2,392 Works

Membrane protein megahertz crystallography at the European XFEL

Christopher Gisriel, Jesse Coe, Romain Letrun, Oleksandr Yefanov, Cesar Luna-Chavez, Natasha E. Stander, Stella Lisova, Valerio Mariani, Manuela Kuhn, Steven Aplin, Thomas D Grant, Katerina Henrike Dörner, Tokushi Sato, Austin Echelmeier, Jorvani Cruz Villarreal, Mark S. Hunter, Max Oliver Wiedorn, Juraj Knoška, Victoria Mazalova, Shatabdi Roy-Chowdhury, Jay How Yang, Alex Jones, Richard Bean, Johan Bielecki, Yoonhee Kim … & Nadia Zatsepin

Identification of fully coupled anisotropic plasticity and damage constitutive equations using a hybrid experimental–numerical methodology with various triaxialities

Z. M. Yue, Celal Soyarslan, H. Badreddine, K. Saanouni & A. E. Tekkaya
A hybrid experimental–numerical methodology is presented for the parameter identification of a mixed nonlinear hardening anisotropic plasticity model fully coupled with isotropic ductile damage accounting for microcracks closure effects. In this study, three test materials are chosen: DP1000, CP1200, and AL7020. The experiments involve the tensile tests with smooth and notched specimens and two types of shear tests. The tensile tests with smooth specimens are conducted in different directions with respect to the rolling direction....

Investigation of an FFT-based solver applied to dynamic flowsheet simulation of agglomeration processes

Vasyl Skorych, Maksym Dosta, Ernst-Ulrich Hartge, Stefan Heinrich, Robin Ahrens & Sabine Le Borne
The growth of particles due to agglomeration is often mathematically described by population balance equations. The numerical evaluation of these equations and applying new methods to their solution is an area of increasing interest. In this contribution, a new approach for solving the agglomeration population balance model based on a separable approximation of the agglomeration kernel and a fast Fourier transformation is investigated. Its applicability within a dynamic flowsheet simulation of continuous agglomeration processes with...

Eine Methode zur strategischen Planung modularer Produktprogramme

Henry Jonas
Durch den Wechsel von Verkäufer- zu Käufermärkten ist es für die meisten Unternehmen erforderlich, eine hohe Varianz individualisierter Produkte anzubieten. Allerdings führt eine hohe Produktvarianz in der Regel zu einer steigenden Komplexität innerhalb des Unternehmens. Ein zentraler Ansatz muss es deshalb sein, die angebotene Vielfalt marktgerecht auszurichten und die angebotene, extern hohe Varianz unternehmensintern zu reduzieren. Im Rahmen dieser Arbeit wird eine neue Methode zur strategischen Planung modularer Produktprogramme vorgestellt. In der ersten Phase der...

Flexible and automated production of sandwich panels for aircraft interior

Henrik Eschen, Martin Harnisch & Thorsten Schüppstuhl

Label-free photonic biosensors fabricated with low-loss hydrogenated amorphous silicon resonators

Timo Lipka, Lennart Wahn, Hoc Khiem Trieu, Lutz Hilterhaus & Jörg Müller
The precise detection of chemicals and biomolecules is of great interest in the areas of biotechnology and medical diagnostics. Thus, there is a need for highly sensitive, small area, andlow-cost sensors. We fabricated and optically characterized hydrogenated amorphous silicon photonic resonators for label-free lab-on-chip biosensors. The sensing was performed with small-footprint microdisk and microring resonators that detect a refractive-index change via the evanescent electric field. Homogeneous sensing with NaCl and surface-sensing experiments with immobilized bovine...

Energy-efficient wavelength multiplexers based on hydrogenated amorphous silicon resonators

Timo Lipka, Lennart Moldenhauer, Jörg Müller & Hoc Khiem Trieu
Optical multiplexers are key components of modern data transmission systems that have evolved from long-haul fiber communication applications down to the photonic interconnect level on-chip, which demand high bandwidths and low-power photonic links with small footprint. We present compact, energy-efficient, and high-bandwidth optical add/drop multiplexers that are based on complementary metal-oxide-semiconductor (CMOS) backend-compatible hydrogenated amorphous silicon microring resonators. We study the manufacturing nonuniformity of the as-fabricated devices and analyze the static power consumption that is...

