TY  - JOUR
A1  - Mandekar, Swati
A1  - Holland, Abigail
A1  - Thielen, Moritz
A1  - Behbahani, Mehdi
A1  - Melnykowycz, Mark
T1  - Advancing towards Ubiquitous EEG, Correlation of In-Ear EEG with Forehead EEG
JF  - Sensors
N2  - Wearable EEG has gained popularity in recent years driven by promising uses outside of clinics and research. The ubiquitous application of continuous EEG requires unobtrusive form-factors that are easily acceptable by the end-users. In this progression, wearable EEG systems have been moving from full scalp to forehead and recently to the ear. The aim of this study is to demonstrate that emerging ear-EEG provides similar impedance and signal properties as established forehead EEG. EEG data using eyes-open and closed alpha paradigm were acquired from ten healthy subjects using generic earpieces fitted with three custom-made electrodes and a forehead electrode (at Fpx) after impedance analysis. Inter-subject variability in in-ear electrode impedance ranged from 20 kΩ to 25 kΩ at 10 Hz. Signal quality was comparable with an SNR of 6 for in-ear and 8 for forehead electrodes. Alpha attenuation was significant during the eyes-open condition in all in-ear electrodes, and it followed the structure of power spectral density plots of forehead electrodes, with the Pearson correlation coefficient of 0.92 between in-ear locations ELE (Left Ear Superior) and ERE (Right Ear Superior) and forehead locations, Fp1 and Fp2, respectively. The results indicate that in-ear EEG is an unobtrusive alternative in terms of impedance, signal properties and information content to established forehead EEG.
KW  - in-ear EEG
KW  - correlation
KW  - forehead EEG
KW  - impedance spectroscopy
KW  - biopotential electrodes
Y1  - 2022
U6  - https://doi.org/10.3390/s22041568
SN  - 1424-8220
VL  - 22
IS  - 4
SP  - 1
EP  - 19
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Maurischat, Andreas
T1  - Algebraic independence of the Carlitz period and its hyperderivatives
JF  - Journal of Number Theory
KW  - Drinfeld modules
KW  - Periods
KW  - t-modules
KW  - Transcendence
KW  - Higher derivations
Y1  - 2022
U6  - https://doi.org/10.1016/j.jnt.2022.01.006
SN  - 0022-314X
VL  - 240
SP  - 145
EP  - 162
PB  - Elsevier
CY  - Orlando, Fla.
ER  - 
TY  - JOUR
A1  - Stäudle, Benjamin
A1  - Seynnes, Olivier
A1  - Laps, Guido
A1  - Brüggemann, Gert-Peter
A1  - Albracht, Kirsten
T1  - Altered gastrocnemius contractile behavior in former achilles tendon rupture patients during walking
JF  - Frontiers in Physiology
N2  - Achilles tendon rupture (ATR) remains associated with functional limitations years after injury. Architectural remodeling of the gastrocnemius medialis (GM) muscle is typically observed in the affected leg and may compensate force deficits caused by a longer tendon. Yet patients seem to retain functional limitations during—low-force—walking gait. To explore the potential limits imposed by the remodeled GM muscle-tendon unit (MTU) on walking gait, we examined the contractile behavior of muscle fascicles during the stance phase. In a cross-sectional design, we studied nine former patients (males; age: 45 ± 9 years; height: 180 ± 7 cm; weight: 83 ± 6 kg) with a history of complete unilateral ATR, approximately 4 years post-surgery. Using ultrasonography, GM tendon morphology, muscle architecture at rest, and fascicular behavior were assessed during walking at 1.5 m⋅s–1 on a treadmill. Walking patterns were recorded with a motion capture system. The unaffected leg served as control. Lower limbs kinematics were largely similar between legs during walking. Typical features of ATR-related MTU remodeling were observed during the stance sub-phases corresponding to series elastic element (SEE) lengthening (energy storage) and SEE shortening (energy release), with shorter GM fascicles (36 and 36%, respectively) and greater pennation angles (8° and 12°, respectively). However, relative to the optimal fascicle length for force production, fascicles operated at comparable length in both legs. Similarly, when expressed relative to optimal fascicle length, fascicle contraction velocity was not different between sides, except at the time-point of peak series elastic element (SEE) length, where it was 39 ± 49% lower in the affected leg. Concomitantly, fascicles rotation during contraction was greater in the affected leg during the whole stance-phase, and architectural gear ratios (AGR) was larger during SEE lengthening. Under the present testing conditions, former ATR patients had recovered a relatively symmetrical walking gait pattern. Differences in seen AGR seem to accommodate the profound changes in MTU architecture, limiting the required fascicle shortening velocity. Overall, the contractile behavior of the GM fascicles does not restrict length- or velocity-dependent force potentials during this locomotor task.
