TY - JOUR
AB -
AU - Heck, Tamara
AU - Steinhardt, Isabel
AU - Rahal, Rima-Maria
AU - Schubotz, Moritz
AU - Scholl, Dominik
AU - Behrens, Sarah
ID - 43094
JF - Research Ideas and Outcomes
KW - Open Science
SN - 2367-7163
TI - Bootstrapping the Open Science culture: The fellowship approach
VL - 9
ER -
TY - GEN
ED - Meine, Sabine
ED - Otto, Arnold
ED - Süßmann, Johannes
ID - 35062
SN - 978-3-8260-7218-5
TI - Musiklandschaften zwischen Rhein und Weser. Pluralisierung und Verflechtung entlang des Hellwegs in der Frühen Neuzeit. Unter Mitarbeit v. Markus Lauert
VL - 13
ER -
TY - JOUR
AB - High-contrast slab waveguide Bragg gratings with 1D periodicity are investigated. For specific oblique excitation by semi-guided waves at sufficiently high angles of incidence, the idealized structures do not exhibit any radiative losses, such that reflectance and transmittance for the single port mode add strictly up to one. We consider a series of symmetric, fully and partly etched finite gratings, for parameters found in integrated silicon photonics. These can act as spectral filters with a reasonably flattop response. Apodization can lead to more box shaped reflectance and transmittance spectra. Together with a narrowband Fabry–Perot filter, these configurations are characterized by reflection bands, or transmittance peaks, with widths that span three orders of magnitude.
AU - Hammer, Manfred
AU - Farheen, Henna
AU - Förstner, Jens
ID - 43245
IS - 4
JF - Journal of the Optical Society of America B
KW - tet_topic_waveguide
SN - 0740-3224
TI - How to suppress radiative losses in high-contrast integrated Bragg gratings
VL - 40
ER -
TY - GEN
AU - Meier, Torsten
AU - Grisard, S.
AU - Trifonov, A.V.
AU - Rose, Hendrik
AU - Reichhardt, R.
AU - Reichelt, Matthias
AU - Schneider, C.
AU - Kamp, M.
AU - Höfling, S.
AU - Bayer, M.
AU - Akimov, I.A
ID - 43132
T2 - arxiv:2302.02480
TI - Temporal sorting of optical multi-wave-mixing processes in semiconductor quantum dots
ER -
TY - JOUR
AB - We present strong enhancement of third harmonic generation in an amorphous silicon metasurface consisting of elliptical nano resonators. We show that this enhancement originates from a new type of multi-mode Fano mechanism. These ‘Super-Fano’ resonances are investigated numerically in great detail using full-wave simulations. The theoretically predicted behavior of the metasurface is experimentally verified by linear and nonlinear transmission spectroscopy. Moreover, quantitative nonlinear measurements are performed, in which an absolute conversion efficiency as high as ηmax ≈ 2.8 × 10−7 a peak power intensity of 1.2 GW cm−2 is found. Compared to an unpatterned silicon film of the same thickness amplification factors of up to ~900 are demonstrated. Our results pave the way to exploiting a strong Fano-type multi-mode coupling in metasurfaces for high THG in potential applications.
