Das Projekt "Soil-gas transport-processes as key factors for methane oxidation in soils" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Geo- und Umweltnaturwissenschaften, Professur für Bodenökologie durchgeführt. Methane (CH4) is a major greenhouse gas of which the atmospheric concentration has more than doubled since pre-industrial times. Soils can act as both, source and sink for atmospheric CH4, while upland forest soils generally act as CH4 consumers. Oxidation rates depend on factors influenced by the climate like soil temperature and soil moisture but also on soil properties like soil structure, texture and chemical properties. Many of these parameters directly influence soil aeration. CH4 oxidation in soils seems to be controlled by the supply with atmospheric CH4, and thus soil aeration is a key factor. We aim to investigate the importance of soil-gas transport-processes for CH4 oxidation in forest soils from the variability the intra-site level, down to small-scale (0.1 m), using new approaches of field measurements. Further we will investigate the temporal evolution of soil CH4 consumption and the influence of environmental factors during the season. Based on previous results, we hypothesize that turbulence-driven pressure-pumping modifies the transport of CH4 into the soil, and thus, also CH4 consumption. To improve the understanding of horizontal patterns of CH4 oxidation we want to integrate the vertical dimension on the different scales using an enhanced gradient flux method. To overcome the constraints of the classical gradient method we will apply gas-diffusivity measurements in-situ using tracer gases and Finite-Element-Modeling. Similar to the geophysical technique of Electrical Resistivity Tomography we want to develop a Gas Diffusivity Tomography. This will allow to derive the three-dimensional distribution of soil gas diffusivity and methane oxidation.
Das Projekt "Formation of brine channels in sea ice" wird vom Umweltbundesamt gefördert und von Fachhochschule Münster, Fachbereich Physikalische Technik durchgeführt. Within this interdisciplinary project the formation of brine channels in sea ice will be explored. The microscopic properties of sea ice, especially the permeability plays an important role for the energy exchange between ocean and atmosphere and is determined by the brine channel volume. The brine channel structure will be measured by computer tomography and image analysis. We intend to describe the channel structure by two phenomenological models, a morphogenesis approach of Alan Turing in connection with the phase transition theory of Ginzburg and Landau, and the phase field method with respect to the Cahn-Hilliard equation. We solve these nonlinear evolution equations in two and three dimensions and compare the size and texture of the brine channels with the measurements. In addition to the phenomenological equations we support our studies with molecular dynamics simulations and the density functional theory in order to obtain deeper insights at the molecular scale. Comparative first-principles studies will then enhance the trust in the extracted parameters and will lead to classical density functional for the two phases. We will discuss the phase transitions in terms of a phenomenological theory based on microscopic parameters and try to extract the underlying mechanism for the formation of water-ice boundaries. Specifically, we want to explore three theoretical questions: (i) How are ice-water melting fronts moving, (ii) How are brine channels formed and (iii) How do surface properties influence the structure formation of brine channels. The project is based on the experiences of three fields, the theoretical biological physics, chemical physics and the many-body theory. The final aim of the project is to provide input parameters for global climate models.
Das Projekt "Process study of vertical mixing near the sea floor inside the central valley of the Mid-Atlantic Ridge near 37°N" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut für Polar- und Meeresforschung, Fachbereich Klimawissenschaften, Sektion Physikalische Ozeanographie der Polarmeere durchgeführt. Vertical mixing associated with dissipation of turbulent kinetic energy sustains the circulation of the deep and abyssal ocean. New evidence is emerging that the highest mixing rates are found within the central valleys and ridge flank (transform) canyons of mid-oceanic ridge systems. An expedition is proposed to take place in August 2010 during which near-bottom oceanographic and marine-geologic measurements will be carried out in the central valley of the Mid-Atlantic Ridge near 37°N, using an autonomous underwater vehicle (AUV), complemented by 'classical' lowered and mooring-based techniques. It is currently unclear, which physical mechanisms control the intense turbulent dissipation in deep ocean canyons. Recent studies point to a potential role of hydraulic jumps, which have been observed in shallow water studies. We aim at testing whether tidally varying hydraulic jumps can explain the observed large vertical mixing over a sill in the central valley. To resolve the jumps AUV-based high-resolution horizontal fields of near-bottom turbulent kinetic energy dissipation and of flow velocities will be obtained. Further, high-resolution AUV multi-beam echo sounder mapping will allow us to study (i) the relationship between vertical mixing processes and the bathymetry, and (ii) the dynamic processes underlying the 'mixing active' morphology.