KW  - tendon rupture
KW  - muscle fascicle behavior
KW  - walking gait
KW  - force generation
KW  - ultrasound imaging
Y1  - 2022
U6  - https://doi.org/10.3389/fphys.2022.792576
SN  - 1664-042X
VL  - 13
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Kotliar, Konstantin
A1  - Ortner, Marion
A1  - Conradi, Anna
A1  - Hacker, Patricia
A1  - Hauser, Christine
A1  - Günthner, Roman
A1  - Moser, Michaela
A1  - Muggenthaler, Claudia
A1  - Diehl-Schmid, Janine
A1  - Priller, Josef
A1  - Schmaderer, Christoph
A1  - Grimmer, Timo
T1  - Altered retinal cerebral vessel oscillation frequencies in Alzheimer's disease compatible with impaired amyloid clearance
JF  - Neurobiology of Aging
N2  - Retinal vessels are similar to cerebral vessels in their structure and function. Moderately low oscillation frequencies of around 0.1 Hz have been reported as the driving force for paravascular drainage in gray matter in mice and are known as the frequencies of lymphatic vessels in humans. We aimed to elucidate whether retinal vessel oscillations are altered in Alzheimer's disease (AD) at the stage of dementia or mild cognitive impairment (MCI). Seventeen patients with mild-to-moderate dementia due to AD (ADD); 23 patients with MCI due to AD, and 18 cognitively healthy controls (HC) were examined using Dynamic Retinal Vessel Analyzer. Oscillatory temporal changes of retinal vessel diameters were evaluated using mathematical signal analysis. Especially at moderately low frequencies around 0.1 Hz, arterial oscillations in ADD and MCI significantly prevailed over HC oscillations and correlated with disease severity. The pronounced retinal arterial vasomotion at moderately low frequencies in the ADD and MCI groups would be compatible with the view of a compensatory upregulation of paravascular drainage in AD and strengthen the amyloid clearance hypothesis.
KW  - Alzheimer's disease
KW  - Retinal vessel analysis
KW  - Vasomotions
KW  - Pulsations
KW  - Mild cognitive impairment
Y1  - 2022
U6  - https://doi.org/10.1016/j.neurobiolaging.2022.08.012
SN  - 0197-4580
VL  - 120
SP  - 117
EP  - 127
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Colombo, Daniele
A1  - Drira, Slah
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis
JF  - International Journal for Numerical Methods in Engineering
N2  - Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.
KW  - distorted element
KW  - ES-FEM
KW  - FS-FEM
KW  - non-simplex S-FEM elements
KW  - S-FEM
Y1  - 2022
U6  - https://doi.org/10.1002/nme.7126
SN  - 1097-0207
VL  - 124
IS  - 2
SP  - 402
EP  - 433
PB  - Wiley
CY  - Chichester
ER  - 
TY  - JOUR
A1  - Vahidpour, Farnoosh
A1  - Alghazali, Yousef
A1  - Akca, Sevilay
A1  - Hommes, Gregor
A1  - Schöning, Michael Josef
T1  - An Enzyme-Based Interdigitated Electrode-Type Biosensor for Detecting Low Concentrations of H₂O₂ Vapor/Aerosol
JF  - Chemosensors
N2  - This work introduces a novel method for the detection of H₂O₂ vapor/aerosol of low concentrations, which is mainly applied in the sterilization of equipment in medical industry. Interdigitated electrode (IDE) structures have been fabricated by means of microfabrication techniques. A differential setup of IDEs was prepared, containing an active sensor element (active IDE) and a passive sensor element (passive IDE), where the former was immobilized with an enzymatic membrane of horseradish peroxidase that is selective towards H₂O₂. Changes in the IDEs’ capacitance values (active sensor element versus passive sensor element) under H₂O₂ vapor/aerosol atmosphere proved the detection in the concentration range up to 630 ppm with a fast response time (<60 s). The influence of relative humidity was also tested with regard to the sensor signal, showing no cross-sensitivity. The repeatability assessment of the IDE biosensors confirmed their stable capacitive signal in eight subsequent cycles of exposure to H₂O₂ vapor/aerosol. Room-temperature detection of H₂O₂ vapor/aerosol with such miniaturized biosensors will allow a future three-dimensional, flexible mapping of aseptic chambers and help to evaluate sterilization assurance in medical industry.
