Publication Server of Aschaffenburg University
Not a member yet
1531 research outputs found
Sort by
Keine Heilbarkeit eines Mangels unzureichender interkommunaler Abstimmung im ergänzenden Verfahren nach §215 a BauGB, Urteilsbesprechung
No full textEin Besucherexperiment zur astronomischen Röntgenoptik für das Deutsche Röntgen-Museum
No full textDas Deutsche Röntgen-Museum in Remscheid ist eine weltweit einzigartige Institution, die das Leben und Werk des ersten Nobelpreisträgers Wilhelm Conrad Röntgen und die Auswirkungen seiner Entdeckung der Röntgenstrahlung erforscht und dokumentiert. Als integraler Bestandteil des Museums bietet das Museumslabor RöLab die Möglichkeit, durch eigene Experimente praktische Erfahrungen rund um Röntgenstrahlung, Optik und Technik zu sammeln. Im Rahmen eines gemeinsamen Entwicklungsprojekts konzipieren Studierende der Technischen Hochschule Aschaffenburg derzeit ein Besucherexperiment zur astronomischen Röntgenoptik für das Museumslabor. Optische Experimente mit sichtbarem Licht verdeutlichen das Fokussierungsprinzip von Röntgenteleskopen, z.B. für Weitwinkeloptiken nach dem Lobster-Eye Prinzip. Auf Schautafeln werden Optiken verschiedener Typen von Teleskopen mit Begleittexten und zugehörigen Abbildungen erläutert sowie moderne Röntgenobservatorien wie CHANDRA, XMM-Newton und eROSITA übersichtlich dargestellt. Das neue Besucherexperiment soll nach seiner Realisierung junge Forscherinnen und Forscher für die faszinierende Welt der Röntgenoptik und der Röntgenastronomie begeistern.Poste
Ellipsometrical characterization of poly-dopamine layers considered for technical applications
No full textAlthough the organic molecule dopamine (3,4-dihydroxyphenethylamine) is commonly known as the “hormone of happiness”, thin films of poly-dopamine also have interesting technical properties. When produced by dip coating, the self-organizing layers grow in a reproducible thickness of single or multiple molecule monolayers of a few nanometer thickness only. In this work, we introduce a method of determining the layer thickness of poly-dopamine on mirrors for astronomical X-ray telescopes. This work is based on spectroscopic ellipsometry measurements and involves the development of an optical model for the poly-dopamine layers including the dielectric function. Thereby the complex refractive index of the produced layers was determined, covering the range from the ultraviolet to the near infrared spectral region. These measurement results and the corresponding technical challenges are presented in this contribution. Furthermore, an outlook to potential technical applications of this interesting material is given and poly-dopamine layers will make scientist and engineers hopefully happy as an innovative and fascinating technical solution for the future
Spectral measurements and life science experiments using extreme radiation exposures at high altitude
No full textThe ASTRABAX project ("Aschaffenburg Stratospheric Balloon Experiment"), being funded for the years 2024 to 2026, is designed as a multimodal platform for the investigation of radiation exposures at high altitude. Miniature UV-VIS spectrometers observe the UV-C spectral region. The platform also contains a radiation dosimetry, a power source for on-board electronics, and common shielding setups for multiple spectral combinations. The effects of combinations of high- and low-energy rays on human cells haven´t been sufficiently investigated and described so far. Investigations under such conditions are realistic and crucial for high altitude flights in the atmosphere, for space flights as well as for comparable exposures on other objects of the solar system, and even for exoplanet habitats to some extent.Poste
Femtosecond reductive Laser Sintering under multiple focus conditions for rapid production of conductive copper layers
No full textReductive laser sintering is an advantageous alternative to conventional precious metal- or mask-based processes for the electrification of polymers and has been demonstrated in a variety of sensor applications. Ultrashort pulsed lasers promise precise control of the energy applied during sintering and ablation. Besides fine tracks, microelectronic circuits include wide contact pads, which leads to time-consuming processing with small laser spot sizes. The use of larger focal diameters, which results in wider lines and thus a higher metallization rate, is accompanied by a loss of structure resolution. We show the influence of focusing on the femtosecond reductive laser sintering of copper(II) oxide on cyclic olefin copolymers. While small focus diameters down to 23 µm provide high accuracy, increasing the laser power and the focus diameter up to 400 µm significantly accelerates the process, first by enlarging the line width and second by increasing the scanning speed due to the exposure time. Two-dimensional copper electrodes for 23 µm and 200 µm focal diameters were generated by hatching individual lines and compared with respect to their morphology. The enlarged spot can be used for high-speed generation of electrodes with a surface conductivity of 117 mΩ/sq. Hybrid processes with production under combined focusing conditions are presented for the first time
