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Schmidt H.-P.,Amberg-Weiden University of Applied Sciences | Anheuser M.,Siemens AG | Kosse S.,Siemens AG
Studies in Applied Electromagnetics and Mechanics | Year: 2011

A diagnostic method for low voltage switching arcs is proposed where the magnetic field of the switching current is used to determine the arc movement. The magnetic field of the switching current density is recorded with an array of field sensors. The time and space resolved readings are compared with results from simulations of the arc. Parameters of the simulation and therefore current densities are adapted to reconstruct the measurement readings. So an inversion of the ill conditioned integral equation is not necessary. Results with a hardly optimized set up showed that this approach may be successfully applied to measure arc movements. © 2011 The authors and IOS Press. All rights reserved.

Martinez-Sosa D.,TU Munich | Helmreich B.,TU Munich | Netter T.,Huber SE | Paris S.,Huber SE | And 2 more authors.
Bioresource Technology | Year: 2011

A pilot scale anaerobic submerged membrane bioreactor (AnSMBR) with an external filtration unit for municipal wastewater treatment was operated for 100days. Besides gas sparging, additional shear was created by circulating sludge to control membrane fouling. During the first 69days, the reactor was operated under mesophilic temperature conditions. Afterwards, the temperature was gradually reduced to 20°C. A slow and linear increase in the filtration resistance was observed under critical flux conditions (7L/(m2h)) at 35°C. However, an increase in the fouling rate probably linked to an accumulation of solids, a higher viscosity and soluble COD concentrations in the reactor was observed at 20°C. The COD removal efficiency was close to 90% under both temperature ranges. Effluent COD and BOD5 concentrations were lower than 80 and 25mg/L, respectively. Pathogen indicator microorganisms (fecal coliforms bacteria) were reduced by log105. Hence, the effluent could be used for irrigation purposes in agriculture. © 2011 Elsevier Ltd.

Martinez-Sosa D.,TU Munich | Helmreich B.,TU Munich | Netter T.,Huber SE | Paris S.,Huber SE | And 2 more authors.
Water Science and Technology | Year: 2011

An anaerobic submerged membrane bioreactor (AnSMBR) on pilot-scale treating a mixture composed of municipal wastewater and glucose under mesophilic temperature conditions was operated for 206 days. The performance of the AnSMBR was evaluated at different fluxes, biomass concentrations and gas sparging velocities (GSV). GSV was used to control fouling. In addition, the AnSMBR was operated in cycles that included relaxation and backwashing phases. The increase in the transmembrane pressure (fouling rate) was measured under different operational conditions and was used to evaluate the stability of the process. The fouling rate could be controlled for a long period of time at a flux of 7 l m-2 h-1 with a GSV of 62 m/h and an average biomass concentration of 14.8 g TSS/L. The membrane was physically cleaned after 156 days of operation. The cleaning efficiency was almost 100% indicating that no irreversible fouling was developed inside the pores of the membrane. The COD removal efficiency was close to 90%. As in anaerobic processes, nutrients were not exposed to degradation and almost no pathogens were found in the effluent, hence the effluent could be used for irrigation in agriculture. © IWA Publishing 2011.

Vogl U.,Amberg-Weiden University of Applied Sciences
International Multi-Conference on Systems, Signals and Devices, SSD 2012 - Summary Proceedings | Year: 2012

One of the most interesting paradigms of chaos control is the possibility of switching a system between different unstable periodic orbits (UPOs) with effectively zero control energy. We give a robust method to find finite-time optimal transient trajectories, and show how to stabilize both, UPOs and transients, within the same LQ-framework. The method is quite general, and can also be used to drive a system from static stationary points to an UPO. To illustrate our approach we apply it to the controlled logistic map, and also to an experimental driven-pendulum setup. © 2012 IEEE.

Kurzweil P.,Amberg-Weiden University of Applied Sciences
Journal of Power Sources | Year: 2010

In 1860, the Frenchman Gaston Planté (1834-1889) invented the first practical version of a rechargeable battery based on lead-acid chemistry-the most successful secondary battery of all ages. This article outlines Planté's fundamental concepts that were decisive for later development of practical lead-acid batteries. The 'pile secondaire' was indeed ahead its time in that an appropriate appliance for charging the accumulator was not available. The industrial success came after the invention of the Gramme machine. In 1879, Planté obtained acceptance for his work by publishing a book entitled Recherches sur l'Electricité. He never protected his inventions by patents, and spent much of his fortune on assisting impoverished scientists. © 2010 Elsevier B.V. All rights reserved.

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