Y1  - 2022
U6  - https://doi.org/10.3390/chemosensors10060202
SN  - 2227-9040
N1  - This article belongs to the Special Issue "Bioinspired Chemical Sensors and Micro-Nano Devices"
VL  - 10
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Schuba, Marko
A1  - Höfken, Hans-Wilhelm
A1  - Linzbach, Sophie
T1  - An ICS Honeynet for Detecting and Analyzing Cyberattacks in Industrial Plants
T2  - 2021 International Conference on Electrical, Computer and Energy Technologies (ICECET)
N2  - Cybersecurity of Industrial Control Systems (ICS) is an important issue, as ICS incidents may have a direct impact on safety of people or the environment. At the same time the awareness and knowledge about cybersecurity, particularly in the context of ICS, is alarmingly low. Industrial honeypots offer a cheap and easy to implement way to raise cybersecurity awareness and to educate ICS staff about typical attack patterns. When integrated in a productive network, industrial honeypots may not only reveal attackers early but may also distract them from the actual important systems of the network. Implementing multiple honeypots as a honeynet, the systems can be used to emulate or simulate a whole Industrial Control System. This paper describes a network of honeypots emulating HTTP, SNMP, S7communication and the Modbus protocol using Conpot, IMUNES and SNAP7. The nodes mimic SIMATIC S7 programmable logic controllers (PLCs) which are widely used across the globe. The deployed honeypots' features will be compared with the features of real SIMATIC S7 PLCs. Furthermore, the honeynet has been made publicly available for ten days and occurring cyberattacks have been analyzed
KW  - Conpot
KW  - honeypot
KW  - honeynet
KW  - ICS
KW  - cybersecurity
Y1  - 2022
SN  - 978-1-6654-4231-2
SN  - 978-1-6654-4232-9
U6  - https://doi.org/10.1109/ICECET52533.2021.9698746
N1  - 2021 International Conference on Electrical, Computer and Energy Technologies (ICECET). 09-10 December 2021. Cape Town, South Africa.
PB  - IEEE
ER  - 
TY  - CHAP
A1  - Pütz, Sebastian
A1  - Baier, Ralph
A1  - Brauner, Philipp
A1  - Brillowski, Florian
A1  - Dammers, Hannah
A1  - Liehner, Luca
A1  - Mertens, Alexander
A1  - Rodemann, Niklas
A1  - Schneider, Sebastian
A1  - Schollemann, Alexander
A1  - Steuer-Dankert, Linda
A1  - Vervier, Luisa
A1  - Gries, Thomas
A1  - Leicht-Scholten, Carmen
A1  - Nagel, Saskia K.
A1  - Piller, Frank T.
A1  - Schuh, Günther
A1  - Ziefle, Martina
A1  - Nitsch, Verena
T1  - An interdisciplinary view on humane interfaces for digital shadows in the internet of production
T2  - 2022 15th International Conference on Human System Interaction (HSI)
N2  - Digital shadows play a central role for the next generation industrial internet, also known as Internet of Production (IoP). However, prior research has not considered systematically how human actors interact with digital shadows, shaping their potential for success. To address this research gap, we assembled an interdisciplinary team of authors from diverse areas of human-centered research to propose and discuss design and research recommendations for the implementation of industrial user interfaces for digital shadows, as they are currently conceptualized for the IoP. Based on the four use cases of decision support systems, knowledge sharing in global production networks, human-robot collaboration, and monitoring employee workload, we derive recommendations for interface design and enhancing workers’ capabilities. This analysis is extended by introducing requirements from the higher-level perspectives of governance and organization.
