TY  - JOUR
A1  - Bayon, Arnau
A1  - Valero, Daniel
A1  - Garcia-Bartual, Rafael
A1  - Vallés-Morán, Francisco José
A1  - López-Jiménez, P. Amparo
T1  - Performance assessment of OpenFOAM and FLOW-3D in the numerical modeling of a low Reynolds number hydraulic jump
JF  - Environmental Modelling & Software
N2  - A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the air–water interface, consequently aeration is modeled using an Eulerian–Eulerian approach. Structured meshes of cubic elements are used to discretize the channel geometry. The numerical model accuracy is assessed comparing representative hydraulic jump variables (sequent depth ratio, roller length, mean velocity profiles, velocity decay or free surface profile) to experimental data. The model results are also compared to previous studies to broaden the result validation. Both codes reproduced the phenomenon under study concurring with experimental data, although special care must be taken when swirling flows occur. Both models can be used to reproduce the hydraulic performance of energy dissipation structures at low Reynolds numbers.
Y1  - 2016
SN  - 1364-8152
U6  - https://doi.org/10.1016/j.envsoft.2016.02.018
VL  - 80
SP  - 322
EP  - 335
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Takenaga, Shoko
A1  - Wagner, Patrick
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli K12 with a multi-​chamber-​based LAPS system
JF  - Physica status solidi (a)
N2  - On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable “down times” during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements.
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201533043
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1479
EP  - 1485
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Schreiber, Marc
A1  - Kraft, Bodo
A1  - Zündorf, Albert
T1  - Cost-efficient quality assurance of natural language processing tools through continuous monitoring with continuous integration
T2  - 3rd International Workshop on Software Engineering Research and Industrial Practice
Y1  - 2016
U6  - https://doi.org/10.1145/2897022.2897029
N1  - SER&IP’16, May 17 2016, Austin, TX, USA
SP  - 46
EP  - 52
ER  - 
TY  - CHAP
A1  - Hüning, Felix
T1  - Power Semiconductors for the automotive 48V board net
T2  - PCIM Europe 2016 Conference Proceedings
Y1  - 2016
SN  - 978-3-8007-4186-1
SP  - 1963
EP  - 1969
PB  - VDE Verl.
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Raue, Markus
A1  - Strobel, M.
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, R.
A1  - Wagner, Torsten
T1  - Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems
JF  - Physica status solidi (a)
N2  - Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201533056
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1520
EP  - 1525
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Pookhalil, Ali
A1  - Amoabediny, Ghassem
A1  - Tabesh, Hadi
A1  - Behbahani, Mehdi
A1  - Mottaghy, Khosrow
T1  - A new approach for semiempirical modeling of mechanical blood trauma
JF  - The international journal of artificial organs
N2  - Purpose
Two semi-empirical models were recently published, both making use of existing literature data, but each taking into account different physical phenomena that trigger hemolysis. In the first model, hemoglobin (Hb) release is described as a permeation procedure across the membrane, assuming a shear stress-dependent process (sublethal model). The second model only accounts for hemoglobin release that is caused by cell membrane breakdown, which occurs when red blood cells (RBC) undergo mechanically induced shearing for a period longer than the threshold time (nonuniform threshold model). In this paper, we introduce a model that considers the hemolysis generated by both these possible phenomena.
Methods
Since hemolysis can possibly be caused by permeation of hemoglobin through the RBC functional membrane as well as by release of hemoglobin from RBC membrane breakdown, our proposed model combines both these models. An experimental setup consisting of a Couette device was utilized for validation of our proposed model.
Results
A comparison is presented between the damage index (DI) predicted by the proposed model vs. the sublethal model vs. the nonthreshold model and experimental datasets. This comparison covers a wide range of shear stress for both human and porcine blood. An appropriate agreement between the measured DI and the DI predicted by the present model was obtained.
Conclusions
The semiempirical hemolysis model introduced in this paper aims for significantly enhanced conformity with experimental data. Two phenomenological outcomes become possible with the proposed approach: an estimation of the average time after which cell membrane breakdown occurs under the applied conditions, and a prediction of the ratio between the phenomena involved in hemolysis.
