API src

Found 54 results.

Related terms

Sonderforschungsbereich (SFB) 607: Wachstum oder Parasitenabwehr? Wettbewerb um Ressourcen in Nutzpflanzen aus Land- und Forstwirtschaft, Teilprojekt B1: Allometrie und Raumbesetzung von krautigen und holzigen Pflanzen. Integration von Pflanzen- und Bestandesebene

Das Projekt B1 'Allometrie und Raumbesetzung von krautigen und holzigen Pflanzen' ist Teil des Sonderforschungsbereiches 607 Wachstum und Parasitenabwehr und befindet sich bereits in der vierten Phase des seit 1998 laufenden Forschungsprojektes. Bisher wurde im Projekt B1 die Allometrie als Resultat der pflanzeninternen Steuerung der Allokation untersucht. Auf Individuenebene wurden Allometrie und ihre Veränderung für verschiedene Baumarten in verschiedenen ontogenetischen Stadien untersucht. Auf Bestandesebene wurden die self-thinning-Linien von Yoda und Reineke für krautige bzw. holzige Pflanzenbestände analysiert. Bisherige Allometriebestimmungen erbrachten für diese Arten zwar ähnliche Größenordnung aber auch charakteristische Unterschiede, die Ausdruck spezifischer Strategien der Raumbesetzung und -ausbeutung widerspiegeln. Die bisher vereinzelten Auswertungen sollen in Phase IV in eine übergreifende Analyse (versch. Arten, ontogenetische Stadien, Konkurrenzsituationen, Störfaktoren) der Allometrie auf Pflanzen- und Bestandesebene münden.

Fire, climate change and human impact in tropical ecosystems: paleoecological insights from the East African region

Fire is an important ecological factor of disturbance in African tropical ecosystems, driving vegetation dynamics and regulating nutrient cycling and biomass. The significance of wildfires for future environmental processes is underlined by recent projections of global warming, which predict more frequent and more intense extremes of natural events. Particularly in East Africa, where population growth and natural resource exploitation are among the highest in the world, strategies for sustainable economic development will have to deal with environmental changes at regional to continental scales. Understanding such complex responses to global change requires long-term records, since only they provide a way to observe the response of ecosystems to large-magnitude environmental change on decadal and longer time scales. We use high-resolution charcoal data from lake-sediment cores to reconstruct past fire/climate/human interactions in East Africa, aiming in particular 1) to understand how the fire regime influenced vegetation dynamics during the last millennia in savannah-type and sub-humid tropical ecosystems, 2) to test whether changes in fire regime are coupled with episodes of past climatic extremes inferred from the available sedimentological data, and 3) to detect early human deforestation and the timing of increased fire frequencies beyond its natural variability. Additionally, we will apply novel techniques such as molecular markers (benzene polycarboxylic acids, BPCAs) to complement the standard sedimentary approaches to reconstruct Holocene fire history. The proposed research addresses new, highly relevant questions for today's key issue of sustainability (economic development, natural resource management, adaptation of vulnerable communities to global change). Additionally, it will contribute with new high-quality data to ongoing multi-proxy research concerning the magnitude, frequency, and rates of past climate change in equatorial East Africa. Finally, the project will contribute to our understanding of tropical ecosystem functioning and its interaction with regional, cultural, and economic systems.

