase, and none of them provides consistency analyses of sketches produced by architects. To give architects a greater support at the conceptual design phase, we develop a CAD tool for conceptual design and a knowledge specification tool allowing the definition of conceptually relevant knowledge. The knowledge is specific to one class of buildings and can be reused. Based on a dynamic knowledge model, different types of design rules formalize the knowledge in a graph-based realization. An expressive visual language provides a user-friendly, human readable representation. Finally, consistency analyses enable conceptual designs to be checked against this defined knowledge. In this paper we concentrate on the knowledge specification part of our project.}, subject = {CAD}, language = {en} } @inproceedings{KraftWilhelms2004, author = {Kraft, Bodo and Wilhelms, N.}, title = {Interactive distributed knowledge support for conceptual building design}, isbn = {3-86068-213-X}, year = {2004}, abstract = {In: Net-distributed Co-operation : Xth International Conference on Computing in Civil and Building Engineering, Weimar, June 02 - 04, 2004 ; proceedings / [ed. by Karl Beuke ...] . - Weimar: Bauhaus-Univ. Weimar 2004. - 1. Aufl. . Seite 1-14 ISBN 3-86068-213-X International Conference on Computing in Civil and Building Engineering <10, 2004, Weimar> Summary In our project, we develop new tools for the conceptual design phase. During conceptual design, the coarse functionality and organization of a building is more important than a detailed worked out construction. We identify two roles, first the knowledge engineer who is responsible for knowledge definition and maintenance; second the architect who elaborates the conceptual de-sign. The tool for the knowledge engineer is based on graph technology, it is specified using PROGRES and the UPGRADE framework. The tools for the architect are integrated to the in-dustrial CAD tool ArchiCAD. Consistency between knowledge and conceptual design is en-sured by the constraint checker, another extension to ArchiCAD.}, subject = {CAD}, language = {en} } @inproceedings{KraftSchneider2005, author = {Kraft, Bodo and Schneider, Gerd}, title = {Semantic Roomobjects for Conceptual Design Support : A Knowledge-based Approach}, isbn = {978-1-4020-3460-2}, year = {2005}, abstract = {In: Computer Aided Architectural Design Futures 2005 2005, Part 4, 207-216, DOI: http://dx.doi.org/10.1007/1-4020-3698-1_19 The conceptual design at the beginning of the building construction process is essential for the success of a building project. Even if some CAD tools allow elaborating conceptual sketches, they rather focus on the shape of the building elements and not on their functionality. We introduce semantic roomobjects and roomlinks, by way of example to the CAD tool ArchiCAD. These extensions provide a basis for specifying the organisation and functionality of a building and free architects being forced to directly produce detailed constructive sketches. Furthermore, we introduce consistency analyses of the conceptual sketch, based on an ontology containing conceptual relevant knowledge, specific to one class of buildings.}, subject = {CAD}, language = {en} } @inproceedings{KraftRetkowitz2006, author = {Kraft, Bodo and Retkowitz, Daniel}, title = {Rule-Dependencies for Visual Knowledge Specification in Conceptual Design}, year = {2006}, abstract = {In: Proc. of the 11th Intl. Conf. on Computing in Civil and Building Engineering (ICCCBE-XI) ed. Hugues Rivard, Montreal, Canada, Seite 1-12, ACSE (CD-ROM), 2006 Currently, the conceptual design phase is not adequately supported by any CAD tool. Neither the support while elaborating conceptual sketches, nor the automatic proof of correctness with respect to effective restrictions is currently provided by any commercial tool. To enable domain experts to store the common as well as their personal domain knowledge, we develop a visual language for knowledge formalization. In this paper, a major extension to the already existing concepts is introduced. The possibility to define rule dependencies extends the expressiveness of the knowledge definition language and contributes to the usability of our approach.