Low-pressure micro-mechanical re-adaptation device sustainably and effectively improves locomotor recovery from complete spinal cord injury

Veronica Estrada, Julia Krebbers, Christian Voss, Nicole Brazda, Heinrich Blazyca, Jennifer Illgen, Klaus Seide, Christian Jürgens, Jörg Müller, Rudolf Martini, Hoc Khiem Trieu & Hans Werner Müller
Traumatic spinal cord injuries result in impairment or even complete loss of motor, sensory and autonomic functions. Recovery after complete spinal cord injury is very limited even in animal models receiving elaborate combinatorial treatments. Recently, we described an implantable microsystem (microconnector) for low-pressure re-adaption of severed spinal stumps in rat. Here we investigate the long-term structural and functional outcome following microconnector implantation after complete spinal cord transection. Re-adaptation of spinal stumps supports formation of a...

Iron oxide-based nanostructured ceramics with tailored magnetic and mechanical properties: Development of mechanically robust, bulk superparamagnetic materials

Diletta Giuntini, Elisa Torresani, Kyle T. Chan, Malte Blankenburg, Lucien Saviot, Büsra Bor, Berta Domènech Garcia, Meir Shachar, Martin Müller, Eugene A. Olevsky, Javier E. Garay & Gerold A. Schneider
Nanostructured iron-oxide based materials with tailored mechanical and magnetic behavior are produced in bulk form. By applying ultra-fast heating routines via spark plasma sintering (SPS) to supercrystalline pellets, materials with an enhanced combination of elastic modulus, hardness and saturation magnetization are achieved. Supercrystallinity-namely the arrangement of the constituent nanoparticles into periodic structures-is achieved through self-assembly of the organically-functionalized iron oxide nanoparticles. The optimization of the following SPS regime allows the control of organics' removal, necking,...

Toward a gecko-inspired, climbing soft robot

Lars Schiller, Arthur Seibel & Josef Schlattmann

Partial least squares structural equation modeling-based discrete choice modeling: an illustration in modeling retailer choice

Joseph F. Hair, Christian M. Ringle, Siegfried Gudergan, Andreas Fischer, Christian Nitzl & Con Menictas
Commonly used discrete choice model analyses (e.g., probit, logit and multinomial logit models) draw on the estimation of importance weights that apply to different attribute levels. But directly estimating the importance weights of the attribute as a whole, rather than of distinct attribute levels, is challenging. This article substantiates the usefulness of partial least squares structural equation modeling (PLS-SEM) for the analysis of stated preference data generated through choice experiments in discrete choice modeling. This...

Code-inherent traffic shaping for hard real-time systems

Dominic Paul Oehlert, Selma Saidi & Heiko Falk

Computation of thickness and mechanical properties of interconnected structures: accuracy, deviations, and approaches for correction

Claudia Richert, Anton Odermatt & Norbert Huber

On the deterministic prediction of water waves

Marco Klein, Matthias Dudek, Günther F. Clauss, Sören Ehlers, Jasper Behrendt, Norbert Hoffmann & Miguel Onorato
This paper discusses the potential of deterministic wave prediction as one basic module for decision support of offshore operations. Therefore, methods of different complexity—the linear wave solution, the non-linear Schrödinger equation (NLSE) of two different orders and the high-order spectral method (HOSM)—are presented in terms of applicability and limitations of use. For this purpose, irregular sea states with varying parameters are addressed by numerical simulations as well as model tests in the controlled environment of...

