Time filter

Source Type

Innsbruck, Austria

Theuretzbacher F.,University of Natural Resources and Life Sciences, Vienna | Bauer A.,University of Natural Resources and Life Sciences, Vienna | Bauer A.,AlpS GmbH | Lizasoain J.,University of Natural Resources and Life Sciences, Vienna | And 6 more authors.

The objective of this study is to estimate the energetic yields of a combined ethanol and biogas production from three different sorghum varieties, and to compare them to a similar estimate for maize in order to demonstrate the suitability of sorghum as an alternative biomass source. The sorghum varieties "SG1" (Sugargraze I) and "SG2" (Sugargraze II), which produce fermentable sugars, as well as the grain variety "C" (Chopper), which produces starch, were grown on experimental plots in eastern Austria. The harvested biomass was analysed for its contents of cellulose, hemicellulose, lignin, crude protein, crude fats, starch and sugar. For the calculation of the energy output, ethanol and biogas yields were calculated corresponding to accepted standard methods. The potential of sorghum for energy production has been demonstrated. The highest energy outputs were achieved by the SG1 and the C varieties, delivering approximately 150GJha-1 and 156GJha-1. Compared to data obtained from different maize varieties in the same year and under similar conditions, this means an equal or even increased energy output per hectare. The SG2 variety only yielded 121GJha-1 worth of ethanol and biogas. Bioethanol and biogas production were unequally distributed between sugar and starch varieties: SG1 provided 70% of its energy output as methane and the rest as bioethanol, whereas the grain variety C yielded 46% methane and 54% bioethanol. © 2013 Elsevier Ltd. Source

Scharf A.,Free University of Berlin | Handy M.R.,Free University of Berlin | Favaro S.,Free University of Berlin | Schmid S.M.,Free University of Berlin | And 3 more authors.
International Journal of Earth Sciences

The Tauern Window exposes a Paleogene nappe stack consisting of highly metamorphosed oceanic (Alpine Tethys) and continental (distal European margin) thrust sheets. In the eastern part of this window, this nappe stack (Eastern Tauern Subdome, ETD) is bounded by a Neogene system of shear (the Katschberg Shear Zone System, KSZS) that accommodated orogen-parallel stretching, orogen-normal shortening, and exhumation with respect to the structurally overlying Austroalpine units (Adriatic margin). The KSZS comprises a ≤5-km-thick belt of retrograde mylonite, the central segment of which is a southeast-dipping, low-angle extensional shear zone with a brittle overprint (Katschberg Normal Fault, KNF). At the northern and southern ends of this central segment, the KSZS loses its brittle overprint and swings around both corners of the ETD to become subvertical, dextral, and sinistral strike-slip faults. The latter represent stretching faults whose displacements decrease westward to near zero. The kinematic continuity of top-east to top-southeast ductile shearing along the central, low-angle extensional part of the KSZS with strike-slip shearing along its steep ends, combined with maximum tectonic omission of nappes of the ETD in the footwall of the KNF, indicates that north-south shortening, orogen-parallel stretching, and normal faulting were coeval. Stratigraphic and radiometric ages constrain exhumation of the folded nappe complex in the footwall of the KSZS to have begun at 23-21 Ma, leading to rapid cooling between 21 and 16 Ma. This exhumation involved a combination of tectonic unroofing by extensional shearing, upright folding, and erosional denudation. The contribution of tectonic unroofing is greatest along the central segment of the KSZS and decreases westward to the central part of the Tauern Window. The KSZS formed in response to the indentation of wedge-shaped blocks of semi-rigid Austroalpine basement located in front of the South-Alpine indenter that was part of the Adriatic microplate. Northward motion of this indenter along the sinistral Giudicarie Belt offsets the Periadriatic Fault and triggered rapid exhumation of orogenic crust within the entire Tauern Window. Exhumation involved strike-slip and normal faulting that accommodated about 100 km of orogen-parallel extension and was contemporaneous with about 30 km of orogen-perpendicular, north-south shortening of the ETD. Extension of the Pannonian Basin related to roll-back subduction in the Carpathians began at 20 Ma, but did not affect the Eastern Alps before about 17 Ma. The effect of this extension was to reduce the lateral resistance to eastward crustal flow away from the zone of greatest thickening in the Tauern Window area. Therefore, we propose that roll-back subduction temporarily enhanced rather than triggered exhumation and orogen-parallel motion in the Eastern Alps. Lateral extrusion and orogen-parallel extension in the Eastern Alps have continued from 12 to 10 Ma to the present and are driven by northward push of Adria. © 2013 Springer-Verlag Berlin Heidelberg. Source

