TY - JOUR
AB - AbstractWe conducted an investigation into the palladium‐catalyzed carbon‐sulfur cross‐coupling reaction involving a 2‐bromothiophene derivative and potassium thioacetate as a substitute for hydrogen sulfide. This investigation utilized kinetic and computational methods. We synthesized two palladium complexes supported by the bisphosphane ligands bis(diphenylphosphino)ferrocene (DPPF) and bis(diisopropylphosphino)ferrocene (DiPPF), as well as their tentative intermediates in the catalytic cycle. Reaction rates were measured and then compared to computational predictions.
AU - Peschtrich, Sebastian
AU - Schoch, Roland
AU - Kuckling, Dirk
AU - Paradies, Jan
ID - 52541
IS - 8
JF - European Journal of Organic Chemistry
KW - Organic Chemistry
KW - Physical and Theoretical Chemistry
SN - 1434-193X
TI - A Comparative Kinetic and Computational Investigation of the Carbon‐Sulfur Cross Coupling of Potassium Thioacetate and 2‐Bromo Thiophene Using Palladium/Bisphosphine Complexes
VL - 27
ER -
TY - JOUR
AB - A series of substituted ferrocenyl boron derivatives was synthesized. The oxidation of the ferrocenyl unit resulted in a significant increase of the boron‐centered Lewis acidity. The neutral and cationic Lewis acids were characterized by NMR‐spectroscopy, crystal structure analysis and by computational methods. The new Lewis acids were then applied in the Meinwald rearrangement of epoxides, predominantly furnishing aldehydes as the kinetic products.
AU - Köring, Laura
AU - Birenheide, Bernhard
AU - Krämer, Felix
AU - Wenzel, Jonas O.
AU - Schoch, Roland
AU - Brehm, Martin
AU - Breher, Frank
AU - Paradies, Jan
ID - 52572
JF - European Journal of Inorganic Chemistry
KW - Inorganic Chemistry
SN - 1434-1948
TI - Synthesis of Ferrocenyl Boranes and their Application as Lewis Acids in Epoxide Rearrangements
ER -
TY - JOUR
AU - Bauch, Fabian
AU - Dong, Chuan-Ding
AU - Schumacher, Stefan
ID - 52534
IS - 8
JF - The Journal of Physical Chemistry C
KW - Surfaces
KW - Coatings and Films
KW - Physical and Theoretical Chemistry
KW - General Energy
KW - Electronic
KW - Optical and Magnetic Materials
SN - 1932-7447
TI - Dynamics of Electron–Hole Coulomb Attractive Energy and Dipole Moment of Hot Excitons in Donor–Acceptor Polymers
VL - 128
ER -
TY - GEN
AU - Dechert, Christopher
AU - Kenig, Eugeny
ID - 52573
TI - Der Einfluss von Mikrostrukturen auf die Flüssigkeitsausbreitung in strukturierten Packungen
ER -
TY - THES
AU - Frank, Maximilian
ID - 52576
SN - 978-3-8440-9444-2
TI - Simulationsgestützte Bestimmung und Optimierung der Mischgüte in der Einschneckenextrusion
VL - 2024,5
ER -
TY - GEN
AU - Hami Dindar, Iman
AU - Lutters, Nicole
AU - Kenig, Eugeny Y.
ID - 52579
TI - Wässrige Glucosaminlösung als neues Lösungsmittel zur CO2-Abscheidung
ER -
TY - JOUR
AB - In applications of piezoelectric actuators and sensors, the dependability and particularly the reliability throughout their lifetime are vital to manufacturers and end-users and are enabled through condition-monitoring approaches. Existing approaches often utilize impedance measurements over a range of frequencies or velocity measurements and require additional equipment or sensors, such as a laser Doppler vibrometer. Furthermore, the non-negligible effects of varying operating conditions are often unconsidered. To minimize the need for additional sensors while maintaining the dependability of piezoelectric bending actuators irrespective of varying operating conditions, an online diagnostics approach is proposed. To this end, time- and frequency-domain features are extracted from monitored current signals to reflect hairline crack development in bending actuators. For validation of applicability, the presented analysis method was evaluated on piezoelectric bending actuators subjected to accelerated lifetime tests at varying voltage amplitudes and under external damping conditions. In the presence of a crack and due to a diminished stiffness, the resonance frequency decreases and the root-mean-square amplitude of the current signal simultaneously abruptly drops during the lifetime tests. Furthermore, the piezoelectric crack surfaces clapping is reflected in higher harmonics of the current signal. Thus, time-domain features and harmonics of the current signals are sufficient to diagnose hairline cracks in the actuators.