Miscanthus 'Giganteus' als Industrierohstoff und für die thermische Nutzung

Die Bereitstellung von Industrierohstoffen und Energie in der Form von Wärme und elektrischen Strom aus Einjahres-, zweijährigen und ausdauernden Pflanzen stellt in allen industrialisierten Ländern und auch in Österreich mittel- und langfristig eine bedeutende Alternative zum Verbrauch fossiler Resourcen dar. Miscanthus Giganteus, eine ausdauernde Pflanze, benötigt eine stark vom Standort abhängige ein- bis zweijährige Etablierungsphase. Die Ernte des Aufwuchses ist erst ab dem zweiten Vegetationsjahr wirtschaftlich. Nach bisherigen Ergebnissen und Erwartungen ist eine ca. 20jährige Nutzungsdauer möglich. Die Feldversuche an fünf bezüglich Klima und Bodenform (Bodentyp und Art) unterschiedlichen Standorten ergaben von 1989 bis 2001 jährlich Trockensubstanzerträge von 17500 bis 24000 kg/ha. Die Ertragsschwankungen zwischen den Jahren sind relativ niedrig, standortbezogen zwischen 2000 und 4000 kg/ha. Zwischen den einzelnen Standorten gibt es bedeutende Ertragsunterschiede. Jährlich hohe Erträge werden an den Standorten ILZ (Steiermark) und in ST. FLORIAN (Oberösterreich) bei durchschnittlichen Jahresniederschlagsmengen zwischen 700 und 900 mm erzielt. Durch die geringeren Niederschläge bedingt ist das Ertragsniveau in MICHELNDORF, MARKGRAFNEUSIEDL, GROSS ENZERSDORF und STEINBRUNN niedriger. Bei Bewässerung in einer Menge von 100 bis 150 mm (Juli bis September) steigt der Biomasseertrag um ca. 2000 bis 5000 kg/ha an. Das Ertragsmaximum wird Ende November - Anfang Dezember erreicht. Bis zum üblichen Erntetermin Ende Februar - Mitte März fällt der Ertrag aufgrund des Blattfalles und Abbrechen der dünnen Stängel und Triebspitzen ab. Der Wassergehalt im Erntegut liegt bei einer Ernte Ende November - Anfang Dezember über 50 Prozent, er fällt je nach mittlerem Stängeldurchmesser und Winter-Witterungsverlauf bis Ende Februar auf 30 bis ca. 42 Prozent ab. Eine Stickstoffdüngermenge über 60 kg N/ha führt nur selten zu steigenden Erträgen. Gülle als Dünger erreicht wegen der meist dichten Blattmulchauflage nur eine geringe Düngerwirkung. Die wesentlichen Qualitätskriterien bei einer thermisch energetischen bzw. stofflichen Nutzung sind konstant. Der Aschegehalt im Erntegut weist ab dem dritten Aufwuchsjahr Werte zwischen 3,2 und 5,0 Prozent auf. Auch der N- Gehalt im Erntegut bleibt ab dem Dritten Aufwuchsjahr beinahe konstant und liegt zwischen 0,3 und 0,42 Prozent. Den größten Anteil der Miscanthusasche bilden Siliciumoxyd (ca. 40 bis 50 5) und K2O (12 bis 20 Prozent). Miscanthuserntegut ist bei entsprechender Technologie ein Rohstoff für die Zellulosegewinnung. Der Gehalt ab dem dritten Aufwuchsjahr liegt bei ca. 47,5 Prozent und ist nur geringfügig niedriger als im Laub- oder Nadelholz.

Hydrogeological and hydrochemical modelling of density-driven flow in the Tiberias Basin, in particular between Ha'on and Tiberias Regions, Jordan Valley