KW  - digital twin
KW  - digital shadow
KW  - cyber-physical production system
KW  - human-machine interface
Y1  - 2022
SN  - 978-1-6654-6823-7 (Print)
SN  - 978-1-6654-6822-0 (Online)
U6  - https://doi.org/10.1109/HSI55341.2022.9869467
SN  - 2158-2246 (Print)
SN  - 2158-2254 (Online)
N1  - 15th International Conference on Human System Interaction (HSI), 28-31 July 2022, Melbourne, Australia.
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Harris, Isaac
A1  - Kleefeld, Andreas
T1  - Analysis and computation of the transmission eigenvalues with a conductive boundary condition
JF  - Applicable Analysis
N2  - We provide a new analytical and computational study of the transmission eigenvalues with a conductive boundary condition. These eigenvalues are derived from the scalar inverse scattering problem for an inhomogeneous material with a conductive boundary condition. The goal is to study how these eigenvalues depend on the material parameters in order to estimate the refractive index. The analytical questions we study are: deriving Faber–Krahn type lower bounds, the discreteness and limiting behavior of the transmission eigenvalues as the conductivity tends to infinity for a sign changing contrast. We also provide a numerical study of a new boundary integral equation for computing the eigenvalues. Lastly, using the limiting behavior we will numerically estimate the refractive index from the eigenvalues provided the conductivity is sufficiently large but unknown.
KW  - Boundary integral equations
KW  - Inverse spectral problem
KW  - Conductive boundary condition
KW  - Transmission eigenvalues
Y1  - 2020
U6  - https://doi.org/10.1080/00036811.2020.1789598
SN  - 1563-504X
VL  - 101
IS  - 6
SP  - 1880
EP  - 1895
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - CHAP
A1  - Gedle, Yibekal
A1  - Schmitz, Mark
A1  - Gielen, Hans
A1  - Schmitz, Pascal
A1  - Herrmann, Ulf
A1  - Teixeira Boura, Cristiano José
A1  - Mahdi, Zahra
A1  - Caminos, Ricardo Alexander Chico
A1  - Dersch, Jürgen
T1  - Analysis of an integrated CSP-PV hybrid power plant
T2  - SOLARPACES 2020
N2  - In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] – [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution.
KW  - Hybrid energy system
KW  - Power plants
KW  - Electricity generation
KW  - Energy storage
KW  - Associated liquids
Y1  - 2022
SN  - 978-0-7354-4195-8
U6  - https://doi.org/10.1063/5.0086236
SN  - 1551-7616 (online)
SN  - 0094-243X (print)
N1  - SOLARPACES 2020: 26th International Conference on Concentrating Solar Power and Chemical Energy Systems, 28 September–2 October 2020, Freiburg, Germany
IS  - 2445 / 1
PB  - AIP conference proceedings / American Institute of Physics
CY  - Melville, NY
ER  - 
TY  - JOUR
A1  - Funke, Harald
A1  - Esch, Thomas
A1  - Roosen, Petra
T1  - Antriebssystemanpassungen zur Verwendung von LPG als Flugkraftstoff
JF  - Motortechnische Zeitschrift (MTZ)
N2  - Auch in der allgemeinen Luftfahrt wäre es wünschenswert, die bereits vorhandenen Verbrennungsmotoren mit weniger CO₂-trächtigen Kraftstoffen als dem heute weit verbreiteten Avgas 100LL betreiben zu können. Es ist anzunehmen, dass im Vergleich die unter Normalbedingungen gasförmigen Kraftstoffe CNG, LPG oder LNG deutlich weniger Emissionen produzieren. Erforderliche Antriebssystemanpassungen wurden im Rahmen eines Forschungsprojekts an der FH Aachen untersucht.