AU - Hähnel, David
AU - Golla, Christian
AU - Albert, Maximilian
AU - Zentgraf, Thomas
AU - Myroshnychenko, Viktor
AU - Förstner, Jens
AU - Meier, Cedrik
ID - 44097
IS - 1
JF - Light: Science & Applications
KW - tet_topic_meta
SN - 2047-7538
TI - A multi-mode super-fano mechanism for enhanced third harmonic generation in silicon metasurfaces
VL - 12
ER -
TY - BOOK
AU - Bauer, Anna Brigitte
ID - 44083
SN - 978-3-8325-5625-9
TI - Experimentelle Kompetenz Physikstudierender. Entwicklung und erste Erprobung eines performanzorientierten Kompetenzstrukturmodells unter Nutzung qualitativer Methoden
VL - 352
ER -
TY - GEN
AU - Schürmann, Patrick
ID - 43374
TI - A Formal Comparison of Advanced Digital Signature Primitives
ER -
TY - JOUR
AB - Microcellular wood fiber reinforced polymers offer the possibility to reduce the use of fossil raw materials. In particular, thick-walled structures with thicknesses greater than 6 mm offer a high potential for weight savings. This study investigates the cell structures and mechanical properties of injection-molded test specimens. The influence of different thicknesses (6–10 mm) along with different chemical blowing agents (endothermic, exothermic) with varying dosages (0–2 wt%) is analyzed. The investigations reveal that exothermic chemical blowing agents form finer cells consistently to thin-walled structures than endothermic ones. Higher foaming agent content leads to higher pore fractions, with many small cells coalescing into a large open-pore cell network. The mechanical properties depend mainly on the pore content of the sample. The specific tensile properties deteriorate with the use of chemical blowing agents (CFA), whereas the sandwich structure produced with compact edge layers has a positive influence on the specific flexural properties.
AU - Moritzer, Elmar
AU - Flachmann, Felix
ID - 42515
IS - 3
JF - Journal of Cellular Plastics
KW - Materials Chemistry
KW - Polymers and Plastics
KW - General Chemistry
SN - 0021-955X
TI - Morphological and mechanical properties of foamed thick-walled Wood-Plastic-Composite structures
VL - 59
ER -
TY - JOUR
AU - Burmeister, Sascha Christian
AU - Schryen, Guido
ID - 42179
JF - Energy Systems
TI - Distribution Network Optimization: Predicting computation times to design scenario analysis for network operators
ER -
TY - JOUR
AB - Abstract
The accessibility to rheological parameters for concrete is becoming more and more relevant. This is mainly related to the constantly emerging challenges, such as not only the development of high-strength concretes is progressing very fast but also the simulation of the flow behaviour is of high importance. The main problem, however, is that the rheological characterisation of fresh concrete is not possible via commercial rheometers. The so-called concrete rheometers provide valuable relative values for comparing different concretes, but they cannot measure absolute values. Therefore, we developed an adaptive coaxial concrete rheometer (ACCR) that allows the measurement of fresh concrete with particles up to
d
max
=
5.5
mm
{d}_{{\rm{\max }}}=5.5\hspace{.5em}{\rm{mm}}
. The comparison of the ACCR with a commercial rheometer showed very good agreement for selected test materials (Newtonian fluid, shear thinning fluid, suspension, and yield stress fluid), so that self-compacting concrete was subsequently measured. Since these measurements showed a very high reproducibility, the rheological properties of the fresh concrete could be determined with high accuracy. The common flow models (Bingham (B), Herschel–Bulkley, modified Bingham (MB) models) were also tested for their applicability, with the Bingham and the modified Bingham model proving to be the best suitable ones.
AU - Josch, Sebastian
AU - Jesinghausen, Steffen
AU - Schmid, Hans-Joachim
ID - 43034
IS - 1
JF - Applied Rheology
KW - Condensed Matter Physics
KW - General Materials Science
SN - 1617-8106
TI - Development of an adaptive coaxial concrete rheometer and rheological characterisation of fresh concrete
VL - 33
ER -
TY - CHAP
AB - State education in honest tax payment can be understood as a facet of training in citizenship, i.e. as an attempt by the modern state to standardize the behavior of its citizens and to prevent deviations. Based on this Foucauldian understanding, this exploratory article examines tax education in the United States, Spain, and West Germany from the mid-1940s to the late 1980s. During this period, the USA asserted itself as the champion of tax education and Spain consistently tried to emulate this example, albeit with more modest means and different semantic strategies from as early as the 1960s, when it was still under a autoritarian regime. The FRG, however, completely discontinued its few early attempts at tax education from the mid-1950s onwards. Even during the economic crises and tax scandals of the 1970s, there was no relaunch of the programs. The article locates the reasons for this highly uneven development in the different ideal images of the citizen in the three states.