Barthold F.K.,Justus Liebig University | Barthold F.K.,University of Potsdam | Tyralla C.,Justus Liebig University | Tyralla C.,Ruhr University Bochum | And 6 more authors.
Water Resources Research

End member mixing analysis (EMMA) is a commonly applied method to identify and quantify the dominant runoff producing sources of water. It employs tracers to determine the dimensionality of the hydrologic system. Many EMMA studies have been conducted using two to six tracers, with some of the main tracers being Ca, Na, Cl -, water isotopes, and alkalinity. Few studies use larger tracer sets including minor trace elements such as Li, Rb, Sr, and Ba. None of the studies has addressed the question of the tracer set size and composition, despite the fact that these determine which and how many end members (EM) will be identified. We examine how tracer set size and composition affects the conceptual model that results from an EMMA. We developed an automatic procedure that conducts EMMA while iteratively changing tracer set size and composition. We used a set of 14 tracers and 9 EMs. The validity of the resulting conceptual models was investigated under the aspects of dimensionality, EM combinations, and contributions to stream water. From the 16,369 possibilities, 23 delivered plausible results. The resulting conceptual models are highly sensitive to the tracer set size and composition. The moderate reproducibility of EM contributions indicates a still missing EM. It also emphasizes that the major elements are not always the most useful tracers and that larger tracer sets have an enhanced capacity to avoid false conclusions about catchment functioning. The presented approach produces results that may not be apparent from the traditional approach and it is a first step to add the idea of statistical significance to the EMMA approach. Copyright 2011 by the American Geophysical Union. Source

Bremer M.,University of Innsbruck | Rutzinger M.,University of Innsbruck | Rutzinger M.,Austrian Academy of Sciences | Wichmann V.,AlpS GmbH
ISPRS Journal of Photogrammetry and Remote Sensing

The architecture of trees is of particular interest for 3D model creation in forestry and ecolocical applications. Terrestrial (TLS) and mobile laser scanning (MLS) systems are used to acquire detailed geometrical data of trees. Since 3D point clouds from laser scanning consist of large data amounts representing uninterpreted topographical information including noise and data gaps, an extraction of salient tree structures is important for further applications. We present a fully automated modular workflow for topological reliable reconstruction of tree architecture. Object-based point cloud processing such as branch extraction is combined with tree skeletonization. Branch extraction is performed using a segmentation procedure followed by segment-based analysis of form indices derived from eigenvector metrics. Extracted branch primitives are simplified and connected to line features during skeletonization. The modular workflow allows comprehensive parameter tests and error assessments that are used for a calibration of the module parameters with respect to various characteristics of the input data (e.g noise, scanning resolution, and the number of scan positions). The estimated parameter settings are validated using an exemplary MLS data set. The quality of input point cloud data, strongly influencing the quality of the skeleton results, can be improved by the presented branch extraction procedure. The potential for data improvement increases with increasing point densities. For our object-based appoach, we can show that the presence of erroneous structures and filtering artifacts have the strongest influence onto the quality of the derived skeletons. In contrast to traditional skeletonization approaches, the existance of data gaps has less influence onto the results. © 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Source

Ragg H.,University of Innsbruck | Fey C.,AlpS GmbH
GIM International

The UAS technology based on a multicopter enables a rockslide to be monitored at an altitude of 2,900m. The area to be monitored is part of a famous trekking trail in the Alps near Vent/Sölden in Austria, threatened by active rockslides and formation of crevices. The site covers an area measuring 900m by 400m, and the altitudes vary from 2,450m to 2,850m. Both were easily transportable, which was important since accessing the remote location entailed hiking for three hours. Both were capable of operating in Alpine conditions. Fixed-wing UASs can stay in the air longer than multi-rotor ones and capture larger sites, but they also need launch and landing space which is rare in mountainous regions, which is why the multicopter was chosen. UAS technology is valuable for monitoring natural hazards in Alpine environments. Flight planning and collision checks are key factors in ensuring a safe and successful flight mission. Source

Discover hidden collaborations