The aim of the current research is to identify regional sources and trans-boundary flow leading to the observed salinity of Lake Tiberias (LT) -also known as the Sea of Galilee or Lake Kinneret-, and its surroundings, which is considered the only natural surface fresh water reservoir of the area. The current study will include all sources of brines in the Tiberias Basin (TB) with specific emphasis of the relationship between the brines from the Ha'on and Tiberias Regions (HTR).The tasks will be achieved by a multidisciplinary approach involving: (i) numerical modelling of density-driven flow processes (i.e., coupled heat and dissolution of evaporites), (ii) hydrochemical studies, supplemented by investigations of subsurface structures.(i) Numerical modelling will be carried out by applying the commercial software FEFLOW® (WASY, GmbH) complemented with the open source code OpenGeoSys developed at the UFZ of Leipzig (Wang et al., 2009). The final goal is to build a 3D regional-scale model of density-driven flow that will result in: (1) revealing the different interactions between fresh groundwater and natural salinity sources (2) elucidate the driving mechanisms of natural brines and brackish water body's movements.(ii) Hydrochemical study will include major, minor and, if possible, rare earth elements (REE) as well as isotope studies. The samples will be analysed at the FU Berlin and UFZ Halle laboratories. Geochemical data interpretation and inverse modelling will be supported by PHREEQC. Hydrochemical field investigations will be carried out in Tiberias basin and its enclosing heights, i.e. the Golan, Eastern Galilee and northern Ajloun in order to search for indications of the presence of deep, relic saline groundwater infested by the inferred Ha'on mother-brine. The current approaches will be supplemented by seismic and statistical data analysis as well as GIS software applications for the definition of the subsurface structures. The key research challenges are: building a 3D structural model of selected regions of TB, adapting both structural and hydrochemical data to the numerical requirements of the model; calibrating the 3D regional-scale model with observational data. The results of this work are expected to establish suitable water-management strategies for the exploitation of freshwater from the lake and from the adjacent aquifers while reducing salinization processes induced by both local and regional brines.

Landschaftsveränderungsdienst - Laverdi

Die Erkennung von Veränderungen der Landbedeckung der Erdoberfläche auf der Basis von satellitengestützten Fernerkundungsdaten ist seit Jahrzehnten ein sehr aktives Forschungsfeld. Das Ziel des Landschaftsveränderungsdiensts ist es, freie Copernicus-Satellitendaten für eine automatische Ableitung von Landbedeckungsänderungen zu nutzen und diese Informationen regelmäßig für einzelne Landschaftselemente (z.B. für Waldgebiete, Wasserflächen, Landwirtschaftsflächen usw.) über einen Web Service bereitzustellen. Copernicus Daten eignen sich aufgrund der hohen zeitlichen (ca. 3-5 Tage, je nach Sensor) und mittleren räumlichen Auflösung (ab 10m) ideal für eine regelmäßige bundesweite flächendeckende Analyse der Landbedeckung. Um eine hohe Bearbeitungsleistung zu erreichen wird die 'Copernicus Data and Exploitation Platform - Deutschland' (CODE-DE) für die Datenverarbeitung und -analyse genutzt. Es können aktuelle und konsistenteste Informationen über Landdeckungsänderungen abgeleitet werden, um kontinuierlich Geodaten in einer einheitlichen Qualität zu pflegen (siehe Abbildung 1). Andererseits können die gewonnenen Informationen genutzt werden, um statistisch relevante Geoinformationen zur quantitativen Beschreibung der UN-SDG-Indikatoren zu extrahieren. Die 2015 verabschiedete Agenda 2030 mit 17 Entwicklungszielen (SDG) und 169 Unterzielen verknüpft das Prinzip der Nachhaltigkeit mit der ökonomischen, ökologischen und sozialen Entwicklung. Die Umsetzung erfordert einen soliden Überprüfungsmechanismus. Dieser soll durch eine regemäßige nationale Erfassung von ca. 200 definierten UN-SDG-Indikatoren erfolgen, mit dem Ziel Fortschritte zu monitoren und die Politik zu informieren.

Nano-particle products from new mineral resources in Europe (ProMine)