Y1  - 2016
U6  - https://doi.org/10.5301/ijao.5000474
SN  - 1724-6040
VL  - 39
IS  - 4
SP  - 171
EP  - 177
PB  - Sage
CY  - London
ER  - 
TY  - BOOK
A1  - Gebhardt, Andreas
A1  - Hötter, Jan-Steffen
T1  - Additive manufacturing : 3D printing for prototyping and manufacturing
Y1  - 2016
SN  - 978-1-56990-582-1 ; 978-1-56990-583-8
PB  - Hanser Publishers
CY  - Munich
ER  - 
TY  - CHAP
A1  - Kasper, Katharina
A1  - Schiffels, Johannes
A1  - Krafft, Simone
A1  - Kuperjans, Isabel
A1  - Elbers, Gereon
A1  - Selmer, Thorsten
T1  - Biogas Production on Demand Regulated by Butyric Acid Addition
T2  - IOP Conference Series: Earth and Environmental Science. Bd. 32
Y1  - 2016
U6  - https://doi.org/10.1088/1755-1315/32/1/012009
SN  - 1755-1315
N1  - ICARET 2016, International Conference on Advances in Renewable Energy and Technologies, Putrajaya, MY, Feb 23-25, 2016
VL  - 32
SP  - 012009/1
EP  - 012009/4
ER  - 
TY  - JOUR
A1  - Bertz, Morten
A1  - Schöning, Michael Josef
A1  - Molinnus, Denise
A1  - Homma, Takayuki
T1  - Influence of temperature, light, and H₂O₂ concentration on microbial spore inactivation: in-situ Raman spectroscopy combined with optical trapping
JF  - Physica status solidi (a) applications and materials science
N2  - To gain insight on chemical sterilization processes, the influence of temperature (up to 70 °C), intense green light, and hydrogen peroxide (H₂O₂) concentration (up to 30% in aqueous solution) on microbial spore inactivation is evaluated by in-situ Raman spectroscopy with an optical trap. Bacillus atrophaeus is utilized as a model organism. Individual spores are isolated and their chemical makeup is monitored under dynamically changing conditions (temperature, light, and H₂O₂ concentration) to mimic industrially relevant process parameters for sterilization in the field of aseptic food processing. While isolated spores in water are highly stable, even at elevated temperatures of 70 °C, exposure to H₂O₂ leads to a loss of spore integrity characterized by the release of the key spore biomarker dipicolinic acid (DPA) in a concentration-dependent manner, which indicates damage to the inner membrane of the spore. Intensive light or heat, both of which accelerate the decomposition of H₂O₂ into reactive oxygen species (ROS), drastically shorten the spore lifetime, suggesting the formation of ROS as a rate-limiting step during sterilization. It is concluded that Raman spectroscopy can deliver mechanistic insight into the mode of action of H₂O₂-based sterilization and reveal the individual contributions of different sterilization methods acting in tandem.
KW  - hydrogen peroxide
KW  - optical spore trapping
KW  - Raman spectroscopy
KW  - sterilization conditions
KW  - temperature
Y1  - 2024
U6  - https://doi.org/10.1002/pssa.202300866
SN  - 1862-6319 (Online)
SN  - 1862-6300 (Print)
N1  - Corresponding author: Michael J. Schöning
IS  - Early View
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schoenrock, Britt
A1  - Muckelt, Paul E.
A1  - Hastermann, Maria
A1  - Albracht, Kirsten
A1  - MacGregor, Robert
A1  - Martin, David
A1  - Gunga, Hans-Christian
A1  - Salanova, Michele
A1  - Stokes, Maria J.
A1  - Warner, Martin B.
A1  - Blottner, Dieter
T1  - Muscle stiffness indicating mission crew health in space
JF  - Scientific Reports
N2  - Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes.
KW  - Ageing
KW  - Anatomy
KW  - Muscle
KW  - Musculoskeletal system
KW  - Physiology
Y1  - 2024
U6  - https://doi.org/10.1038/s41598-024-54759-6
SN  - 2045-2322
N1  - Corresponding author: Dieter Blottner
VL  - 14
IS  - Article number: 4196
PB  - Springer Nature
CY  - London
ER  - 
TY  - RPRT
A1  - Drescher, Hans Paul
T1  - Turbulence - minimum dissipation and maximum macroscopic momentum exchange
N2  - The minimum dissipation requirement of the thermodynamics of irreversible processes is applied to characterize the existence of laminar and non-laminar, and the co-existence of laminar and turbulent flow zones. Local limitations of the different zones and three different forms of transition are defined. For the Couette flow a non-local “corpuscular” flow mechanism explains the logarithmic law-of-the-wall, maximum turbulent dimensions and a value x=0,415 for the v. Kármán constant. Limitations of the logarithmic law near the wall and in the centre of the experiment are interpreted.