AU - Schönhärl, Korinna
AU - Düll, Nasrin
AU - Ramírez Lugo , Nadya Melina
ED - Sébastien, Guex
ED - Hadrien, Buclin
ID - 44249
T2 - Tax Evasion and Tax Havens since the Nineteenth Century
TI - Tax Education After WWII: How Spain, the USA, and West Germany Tried to Make Their Citizens Pay Honestly
ER -
TY - JOUR
AU - Neumann, Phillip
ID - 44321
IS - 5
JF - Zeitschrift für Heilpädagogik
KW - Inklusion
KW - Sonderpädagogik
KW - Bildung
KW - Bildungsstudien
KW - Integration
SN - 0513-9066
TI - Studien zu Schulleistungen und ihre Aufbereitung
VL - 74
ER -
TY - CHAP
AU - Meine, Sabine
AU - Otto, Arnold
AU - Süßmann, Johannes
ID - 35063
SN - 978-3-8260-7218-5
T2 - Musiklandschaften zwischen Rhein und Weser. Pluralisierung und Verflechtung entlang des Hellwegs in der Frühen Neuzeit. Unter Mitarbeit v. Markus Lauert
TI - Musiklandschaften zwischen Rhein und Weser – Einführung
ER -
TY - CONF
AU - Gharibian, Sevag
AU - Watson, James
AU - Bausch, Johannes
ID - 20841
T2 - Proceedings of the 40th International Symposium on Theoretical Aspects of Computer Science (STACS)
TI - The Complexity of Translationally Invariant Problems beyond Ground State Energies
VL - 254
ER -
TY - GEN
AB - For open world applications, deep neural networks (DNNs) need to be aware of
previously unseen data and adaptable to evolving environments. Furthermore, it
is desirable to detect and learn novel classes which are not included in the
DNNs underlying set of semantic classes in an unsupervised fashion. The method
proposed in this article builds upon anomaly detection to retrieve
out-of-distribution (OoD) data as candidates for new classes. We thereafter
extend the DNN by $k$ empty classes and fine-tune it on the OoD data samples.
To this end, we introduce two loss functions, which 1) entice the DNN to assign
OoD samples to the empty classes and 2) to minimize the inner-class feature
distances between them. Thus, instead of ground truth which contains labels for
the different novel classes, the DNN obtains a single OoD label together with a
distance matrix, which is computed in advance. We perform several experiments
for image classification and semantic segmentation, which demonstrate that a
DNN can extend its own semantic space by multiple classes without having access
to ground truth.
AU - Uhlemeyer, Svenja
AU - Lienen, Julian
AU - Hüllermeier, Eyke
AU - Gottschalk, Hanno
ID - 44512
T2 - arXiv:2305.00983
TI - Detecting Novelties with Empty Classes
ER -
TY - JOUR
AB - With enhancing digitalization, condition monitoring is used in an increasing number of application fields across various industrial sectors. By its application, increased reliability as well as reduced risks and costs can be achieved. Based on different approaches, technical systems are monitored and measured data is analyzed to enable condition-based or predictive maintenance. To this end, machine learning approaches are usually implemented to diagnose the health states or predict the health index of the monitored system. However, these trained models are often black-box models, not intuitively explainable for a human. To overcome this shortcoming, a model-based approach based on physics is developed for piezoelectric bending actuators. Such a model enables a transparent representation of the system. Moreover, the model-based approach is extended by a parameter-estimation to account for sudden changes in behavior e. g. caused by occurring cracks.