Y1  - 2022
U6  - https://doi.org/10.1007/s35146-021-0778-2
VL  - 2022
IS  - 83
SP  - 58
EP  - 62
PB  - Springer Nature
CY  - Basel
ER  - 
TY  - CHAP
A1  - Crookston, Brian M.
A1  - Bung, Daniel Bernhard
ED  - Ortega-Sánchez, Miguel
T1  - Application of RGB-D cameras in hydraulic laboratory studies
T2  - Proceedings of the 39th IAHR World Congress
N2  - Non-intrusive measuring techniques have attained a lot of interest in relation to both hydraulic modeling and prototype applications. Complimenting acoustic techniques, significant progress has been made for the development of new optical methods. Computer vision techniques can help to extract new information, e. g. high-resolution velocity and depth data, from videos captured with relatively inexpensive, consumer-grade cameras. Depth cameras are sensors providing information on the distance between the camera and observed features. Currently, sensors with different working principles are available. Stereoscopic systems reference physical image features (passive system) from two perspectives; in order to enhance the number of features and improve the results, a sensor may also estimate the disparity from a detected light to its original projection (active stereo system). In the current study, the RGB-D camera Intel RealSense D435, working on such stereo vision principle, is used in different, typical hydraulic modeling applications. All tests have been conducted at the Utah Water Research Laboratory. This paper will demonstrate the performance and limitations of the RGB-D sensor, installed as a single camera and as camera arrays, applied to 1) detect the free surface for highly turbulent, aerated hydraulic jumps, for free-falling jets and for an energy dissipation basin downstream of a labyrinth weir and 2) to monitor local scours upstream and downstream of a Piano Key Weir. It is intended to share the authors’ experiences with respect to camera settings, calibration, lightning conditions and other requirements in order to promote this useful, easily accessible device. Results will be compared to data from classical instrumentation and the literature. It will be shown that even in difficult application, e. g. the detection of a highly turbulent, fluctuating free-surface, the RGB-D sensor may yield similar accuracy as classical, intrusive probes.
Y1  - 2022
SN  - 978-90-832612-1-8
U6  - https://doi.org/10.3850/IAHR-39WC252171192022964
SN  - 2521-7119 (print)
SN  - 2521-716X (online)
N1  - 39th IAHR World Congress, 19. - 24. Juni 2022, Granada
SP  - 5127
EP  - 5133
PB  - International Association for Hydro-Environment Engineering and Research (IAHR)
CY  - Madrid
ER  - 
TY  - CHAP
A1  - Eggert, Mathias
A1  - Dyong, Julian
T1  - Applying process mining in small and medium sized IT enterprises – challenges and guidelines
T2  - Business Process Management, 20th International Conference, BPM 2022, Proceedings
N2  - Process mining gets more and more attention even outside large enterprises and can be a major benefit for small and medium sized enterprises (SMEs) to gain competitive advantages. Applying process mining is challenging, particularly for SMEs because they have less resources and process maturity. So far, IS researchers analyzed process mining challenges with a focus on larger companies. This paper investigates the application of process mining by means of a case study and sheds light into the particular challenges of an IT SME. The results reveal 13 SME process mining challenges and seven guidelines to address them. In this way, the paper contributes to the understanding of process mining application in SME and shows similarities and differences to larger companies.
KW  - Process mining
KW  - Challenges
KW  - Guidelines
KW  - SME
KW  - Case Study
Y1  - 2022
SN  - 978-3-031-16103-2
U6  - https://doi.org/10.1007/978-3-031-16103-2_11
N1  - International Conference on Business Process Management (BPM 2022), Münster, Germany, Sept. 11-16, 2022
SP  - 125
EP  - 142
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Ojovan, Michael I.
