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Mittweida, Germany

Weber J.,TU Dresden | Helbig K.,TU Dresden | Hewllig R.,Hochschule Mittweida | Krujatz F.,TU Dresden | Bley T.,TU Dresden

Hydrogen produced by phototrophic microorganisms may become an ideal energy source because of the ubiquitous availability of sunlight and water. A deeper understanding of the effect of operational conditions and choice of substrates on the productivity are crucial because the demands of Rhodobacter sphaeroides on substrates are complex, e.g., light as a source of energy, glutamic acid as both nitrogen and carbon source, lactid acid as an electron donor, and nitrogen limitation to force the bacteria to produce hydrogen. The substrate uptake, growth, and hydrogen production kinetics of Rhodobacter sphaeroides DSM 158 were studied. A setup was developed that allows to perform phototrophic chemostat cultivations and quantify the hydrogen. Thus, the substrate composition, the spectrum of light, and the dilution rate with the hydrogen production achieving hydrogen production rates of ∼ 150mL/L?hr. This demonstrates that a continuous supply of hydrogen is possible by phototrophic bioprocesses and that a better understanding of interplay of the substrates opens the potential to improve the process. Source

Muller R.,Norwegian University of Science and Technology | Lampe A.,Hochschule Mittweida
AEU - International Journal of Electronics and Communications

This paper studies the spectral efficiency of code-division multiple access with constant envelope modulation in the large system limit. Despite the fact that continuous phase modulation is hit by a severe drawback in spectral efficiency as compared to quadrature amplitude modulation on a single user communication link, the gap in terms of spectral efficiency is found to be negligible when employed on a multiple access channel with the CDMA protocol. Accounting for the efficiency of the transmit amplifier, the latter comparison becomes even favorable for constant envelope modulation. © 2011 Elsevier GmbH. All rights reserved. Source

Zimmer K.,Leibniz Institute fur Oberflachenmodifizierung E.V. | Ehrhardt M.,Leibniz Institute fur Oberflachenmodifizierung E.V. | Lorenz P.,Leibniz Institute fur Oberflachenmodifizierung E.V. | Stephan T.,Leibniz Institute fur Oberflachenmodifizierung E.V. | And 2 more authors.
Optics and Laser Technology

The joining of micron devices by bonding of thin films is required for the electrical or mechanical connection of thin film components. Current developments of flexible electronics call for advanced micron interconnection technologies. For the joining of thin film devices on flexible polymer substrates a novel technique called laser microriveting (LMR) is introduced and demonstrated which enables the bonding of two thin metal layers of different materials for mechanical and electrical connections. In this approach the mechanical and electrical connections are achieved by geometrical interlocking of the thin film materials as a consequence of pulsed laser irradiation. Imaging by SEM and EDX shows clearly that a hollow rivet of copper is formed interlocking the copper layer with the overlaying molybdenum film. The copper hollow rivet formation is the result of highly-dynamic laser-driven processes of melting, evaporation, recoil pressure formation, material transport processes, and resolidification of the molten copper within a single laser pulse. A contact resistance of less than 100 mΩ for one rivet of approximately 20 μm size was measured. This new approach provides a solution for current problems of joining very dissimilar materials. © 2013 Elsevier Ltd. Source

Huebelt J.,Hochschule Mittweida | Lindemann J.,TU Dresden | Zander U.,University of Siegen | Wellner F.,TU Dresden
42nd International Congress and Exposition on Noise Control Engineering 2013, INTER-NOISE 2013: Noise Control for Quality of Life

The long term durability of road pavements plays an important role when calculating the expenses of road construction. Among others, this durability is influenced by the conditions during the laying process of the pavement. Here, as important factors, the environmental temperature and the time duration between the laying process and the opening for traffic has to be mentioned. In Germany, for constructing a double layer, the required duration time is about 36 hours. During this time, the road has to be remaining closed. This can lead to big traffic jams, not only in urban areas. To shorten this time gap accurate information about the properties of the asphalt during and after the laying process are required. An indicator for the durability of the pavement could be the mechanical input impedance. Therefore, in the paper, the convenience of the use of the measurement of the mechanical input impedance for predicting the durability of the pavement will be discussed. Copyright© (2013) by Austrian Noise Abatement Association (OAL). Source

This article is designed to the currently heated debate of an amendment to the German psychotherapist law and the connected factional dispute wether psychotherapy education will be strong adapted to the biomedical paradigm or will prefer the biopsychosocial paradigm (public health). Source

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