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Kalash S.,Damascus University | Naimeh W.,Damascus University | Ajib S.,Nurnberg University of Applied Sciences
Solar Energy | Year: 2013

A pilot sloped solar updraft power plant has been built in the south campus at Damascus University, Syria. The sloped solar collector has a triangular shape and is tilted at 35° towards the south with an approximate area of 12.5m2. The chimney diameter is 0.31m and it is 9m tall. Eighteen temperature sensors were installed inside the sloped solar collector to measure glass, air, and absorption layer temperatures in different points along the collector. Practical data were recorded every 10min for a total of 40 consecutive days to investigate the temperature changes in the sloped collector. Although measurements were taken during the winter season, the air temperature increased to reach a maximum value of 19°C which generates an updraft velocity in the chimney with a maximum value of 2.9m/s. As a result of this experiment, it is obvious that any change in the solar radiation and the ambient temperature has a direct impact on varying the air temperature between the collector outlet and the ambient. It was also noticed that the absorption layer emits most of stored thermal energy, which is absorbed from the morning to noon, back to the collector air in a short period of time when solar radiation starts to decrease in the afternoon. © 2013 Elsevier Ltd. Source

Schupp T.,Nurnberg University of Applied Sciences
Journal of Hazardous Materials | Year: 2013

Toluene diisocyanate (TDI) is a large volume chemical used for the production of polyurethanes. It is sparingly soluble in water, but hydrolyses instantaneously liberating toluene diamine (TDA), which is highly reactive to TDI. The ecotoxicity of TDI is dominated by TDA. The hydrolysis of TDI under static and dynamic conditions was investigated previously. Previously published data on TDI hydrolysis were re-visited, and based on these data a model was developed that allows a conservative and quick estimation of TDA concentrations in rivers following a major incident with TDI. As earlier published model experiments indicate, the maximum achievable TDA concentration is about 30. mg/L. Model simulations based on these experiments indicate that the TDA concentrations in a river after TDI discharge may be up to three orders of magnitude lower. © 2013 Elsevier B.V. Source

Strehmel V.,Nurnberg University of Applied Sciences
ChemPhysChem | Year: 2012

Stable radicals and recombination of photogenerated lophyl radicals are investigated in ionic liquids. The 2,2,6,6-tetramethylpiperidine-1-yloxyl derivatives contain various substituents at the 4-position to the nitroxyl group, including hydrogen-bond-forming or ionic substituents that undergo additional interactions with the individual ions of the ionic liquids. Some of these spin probes contain similar ions to ionic liquids to avoid counter-ion exchange with the ionic liquid. Depending on the ionic liquid anion, the Stokes-Einstein theory or the Spernol-Gierer-Wirtz theory can be applied to describe the temperature dependence of the average rotational correlation time of the spin probe in the ionic liquids. Furthermore, the spin probes give information about the micropolarity of the ionic liquids. In this context the substituent at the 4-position to the nitroxyl group plays a significant role. Covalent bonding of a spin probe to the imidazolium ion results in bulky spin probes that are strongly immobilized in the ionic liquid. Furthermore, lophyl radical recombination in the dark, which is chosen to understand the dynamics of bimolecular reactions in ionic liquids, shows a slow process at longer timescale and a rise time at a shorter timescale. Although various reactions may contribute to the slower process during lophyl radical recombination, it follows a second-order kinetics that does not clearly show solvent viscosity dependence. However, the rise time, which may be attributed to radical pair formation, increases with increasing solvent viscosity. © 2012 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim. Source

Nurnberg University of Applied Sciences | Date: 2013-10-31

The invention relates to an optical rotary transmitter for transmitting optical signals, comprising a first light coupler (

Nurnberg University of Applied Sciences | Date: 2011-04-21

An optical rotary transmitter which ensures the reliable transmission of optical signals in conjunction with a comparatively simple construction comprises two parts spaced apart from one another which are rotatable relative to one another about a common centre axis and the first of which comprises a first circular light coupler (

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