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Angesichts der starken Effekte, die eine von der allgemeinen bzw. vorgeschriebenen Vorgehensweise abweichende Zuordnung der Hierarchiestufen zu den Management-ebenen haben kann, wäre ein Instrument wünschenswert, dass zumindest Indizien für eine solche abweichende Vorgehensweise liefern kann. Im vorliegenden Beitrag werden entsprechende Kennzahlen entworfen und deren Tauglichkeit diskutiert.
Der vorliegende Beitrag widmet sich einem in der Literatur wenig diskutiertem Aspekt: der Tauglichkeit verschiedener Berechnungsweisen von Fluktuationskennzahlen, d. h. vor allem unter Betrachtung mathematischer Gesichtspunkte. Dazu werden vier unterschiedliche Berechnungsweisen betrachtet:
1) die Basisformel,
2) die Schlüter-Formel,
3) die ZVEI-Formel und
4) die BDA-Formel.
MEMS-based Micro-Heaters, in combination with thin-film temperature sensors, are often used for providing the necessary amount of thermal energy for sensor-applications. In this work, we propose an integrated micro-heater as actuator for fusion bonding of polymers, which can optimize the production process of electret-based micro-energy-harvesters. By adjusting the design parameters of thermoforming-molds, we can implement thin-film micro-heaters that are capable of generating temperatures of above 300°C for numerous cycles. Utilizing the integrated micro-heater allows local fusion bonding of Fluoroethylenepropylene (Teflon-FEP) foils on a micrometer-scale while reducing unnecessary thermal stress. This is beneficial for the longevity of the micro-energy-harvesters, while simultaneously improving its performance.
In Vitro Platform for Acoustic and Electrophysiological Investigations of Ultrasound Neuromodulation
(2017)
The quality of life has increased dramatically over the past decades. Approximately one billion individuals worldwide will be aged 65 years or older by 2030. With the increasing age of human population, prevalence of neurodegenerative ailments, such as Parkinson’s disease or Alzheimer’s disease, increases. Brain pacemakers are proposed to treat their symptoms. They provide the electrical stimulation of neuronal regions of the central or peripheral nervous system. But for the implantation of brain pacemakers, surgery is needed. Those surgical interventions can be avoided by using transcranial stimulation methods such as Transcranial Magnetic Stimulation (TMS). However, magnetic fields lack the possibility of focusing. Ultrasound (US) offers transcranial characteristics as well and allows focusing on a specific target area in the brain. Over 60 years ago, the Hodgkin-Huxley (H-H) model was presented to simulate the electrophysiological activity of neurons but it lacks to describe the impact of mechanical soundwaves on action potentials in a neuron.
In the years 2016 to 2018 the Bavarian-Czech Academic Agency (BTHA) funded in summary four bilateral projects between
Aschaffenburg University and CVUT Prague: JEUMICO, TRILAMICO, JODEXRA, and AXROCO. The effective combination
of equipment, manpower, and know-how of both partners resulted in the development of stress-compensated iridium
coatings for astronomical X-ray mirrors. The findings have been published at scientific conferences and in joint papers. This
poster gives a review on the social , political and educational aspects of the collaborations in form of a photo documentation.
Nickel-iron (NiFe) nanowires with a high contentof nickel and large aspect-ratio show promising characteris-tics for applications in modern micro-systems. In this study,nanowires with well-controlled diameter, height and compo-sition are fabricated using nanoporous poly-carbonate (PC)and anodized aluminum-oxide (AAO) membranes. Differ-ences between potentiostatic and pulsed deposition methodswere studied with regard to their flexibility and a recommen-dation for the best use of the individual types is given. Withthe application of the presented processes, future technolo-gies as magnetic energy-harvesting or nano-fluxgate sensorscan be improved.
Applying technologies of additive manufacturing to the field of tissue engineering created a pioneering new approach tomodelcomplex cell systemsartificially. Regarding its huge potential, bioprinting is still in its infancies and many questions are still unanswered. To address this issue, an extrusion-based bioprinting process was used to deposit human embryonic kidney (HEK) cellsin a defined pattern.It wasshownthat cells remained viable in the bioprinted construct for up to 8 days after printing (DAP). This work displays a proof of principle for a controlled cell formation which shall later be appliedtoin vitro drug screening tests.
Understanding the complexity of biological neural
networks like the human brain is one of the scientific
challenges of our century. The organization of the brain
can be described at different levels, ranging from small neural
networks to entire brain regions. Existing methods for
the description of functionally or effective connectivity are
based on the analysis of relations between the activities of
different neural units by detecting correlations or information
flow. This is a crucial step in understanding neural disorders
like Alzheimer’s disease and their causative factors.
To evaluate these estimation methods, it is necessary to refer
to a neural network with known connectivity, which is
typically unknown for natural biological neural networks.
Therefore, network simulations, also in silico, are available.
In this work, the in silico simulation of large scale neural
networks is established and the influence of different topologies
on the generated patterns of neuronal signals is investigated.
The goal is to develop standard evaluation methods
for neurocomputational algorithms with a realistic large
scale model to enable benchmarking and comparability of
different studies.
The goal of this project is to develop satellite components for space-based astronomical satellite payloads. Thereby advanced materials like iridium and innovative manufacturing technologies will be applied. After environmental testing and space qualifications tests it is planned to do an astronomical experiment with a stratospheric balloon or a sounding rocket. The work is embedded in ACCASI („Aschaffenburg Competence Center for Astronomical and Space Instumentation“)
X-ray telescopes usually operate in space and are quite different from astronomical telescopes for visible light. For normal angles of incidence, optical light is reflected on the mirror surface, whereas X-rays are either transmitted or absorbed. However, also high reflectivity X-rays mirrors are possible, when the incident rays direction is almost parallel to the mirror surface. Such grazing incidence mirrors are usually coated with thin layers of precious metals like iridium, gold or platinum, as this result in high X-ray reflectivity. These noble metals offer a wide range of reflection up to high photon energies, but, due to a series of absorption edges, have low reflectivity in the 2 - 4 keV band and below. This contribution presents the development of innovative material combinations based on thin layers of iridium and chromium, followed by an additional layer of carbon-based materials. We also discuss corresponding production methods (like dip coating) for enhanced reflectivity mirror coatings of future X-ray telescopes.