}, subject = {CAD}, language = {en} } @article{KraftNagl2007, author = {Kraft, Bodo and Nagl, Manfred}, title = {Visual Knowledge Specification for Conceptual Design: Definition and Tool Support}, year = {2007}, abstract = {In: Advanced Engineering Informatics. Vol 21, Issue 1, 2007, Pages 67-83 http://dx.doi.org/10.1016/j.aei.2006.10.001 eds. J.C. Kunz, I.F.C. Smith and T. Tomiyama, Elsevier, Seite 1-22 Current CAD tools are not able to support the conceptual design phase, and none of them provides a consistency analysis for sketches produced by architects. This phase is fundamental and crucial for the whole design and construction process of a building. To give architects a better support, we developed a CAD tool for conceptual design and a knowledge specification tool. The knowledge is specific to one class of buildings and it can be reused. Based on a dynamic and domain-specific knowledge ontology, different types of design rules formalize this knowledge in a graph-based form. An expressive visual language provides a user-friendly, human readable representation. Finally, a consistency analysis tool enables conceptual designs to be checked against this formal conceptual knowledge. In this article, we concentrate on the knowledge specification part. For that, we introduce the concepts and usage of a novel visual language and describe its semantics. To demonstrate the usability of our approach, two graph-based visual tools for knowledge specification and conceptual design are explained.}, subject = {CAD}, language = {en} } @inproceedings{KraftNagl2003, author = {Kraft, Bodo and Nagl, Manfred}, title = {Semantic tool support for conceptual design}, year = {2003}, abstract = {ITCE-2003 - 4th Joint Symposium on Information Technology in Civil Engineering ed Flood, I., Seite 1-12, ASCE (CD-ROM), Nashville, USA In this paper we discussed graph based tools to support architects during the conceptual design phase. Conceptual Design is defined before constructive design; the used concepts are more abstract. We develop two graph based approaches, a topdown using the graph rewriting system PROGRES and a more industrially oriented approach, where we extend the CAD system ArchiCAD. In both approaches, knowledge can be defined by a knowledge engineer, in the top-down approach in the domain model graph, in the bottom-up approach in the in an XML file. The defined knowledge is used to incrementally check the sketch and to inform the architect about violations of the defined knowledge. Our goal is to discover design error as soon as possible and to support the architect to design buildings with consideration of conceptual knowledge.}, subject = {CAD}, language = {en} } @inproceedings{KraftMeyerNagl2002, author = {Kraft, Bodo and Meyer, Oliver and Nagl, Manfred}, title = {Graph technology support for conceptual design in civil engineering}, isbn = {3-18-318004-9}, year = {2002}, abstract = {In: Advances in intelligent computing in engineering : proceedings of the 9.International EG-ICE Workshop ; Darmstadt, (01 - 03 August) 2002 / Martina Schnellenbach-Held ... (eds.) . - D{\"u}sseldorf: VDI-Verl., 2002 .- Fortschritt-Berichte VDI, Reihe 4, Bauingenieurwesen ; 180 ; S. 1-35 The paper describes a novel way to support conceptual design in civil engineering. The designer uses semantical tools guaranteeing certain internal structures of the design result but also the fulfillment of various constraints. Two different approaches and corresponding tools are discussed: (a) Visually specified tools with automatic code generation to determine a design structure as well as fixing various constraints a design has to obey. These tools are also valuable for design knowledge specialist. (b) Extensions of existing CAD tools to provide semantical knowledge to be used by an architect. It is sketched how these different tools can be combined in the future. The main part of the paper discusses the concepts and realization of two prototypes following the two above approaches. The paper especially discusses that specific graphs and the specification of their structure are useful for both tool realization projects.}, subject = {CAD}, language = {en} } @inproceedings{Kraft2004, author = {Kraft, Bodo}, title = {Conceptual design tools for civil engineering}, year = {2004}, abstract = {Applications of Graph Transformations with Industrial Relevance Lecture Notes in Computer Science, 2004, Volume 3062/2004, 434-439, DOI: http://dx.doi.org/10.1007/978-3-540-25959-6_33 This paper gives a brief overview of the tools we have developed to support conceptual design in civil engineering. Based on the UPGRADE framework, two applications, one for the knowledge engineer and another for architects allow to store domain specific knowledge and to use this knowledge during conceptual design. Consistency analyses check the design against the defined knowledge and inform the architect if rules are violated.