AU - Bender, Amelie
ID - 44672
JF - Sensors and Actuators A: Physical
KW - Condition Monitoring
KW - Model-based approach Diagnostics
KW - Varying conditions
KW - Explainability
KW - Piezoelectric bending actuators
SN - 0924-4247
TI - Model-based condition monitoring of piezoelectric bending actuators
VL - 357
ER -
TY - CONF
AU - Ahmed, Qazi Arbab
AU - Awais, Muhammad
AU - Platzner, Marco
ID - 44194
T2 - The 24th International Symposium on Quality Electronic Design (ISQED'23), San Francisco, Califorina USA
TI - MAAS: Hiding Trojans in Approximate Circuits
ER -
TY - JOUR
AB - Dispersion is present in every optical setup and is often an undesired effect, especially in nonlinear-optical experiments where ultrashort laser pulses are needed. Typically, bulky pulse compressors consisting of gratings or prisms are used
to address this issue by precompensating the dispersion of the optical components. However, these devices are only able to compensate for a part of the dispersion (second-order dispersion). Here, we present a compact pulse-shaping device that uses plasmonic metasurfaces to apply an arbitrarily designed spectral phase delay allowing for a full dispersion control. Furthermore, with specific phase encodings, this device can be used to temporally reshape the incident laser pulses into more complex pulse forms such as a double pulse. We verify the performance of our device by using an SHG-FROG measurement setup together with a retrieval algorithm to extract the dispersion that our device applies to an incident laser pulse.
AU - Geromel, René
AU - Georgi, Philip
AU - Protte, Maximilian
AU - Lei, Shiwei
AU - Bartley, Tim
AU - Huang, Lingling
AU - Zentgraf, Thomas
ID - 44044
IS - 8
JF - Nano Letters
KW - Mechanical Engineering
KW - Condensed Matter Physics
KW - General Materials Science
KW - General Chemistry
KW - Bioengineering
SN - 1530-6984
TI - Compact Metasurface-Based Optical Pulse-Shaping Device
VL - 23
ER -
TY - JOUR
AB - Hydrothermal carbonization (HTC) is an efficient thermochemical method for the conversion of organic feedstock to carbonaceous solids. HTC of different saccharides is known to produce microspheres (MS) with mostly Gaussian size distribution, which are utilized as functional materials in various applications, both as pristine MS and as a precursor for hard carbon MS. Although the average size of the MS can be influenced by adjusting the process parameters, there is no reliable mechanism to affect their size distribution. Our results demonstrate that HTC of trehalose, in contrast to other saccharides, results in a distinctly bimodal sphere diameter distribution consisting of small spheres with diameters of (2.1 ± 0.2) μm and of large spheres with diameters of (10.4 ± 2.6) μm. Remarkably, after pyrolytic post-carbonization at 1000 °C the MS develop a multimodal pore size distribution with abundant macropores > 100 nm, mesopores > 10 nm and micropores < 2 nm, which were examined by small-angle X-ray scattering and visualized by charge-compensated helium ion microscopy. The bimodal size distribution and hierarchical porosity provide an extraordinary set of properties and potential variables for the tailored synthesis of hierarchical porous carbons, making trehalose-derived hard carbon MS a highly promising material for applications in catalysis, filtration, and energy storage devices.
AU - Wortmann, Martin
AU - Keil, Waldemar
AU - Diestelhorst, Elise
AU - Westphal, Michael
AU - Haverkamp, René
AU - Brockhagen, Bennet
AU - Biedinger, Jan
AU - Bondzio, Laila
AU - Weinberger, Christian
AU - Baier, Dominik
AU - Tiemann, Michael
AU - Hütten, Andreas
AU - Hellweg, Thomas
AU - Reiss, Günter
AU - Schmidt, Claudia
AU - Sattler, Klaus
AU - Frese, Natalie
ID - 44837
IS - 21
JF - RSC Advances
KW - General Chemical Engineering
KW - General Chemistry
SN - 2046-2069
TI - Hard carbon microspheres with bimodal size distribution and hierarchical porosity via hydrothermal carbonization of trehalose
VL - 13
ER -
TY - CONF
AU - Dreiling, Dmitrij
AU - Itner, Dominik
AU - Hetkämper, Tim
AU - Birk, Carolin
AU - Gravenkamp, Hauke
AU - Henning, Bernd
ID - 45205
SN - 978-3-9819376-8-8
T2 - SMSI 2023 Conference
TI - Improved determination of viscoelastic material parameters using a pulse-echo measurement setup
ER -