AU - Aimiyekagbon, Osarenren Kennedy
AU - Bender, Amelie
AU - Hemsel, Tobias
AU - Sextro, Walter
ID - 51518
IS - 3
JF - Electronics
KW - piezoelectric transducer
KW - self-sensing
KW - fault detection
KW - diagnostics
KW - hairline crack
KW - condition monitoring
SN - 2079-9292
TI - Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions
VL - 13
ER -
TY - CHAP
AU - Fuchs, Christian
ED - Litschka, Michael
ED - Paganini, Claudia
ED - Rademacher, Lars
ID - 51364
SN - 9783748942801
T2 - Digitalisierte Massenkommunikation und Verantwortung
TI - Grundlagen einer Ethik des Radikalen Digitalen Humanismus
ER -
TY - JOUR
AU - Rezat, Sebastian
ID - 52584
JF - ZDM – Mathematics Education
TI - Research on curriculum resources in mathematics education: a survey of the field
ER -
TY - JOUR
AU - Bodden, Eric
AU - Pottebaum, Jens
AU - Fockel, Markus
AU - Gräßler, Iris
ID - 52587
IS - 1
JF - IEEE Security & Privacy
KW - Law
KW - Electrical and Electronic Engineering
KW - Computer Networks and Communications
SN - 1540-7993
TI - Evaluating Security Through Isolation and Defense in Depth
VL - 22
ER -
TY - GEN
AU - Treder, Alexandra
ID - 50208
T2 - Forschungsportal für Spracherwerb und Migration (daz-portal)
TI - Alexandra Treder (Universität Paderborn) rezensiert: Döll, Marion & Michalak, Magdalena (2023): Deutsch als Zweitsprache und inklusive Bildung. [Deutsch als Zweitsprache – Positionen, Perspektiven, Potenziale, Bd. 3]. Münster: Waxmann, 142 Seiten. ISBN 978-3-8309-4711-0.
VL - 26
ER -
TY - BOOK
ED - Tatari, Muna
ED - Husic, Ahmed
ID - 52590
TI - The Divine Attributes in Classical Islamic Thought and Con-temporary Islamic Theology
ER -
TY - JOUR
AB - Data-driven models for nonlinear dynamical systems based on approximating the underlying Koopman operator or generator have proven to be successful tools for forecasting, feature learning, state estimation, and control. It has become well known that the Koopman generators for control-affine systems also have affine dependence on the input, leading to convenient finite-dimensional bilinear approximations of the dynamics. Yet there are still two main obstacles that limit the scope of current approaches for approximating the Koopman generators of systems with actuation. First, the performance of existing methods depends heavily on the choice of basis functions over which the Koopman generator is to be approximated; and there is currently no universal way to choose them for systems that are not measure preserving. Secondly, if we do not observe the full state, we may not gain access to a sufficiently rich collection of such functions to describe the dynamics. This is because the commonly used method of forming time-delayed observables fails when there is actuation. To remedy these issues, we write the dynamics of observables governed by the Koopman generator as a bilinear hidden Markov model, and determine the model parameters using the expectation-maximization (EM) algorithm. The E-step involves a standard Kalman filter and smoother, while the M-step resembles control-affine dynamic mode decomposition for the generator. We demonstrate the performance of this method on three examples, including recovery of a finite-dimensional Koopman-invariant subspace for an actuated system with a slow manifold; estimation of Koopman eigenfunctions for the unforced Duffing equation; and model-predictive control of a fluidic pinball system based only on noisy observations of lift and drag.