}, subject = {CAD}, language = {en} } @inproceedings{KoplinSiemonsOcenValentinetal.2006, author = {Koplin, Tobias J. and Siemons, Maike and Oc{\´e}n-Val{\´e}ntin, C{\´e}sar and Sanders, Daniel and Simon, Ulrich}, title = {Workflow for high throughput screening of gas sensing materials}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1407}, year = {2006}, abstract = {The workflow of a high throughput screening setup for the rapid identification of new and improved sensor materials is presented. The polyol method was applied to prepare nanoparticular metal oxides as base materials, which were functionalised by surface doping. Using multi-electrode substrates and high throughput impedance spectroscopy (HT-IS) a wide range of materials could be screened in a short time. Applying HT-IS in search of new selective gas sensing materials a NO2-tolerant NO sensing material with reduced sensitivities towards other test gases was identified based on iridium doped zinc oxide. Analogous behaviour was observed for iridium doped indium oxide.}, subject = {Biosensor}, language = {en} } @inproceedings{KirchhofKraft2004, author = {Kirchhof, M. and Kraft, Bodo}, title = {UML-based modeling of architectural knowledge and design}, year = {2004}, abstract = {IASSE-2004 - 13th International Conference on Intelligent and Adaptive Systems and Software Engineering eds. W. Dosch, N. Debnath, pp. 245-250, ISCA, Cary, NC, 1-3 July 2004, Nice, France We introduce a UML-based model for conceptual design support in civil engineering. Therefore, we identify required extensions to standard UML. Class diagrams are used for elaborating building typespecific knowledge: Object diagrams, implicitly contained in the architect's sketch, are validated against the defined knowledge. To enable the use of industrial, domain-specific tools, we provide an integrated conceptual design extension. The developed tool support is based on graph rewriting. With our approach architects are enabled to deal with semantic objects during early design phase, assisted by incremental consistency checks.}, subject = {UML}, language = {en} } @inproceedings{KernKrichelMueller2001, author = {Kern, Alexander and Krichel, Frank and M{\"u}ller, Klaus-Peter}, title = {Lightning protection design of a renewable energy hybrid-system without power mains connection}, year = {2001}, abstract = {In the year 2000 a direct lightning strike to the hybridsystem without power mains connection VATALI on the Greek island Crete results in the destruction and damage of some mechanical and electrical components. The hybrid-system VATALI was not lightning protected at that time. The hardware damage costs are approx. 60,000 €. The exposed site of the hybrid-system on top of a mountain was and still is the reason for a high risk of lightning strikes. Also in the future further lightning strikes have to be taken into consideration. In the paper a fundamental lightning protection design concept for renewable energy hybrid-systems without power mains connection and protection measures against direct strikes and overvoltages are shown in detail. The design concept was realized exemplarily for the hybrid-system VATALI. The hardware costs for the protection measures were about 15,000 €. About 50\% of the costs are due to protection measures against direct strikes, 50\% are due to overvoltage protection. Future extensions, new installations, or modifications have to be included into the lightning protection design concept of the hybrid-system.}, language = {en} } @inproceedings{KernKrichel2002, author = {Kern, Alexander and Krichel, Frank}, title = {Considerations about the lightning protection system of mains independent renewable energy hybrid-systems - practical experiences}, year = {2002}, abstract = {In the paper a lightning protection design concept for renewable energy hybrid-systems without power mains connection is described. Based on a risk analysis protection measures against direct strikes and overvoltages are shown in an overview. The design concept is realized exemplarily for the hybrid-system VATALI on the Greek island Crete. VATALI, not lightning protected at that time, was a victim of a lightning strike in the year 2000 causing destructions and damages of some mechanical and electrical components with costs of approx. 60.000 €. The hardware costs for the protection measures were about 15.000 €: about 50\% of the costs are due to protection measures against direct strikes, 50\% are due to overvoltage protection.