Article
Refine
Year of publication
- 2024 (38)
- 2023 (76)
- 2022 (91)
- 2021 (109)
- 2020 (132)
- 2019 (120)
- 2018 (125)
- 2017 (108)
- 2016 (116)
- 2015 (126)
- 2014 (142)
- 2013 (139)
- 2012 (130)
- 2011 (182)
- 2010 (178)
- 2009 (199)
- 2008 (180)
- 2007 (176)
- 2006 (180)
- 2005 (188)
- 2004 (214)
- 2003 (154)
- 2002 (167)
- 2001 (157)
- 2000 (173)
- 1999 (153)
- 1998 (165)
- 1997 (154)
- 1996 (140)
- 1995 (147)
- 1994 (135)
- 1993 (107)
- 1992 (102)
- 1991 (74)
- 1990 (82)
- 1989 (79)
- 1988 (80)
- 1987 (77)
- 1986 (65)
- 1985 (59)
- 1984 (56)
- 1983 (47)
- 1982 (38)
- 1981 (39)
- 1980 (50)
- 1979 (43)
- 1978 (41)
- 1977 (22)
- 1976 (25)
- 1975 (18)
- 1974 (13)
- 1973 (6)
- 1972 (15)
- 1971 (7)
- 1970 (2)
- 1968 (2)
- 1967 (1)
Institute
- Fachbereich Medizintechnik und Technomathematik (1591)
- Fachbereich Wirtschaftswissenschaften (705)
- Fachbereich Elektrotechnik und Informationstechnik (638)
- Fachbereich Energietechnik (609)
- Fachbereich Chemie und Biotechnologie (602)
- INB - Institut für Nano- und Biotechnologien (542)
- Fachbereich Maschinenbau und Mechatronik (484)
- IfB - Institut für Bioengineering (449)
- Fachbereich Luft- und Raumfahrttechnik (379)
- Fachbereich Bauingenieurwesen (333)
Language
Document Type
- Article (5644) (remove)
Keywords
- Einspielen <Werkstoff> (7)
- Multimediamarkt (6)
- Rapid prototyping (5)
- avalanche (5)
- Earthquake (4)
- FEM (4)
- Finite-Elemente-Methode (4)
- LAPS (4)
- Rapid Prototyping (4)
- biosensors (4)
Learning from Brachelen
(2002)
Focus Artaud : Textcollage
(1997)
Welcome to the training: Actionist Respoke interaktiv by Michael Jonoschek und Rüdiger Schlömer
(2002)
Metamorphose und Morphing
(1995)
Museen und neue Medien
(1997)
Im Reich der Sinne
(2011)
Kunstwerke sowie ihre Präsentation und Vermittlung werden zunehmend von digitalen Technologien unterstützt. Virtuelle Ausstellungen, Internet-Projekte und komplexe Datenarchive stellen das Kunstwerk in einen medialen Kontext, der weit über das Moment einer technischen Reproduzierbarkeit hinausgeht. Das allgegenwärtige Konzept der Vernetzung dynamisiert Kunst, ihre Rezipienten und Ausstellungsorte. Die Beziehungen zwischen diesen Feldern werden mit Hilfe physiologischer Metaphern definiert und visualisiert. Frühere Speicher und Archive geraten in einen prozessualen Sog, in dem alles fluktuiert, sich kurzweilig verknüpft, auflöst und in permanente Dialoge mit seiner Umgebung tritt - das virtuelle Museum gerät in aktuellen Standortbestimmungen in die definitorische Nähe des Künstlichen Lebens.
The Kremer–Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.
Möglichkeiten der ottomotorischen Prozeßführung bei Verwendung des elektromechanischen Ventiltriebs
(1998)
Low emission zones and truck bans, the rising price of diesel and increases in road tolls: all of these factors are putting serious pressure on the transport industry. Commercial vehicle manufacturers and their suppliers are in the process of identifying new solutions to these challenges as part of their efforts to meet the EEV (enhanced environmentally friendly vehicle) limits, which are currently the most robust European exhaust and emissions standards for trucks and buses.
