Cologne University of Applied science is a higher education institution in Cologne, Germany, established in 1971. It was created from a merger of numerous smaller colleges, the oldest of which was the Royal Provincial Trade School, founded in 1833, and renamed Trade College of the City of Cologne on 15 December 1879.The Cologne University of Applied science is the largest university of Applied science in Germany by number of students. Wikipedia.
Qoaider L.,Cologne University of Applied Sciences |
Steinbrecht D.,University of Rostock
Applied Energy | Year: 2010
The main objective of this work is to investigate the economic feasibility of photovoltaic technology to supply the entire energy demands to off-grid irrigated-farming-based communities in the arid regions. This aims at helping these communities to find practical solutions to cope with the rapid rising electricity generation costs, mainly by diesel generators (gensets). The genset electricity costs are typically affected by the high fossil fuel prices, the fuel transport costs and the intensive operation and maintenance (O&M) requirements. The work was conducted on a representative site from which conclusions could be drawn for similar regions. The case study was performed in the New Kalabsha Village in the Lake Nasser Region (LNR) in southern Egypt. The work involved the technical design and the calculation of the life cycle costs (LCC) of a PV system, which is able to supply the village with its entire energy demand. The PV generator was sized in such a way to daily pump 111 000 m3 of lake water to irrigate 1260 ha acreage plots and to electrify the adjacent village's households. The required pumps were designed to pump the fluctuating lake's water for a maximum differential head of 17 m in four different locations. Consequently, water from the four pumping stations flows freely by gravity forces to the different plots through overhead open canals. The electricity generation costs and the performance of the designed PV generator were compared with those of an equivalent diesel generator (genset) in order to prove its competitiveness. With this regard, the real market value of the diesel fuel of 86.55 cε l-1 was considered for calculating the costs of genset generated electricity. The results showed that the genset electricity unit costs 39 cε kW h-1 while a unit of PV electricity costs only 13 cε kW h-1 for the equivalent system size and project lifetime. Furthermore, the subsidised genset electricity cost was calculated to be 12 cε kW h-1, which is insignificantly cheaper than that of solar electricity. © 2009 Elsevier Ltd.
Waffenschmidt E.,Cologne University of Applied Sciences
IEEE Transactions on Power Electronics | Year: 2015
Wireless power transmission systems can be optimized by matching the resonance frequency of a receiver. However, in certain applications, such as, e.g., a multireceiver system, it is desired to match the individual resonance frequencies of the receiver to a fixed (e.g., common) operation frequency. In this publication, a method is proposed to match the resonant frequency dynamically without changing the physical value of the components. Instead, it is changed 'virtually' by a method, which is named 'frozen resonance state' by the author. The basic idea is to maintain the state of a resonant circuit (to 'freeze' the state) for a fraction of the resonant period, e.g., by freewheeling the current of the resonant inductor or maintaining the voltage of the resonant capacitor. This additional time extends virtually the resonant period leading to an effective lower resonant frequency. By adjusting the additional time, the effective resonant frequency can be matched to the operation frequency individually for each receiver. This publication explains the basic idea more in detail and gives an overview of the different possible circuit topologies. Furthermore, the method is applied to an exemplary receiver of a capacitive wireless power transmission system, where measurements are presented. © 1986-2012 IEEE.
Leitner S.,Cologne University of Applied Sciences
Journal of European Social Policy | Year: 2010
The article compares the development of childcare policies in Germany and Austria. Although both countries are characterized by a conservative welfare regime, they developed very different childcare policies. Historically speaking, Austria pioneered in the introductory period whereas Germany outpaced Austria with the latest reforms. The article argues that ideological party differences account for policy change. The gender and family models promoted by the governing parties shaped the development of childcare policies decisively. But party positions changed over time due to general emancipation processes, intra-party conflicts and constraints by coalition partners. Thus, the 'parties matter' thesis explains policy development only partly. The historical context of policy making has to be taken into consideration as well. © 2010 The Author(s).
May H.-O.,FH Darmstadt |
Mausbach P.,Cologne University of Applied Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012
The behavior of thermodynamic response functions and the thermodynamic scalar curvature in the supercritical region have been studied for a Lennard-Jones fluid based on a revised modified Benedict-Webb-Rubin equation of state. Response function extrema are sometimes used to estimate the Widom line, which is characterized by the maxima of the correlation lengths. We calculated the Widom line for the Lennard-Jones fluid without using any response function extrema. Since the volume of the correlation length is proportional to the Riemannian thermodynamic scalar curvature, the locus of the Widom line follows the slope of maximum curvature. We show that the slope of the Widom line follows the slope of the isobaric heat capacity maximum only in the close vicinity of the critical point and that, therefore, the use of response function extrema in this context is problematic. Furthermore, we constructed the vapor-liquid coexistence line for the Lennard-Jones fluid using the fact that the correlation length, and therefore the thermodynamic scalar curvature, must be equal in the two coexisting phases. We compared the resulting phase envelope with those from simulation data where multiple histogram reweighting was used and found striking agreement between the two methods. © 2012 American Physical Society.
Agency: Cordis | Branch: FP7 | Program: CP | Phase: FoF-ICT-2011.7.1 | Award Amount: 11.74M | Year: 2012
The production and ramp-up of complex and highly customized products are exceptionally challenging for planning and control, especially in small lot sizes. Daily challenges like late requests for change, immature high technology products and processes create significant risks. The occurring risks are bigger than production of big series such as automotive. Thus, new ICT-based approaches are required. The aim is to develop mitigation strategies to respond faster to unexpected events. Therefore the knowledge base has to be enriched for real-time decision support, to detect early warning and to accelerate learning. Our approach is based on a new generation of service orientated enterprise information platforms, a service orientated bus integrating service-based architecture and knowledge-based multi-agent systems (MAS). A holonic MAS combined with a service architecture will improve performance and scalability beyond the state of the art. The solution integrates multiple layers of sensors, legacy systems and agent-based tools for beneficial services like learning, quality, risk and cost management. Additionally the ecological footprints will be reduced. The ARUM solution will run in two modes: predictive and real time simulation. The predictive mode supports the planning phase whereas the real-time operations mode supports dynamic, time-, cost- and risk-oriented re-planning of operations. The provision of information for engineering to alter in case of immaturity or late requests for changes is supported equally. ARUM is strongly end-user driven and the results will be tested on three industrial use cases with a focus on aircraft, aircraft interiors and ship manufacturing. The solution will be validated in a real industrial environment by industrial partners and benchmarked against todays ICT solutions. In collaboration with universities a test-bed will be established for design and testing of ARUM systems and tools and will be opened for dissemination and demonstration.