}, language = {en} } @inproceedings{KernHeidlerSeeversetal.2004, author = {Kern, Alexander and Heidler, Fridolin and Seevers, M. and Zischank, Wolfgang J.}, title = {Magnetic Fields and Induced Voltages in case of a Direct Strike - Comparison of Results obtained from Measurements at a Scaled Building to those of IEC 62305-4}, isbn = {0304-3886}, year = {2004}, abstract = {In the paper the results obtained from experiments at a modelled reinforced building in case of a direct lightning strike are compared with calculations. The comparison includes peak values of the magnetic field Hmax, its derivative (dH/dt)max and of induced voltages umax in typical cable routings. The experiments are performed at a 1:6 scaled building and the results are extrapolated using the similarity relations theory. The calculations are based on the approximate formulae given in IEC 62305-4 and have to be supplemented by a rough estimation of the additional shielding effect of a second reinforcement layer. The comparison shows, that the measured peak values of the magnetic field and its derivative are mostly lower than the calculated. The induced voltages are in good agreement. Hence, calculations of the induced voltages based on IEC 62305-4 are a good method for lightning protection studies of buildings, where the reinforcement is used as a grid-like electromagnetic shield.}, subject = {Blitz}, language = {en} } @inproceedings{KernDikta2009, author = {Kern, Alexander and Dikta, Gerhard}, title = {Probability of damage of electrical and electronic systems due to indirect lightning flashes - investigation of data from German insurance companies}, year = {2009}, abstract = {In the presented paper data collected from the field related to damage statistics of electrical and electronic apparatus in household are reported and investigated. These damages (total number approx. 74000 cases), registered by five German insurance companies in 2005 and 2006, were adviced by customers as caused by lightning overvoltages. With the use of stochastical methods it is possible, to reasses the collected data and to distinguish between cases, which are with high probability caused by lightning overvoltages, and those, which are not. If there was an indication for a direct strike, this case was excluded, so the focus was only on indirect lightning flashes, i.e. only flashes to ground near the structure and flashes to or nearby an incoming service line were investigated. The data from the field contain the location of damaged apparatus (residence of the policy holder) and the distances of the nearest cloud-to-ground stroke to the location of the damage registered by the German lightning location network BLIDS at the date of damage. The statistical data along with some complementary numerical simulations allow to verify the correspondence of the Standards rules used for IEC 62305-2 with the field data and to define some correction needs. The results could lead to a better understanding whether a damage reported to an insurance company is really caused by indirect lightning, or not.}, subject = {Blitzschutz}, language = {en} } @article{KaulenSchwabedalSchneideretal.2022, author = {Kaulen, Lars and Schwabedal, Justus T. C. and Schneider, Jules and Ritter, Philipp and Bialonski, Stephan}, title = {Advanced sleep spindle identification with neural networks}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {Article number: 7686}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-022-11210-y}, pages = {1 -- 10}, year = {2022}, abstract = {Sleep spindles are neurophysiological phenomena that appear to be linked to memory formation and other functions of the central nervous system, and that can be observed in electroencephalographic recordings (EEG) during sleep. Manually identified spindle annotations in EEG recordings suffer from substantial intra- and inter-rater variability, even if raters have been highly trained, which reduces the reliability of spindle measures as a research and diagnostic tool. The Massive Online Data Annotation (MODA) project has recently addressed this problem by forming a consensus from multiple such rating experts, thus providing a corpus of spindle annotations of enhanced quality. Based on this dataset, we present a U-Net-type deep neural network model to automatically detect sleep spindles. Our model's performance exceeds that of the state-of-the-art detector and of most experts in the MODA dataset. We observed improved detection accuracy in subjects of all ages, including older individuals whose spindles are particularly challenging to detect reliably. Our results underline the potential of automated methods to do repetitive cumbersome tasks with super-human performance.