AU - Otto, Samuel E.
AU - Peitz, Sebastian
AU - Rowley, Clarence W.
ID - 33461
IS - 1
JF - SIAM Journal on Applied Dynamical Systems
TI - Learning Bilinear Models of Actuated Koopman Generators from Partially-Observed Trajectories
VL - 23
ER -
TY - THES
AB - Ultraschallsysteme für das Herstellen für Bond- und Schweißverbindungen in der Halbleiterfertigung zeigen auf Grund des Betriebes unter hohen Anregungsniveaus nichtlineare Materialeigenschaften. Dabei wirken unterschiedliche Einflussfaktoren auf die elektrischen Eigenschaften und die mechanischen Übertragungscharakteristiken der Ultraschallsysteme ein. Die Herausforderungen ein solches geprägtes System auszulegen oder effizient und zuverlässig zu betreiben, sind aufgrund der Nichtlinearitäten relativ groß.
Da für die Beschreibung der nichtlinearen Materialbeziehungen nur wenige Modelle und kaum quantitative Angaben vorliegen, werden die komplexen Wechselwirkungen von Materialparametern, Geometrie und Vorspannung des Schwingers, Betriebsgrößen (Strom, Spannung), Temperatur und Prozesslasten durch systematische Untersuchungen von Keramiken und Langevin-Schwingern messtechnisch erfasst. Aus den Messergebnissen werden einerseits eindimensionale Modelle für Voruntersuchungen als auch vollständige Materialparametersätze für die Simulation mittels dreidimensionaler FE-Modelle hergeleitet.
Eine Methodik zur Ermittlung der Materialparameter und ein auf iterativen Simulationen von FE-Modellen basierendes Werkzeug zur Simulation der komplexen Wechselwirkungen werden vorgestellt. Anhand eines exemplarischen Ultraschallsystems wird gezeigt, dass die Wirkungen temperaturbedingter Vorspannungsverluste, Änderungen des elektrischen Klemmenverhaltens und Amplituden- und Frequenzänderungen während des Betriebes bei großen Amplituden und Prozesslasten durch die Variationen des Keramikvolumens und der Keramikposition positiv beeinflusst werden können.
AU - Dymel, Collin
ID - 52611
KW - Nichtlineares piezoelektrisches Verhalten
KW - Dehnungsabhängigkeit
KW - Vorspannungseinfluss
KW - Temperatureinfluss
KW - Lasteinfluss
KW - Langevin-Schwinger
KW - Ultraschallwandler
KW - Ultraschallbonden
KW - FEM-Modell
KW - Ultraschallschweißen
KW - BVD-Modell
SN - 9783844093964
TI - Modellbasierte Entwicklung von Ultraschallwandlern unter der Berücksichtigung von Nichtlinearitäten
VL - 16
ER -
TY - JOUR
AB - Resistance spot‐welded joints containing press‐hardened steels are seen to exhibit a fracture mode called total dome failure, where the weld nugget completely separates from one steel sheet along the weld nugget edge. The effect of weld nugget shape and material property gradients is studied based on damage mechanics modeling and experimental validation to shed light on the underlying influencing factors. For a three‐steel‐sheet spot‐welded joint combining DP600 (1.5 mm)–CR1900T (1.0 mm)–CR1900T (1.0 mm), experiments under shear loading reveal that fracture occurs in the DP600 sheet along the weld nugget edge. In subsequent numerical simulation studies with damage mechanics models whose parameters are independently calibrated for every involved material configuration, three variations of the geometrical joint configuration are considered—an approximation of the real joint, one variation with a steeper weld nugget shape, and one variation with a less pronounced gradient between weld nugget material and heat‐affected zone material properties. The results of the finite‐element simulations show that a shallower weld nugget and a more pronounced material gradient lead to a faster increase of plastic strain at the edge of the weld nugget and promote the occurrence of total dome failure.