Das Projekt "Towards DNA chip technology as a standard analytical tool for the identification of marine organisms in biodiversity and ecosystem science (FISH & CHIPS)" wird vom Umweltbundesamt gefördert und von Universität Bremen, Zentrum für Umweltforschung und Umwelttechnologie, Abteilung 7 Biotechnologie und Molekulare Genetik durchgeführt. Sustainable development is a fundamental goal of the European Union and loss of biodiversity is emphasised as one of the main threats to it. However, biodiversity and ecosystems of European Seas are under human impact, such as pollution, eutrophication, and overfishing. Therefore it is necessary to monitor changes in biodiversity and ecosystem functioning. The aim of the project is the development of DNA chips for the identification of marine organisms in European Seas as a cost effective, reliable and efficient technology in biodiversity and ecosystem science. Many marine organisms, such as eggs and larvae of fishes, plankton, and benthic invertebrates, are difficult to identify by morphological characters. The classical methods are extremely time consuming and require a high degree of taxonomie expertise. Consequently, the basic step of identifying such organisms is a major bottleneck in biodiversity and ecosystem science. Therefore, the project seeks to demonstrate that DNA chips can be a new powerful and innovative tool for the identification of marine organisms. Three DNA chips for the identification of fishes, phytoplankton, and invertebrates of European Seas will be developed. These chips will facilitate research on dispersal of ichthyoplankton, monitoring of phytoplankton, and identification of bioindicators as well as prey in gut contents analysis. To achieve this goal a combined biological and technical approach has been initiated: The biological material will be sampled by marine biologists. The next step is the sequencing of suitable molecular markers for probe design. The technical part consists mainly in constructing gene probe libraries and determining their specificity. This will be done by biotech research centres in connection with SMEs engaged in bioinformatics and DNA chip technology. Therefore the project has the potential to bring Europe's marine biotechnology to the forefront of this field.
Das Projekt "Development and Comparison of Different Model Concepts for Two-Phase Flow in Fractured Porous Media" wird vom Umweltbundesamt gefördert und von Technische Universität Berlin, Institut für Bauingenieurwesen, Fachgebiet Wasserwirtschaft und Hydrosystemmodellierung durchgeführt. Fast flow processes of water in fracture-like or tube-like structures within porous media occur in number of engineering applications. One example is given by rainfall induced surface-runoff which fast infiltrates via macropores into the subsurface. Another example is given by tube-like failures in dikes caused by animals or dead roots where water can fast infiltrate or exfiltrate. The classical model concept for two-phase flow in porous media assumes the validity of the Darcy law also in the fracture. On the one hand, this model concept should be extended to account for the fast flow in the 'fractures'. On the other hand, it should be compared to other model concepts such as pipe flow or a double-continuum approach which must be further developed for these purposes. The model concepts will be validated by hillslope and dike experiments. The development of upscaling methods, for example with geostatistical methods, is envisaged.
Das Projekt "Simulated field environment with combined salt and drought stresses as a platform for phenotyping plant tolerance to salinity" wird vom Umweltbundesamt gefördert und von Technische Universität München, Lehrstuhl für Pflanzenernährung durchgeführt. Salinity occurs often simultaneously with drought stress. Therefore, breeding for tolerance to combined both stresses can contribute significantly to crop yield. However, classical selection in salinity has generally been unsuccessful, partly due to high variability of salt stress resulting from the different salinity and drought status. Unfortunately, the use of unrealistic stress protocols for mimicking salinity and drought stress is the norm rather than the exception in biotechnological studies. Therefore, the great challenge is to gain knowledge required to develop plants with enhanced tolerance to field conditions. Our overall hypothesis is that a realistic stress protocol simulating a field environment with combined salt and drought stress as a platform for precision phenotyping of plant tolerance to salinity may solve this problem. This study will demonstrate that highly managed stress environments can be created and key traits of plants can be characterised by using advanced non-destructive sensors that are able to identify relevant traits of plants.
Das Projekt "Transformation von Perlhirse zur Verbesserung der Pilzresistenz" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Fachbereich Biologie, Biozentrum Klein Flottbek und Botanischer Garten durchgeführt. Pearl millet is the sixth most important crop world-wide and the main food source for the world's poorest and most food-insecure people in Africa and India. It is a high yielding cereal, tolerant to drought and can be grown in arid areas where maize and even sorghum fail. In Africa alone a total of 13.330.168 t pearl millet were produced during the harvest period of 2001 (FAO, 2001).Pearl millet is susceptible to many fungal diseases, for example downy mildew (Dm) caused by Sclerospora graminicola. Infection with this fungus causes yield losses up to 30Prozent every year (Safeeulla, 1976).Due to the poor nutrition situation in developing countries and the expanding desertification, it is of great interest to develop high-yielding and pathogen resistant pearl millet lines to help attain food security. In addition to classical breeding methods, genetic engineering is a promising approach to insert useful traits into plants. Besides, the use of pesticides to combat fungal attack can be reduced, which results in the preservation of the environment.Efficient regeneration and transformation systems, which are essential prerequisites for the proposed project, have been established in our group (Oldach et al., 2001; Girgi et al., 2002).The aim of the project is the production of fungal resistant pearl millet plants. The already established regeneration and transformation methods will be utilised to introduce fungal resistance genes like those encoding for antimicrobial proteins, defensins, chitinases and glucanases into susceptible pearl millet lines. The improvement of the resistance of transgenic pearl millet lines will be tested by phytopathological assays under laboratory conditions and later in controlled field experiments.