A1  - Steinmetz, Hans-Jürgen
T1  - Approaches to Disposal of Nuclear Waste
JF  - Energies
N2  - We present a concise mini overview on the approaches to the disposal of nuclear waste currently used or deployed. The disposal of nuclear waste is the end point of nuclear waste management (NWM) activities and is the emplacement of waste in an appropriate facility without the intention to retrieve it. The IAEA has developed an internationally accepted classification scheme based on the end points of NWM, which is used as guidance. Retention times needed for safe isolation of waste radionuclides are estimated based on the radiotoxicity of nuclear waste. Disposal facilities usually rely on a multi-barrier defence system to isolate the waste from the biosphere, which comprises the natural geological barrier and the engineered barrier system. Disposal facilities could be of a trench type, vaults, tunnels, shafts, boreholes, or mined repositories. A graded approach relates the depth of the disposal facilities’ location with the level of hazard. Disposal practices demonstrate the reliability of nuclear waste disposal with minimal expected impacts on the environment and humans.
KW  - borehole disposal
KW  - geological disposal
KW  - disposal facility
KW  - retention time
KW  - nuclear waste
Y1  - 2022
U6  - https://doi.org/10.3390/en15207804
SN  - 1996-1073
N1  - This article belongs to the Special Issue "Treatment of Radioactive Waste and Sustainability Energy"
VL  - 15
IS  - 20
PB  - MDPI
CY  - Basel
ER  - 
TY  - THES
A1  - Vogt, Lena
T1  - Archäologischer Restaurator : Ausstellungskonzept Römisch-Germanisches Museum Köln
N2  - Alte, geschichtsrelevante und thematisch angeordnete Objekte, welche man in den Vitrinen der Museen betrachten kann, das kennt sicher jeder. Doch wie kommen diese Artefakte eigentlich in die Vitrinen? Welche Menschen sind dafür verantwortlich, dass wir diese Kulturgüter bestaunen können? In diesem temporären Ausstellungskonzept für das Römisch-Germanische Museum Köln geht es darum, die sonst verborgene Arbeit der Restauratoren des Museums für die Besucher:innen sichtbar zu machen, ihnen genauere Einblicke in die Arbeit mit ihren Anforderungen zu geben und Restaurierungsprozesse auf zu zeigen. Diese Arbeit demonstriert, wie es abseits der Öffentlichkeit aussieht und wer dafür verantwortlich ist, dass wir einen Einblick in die vergangenen Zeit erhalten können. Das Projekt zeigt eine mögliche Bespielung des Museums, wie das Berufsbild der Restauratoren in die Dauerausstellung integriert werden könnte.
KW  - Ausstellungsdesign
KW  - Fotografie
KW  - Museumsdesign
KW  - Restauratoren
KW  - Restaurierung
Y1  - 2022
PB  - FH Aachen
CY  - Aachen
ER  - 
TY  - JOUR
A1  - Vahidpour, Farnoosh
A1  - Guthman, Eric
A1  - Arreola, Julia
A1  - Alghazali, Yousef H. M.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Assessment of Various Process Parameters for Optimized Sterilization Conditions Using a Multi-Sensing Platform
JF  - Foods
N2  - In this study, an online multi-sensing platform was engineered to simultaneously evaluate various process parameters of food package sterilization using gaseous hydrogen peroxide (H₂O₂). The platform enabled the validation of critical aseptic parameters. In parallel, one series of microbiological count reduction tests was performed using highly resistant spores of B. atrophaeus DSM 675 to act as the reference method for sterility validation. By means of the multi-sensing platform together with microbiological tests, we examined sterilization process parameters to define the most effective conditions with regards to the highest spore kill rate necessary for aseptic packaging. As these parameters are mutually associated, a correlation between different factors was elaborated. The resulting correlation indicated the need for specific conditions regarding the applied H₂O₂ gas temperature, the gas flow and concentration, the relative humidity and the exposure time. Finally, the novel multi-sensing platform together with the mobile electronic readout setup allowed for the online and on-site monitoring of the sterilization process, selecting the best conditions for sterility and, at the same time, reducing the use of the time-consuming and costly microbiological tests that are currently used in the food package industry.