Dataset -- Towards a gecko-inspired, climbing soft robot

Lars Schiller

Numerical analysis of shear crack propagation in a concrete beam without transverse reinforcement

Günter Axel Rombach & Adrian Faron

The impact of modular product architectures in PSS design: a systematic literature review

Christoph Rennpferdt, Erik Greve & Dieter Krause

Can cloud point-based enrichment, preservation, and detection methods help to bridge gaps in aquatic nanometrology?

Lars Duester, Anne-Lena Fabricius, Sven Jakobtorweihen, Allan Philippe, Florian Weigl, Andreas Wimmer, Michael Schuster & Muhammad Faizan Nazar
Coacervate-based techniques are intensively used in environmental analytical chemistry to enrich and extract different kinds of analytes. Most methods focus on the total content or the speciation of inorganic and organic substances. Size fractionation is less commonly addressed. Within coacervate-based techniques, cloud point extraction (CPE) is characterized by a phase separation of non-ionic surfactants dispersed in an aqueous solution when the respective cloud point temperature is exceeded. In this context, the feature article raises the...

Technological University Libraries in the '90s

Thomas Hapke
15. Biennial IATUL-Conference vom 19. bis 23. Juli 1993 an der Universitätsbibliothek der Technischen Universität Hamburg-Harburg. Ein persönlicher Tagungsbericht

Predicting industrial-scale cell culture seed trains–A Bayesian framework for model fitting and parameter estimation, dealing with uncertainty in measurements and model parameters, applied to a nonlinear kinetic cell culture model, using an MCMC method

Tanja Hernández Rodríguez, Christoph Posch, Julia Schmutzhard, Josef Stettner, Claus Weihs, Ralf Pörtner & Björn Frahm
Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. For production of biopharmaceuticals in suspension cell culture, seed trains are required to increase cell number from cell thawing up to production scale. Because cultivation conditions during the seed train have a significant impact on cell performance in production scale, seed train design, monitoring, and development of optimization strategies is important. This can be facilitated by model-assisted prediction methods, whereby the performance depends on the prediction accuracy,...

An analytical model for wireless mesh networks with collision-free TDMA and finite queues

Florian Kauer & Volker Turau
Wireless mesh networks are a promising technology for connecting sensors and actuators with high flexibility and low investment costs. In industrial applications, however, reliability is essential. Therefore, two time-slotted medium access methods, DSME and TSCH, were added to the IEEE 802.15.4 standard. They allow collision-free communication in multi-hop networks and provide channel hopping for mitigating external interferences. The slot schedule used in these networks is of high importance for the network performance. This paper supports...

Cooperative source seeking and level curve tracking for multi-agent systems

Esteban Emilio Rosero García
In this thesis, the cooperative source seeking and the level curve tracking problem using a group of agents under an undirected constrained communication topology are addressed. To solve it, distributed control algorithms enabling agents to drive towards an unknown scalar field's source or to move along a desired scalar field's level curve are proposed. Each agent estimates a gradient direction based only on neighbouring agents' relative position information and scalar field's concentration values at their...

Linear parameter-varying control of systems of high complexity

Christian Hoffmann
Der Entwurf von Reglern für komplexe nichtlineare Regelstrecken im Framework Linear Parameterveränderlicher (LPV) Systeme führt zu hohem Modellierungs-, Synthese- und Implementierungsaufwand. Zugleich können Regelstrecken durch eine verteilte Struktur ähnlicher interagierender LPV-Subsysteme eine hohe Komplexität erlangen. Die vorliegende Arbeit behandelt Methoden zur Modellierung komplexer LPV-Systeme, sowohl im Sinne nichtlinearer, als auch verteilter Regelstrecken, und beinhaltet verbesserte Entwurfswerkzeuge, die zu niedrigerem Synthese- und Implementierungsaufwand führen.

Principle of Verified Numerical Computations

Shin’ichi Oishi, K. Ichihara, M. Kashiwagi, K. Kimura, X. Liu, H. Masai, Y. Morikura, Takeshi Ogita, K. Ozaki, Siegfried M. Rump, K. Sekine, A. Takayasu & N. Yamanaka

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