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  - https://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  - 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  - https://doi.org/10.1002/pssa.202000765
SN  - 1862-6319
N1  - Corresponding author: Melanie Jablonski
VL  - 218
IS  - 13
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bergmann, Ole
A1  - Götten, Falk
A1  - Braun, Carsten
A1  - Janser, Frank
T1  - Comparison and evaluation of blade element methods against RANS simulations and test data
JF  - CEAS Aeronautical Journal
N2  - This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10% relative error, while appropriate BET tools overpredict the RANS results by 15–20% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results.
KW  - BET
KW  - CFD propeller simulation
KW  - Propeller aerodynamics
KW  - Actuator disk modelling
KW  - Propeller performance
Y1  - 2022
U6  - https://doi.org/10.1007/s13272-022-00579-1
SN  - 1869-5590 (Online)
SN  - 1869-5582 (Print)
N1  - Corresponding author: Ole Bergmann
VL  - 13
SP  - 535
EP  - 557
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Roth, Jasmine
T1  - Purified Butanol from Lignocellulose – Solvent‐Impregnated Resins for an Integrated Selective Removal
JF  - Chemie Ingenieur Technik
N2  - In traditional microbial biobutanol production, the solvent must be recovered during fermentation process for a sufficient space-time yield. Thermal separation is not feasible due to the boiling point of n-butanol. As an integrated and selective solid-liquid separation alternative, solvent impregnated resins (SIRs) were applied. Two polymeric resins were evaluated and an extractant screening was conducted. Vacuum application with vapor collection in fixed-bed column as bioreactor bypass was successfully implemented as butanol desorption step. In course of further increasing process economics, fermentation with renewable lignocellulosic substrates was conducted using Clostridium acetobutylicum. Utilization of SIR was shown to be a potential strategy for solvent removal from fermentation broth, while application of a bypass column allows for product removal and recovery at once.
KW  - Biofuel
KW  - Biorefinery
KW  - Butanol
KW  - Clostridium acetobutylicum
KW  - Lignocellulose
Y1  - 2020
U6  - https://doi.org/10.1002/cite.202000200
SN  - 1522-2640
N1  - Corresponding author: Nils Tippkötter
VL  - 92
IS  - 11
SP  - 1741
EP  - 1751
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ulamec, Stephan
A1  - Postberg, Frank
A1  - Sohl, Frank
A1  - Vera, Jean-Pierre de
A1  - Christoph, Waldmann
A1  - Lorenz, Ralph D.
A1  - Hellard, Hugo
A1  - Biele, Jens
A1  - Rettberg, Petra
T1  - Key technologies and instrumentation for subsurface exploration of ocean worlds
JF  - Space Science Reviews
N2  - In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter’s moon Europa and Saturn’s moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find life, if it exists. Technologically, such missions are extremely challenging. The required key technologies include power generation, communications, pressure resistance, radiation hardness, corrosion protection, navigation, miniaturization, autonomy, and sterilization and cleaning. Simpler mission concepts involve impactors and penetrators or – in the case of Enceladus – plume-fly-through missions.
Y1  - 2020
U6  - https://doi.org/10.1007/s11214-020-00707-5
SN  - 1572-9672
N1  - Corresponding author: Bernd Dachwald
VL  - 216
IS  - Art. 83
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - 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  - https://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  - Finger, Felix
A1  - Götten, Falk
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Mass, primary energy, and cost: the impact of optimization objectives on the initial sizing of hybrid-electric general aviation aircraft
JF  - CEAS Aeronautical Journal
N2  - For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft.
Y1  - 2020
U6  - https://doi.org/10.1007/s13272-020-00449-8
SN  - 1869-5590
N1  - Corresponding author: Felix Finger
VL  - 2020
IS  - 11
SP  - 713
EP  - 730
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Özsoylu, Dua
A1  - Kizildag, Sefa
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Effect of plasma treatment on the sensor properties of a light‐addressable potentiometric sensor (LAPS)
JF  - physica status solidi a : applications and materials sciences
N2  - A light-addressable potentiometric sensor (LAPS) is a field-effect-based (bio-) chemical sensor, in which a desired sensing area on the sensor surface can be defined by illumination. Light addressability can be used to visualize the concentration and spatial distribution of the target molecules, e.g., H+ ions. This unique feature has great potential for the label-free imaging of the metabolic activity of living organisms. The cultivation of those organisms needs specially tailored surface properties of the sensor. O2 plasma treatment is an attractive and promising tool for rapid surface engineering. However, the potential impacts of the technique are carefully investigated for the sensors that suffer from plasma-induced damage. Herein, a LAPS with a Ta2O5 pH-sensitive surface is successfully patterned by plasma treatment, and its effects are investigated by contact angle and scanning LAPS measurements. The plasma duration of 30 s (30 W) is found to be the threshold value, where excessive wettability begins. Furthermore, this treatment approach causes moderate plasma-induced damage, which can be reduced by thermal annealing (10 min at 300 °C). These findings provide a useful guideline to support future studies, where the LAPS surface is desired to be more hydrophilic by O2 plasma treatment.
Y1  - 2019
U6  - https://doi.org/10.1002/pssa.201900259
SN  - 1862-6319
N1  - Corresponding author: Torsten Wagner
VL  - 216
IS  - 20
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Baader, Fabian
A1  - Reiswich, M.
A1  - Bartsch, M.
A1  - Keller, D.
A1  - Tiede, E.
A1  - Keck, G.
A1  - Demircian, A.
A1  - Friedrich, M.
A1  - Dachwald, Bernd
A1  - Schüller, K.
A1  - Lehmann, R.
A1  - Chojetzki, R.
A1  - Durand, C.
A1  - Rapp, L.
A1  - Kowalski, Julia
A1  - Förstner, R.
T1  - VIPER - Student research on extraterrestrical ice penetration technology
T2  - Proceedings of the 2nd Symposium on Space Educational Activities
N2  - Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process.
Y1  - 2018
SP  - 1
EP  - 6
ER  - 
TY  - CHAP
A1  - Jung, Alexander
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts
T2  - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK
N2  - 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.
Y1  - 2018
ER  -