Y1  - 2021
ER  - 
TY  - RPRT
A1  - Drescher, Hans Paul
T1  - The irreversible thermodynamic’s theorem of minimum entropy production applied to the laminar and the turbulent Couette flow
N2  - Analyzing thermodynamic non-equilibrium processes, like the laminar and turbulent fluid flow, the dissipation is a key parameter with a characteristic minimum condition. That is applied to characterize laminar and turbulent behaviour of the Couette flow, including its transition in both directions. The Couette flow is chosen as the only flow form with constant shear stress over the flow profile, being laminar, turbulent or both. The local dissipation defines quantitative and stable criteria for the transition and the existence of turbulence. There are basic results: The Navier Stokes equations cannot describe the experimental flow profiles of the turbulent Couette flow. But they are used to quantify the dissipation of turbulent fluctuation. The dissipation minimum requires turbulent structures reaching maximum macroscopic dimensions, describing turbulence as a “non-local” phenomenon. At the transition the Couette flow profiles and the shear stress change by a factor ≅ 5 due to a change of the “apparent” turbulent viscosity by a calculated factor ≅ 27. The resulting difference of the laminar and the turbulent profiles results in two different Reynolds numbers and different loci of transition, which are identified by calculation.
KW  - Turbulence
KW  - Transition
KW  - Minimum dissipation
Y1  - 2018
ER  - 
TY  - CHAP
A1  - Schneider, Dominik
A1  - Wisselink, Frank
A1  - Czarnecki, Christian
A1  - Nölle, Nikolai
T1  - Benefits and framework conditions for information-driven business models concerning the Internet of Things
T2  - Digitalization in companies
N2  - In the context of the increasing digitalization, the Internet of Things (IoT) is seen as a technological driver through which completely new business models can emerge in the interaction of different players. Identified key players include traditional industrial companies, municipalities and telecommunications companies. The latter, by providing connectivity, ensure that small devices with tiny batteries can be connected almost anywhere and directly to the Internet. There are already many IoT use cases on the market that provide simplification for end users, such as Philips Hue Tap. In addition to business models based on connectivity, there is great potential for information-driven business models that can support or enhance existing business models. One example is the IoT use case Park and Joy, which uses sensors to connect parking spaces and inform drivers about available parking spaces in real time. Information-driven business models can be based on data generated in IoT use cases. For example, a telecommunications company can add value by deriving more decision-relevant information – called insights – from data that is used to increase decision agility. In addition, insights can be monetized. The monetization of insights can only be sustainable, if careful attention is taken and frameworks are considered. In this chapter, the concept of information-driven business models is explained and illustrated with the concrete use case Park and Joy. In addition, the benefits, risks and framework conditions are discussed.
Y1  - 2024
SN  - 978-3-658-39093-8 (Print)
SN  - 978-3-658-39094-5 (eBook)
U6  - https://doi.org/10.1007/978-3-658-39094-5_5
SP  - 59
EP  - 75
PB  - Springer
CY  - Wiesbaden
ER  - 
TY  - JOUR
A1  - Polen, T.
A1  - Krämer, Marco
A1  - Bongaerts, Johannes
A1  - Wubbolts, Marcel
A1  - Wendisch, V. F.
T1  - The global gene expression response of Escherichia coli to L-phenylalanine
JF  - Journal of biotechnology
Y1  - 2005
SN  - 1873-4863 (E-Journal); 0168-1656 (Print)
VL  - Vol. 115
IS  - Iss. 3
SP  - 221
EP  - 237
ER  - 
TY  - JOUR
A1  - Bongaerts, Johannes
A1  - Krämer, Marco
A1  - Müller, Ulrike
A1  - Raeven, Leon
A1  - Wubbolts, Marcel
T1  - Metabolic engineering for microbial production of aromatic amino acids and derived compounds
JF  - Metabolic engineering
Y1  - 2001
SN  - 1096-7184 (E-Journal); 1096-7176 (Print)
VL  - Vol. 3
IS  - Iss. 4
SP  - 289
EP  - 300
ER  - 
TY  - THES
A1  - Bung, Daniel Bernhard
T1  - Imaging techniques for investigation of free-surface flows in hydraulic laboratories
N2  - This thesis aims at the presentation and discussion of well-accepted and new
imaging techniques applied to different types of flow in common hydraulic
engineering environments. All studies are conducted in laboratory conditions and
focus on flow depth and velocity measurements. Investigated flows cover a wide
range of complexity, e.g. propagation of waves, dam-break flows, slightly and fully
aerated spillway flows as well as highly turbulent hydraulic jumps.