The objectives of the ProMine IP address the Commission s concerns over the annual 11 billion trade deficit in metal and mineral imports. Europe has to enhance the efficiency of its overall production chain putting higher quality and added value products on the market. ProMine focuses on two parts of this chain, targeting extractive and end-user industries. Upstream, the first ever Pan-EU GIS based mineral resource and advanced modeling system for the extractive industry will be created, showing known and predicted, metallic and non-metallic mineral occurrences across the EU. Detailed 4D computer models will be produced for four metalliferous regions. Upstream work will also include demonstrating the reliability of new (Bio) technologies for an eco-efficient production of strategic metals, driven by the creation of on-site added value and the identification of specific needs of potential end-users. Downstream, a new strategy will be developed for the European extractive industry which looks not only at increasing production but also at delivering high value, tailored nano-products which will form the new raw materials for the manufacturing industry. ProMine research will focus on five nano-products, (Conductive metal (Cu, Ag, Au) fibres, rhenium and rhenium alloy powders, nano-silica, iron oxyhydroxysulphate and new nano-particle based coatings for printing paper), which will have a major impact on the economic viability of the extractive industry. They will be tested at bench scale, and a number selected for development to pilot scale where larger samples can be provided for characterisation and testing by end-user industries. It will include production, testing and evaluation of these materials, with economic evaluation, life cycle cost analysis, and environmental sustainability. ProMine with 26 partners from 11 EU member states, has a strong industrial involvement while knowledge exploitation will transfer ProMine results to the industrial community.

Combined development of compact thermal energy storage technologies (COMTES)

The COMTES project has as goal to develop and demonstrate three novel systems for compact seasonal storage of solar thermal energy. These systems will contribute to the EU 20-20-20 targets by covering a larger share of the domestic energy demand with solar thermal energy. Main objective of COMTES is to develop and demonstrate systems for seasonal storage that are significantly better than water based systems. The three technologies are covered in COMTES by three parallel development lines: solid sorption, liquid sorption and supercooling PCM. Strength of this approach is the collaboration of three development groups in activities that pertain to the analyses, methods and techniques that concern all technologies, without risking the exchange of confidential material. In this way, the development is much more effective than in three separate projects. The project starts with a definition of system boundary conditions and target applications. Next comes the investigation of the best available storage materials. Detailed numerical modelling of the physical processes, backed by experimental validations, will lead to optimum component design. Full-scale prototypes are simulated, constructed and tested in the laboratory in order to optimize process design. One year of fully monitored operation in demonstration buildings is followed by an integrated evaluation of the systems and their potential. When deemed successful, the involved industry partners will pick up the developed storage concepts and bring them further to a commercial level. The COMTES project is a cooperation of key scientific institutions active in the above mentioned heat storage technologies. For the first time, all relevant research disciplines are covered in an international effort. For each development line, a top-Ieading industry partner contributes its know-how and experience, providing the basis for further industrial development and exploitation of project results.

Schwerpunkt der deutschen Partner: Effektive Architekturen und Leistungswandler für Solarstromgeneratoren (PV/CPV) - ERG: Energy for a green society: from sustainable harvesting to smart distribution. Equipment, materials, design solutions and their applications

The research, development and demonstration activities planned for the ERG project focus on the solar energy supply chain, starting form solar cells and proceeding along with innovative energy extraction (harvesting) techniques, high efficiency power conversion and finally managing the energy distribution inside a smart grid, with the target of different classes of applications, from house to small area, as well as application specific 'local grid' (healthcare, automotive, etc). By considering the full solar energy supply chain, we expect to produce relevant improvements of the industrial state-of-the-art in the efficiency of solar cells, in the optimization of energy generated by photovoltaic systems, in the loss reduction of power converters and, finally, in energy management strategy. At the initial chain-link of the energy value chain, the project aims to design and develop a set of innovative solar cells. In particular we primarily target the development of ultra-thin (20 micron) Si wafer PV cells, Si hetero-junction cells (tandem/multi-junction and hetero-junction contacts), novel architectures (e.g., back-contact), novel materials (for Si hetero-junctions, ARC, and passivation dielectrics), novel approaches for screen printing and laser processing, with focus to the case of back-contact cells. As a promising low-cost alternative to Si, ERG will pursue the goal of totally printable dye-sensitized-solar-cells (DSSC). This will include (a) printable electrolyte (to replace liquid electrolyte), (b) advanced TiO2 electrode, and (c) counter electrode (to meet high performance DSSC applications). The overall objective is to demonstrate DSSC products for commercial applications. The next downward chain-link addressed by the project deals with optimization of the energy generated by photovoltaic systems by focusing on power management electronics for silicon cell panels and on micro electromechanical systems for Concentrated Photovoltaic cells (CPV). The complete supply chains will be considered for optimum energy exploitation by Maximum Power Point Tracking (MPPT) and power conversion on module / segment levels for PV and also CPV solar generators. The architecture study will elaborate different profiles of end-users, including direct grid connection, energy storage option and E-mobility support. As the final chain-link is concerned, the project will develop behavioural models for the individual components of the 'Smart Grid'. This allows the development of optimal energy dispatching and battery charging algorithms. These algorithms will obtain their input from sensors distributed over the network, with typically, but not exclusive, a wireless communication infrastructure. A full set of demonstrators, including innovative PV cells, novel conversion systems for PV and CPV inverters, and network demonstrators based on a household application and an industrial application will complete the project deliverables.