}, language = {en} } @inproceedings{KatzWillner2006, author = {Katz, Eugenii and Willner, Itamar}, title = {Magneto-controlled quantized electron transfer to surface-confined redox units and metal nanoparticles}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1528}, year = {2006}, abstract = {Hydrophobic magnetic nanoparticles (NPs) consisting of undecanoate-capped magnetite (Fe3O4, average diameter ca. 5 nm) are used to control quantized electron transfer to surface-confined redox units and metal NPs. A two-phase system consisting of an aqueous electrolyte solution and a toluene phase that includes the suspended undecanoatecapped magnetic NPs is used to control the interfacial properties of the electrode surface. The attracted magnetic NPs form a hydrophobic layer on the electrode surface resulting in the change of the mechanisms of the surface-confined electrochemical processes. A quinone-monolayer modified Au electrode demonstrates an aqueous-type of the electrochemical process (2e-+2H+ redox mechanism) for the quinone units in the absence of the hydrophobic magnetic NPs, while the attraction of the magnetic NPs to the surface results in the stepwise single-electron transfer mechanism characteristic of a dry nonaqueous medium. Also, the attraction of the hydrophobic magnetic NPs to the Au electrode surface modified with Au NPs (ca. 1.4 nm) yields a microenvironment with a low dielectric constant that results in the single-electron quantum charging of the Au NPs.}, subject = {Biosensor}, language = {en} } @article{KarschuckSchmidtAchtsnichtetal.2023, author = {Karschuck, Tobias and Schmidt, Stefan and Achtsnicht, Stefan and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Multiplexing system for automated characterization of a capacitive field-effect sensor array}, series = {Physica Status Solidi A}, volume = {220}, journal = {Physica Status Solidi A}, number = {22}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300 (Print)}, doi = {10.1002/pssa.202300265}, pages = {7 Seiten}, year = {2023}, abstract = {In comparison to single-analyte devices, multiplexed systems for a multianalyte detection offer a reduced assay time and sample volume, low cost, and high throughput. Herein, a multiplexing platform for an automated quasi-simultaneous characterization of multiple (up to 16) capacitive field-effect sensors by the capacitive-voltage (C-V) and the constant-capacitance (ConCap) mode is presented. The sensors are mounted in a newly designed multicell arrangement with one common reference electrode and are electrically connected to the impedance analyzer via the base station. A Python script for the automated characterization of the sensors executes the user-defined measurement protocol. The developed multiplexing system is tested for pH measurements and the label-free detection of ligand-stabilized, charged gold nanoparticles.}, language = {en} } @inproceedings{JungStaatMueller2014, author = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram}, title = {Optimization of the flight style in ski jumping}, series = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20 - 25, 2014, Barcelona}, booktitle = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20 - 25, 2014, Barcelona}, editor = {Onate, E.}, organization = {World Congress on Computational Mechanics <11, 2014, Barcelona>}, pages = {799 -- 810}, year = {2014}, language = {en} } @inproceedings{JungFrotscherStaat2018, author = {Jung, Alexander and Frotscher, Ralf and Staat, Manfred}, title = {Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts}, series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, pages = {11 Seiten}, year = {2018}, abstract = {The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample.}, language = {en} } @article{JildehWagnerSchoening2021, author = {Jildeh, Zaid B. and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef}, title = {Sterilization of Objects, Products, and Packaging Surfaces and Their Characterization in Different Fields of Industry: The Status in 2020}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000732}, pages = {27 Seiten}, year = {2021}, abstract = {The treatment method to deactivate viable microorganisms from objects or products is termed sterilization. There are multiple forms of sterilization, each intended to be applied for a specific target, which depends on—but not limited to—the thermal, physical, and chemical stability of that target. Herein, an overview on the currently used sterilization processes in the global market is provided. Different sterilization techniques are grouped under a category that describes the method of treatment: radiation (gamma, electron beam, X-ray, and ultraviolet), thermal (dry and moist heat), and chemical (ethylene oxide, ozone, chlorine dioxide, and hydrogen peroxide). For each sterilization process, the typical process parameters as defined by regulations and the mode of antimicrobial activity are summarized. Finally, the recommended microorganisms that are used as biological indicators to validate sterilization processes in accordance with the rules that are established by various regulatory agencies are summarized.}, language = {en} } @article{JanusAchtsnichtTempeletal.2023, author = {Janus, Kevin Alexander and Achtsnicht, Stefan and Tempel, Laura and Drinic, Aleksaner and Kopp, Alexander and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Influence of fibroin membrane composition and curing parameters on the performance of a biodegradable enzymatic biosensor manufactured from Silicon-Free Carbon}, series = {Physica status solidi : pss. A, Applications and materials science}, volume = {220}, journal = {Physica status solidi : pss. A, Applications and materials science}, number = {22}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300 (Print)}, doi = {10.1002/pssa.202300081}, pages = {10 Seiten}, year = {2023}, abstract = {Herein, fibroin, polylactide (PLA), and carbon are investigated for their suitability as biocompatible and biodegradable materials for amperometric biosensors. For this purpose, screen-printed carbon electrodes on the biodegradable substrates fibroin and PLA are modified with a glucose oxidase membrane and then encapsulated with the biocompatible material Ecoflex. The influence of different curing parameters of the carbon electrodes on the resulting biosensor characteristics is studied. The morphology of the electrodes is investigated by scanning electron microscopy, and the biosensor performance is examined by amperometric measurements of glucose (0.5-10 mM) in phosphate buffer solution, pH 7.4, at an applied potential of 1.2 V versus a Ag/AgCl reference electrode. Instead of Ecoflex, fibroin, PLA, and wound adhesive are tested as alternative encapsulation compounds: a series of swelling tests with different fibroin compositions, PLA, and Ecoflex has been performed before characterizing the most promising candidates by chronoamperometry. Therefore, the carbon electrodes are completely covered with the particular encapsulation material. Chronoamperometric measurements with H2O2 concentrations between 0.5 and 10 mM enable studying the leakage current behavior.}, language = {en} } @article{JanusAchtsnichtDrinicetal.2023, author = {Janus, Kevin Alexander and Achtsnicht, Stefan and Drinic, Aleksander and Kopp, Alexander and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Transient magnesium-based thin-film temperature sensor on a flexible, bioabsorbable substrate for future medical applications}, series = {Applied Research}, journal = {Applied Research}, number = {Accepted manuscript}, publisher = {Wiley-VCH}, issn = {2702-4288 (Print)}, doi = {10.1002/appl.202300102}, pages = {22 Seiten}, year = {2023}, abstract = {In this work, the bioabsorbable materials, namely fibroin, polylactide acid (PLA), magnesium and magnesium oxide are investigated for their application as transient, resistive temperature detectors (RTD). For this purpose, a thin-film magnesium-based meander-like electrode is deposited onto a flexible, bioabsorbable substrate (fibroin or PLA) and encapsulated (passivated) by additional magnesium oxide layers on top and below the magnesium-based electrode. The morphology of different layered RTDs is analyzed by scanning electron microscopy. The sensor performance and lifetime of the RTD is characterized both under ambient atmospheric conditions between 30°C and 43°C, and wet tissue-like conditions with a constant temperature regime of 37°C. The latter triggers the degradation process of the magnesium-based layers. The 3-layers RTDs on a PLA substrate could achieve a lifetime of 8.5 h. These sensors also show the best sensor performance under ambient atmospheric conditions with a mean sensitivity of 0.48 Ω/°C ± 0.01 Ω/°C.}, language = {en} }