Technische und wirtschaftliche Prüfung eines zweiten Tagaufschlusses der Reviere V & VI (VII) des Bergbaues Breitenau

As a master thesis the possibilities of an additional access to the lower regions of the magnesite mine of Breitenau, Styria, Austria, were evaluated. After identifying and determining all the required parameters, the various types of openings to access a mineral deposit and their combinations were prepared and their advantages and disadvantages as well as the applicability examined. Transport systems for the respective variants of access were developed and economic considerations about construction costs and running costs were made. Furthermore, changes in safety and mine winding were assessed. The aim of this work was to identify the best type of opening in terms of investment, running costs and safety.     

Thermodynamic real gas analysis of a tank filling process

A zero-dimensional thermodynamic real gas simulation model for a tank filling process with hydrogen is presented in this paper. Ideal gas and real gas simulations are compared and the entropy balance of the filling process is formulated. Calculated results are validated for a type I tank (steel vessel) with measurements.     

Nährstoffbewirtschaftung im Donauraum

A pressing management question in the Danube river basin is how to reduce nutrient emissions so as to improve the status of the Danube and the Black Sea. This article describes the fundamentals and goals of nutrient management, presents the current level of nutrient load and input pathways, and offers insights into efforts to reduce nutrient emissions. With the help of the simulation model MONERIS we have been able to quantify the nutrient emissions from household and industrial wastewater, from atmospheric deposition and from agriculture, and to analyze the temporal and spatial effects of various management scenarios. Major investments have been and are being made in wastewater treatment plants in the Danube countries, and the EU-wide limit on the phosphate content in household detergents marks a major success. Through European environmental policy and the EU’s Common Agricultural Policy (CAP), efforts are being made to more quickly arrive at agricultural methods that are safer for our waters. At the same time, awareness campaigns and a “greening” of the CAP are already underway.     

A Facile Molten‐Salt Route to Graphene Synthesis

Efficient synthetic routes are continuously pursued for graphene in order to implement its applications in different areas. However, direct conversion of simple monomers to graphene through polymerization in a scalable manner remains a major challenge for chemists. Herein, a molten‐salt (MS) route for the synthesis of carbon nanostructures and graphene by controlled carbonization of glucose in molten metal chloride is reported. In this process, carbohydrate undergoes polymerization in the presence of strongly interacting ionic species, which leads to nanoporous carbon with amorphous nature and adjustable pore size. At a low precursor concentration, the process converts the sugar molecules (glucose) to rather pure few‐layer graphenes. The MS‐derived graphenes are strongly hydrophobic and exhibit remarkable selectivity and capacity for absorption of organics. The methodology described may open up a new avenue towards the synthesis and manipulation of carbon materials in liquid media.     

A novel mechanism of cochlear excitation during simultaneous stimulation and pressure relief through the round window

The round window (RW) membrane provides pressure relief when the cochlea is excited by sound. Here, we report measurements of cochlear function from guinea pigs when the cochlea was stimulated at acoustic frequencies by movements of a miniature magnet which partially occluded the RW. Maximum cochlear sensitivity, corresponding to subnanometre magnet displacements at neural thresholds, was observed for frequencies around 20 kHz, which is similar to that for acoustic stimulation. Neural response latencies to acoustic and RW stimulation were similar and taken to indicate that both means of stimulation resulted in the generation of conventional travelling waves along the cochlear partition. It was concluded that the relatively high impedance of the ossicles, as seen from the cochlea, enabled the region of the RW not occluded by the magnet, to act as a pressure shunt during RW stimulation. We propose that travelling waves, similar to those owing to acoustic far-field pressure changes, are driven by a jet-like, near-field component of a complex pressure field, which is generated by the magnetically vibrated RW. Outcomes of research described here are theoretical and practical design principles for the development of new types of hearing aids, which use near-field, RW excitation of the cochlea.     

Maximising low voltage grid hosting capacity for PV and electric mobility by distributed voltage control

European low voltage grids host an increasing amount of energy from rooftop PV installations. Experience in Germany has shown that PV installations do not grow uniformly but with regional hot spots. Meanwhile it is widely agreed that low voltage grids should only be updated to accommodate some 90 % or less of available PV power in peak times in order to avoid extensive costs for grid reinforcement. The main limiting factor in rural distribution grids is the grid voltage. In the Austrian research project “DG DemoNet—Smart LV Grid” new approaches to deal with restricted grid capacities are analysed using active voltage control. In three pilot regions, the actual amount of installed PV is increased to reach physical limits. Voltage control schemes are developed, tested in simulations and then validated in the field. In one pilot region, electric mobility as additional future load in low voltage grids and its integration into the overall system is considered. This paper analyses the performance of the developed control approaches in simulation.