KW  - spore kill rate
KW  - sterility
KW  - aseptic parameters
KW  - multi-sensing platform
KW  - gaseous hydrogen peroxide
Y1  - 2022
U6  - https://doi.org/10.3390/foods11050660
SN  - 2304-8158
N1  - This article belongs to the Special Issue "Sensors and Biosensors Application for Food Industries"
VL  - 11
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Hoffmann, Andreas
A1  - Uhl, Matthias
A1  - Ceblin, Maximilian
A1  - Rohrbach, Felix
A1  - Bansmann, Joachim
A1  - Mallah, Marcel
A1  - Heuermann, Holger
A1  - Jacob, Timo
A1  - Kuehne, Alexander J.C.
T1  - Atmospheric pressure plasma-jet treatment of PAN-nonwovens—carbonization of nanofiber electrodes
JF  - C - Journal of Carbon Research
N2  - Carbon nanofibers are produced from dielectric polymer precursors such as polyacrylonitrile (PAN). Carbonized nanofiber nonwovens show high surface area and good electrical conductivity, rendering these fiber materials interesting for application as electrodes in batteries, fuel cells, and supercapacitors. However, thermal processing is slow and costly, which is why new processing techniques have been explored for carbon fiber tows. Alternatives for the conversion of PAN-precursors into carbon fiber nonwovens are scarce. Here, we utilize an atmospheric pressure plasma jet to conduct carbonization of stabilized PAN nanofiber nonwovens. We explore the influence of various processing parameters on the conductivity and degree of carbonization of the converted nanofiber material. The precursor fibers are converted by plasma-jet treatment to carbon fiber nonwovens within seconds, by which they develop a rough surface making subsequent surface activation processes obsolete. The resulting carbon nanofiber nonwovens are applied as supercapacitor electrodes and examined by cyclic voltammetry and impedance spectroscopy. Nonwovens that are carbonized within 60 s show capacitances of up to 5 F g⁻¹.
Y1  - 2022
U6  - https://doi.org/10.3390/c8030033
SN  - 2311-5629
N1  - This article belongs to the Collection "Nanoporous Carbon Materials for Advanced Technological Applications"
VL  - 8
IS  - 3
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Hoffmann, Andreas
A1  - Rohrbach, Felix
A1  - Uhl, Matthias
A1  - Ceblin, Maximilian
A1  - Bauer, Thomas
A1  - Mallah, Marcel
A1  - Jacob, Timo
A1  - Heuermann, Holger
A1  - Kuehne, Alexander J. C.
T1  - Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing
JF  - Journal of Applied Polymer Science
N2  - Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance.
KW  - batteries and fuel cells
KW  - electrospinning
KW  - fibers
KW  - irradiation
KW  - porous materials
Y1  - 2022
U6  - https://doi.org/10.1002/app.52887
SN  - 0021-8995 (Print)
SN  - 1097-4628 (Online)
N1  - Weitere Informationen: Bundesministerium für Bildung und Forschung, Fördernummer: 13XP5036E. Deutsche Forschungsgemeinschaft, Fördernummern: 390874152, 441209207, 327886311
VL  - 139
IS  - 37
SP  - 1
EP  - 9
PB  - Wiley
ER  - 
TY  - BOOK
A1  - Laack, Walter van
T1  - Aufruf zum Nachdenken: Corona und neue Kriege – Wie kann die Menschheit überleben?
T1  - Call for Reflection: Corona and New Wars – How can Mankind survive?
Y1  - 2022
SN  - 978-3-936624-56-4
N1  - Dritter Band der Buchreihe “Vorträge & Einsichten – Lectures & Insights” und hier das zweite “Upside-Down-Buch”: Deutsche und englische Version in einem Buch.
PB  - van Laack GmbH
CY  - Aachen
ER  - 
TY  - JOUR
A1  - Golland, Alexander
T1  - Aufsicht und Rechtsdurchsetzung bei unzulässigem Einsatz von Cookies & Co. unter Geltung des TTDSG
JF  - DSB Datenschutz-Berater
KW  - Informationstechnik
KW  - Rechtsgebiet
KW  - Datenschutz
KW  - Bundesrepublik Deutschland
Y1  - 2022
SN  - 0170-7256
VL  - 46
IS  - 1
SP  - 14
EP  - 16
PB  - DFV Mediengruppe
CY  - Frankfurt a.M.
ER  -