Modellierung des Antriebsstrangs einer Textilmaschine zum Zweck der modellbasierten Steuerung
No full textZur Produktion von gewirkten Textilien werden mehrere Nadeln auf eine Legebarre gesetzt, die durch Servoantriebe positioniert werden. Aufgrund der erzwungenen Bewegung kann der Antriebsstrang bei hohen Drehzahlen zur Schwingung angeregt werden. Die richtige Wahl der Steuerkurven ist daher eine sehr wichtige und anspruchsvolle Aufgabe, die durch ein Antriebsstrangmodell unterstützt werden soll. Dafür wird am Beispiel eines Teststands ein Modell des Antriebsstranges in MATLAB/Simulink® entwickelt. Für das Antriebsstrangmodell müssen eine geeignete Modellordnung und Modellparameter gewählt werden. Die unbekannten Modellparameter werden durch eine Parameteridentifikation ermittelt. Mit einer Validierung wird ein geeignetes Anregungsspektrum für die Bestimmung der Modellordnung und die Parameteridentifikation ermittelt
Condensed Matter Systems Exposed to Radiation: Multiscale Theory, Simulations, and Experiment
No full textThis roadmap reviews the new, highly interdisciplinary research field studying the behavior of condensed matter systems exposed to radiation. The Review highlights several recent advances in the field and provides a roadmap for the development of the field over the next decade. Condensed matter systems exposed to radiation can be inorganic, organic, or biological, finite or infinite, composed of different molecular species or materials, exist in different phases, and operate under different thermodynamic conditions. Many of the key phenomena related to the behavior of irradiated systems are very similar and can be understood based on the same fundamental theoretical principles and computational approaches. The multiscale nature of such phenomena requires the quantitative description of the radiation-induced effects occurring at different spatial and temporal scales, ranging from the atomic to the macroscopic, and the interlinks between such descriptions. The multiscale nature of the effects and the similarity of their manifestation in systems of different origins necessarily bring together different disciplines, such as physics, chemistry, biology, materials science, nanoscience, and biomedical research, demonstrating the numerous interlinks and commonalities between them. This research field is highly relevant to many novel and emerging technologies and medical applications
Impact of Gold Nanoparticles and Ionizing Radiation on Whole Chromatin Organization as Detected by Single-Molecule Localization Microscopy
No full textIn radiation tumor therapy, irradiation, on one hand, should cause cell death to the tumor. On the other hand, the surrounding non-tumor tissue should be maintained unaffected. Therefore, methods of local dose enhancements are highly interesting. Gold nanoparticles, which are preferentially uptaken by very-fast-proliferating tumor cells, may enhance damaging. However, the results in the literature obtained from cell culture and animal tissue experiments are very contradictory, i.e., only some experiments reveal increased cell killing but others do not. Thus, a better understanding of cellular mechanisms is required. Using the breast cancer cell model SkBr3, the effects of gold nanoparticles in combination with ionizing radiation on chromatin network organization were investigated by Single-Molecule Localization Microscopy (SMLM) and applications of mathematical topology calculations (e.g., Persistent Homology, Principal Component Analysis, etc.). The data reveal a dose and nanoparticle dependent re-organization of chromatin, although colony forming assays do not show a significant reduction of cell survival after the application of gold nanoparticles to the cells. In addition, the spatial organization of γH2AX clusters was elucidated, and characteristic changes were obtained depending on dose and gold nanoparticle application. The results indicate a complex response of ALU-related chromatin and heterochromatin organization correlating to ionizing radiation and gold nanoparticle incorporation. Such complex whole chromatin re-organization is usually associated with changes in genome function and supports the hypothesis that, with the application of gold nanoparticles, not only is DNA damage increasing but also the efficiency of DNA repair may be increased. The understanding of complex chromatin responses might help to improve the gold nanoparticle efficiency in radiation treatment
Ellipsometrische Charakterisierung von Polydopamin für funktionelle technische Schichten
No full textDünne Schichten aus dem bionischen Material Polydopamin (PDA) sind heute
zunehmend auch für innovative technische Anwendungen von Interesse. Mittels
spektroskopischer Ellipsometrie wurde die dielektrische Funktion von PDA vom
ultravioletten bis zum nahen infraroten Spektralbereich vermessen. Über ein Modell wurde auch die Dicke dieser selbstorganisierenden Schichten bestimmt