AU - Schuster, Lilia
AU - Olfert, Viktoria
AU - Sherepenko, Oleksii
AU - Fehrenbach, Clemens
AU - Song, Shiyuan
AU - Hein, David
AU - Meschut, Gerson
AU - Biro, Elliot
AU - Münstermann, Sebastian
ID - 50726
JF - steel research international
KW - Materials Chemistry
KW - Metals and Alloys
KW - Physical and Theoretical Chemistry
KW - Condensed Matter Physics
SN - 1611-3683
TI - Influences of Weld Nugget Shape and Material Gradient on the Shear Strength of Resistance Spot‐Welded Joints
ER -
TY - THES
AU - Hassel, Richard
ID - 52501
TI - Zur Abscheidung von Tröpfchen-Aerosolen in filternden Abscheidern
ER -
TY - JOUR
AB - Der Beitrag stellt ein Qualifizierungsformat für (multi)professionelle Bildungsakteur*innen zur entwicklungsförderlichen Nutzung von Selbstinszenierungspraktiken vor. Die Konzeption und Entwicklung des Weiterbildungsformats ist im Rahmen eines Forschungs- und Entwicklungsprojekts für Jugendliche in ausbildungsvorbereitenden Bildungsgängen angesiedelt, die einen besonderen Förderbedarf im Zuge des Übergangs von der Schule in die Berufs- und Arbeitswelt aufweisen. Diese sollen durch offene und kreative Selbstdarstellungs- und Erhebungsformate dabei unterstützt werden, ihre Stärken zu erkennen, zu dokumentieren und sichtbar zu machen, sowie hierüber gleichsam für den Übergang Schule-Beruf gestärkt werden.
Wir stellen zunächst den Projektrahmen vor und schärfen in diesem Kontext den Zugang über eine Grundlegung zu Selbstinszenierung sowie deren Potenziale im Kontext der inklusiven Berufsbildung und zur Stärkung der Zielgruppe. Das im Projekt entwickelte Rahmenkonzept bietet eine Orientierung zur standort- respektive bildungsgangbezogenen Anpassung und stellt damit Herausforderungen und einen entsprechenden Qualifizierungsbedarf für Bildungsakteur*innen heraus. Darauf basierend stellen wir die konzeptionellen Grundlagen, die methodische und inhaltliche Ausgestaltung zum Ansatz der ‚Kollegialen Weiterbildung‘ zur entwicklungsförderlichen Nutzung von Selbstinszenierungspraktiken vor und adressieren u. a. das Zusammenspiel von innovativer Entwicklung, Schärfung von Rollen und Kompetenzentwicklung der Bildungsakteur*innen. Abschließend diskutieren wir die konzeptionellen Entwicklungen und den Implementations- und Transferansatz.
Abstract
The article presents a qualification format for multi-professional actors in the educational context on the developmental use of 'Selbstinszenierungspraktiken' (which means a combination of practices for self-awareness, self-realisation and self-acceptance in a process which we are developing in our project). The concept and development of the further education format is located within the framework of a research and development project for young people with wide-ranging needs in pre-vocational education units at the transition from school to work. They will be supported in recognizing, documenting and showing their strengths through open and creative self-expression and survey formats, as well as being strengthened for the transition from school to work.
First, we present the project framework and clarify the approach by a theoretical grounding of ‚Selbstinszenierung‘ (similar to a combination of self-awareness, self-realisation and self-acceptance) as well as its potentials in the context of inclusive vocational education by strengthening the target group. The developed framework provides a basis for the adaptation of the concept to a specific location or educational programme and highlights challenges and qualification needs for actors in the educational context. We present the conceptual basis, the methodological and content-related design of the collegial training approach on the developmental use of 'Selbstinszenierungspraktiken'. We address the interaction of innovative development, clarification of roles and competence development of actors in the educational context. Finally, we discuss the conceptual developments and the implementation and transfer approach.
AU - Kundisch, Heike
AU - Kremer, H.-Hugo
AU - Otto, Franziska
ID - 52620
IS - 3
JF - QfI - Qualifizierung für Inklusion. Online-Zeitschrift zur Forschung über Aus-, Fort- und Weiterbildung pädagogischer Fachkräfte
KW - General Medicine
SN - 2699-2477
TI - Selbstinszenierungspraktiken als Weg zu Stärkenorientierung, Selbstbestimmung und Teilhabe – eine Kollegiale Weiterbildung für multiprofessionelle Akteursgruppen im (inklusiven) Übergang Schule-Beruf
VL - 5
ER -
TY - JOUR
AB - AbstractFootball is one of the most played sports in the world and kicking with adequate accuracy increases the likelihood of winning a competition. Although studies with different target-directed movements underline the role of distinctive cortical activity on superior accuracy, little is known about cortical dynamics associated with kicking. Mobile electroencephalography is a popular tool to investigate cortical modulations during movement, however, inherent and artefact-related pitfalls may obscure the reliability of functional sources and their activity. The purpose of this study was therefore to describe consistent cortical dynamics underlying target-directed pass-kicks based on test–retest reliability estimates. Eleven participants performed a target-directed kicking task at two different sessions within one week. Electroencephalography was recorded using a 65-channel mobile system and behavioural data were collected including motion range, acceleration and accuracy performance. Functional sources were identified using independent component analysis and clustered in two steps with the components of first and subsequently both sessions. Reliability estimates of event-related spectral perturbations were computed pixel-wise for participants contributing with components of both sessions. The parieto-occipital and frontal clusters were reproducible for the same majority of the sample at both sessions. Their activity showed consistent alpha desyhronization and theta sychnronisation patterns with substantial reliability estimates revealing visual and attentional demands in different phases of kicking. The findings of our study reveal prominent cortical demands during the execution of a target-directed kick which may be considered in practical implementations and provide promising academic prospects in the comprehension and investigation of cortical activity associated with target-directed movements.
AU - Piskin, Daghan Yuksel
AU - Büchel, Daniel
AU - Lehmann, Tim
AU - Baumeister, Jochen
ID - 52631
JF - Cognitive Neurodynamics
KW - Cognitive Neuroscience
SN - 1871-4080
TI - Reliable electrocortical dynamics of target-directed pass-kicks
ER -
TY - GEN
AU - Zink, Timm Florian
ID - 52639
TI - Untersuchung des Lösungsmitellseinflusses auf die Synthese von Manganoxid-Nanopartikeln in der Flammenspraypyrolyse
ER -
TY - JOUR
AB - ELDIRK methods are defined to have an Explicit Last stage in the general Butcher array of Diagonal Implicit Runge-Kutta methods, with the consequence, that no additional system of equations must be solved, compared to the embedded RK method. Two general formulations for second- and third-order ELDIRK methods have been obtained recently in Mahnken [21] with specific schemes, e.g. for the embedded implicit Euler method, the embedded trapezoidal-rule and the embedded Ellsiepen method. In the first part of this paper, we investigate some general stability characteristics of ELDIRK methods, and it will be shown that the above specific RK schemes are not A-stable. Therefore, in the second part, the above-mentioned general formulations are used for further stability investigations, with the aim to construct new second- and third-order ELDIRK methods which simultaneously are A-stable. Two numerical examples are concerned with the curing for a thermosetting material and phase-field RVE modeling for crystallinity and orientation. The numerical results confirm the theoretical results on convergence order and stability.
AU - Mahnken, Rolf
AU - Westermann, Hendrik
ID - 52233
JF - Computational Mechanics
KW - Applied Mathematics
KW - Computational Mathematics
KW - Computational Theory and Mathematics
KW - Mechanical Engineering
KW - Ocean Engineering
KW - Computational Mechanics
SN - 0178-7675
TI - Construction of A-stable explicit last-stage diagonal implicit Runge–Kutta (ELDIRK) methods
ER -