Entity

Time filter

Source Type


Luschen E.,Leibniz Institute for Applied Geophysics | Gorne S.,Saxon State office for Environment | von Hartmann H.,Leibniz Institute for Applied Geophysics | Thomas R.,Leibniz Institute for Applied Geophysics | Schulz R.,Leibniz Institute for Applied Geophysics
Geophysical Prospecting | Year: 2015

A 3D seismic survey was recorded in 2012 to explore a petrothermal reservoir in a late-Variscan granitic pluton within the Erzgebirge (Ore Mountains) in Saxony, Germany. The main objective was to test this area in the context of the Enhanced Geothermal System concept and to test the 3D seismic technique as an exploration tool. The intention and challenge are to image and characterize potentially permeable fracture zones at target depths of 5-6 km, with temperatures above 150 °C. Unconventional methods were applied for field acquisition and data processing. The vibroseis technique was used in the core experiment, accompanied by a special explosive seismic experiment. Field acquisition was characterized by severe noise conditions and a highly irregular layout. These conditions required extensive preprocessing and data conditioning. The imaging started with conventional Common Midpoint processing for quality control and for a first reference. Better images were obtained by Common Reflection Surface processing with subsequent post-stack time migration. Prestack time migration was also used for comparison. Outstanding results were obtained by the 'operator-oriented' version of the Common Reflection Surface technique. A rich repertoire of structures within the granite pluton was imaged, including steeply dipping fault zones and conjugate faults. Images and indications of fracture and crack porosity of a prominent fault zone provide the background to define an optimum drill path. This is considered as the next stage for a possible geothermal plant, if a decision is taken to drill a research well in the future. The 3D seismic reflection technique was shown to be an indispensable tool for geothermal exploration, even in crystalline basement rocks. © 2015 European Association of Geoscientists & Engineers. Source


Spanhoff B.,Saxon State office for Environment
Renewable and Sustainable Energy Reviews | Year: 2014

Hydropower plays an important role as the main renewable source of energy generation with an installed capacity of 990 GW in 2012 worldwide contributing to climate protection. However, the main sources of electricity generation are large dams contributing to more than 90% of electricity generated from hydropower. In Saxony (ca. 300 hydropower plants with an installed capacity of 88 MW), comparable to most of the other German federal states (Bundesländer, with ca. 7.600 hydropower plants and an installed capacity of ca. 4 GW in total) and industrial nations worldwide the developmental potential for increasing electricity generation by hydropower is almost exploited. Future prospects for development of large hydropower and pump-storage hydropower plants are generally more positive in some countries as the need for storage of surplus electricity generation will increase. Small hydropower might be of increasing interest in developing countries if locations for hydropower that are economical to develop and that can be exploited with respect to environmental protection will be available. Developmental potential for increasing hydropower in Saxony will be mainly the improvement of technical efficiency (refurbishment) of existing hydropower plants and to a much lesser extent the use of existing non-hydropower low head dams that must be not necessarily removed to achieve the environmental objectives for the particular streams according to the Water Framework Directive (WFD). Nevertheless, statutory requirements for environmental protection especially for migratory fish and for improvement of stream ecosystem functions will restrict the future development of hydropower in Germany as well as in most countries of the European Union. © 2013 Elsevier Ltd. All rights reserved. Source


Zoldan K.,Fraunhofer Institute for Cell Therapy and Immunology | Moellmer T.,Saxon State office for Environment | Schneider J.,Fraunhofer Institute for Cell Therapy and Immunology | Fueldner C.,Fraunhofer Institute for Cell Therapy and Immunology | And 2 more authors.
Developmental and Comparative Immunology | Year: 2014

Polymorph-nuclear neutrophils (PMN) in cattle exhibit unique features when compared to human or murine PMN and are of particular interest concerning the risk of post-partum mammary gland or extra-mammary infections related to the periparturient suppression of neutrophil functions. Former studies could show that effects of IL-2 on innate immune cells such as PMN were mediated by the interleukin-2 receptor (IL-2R) β and γ chains. In the current study we could detect IL-2Rα (CD25) expression on bovine PMN using flow-cytometric analysis. CD25 was detected on granulocytes from post-partum and early lactating cows with different inflammatory conditions. The expression of CD25 on PMN in blood and raw milk increased with disease severity. Our results suggest CD25 expression on PMN as a potential biomarker for acute infections in cattle. Furthermore, our data provide a basis to better understanding of the periparturient functional suppressions of PMN that might reveal new molecular targets for therapy or prevention of disease. © 2014 Elsevier Ltd. Source


Pfeifer S.,Leibniz Institute for Tropospheric Research | Birmili W.,Leibniz Institute for Tropospheric Research | Schladitz A.,Leibniz Institute for Tropospheric Research | Schladitz A.,Saxon State office for Environment | And 4 more authors.
Atmospheric Measurement Techniques | Year: 2014

Multiple-charge inversion is an essential procedure to convert the raw mobility distributions recorded by mobility particle size spectrometers, such as the DMPS or SMPS (differential or scanning mobility particle sizers), into true particle number size distributions. In this work, we present a fast and easy-to-implement multiple-charge inversion algorithm with sufficient precision for atmospheric conditions, but extended functionality. The algorithm can incorporate size distribution information from sensors that measure beyond the upper sizing limit of the mobility spectrometer, such as an aerodynamic particle sizer (APS) or an optical particle counter (OPC). This feature can considerably improve the multiple-charge inversion result in the upper size range of the mobility spectrometer, for example, when substantial numbers of coarse particles are present. The program also yields a continuous size distribution from both sensors as an output. The algorithm is able to calculate the propagation of measurement errors, such as those based on counting statistics, into on the final particle number size distribution. As an additional aspect, the algorithm can perform all inversion steps under the assumption of non-spherical particle shape, including constant or size-dependent shape factors. © Author(s) 2014. Source


Schwarzak S.,TU Bergakademie Freiberg | Schwarzak S.,Saxon State office for Environment | Hansel S.,TU Bergakademie Freiberg | Matschullat J.,TU Bergakademie Freiberg
International Journal of Climatology | Year: 2015

Changes in frequency, duration and/or intensity of extreme precipitation events, such as heavy precipitation or drought, profoundly impact both society and the natural environment. Regional climate models are valuable tools to assess any future progress of such events, and to complement the development of regional and local adaptation and mitigation strategies - here for the model region Dresden within the REGKLAM project. Multi-model approaches may alleviate some of the problems related to uncertainties of projected changes. The bandwidth of future climate conditions in Central Eastern Germany has been estimated, using 12 regional climate projections in daily resolution as simulated within the EU-project ENSEMBLES (emission scenario A1B). Validation of the model runs against an observation data set displayed significant difficulties of the models to describe the regional precipitation characteristics. Shortcomings are particularly obvious in realistically simulating dry period characteristics, likely due to an overestimation of precipitation totals. Most models agree in the projection of more frequent and longer-lasting drought events during summer, while wet phase frequency and persistence is projected to increase in winter. Extreme precipitation events (99th percentile) are likely to increase by the end of the 21st century in most seasons - even in summer, despite projected decreasing average precipitation. The suggested display of all individual model results allows comparing the characteristics and the trend behaviour of the individual regional climate projections. This supports selecting the suitable model(s) for specific impact modelling demands. © 2014 Royal Meteorological Society. Source

Discover hidden collaborations