Das Projekt "Multiple-site seismic hazard assessment" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Geophysikalisches Institut durchgeführt. The classical point wise Cornell-McGuire probabilistic seismic hazard assessment (PSHA), which is widely used for seismic hazard mapping and development of design codes, does not allow direct estimation of multiple-location hazard for distributed structures and facilities: what is the (annual) probability that specific level of ground motion will be exceeded simultaneously in several sites? It is possible to extent the classical methodology to the multiple sites problem considering also ground-motion correlation. We study multiple-location PSHA, as compared with the classical point wise PSHA, using Monte Carlo simulation. Specific items are:(1) Development of the algorithms for multiple-location PSHA;(2) Analysis of the role of the geometry of multiple sites, correlation of ground motion, and evel of seimicity for multiple-location PSHA;(3) Study of correspondence and differences between multiple-location PSHA and classical point wise PSHA and analysis of possibility of utilization of classical PSHA procedures for simplified multiple-location hazard assessment.The project is innovative because only few attempts have been made so far regarding our research questions.
Das Projekt "Advanced bipolar membrane processes for remediation of highly saline waste water streams (NEW ED)" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Aachener Verfahrenstechnik, Lehrstuhl für Chemische Verfahrenstechnik durchgeführt. Objective: NEW ED aims at closing industrial water cycles and reducing the amount of waste water streams with highly concentrated salt loads stemming from a broad range of industrial production processes by exploiting the waste components (salts) and transforming them to valuable products. This will be achieved by developing new micro- to nano-porous bipolar membranes for bipolar electrodialysis (BPMED), a new membrane module concept and by integrating this new technology into relevant production processes. The bipolar membrane process produces acids and bases from their corresponding salts by dissociating water at the interface within the bipolar membranes. However, BPMED so far has been applied only in niche markets due to limitations of the current state of membrane and process development. Major drawbacks of the classic BPMED process are low product purity, limited current density and formation of metal hydroxides at or in the bipolar membrane. The objective of this project is to overcome these limitations by developing a new bipolar membrane and membrane module with active, i.e. convective instead of diffusive water transport to the transition layer of the bipolar membranes, where water dissociation takes place. The key feature of the innovative new bipolar membranes is a nano- to micro-porous and at the same time ion conducting intermediate transition layer, through which water is convectively transported from the side into the transition layer. The porous transition layer may have either the character of a cation or an anion exchanger. Several promising intermediate layer materials together with different monopolar ion-exchange layers will be tested and characterized. Membrane manufacturing and new module concepts will be investigated to exploit the full potential of the new bipolar membrane technique. Integration of the developed membranes and modules into relevant production processes is an essential part of the project.
Das Projekt "Assessment of the European Terrestrial Carbon Balance - Spatial interpolation of in-situ data by neural network approaches for the assessment of carbon stock and carbon stock changes in European forests" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Arbeitsbereich für Weltforstwirtschaft und Institut für Weltforstwirtschaft des Friedrich-Löffler-Institut, Bundesforschungsinstitut für Tiergesundheit durchgeführt. Objective: CarboEurope will develop methods for the European Terrestrial Carbon Balance that allows spatial integration and analysis of geo-referenced data sets by applying neural networks and fuzzy techniques. For many decision processes and for causal inference statistical information has to be completed by spatially explicit information in mapped format. The main obstacle to do so is due to the heterogeneity of the individual data sets in terms of formats, spatial and temporal resolutions, regional coverage, statistical scales, or associated assessment errors. This ramification renders the integration of data and the simultaneous analysis difficult. Classical statistical tools such as multivariate analysis fail, as major assumptions and constraints are violated. Neural networks and fuzzy techniques add a new philosophy to causal inference, as they mimic human thinking and reasoning and allow for handling data associated with uncertainty. Those techniques are superior to traditional statistics as their set of constraints and assumptions is considerably low. Results: The integrative module of CarboEurope will result in maps showing a realistic and reliable spatial distribution of carbon stocks and stock changes within forested areas. The results of the pilot study will open the possibility to provide spatially explicit data sets for entire continental Europe. Contribution of University of Hamburg: - Literature research on fuzzy logic and neural networks, - Spatial analysis, - Programming algorithms for a prototype of neural networks.
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