Newimagingmethods are compared to different types of sensorswhich are frequently
employed in contemporary laboratory studies. This classical instrumentation as well
as the general concept of hydraulic modeling is introduced to give an overview on
experimental methods.
Flow depths are commonly measured by means of ultrasonic sensors, also known as
acoustic displacement sensors. These sensors may provide accurate data with high
sample rates in case of simple flow conditions, e.g. low-turbulent clear water flows.
However, with increasing turbulence, higher uncertainty must be considered.
Moreover, ultrasonic sensors can provide point data only, while the relatively large
acoustic beam footprint may lead to another source of uncertainty in case of
relatively short, highly turbulent surface fluctuations (ripples) or free-surface
air-water flows. Analysis of turbulent length and time scales of surface fluctuations
from point measurements is also difficult. Imaging techniques with different
dimensionality, however, may close this gap. It is shown in this thesis that edge
detection methods (known from computer vision) may be used for two-dimensional
free-surface extraction (i.e. from images taken through transparant sidewalls in
laboratory flumes). Another opportunity in hydraulic laboratory studies comes with
the application of stereo vision. Low-cost RGB-D sensors can be used to gather
instantaneous, three-dimensional free-surface elevations, even in flows with very
high complexity (e.g. aerated hydraulic jumps). It will be shown that the uncertainty
of these methods is of similar order as for classical instruments.
Particle Image Velocimetry (PIV) is a well-accepted and widespread imaging
technique for velocity determination in laboratory conditions. In combination with
high-speed cameras, PIV can give time-resolved velocity fields in 2D/3D or even as
volumetric flow fields. PIV is based on a cross-correlation technique applied to small
subimages of seeded flows. The minimum size of these subimages defines the
maximum spatial resolution of resulting velocity fields. A derivative of PIV for
aerated flows is also available, i.e. the so-called Bubble Image Velocimetry (BIV). This
thesis emphasizes the capacities and limitations of both methods, using relatively
simple setups with halogen and LED illuminations. It will be demonstrated that
PIV/BIV images may also be processed by means of Optical Flow (OF) techniques.
OF is another method originating from the computer vision discipline, based on the
assumption of image brightness conservation within a sequence of images. The
Horn-Schunck approach, which has been first employed to hydraulic engineering
problems in the studies presented herein, yields dense velocity fields, i.e. pixelwise
velocity data. As discussed hereinafter, the accuracy of OF competes well with PIV
for clear-water flows and even improves results (compared to BIV) for aerated flow
conditions. In order to independently benchmark the OF approach, synthetic images
with defined turbulence intensitiy are used.
Computer vision offers new opportunities that may help to improve the
understanding of fluid mechanics and fluid-structure interactions in laboratory
investigations. In prototype environments, it can be employed for obstacle detection
(e.g. identification of potential fish migration corridors) and recognition (e.g. fish
species for monitoring in a fishway) or surface reconstruction (e.g. inspection of
hydraulic structures). It can thus be expected that applications to hydraulic
engineering problems will develop rapidly in near future. Current methods have not
been developed for fluids in motion. Systematic future developments are needed to
improve the results in such difficult conditions.
Y1  - 2023
U6  - https://doi.org/10.25926/BUW/0-172
ER  - 
TY  - CHAP
A1  - Butenweg, Christoph
A1  - Marinković, Marko
A1  - Pavese, Alberto
A1  - Lanese, Igor
A1  - Hoffmeister, Benno
A1  - Pinkawa, Marius
A1  - Vulcu, Mihai-Cristian
A1  - Bursi, Oreste
A1  - Nardin, Chiara
A1  - Paolacci, Fabrizio
A1  - Quinci, Gianluca
A1  - Fragiadakis, Michalis
A1  - Weber, Felix
A1  - Huber, Peter
A1  - Renault, Philippe
A1  - Gündel, Max
A1  - Dyke, Shirley
A1  - Ciucci, M.
A1  - Marino, A.