Purpose — to compare the chemical elemental composition of vitreous cavity content taken from cadaveric eyes compared to samples taken from the eyes with terminal stage refractory glaucoma with decompensated intraocular pressure (IOP). Material and methods. The vitreous contents of the eyes from 2 groups were studied. The 1st group included 15 cadaveric eyes; the 2nd group included 15 eyes with refractory glaucoma in the terminal stage of the disease with decompensated IOP in patients with hypertension pain. The vitreal content samples were taken in the course of antiglaucoma surgery aimed at preserving the eye as an organ and involving employment of drainage in the vitreous cavity. The study of virtual contents was carried out on energy dispersive spectrometer Oxford X-Max 50 integrated into scanning electron microscope Zeiss EVO LS10. Results. Increased concentrations of Kalium and Phosphorus were detected in the vitreous content of cadaveric eyes compared with the vitreal content from the eyes with terminal glaucoma with decompensated IOP taken in vivo (K — 0.172/0.093; P — 0.045/0.025 mmol/L). In the vitreous cavity in the eyes with end-stage glaucoma with decompensated IOP, the concentration of Nitrogen was higher in comparison with human cadaver eyes (2.030/1.424 mmol/L). Conclusion. The increased concentrations of Kalium and Phosphorus in the vitreous content of cadaveric eyes is associated with postmortem autolytic processes and with the release of intracellular content in the destruction of cell membranes. The increased Nitrogen concentration in the vitreal contents of the eyes with terminal stage glaucoma with decompensated IOP may be associated with the presence of osmotically active nitrogen-containing compounds in the eyes with increased IOP.
The hybrid K+/Ca2+ sensor based on laser scanned silicon transducer for multi-component analysis
(2002)
Modellfabrik im Zeichen der Automatisierungstechnik / Gall, Jan ; Enning, Manfred ; Abel, Dirk
(2008)
Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human–robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.
Universelle hydraulische Try-Out Presse / Teilprojekt A6 / Wiendahl, H.-P. ; Doege, E. ; Engels, E.
(1999)
Pressen - Vergleich zwischen Raumlenker- und Exzenterantrieb / Doege, Eckhart ; Engels, Elmar
(1999)
Pressen - Hubzahlregelung an Schnelläuferpressen mit Fuzzy-Reglern / Doege, Eckhart ; Engels, Elmar
(1998)
Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled Néel–Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays.
Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90% of the frequency mixing magnetic response signal is generated by the largest 10% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory.
Heating efficiency of magnetic nanoparticles decreases with gradual immobilization in hydrogels
(2019)
Many efforts are made worldwide to establish magnetic fluid hyperthermia (MFH) as a treatment for organ-confined tumors. However, translation to clinical application hardly succeeds as it still lacks of understanding the mechanisms determining MFH cytotoxic effects. Here, we investigate the intracellular MFH efficacy with respect to different parameters and assess the intracellular cytotoxic effects in detail. For this, MiaPaCa-2 human pancreatic tumor cells and L929 murine fibroblasts were loaded with iron-oxide magnetic nanoparticles (MNP) and exposed to MFH for either 30 min or 90 min. The resulting cytotoxic effects were assessed via clonogenic assay. Our results demonstrate that cell damage depends not only on the obvious parameters bulk temperature and duration of treatment, but most importantly on cell type and thermal energy deposited per cell during MFH treatment. Tumor cell death of 95% was achieved by depositing an intracellular total thermal energy with about 50% margin to damage of healthy cells. This is attributed to combined intracellular nanoheating and extracellular bulk heating. Tumor cell damage of up to 86% was observed for MFH treatment without perceptible bulk temperature rise. Effective heating decreased by up to 65% after MNP were internalized inside cells.
Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles’ magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing.