Der Schau- und Lehrstollen Arzberg/Steiermark: Beispiel für eine intelligente Nachnutzung eines Altbergbaus

Touristic mines are by far not only of public interest. During guided tours the importance of mining and mineral resources for society can be explained in a proper way. Mineral deposits, for long time not accessible and only known from old literature can now be studied in detail by scientists. Old underground mines can be used for different purposes. With respect to Arzberg the different possibilities of utilization of old underground workings are described in detail: A touristic mine serves not only as an attraction, but also as a training centre for underground geological mapping, geochemistry and geophysics research laboratory of universities. For many years the ZAMG (Central Institute for Meteorology and Geodynamics) has been operating a seismic station, and parts of the old mine workings have been used for cheese refinery since 2006. Furthermore, the mine water is utilized for extracting geothermal energy and serves the cooling chambers. The combined use of the old mine workings by different parties permits sharing the substantial maintenance costs.     

Verfahren zur Erstellung auswertbarer Bildvorlagen für mikrovisioplastische Untersuchungen

The mechanical properties of polycristalline materials are depent on the type, the combination and the orientation of the elements in the micro structure. By means of the method of Visioplasticity assumptions are currently realized to analyse kinematic parameters inside of single grains and grain groups. Strength of the free surface of the specimen will be rough by its plastical deformation, it was difficult to register the increments of deformation of the grid. By further development of a method of picture analysis it is also possible to reproduce a 3d-surface by utilization of single light microscopical pictures.     

Effects of niacin and whole cottonseed on ruminal fermentation, protein degradability, and nutrient digestibility

Four mature nonlactating Holstein heifers fitted with ruminal and duodenal cannulae were used to investigate in vivo effects of niacin and whole cottonseed. Each heifer was assigned randomly to a treatment in a 2 X 2 factorial arrangement of treatment sequences within a 4 X 4 Latin square design. Heifers were fed isonitrogenous complete mixed rations individually twice daily. Diets contained corn-soybean meal concentrate, corn silage, chopped coastal bermudagrass hay, plus 1) 0% niacin and 0% whole cottonseed, 2) 0% niacin and 15% whole cottonseed, 3) .07% niacin and 0% whole cottonseed, or 4) .07% niacin and 15% whole cottonseed. Dry matter consumption, ruminal pH, ruminal ammonia and VFA concentrations, microbial N production, and DM and ADF digestion were not affected by treatment. Numbers of ruminal protozoa and RNA concentrations were reduced with whole cottonseed feeding and increased by addition of niacin. Whole cottonseed increased molar percentages of acetate while depressing propionate. Niacin supplementation resulted in greater digestion of both CP and NDF. Ether extract digestibility was highest in heifers fed whole cottonseed. Fiber digestion was not affected by whole cottonseed feeding.     

Challenges in modelling the evolution of stress corrosion cracks from pits

The evolution of stress corrosion cracks from pits is important in many industrial applications but continues to be a challenge in both measurement and prediction. Life prediction in these circumstances has to account for pit growth kinetics, the conditions for the transition from pits to cracks, and the growth rate of cracks in the short and long crack domain. An example of importance is the performance of steam turbine rotors in power generation. Although stress corrosion failures are comparatively rare, the consequences can be severe and occasionally catastrophic. Consequently, considerable effort is being focused on evaluating the effect of operational variables on pitting and crack growth and in developing an improved basis for structural integrity assessment. A preliminary mathematical model based on deterministic equations with statistically variable input parameters was developed for simulating the evolution of the pit depth distribution at different exposure times, and the transformation to stress corrosion cracks was based on the Kondo criteria. The model predicted some features of the damage well but recent novel measurements of the evolution of stress corrosion cracks from pits combined with finite element analysis of the strain distribution suggest that the transition from a pit to a crack is more complex than can be accounted for by the Kondo approach.