T1  - Seismic performance of multi-component systems in special risk industrial facilities
T2  - Proceedings of the seventeenth world conference on earthquake engineering
N2  - Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of the process equipment and multiple and simultaneous release of hazardous substances in industrial facilities. Nevertheless, the design of industrial plants is inadequately described in recent codes and guidelines, as they do not consider the dynamic interaction between the structure and the installations and thus the effect of seismic response of the installations on the response of the structure and vice versa. The current code-based approach for the seismic design of industrial facilities is considered not enough for ensure proper safety conditions against exceptional event entailing loss of content and related consequences. Accordingly, SPIF project (Seismic Performance of Multi- Component Systems in Special Risk Industrial Facilities) was proposed within the framework of the European H2020 - SERA funding scheme (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe). The objective of the SPIF project is the investigation of the seismic behavior of a representative industrial structure equipped with complex process technology by means of shaking table tests. The test structure is a three-story moment resisting steel frame with vertical and horizontal vessels and cabinets, arranged on the three levels and connected by pipes. The dynamic behavior of the test structure and installations is investigated with and without base isolation. Furthermore, both firmly anchored and isolated components are taken into account to compare their dynamic behavior and interactions with each other. Artificial and synthetic ground motions are applied to study the seismic response at different PGA levels. After each test, dynamic identification measurements are carried out to characterize the system condition. The contribution presents the numerical simulations to calibrate the tests on the prototype, the experimental setup of the investigated structure and installations, selected measurement data and finally describes preliminary experimental results.
KW  - industrial facilities
KW  - piping
KW  - installations
KW  - seismic loading
KW  - earthquakes
Y1  - 2021
N1  - 17. World Conference on Earthquake Engineering, 17WCEE, Sendai, Japan, 2021-09-27 - 2021-10-02
ER  - 
TY  - INPR
A1  - Ringers, Christa
A1  - Bialonski, Stephan
A1  - Solovev, Anton
A1  - Hansen, Jan N.
A1  - Ege, Mert
A1  - Friedrich, Benjamin M.
A1  - Jurisch-Yaksi, Nathalie
T1  - Preprint: Local synchronization of cilia and tissue-scale cilia alignment are sufficient for global metachronal waves
T2  - bioRxiv
N2  - Motile cilia are hair-like cell extensions present in multiple organs of the body. How cilia coordinate their regular beat in multiciliated epithelia to move fluids remains insufficiently understood, particularly due to lack of rigorous quantification. We combine here experiments, novel analysis tools, and theory to address this knowledge gap. We investigate collective dynamics of cilia in the zebrafish nose, due to its conserved properties with other ciliated tissues and its superior accessibility for non-invasive imaging. We revealed that cilia are synchronized only locally and that the size of local synchronization domains increases with the viscosity of the surrounding medium. Despite the fact that synchronization is local only, we observed global patterns of traveling metachronal waves across the multiciliated epithelium. Intriguingly, these global wave direction patterns are conserved across individual fish, but different for left and right nose, unveiling a chiral asymmetry of metachronal coordination. To understand the implications of synchronization for fluid pumping, we used a computational model of a regular array of cilia. We found that local metachronal synchronization prevents steric collisions and improves fluid pumping in dense cilia carpets, but hardly affects the direction of fluid flow. In conclusion, we show that local synchronization together with tissue-scale cilia alignment are sufficient to generate metachronal wave patterns in multiciliated epithelia, which enhance their physiological function of fluid pumping.
Y1  - 2021
U6  - https://doi.org/10.1101/2021.11.23.469646
N1  - Veröffentlicht in eLife 12:e77701 (https://doi.org/10.7554/eLife.77701).
ER  - 
TY  - JOUR
A1  - Abbas, Karim
A1  - Balc, Nicolae
A1  - Bremen, Sebastian
A1  - Skupin, Marco
T1  - Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding
JF  - Journal of Manufacturing and Materials Processing
N2  - In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking.
KW  - additive manufacturing
KW  - fused filament fabrication
KW  - crystallization
KW  - polyetheretherketone
KW  - rapid tooling
Y1  - 2022
U6  - https://doi.org/10.3390/jmmp6050093
SN  - 2504-4494
N1  - The article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications
VL  - 6
IS  - 5
SP  - 1
EP  - 12
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Rosin, Julia
A1  - Kubalski, Thomas
A1  - Butenweg, Christoph
T1  - Seismic Design of cylindrical liquid storage tanks
T2  - Seismic design of industrial facilities : proceedings of the International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference) ; [Aachen, 26. - 27. September 2013] / Chair of Structural Statics and Dynamics, RWTH Aachen. Sven Klinkel ..., ed.
Y1  - 2014
SN  - 978-3-658-02810-7 (E-Book) ; 978-3-658-02809-1 (Print)
U6  - https://doi.org/10.1007/978-3-658-02810-7_36
SP  - 429
EP  - 440
PB  - Springer Vieweg
CY  - Wiesbaden
ER  -