RP7 Adaptive Food Production Systems and Natural Resources Management with Focus on a Changing Environment (ADFOOD)

The Adaptive Food Production Systems and Natural Resources Water Management is set in a context of the appearing challenges and relevant natural processes, the water balance as well as socio/economic transformations concepts taking into account different soils, climatic conditions and land uses. Inappropriate management lead to a loss of natural resources, of organic matter, salinization, decrease of soil fertility and pollution of ground and surface fresh waters. Research efforts are necessary to allow a more sustainable exploitation of natural resources by African farmers, and support the increasing demand for locally produced food. More sustainable on site food production need to be studied, developed and implemented, which can revitalise the natural regenerative capacities of agricultural soils, reduce fresh water pollution and ensure healthy and resilient environments. Methodologies, devices and indicators, adapted to specific African situations, will be developed for monitoring and assess risk factors for natural resources like soil fertility, as well as for safe fresh water resources. Adapted innovative techniques to improve WRM and keep soil fertility at farm level need to be investigated and field-tested. The prevailing technical/scientific part of the project should be complemented by a true participatory approach by involving local stakeholders at different levels, such as farmers, local NGOs, relevant governmental organisations, as to make better and suitable use of existing potentialities and local knowledge, as well as to facilitate an easier implementation/adoption of the project's selected strategies. Studies on social processes and farmers rationales for implementing, adapting, innovating or rejecting the proposed strategies, should also be part of the project activities, as to ensure their acceptability by the end users (farmers and policy-makers) and thus producing the expected impact. A SWOT analyses is performed to identify the needs, risk and challenges (WP1) for the sustainable management at a cachtment scale and on farm level. Emphasize is given to farmers to have choices and to generate adaptive management concepts. Based on the findings concepts for adaptive management practises are promoted. The expertise of the cooperation partners ensures the coverage of this complex task.

Optimisation and design of biomass combustion systems (OPTICOMB)

The major problems regarding biomass combustion are still the NOx and CO emissions, especially when the fuel becomes more diverse (high peaks during transients). The continuously changing fuel composition, the non-linearity of the process and the multi variability of the process makes it difficult to decrease the emissions further. Therefore classical control strategies are no longer effective. In order to improve the actual process control system, advanced control technologies based upon process models are needed. To achieve this goal static models have to be integrated with dynamic models. At present, no satisfying tools are available to describe the NOx formation in the fuel layer and the gas phase. Therefore, an extensive study on fuel layer and gas phase NOx formation mechanisms will be performed. The developed mechanisms will be integrated in a CFD combustion model and a static fuel layer model in order to be able to minimise the CO and NOx emission. Based upon experimental work and plant data, a new grate will be designed. A dynamic furnace model is developed for biomass combustion. Special measurements techniques will be used to gather actual plant data (2 plants, diverse fuels) to validate the models. The stochastic characteristics of the fuel will be revealed, which is used together with the dynamic model to investigate the disturbance rejection capacity of the plant. All information will be used to develop new control concepts and to design new combustion systems also from a dynamic point of view. These will be tested in an installation. The environmental survey of the influence of the proposed technology, a market analysis, information dissemination and exploitation strategies will be carried out.

1 2 3 4 5 6