Irrigation in the Yanqi Basin, Sinkiang, China has led to water table rise and soil salination. A model is used to assess management options. These include more irrigation with groundwater, water saving irrigation techniques and others. The model relies on input data from remote sensing.The Yanqi Basin is located in the north-western Chinese province of Xinjiang.This agriculturally highly productive region is heavily irrigated with water drawn from the Kaidu River. The Kaidu River itself is mainly fed by snow and glacier melt from the Tian Mountain surrounding the basin. A very poor drainage system and an overexploitation of surface water have lead to a series of environmental problems: 1. Seepage water under irrigated fields has raised the groundwater table during the last years, causing strongly increased groundwater evaporation. The salt dissolved in the groundwater accumulates at the soil surface as the groundwater evaporates. This soil salinization leads to degradation of vegetation as well as to a loss of arable farmland. 2. The runoff from the Bostan Lake to the downstream Corridor is limited since large amount of water is used for irrigation in the Yanqi Basin. Nowadays, the runoff is maintained by pumping water from the lake to the river. The environmental and ecological system is facing a serious threat.In order to improve the situation in the Yanqi Basin, a jointly funded cooperation has been set up by the Institute of Environmental Engineering, Swiss Federal Institute of Technology (ETH) , China Institute of Geological and Environmental Monitoring (CIGEM) and Xinjiang Agricultural University. The situation could in principle be improved by using groundwater for irrigation, thus lowering the groundwater table and saving unproductive evaporation. However, this is associated with higher cost as groundwater has to be pumped. The major decision variable to steer the system into a desirable state is thus the ratio of irrigation water pumped from the aquifer and irrigation water drawn from the river. The basis to evaluate the ideal ratio between river and groundwater - applied to irrigation - will be a groundwater model combined with models describing the processes of the unsaturated zone. The project will focus on the following aspects of research: (...)
The natural capital of forests consists to a great extend of the forests environmental functions for human well-being, which not only include goods and services (source and sink functions) but also include life-support functions that reflect ecosystem performance (ecosystem functioning). Shifting the management approach from a traditional one to one that is more aware of the ecosystem complexity, the idea of 'ecosystem functioning is appearing to tackle gradual declines of ecosystem functions. Within CBDs framework, the Ecosystem Approach has been introduced on account of the necessity for open decision making with strong links between all stakeholders and the latest scientific knowledge due to uncertainty and unpredictability in nature. The Ecosystem Approach is still in need of further elaboration, even though as a concept Ecosystem Approach has been widely accepted. To aim forest enhancement, this approach has been regarded as the most feasible concept for the study area, the Bengawan Solo River Basin - Java, Indonesia. Therefore the principles and operational guidelines will be used to analyse and evaluate the current forest management in those areas of the Bengawan Solo River Basin, in which ecosystem function is the basis for forest development area. This research focuses on ecological functions of forests at various levels of ecosystem management planning, from the forestry sectors point of view.
The broad objective of the research is to gain a fundamental understanding of the surface reaction chemistry of exhaust catalysts operating under cycling conditions. Using an integrated theoretical approach we specifically target NOx abatement, with particular emphasis on the appearance and destruction of surface oxide phases as the reactor conditions cycle from oxidative to reductive during the operation of the NOx Storage Reduction (NSR) catalyst system. Methodologically this requires material-specific, quantitative and explicitly time-dependent simulation tools that can follow the evolution of the system over the macroscopic time-scales of NSR cycles, while simultaneously accounting for the atomic-scale site heterogeneity and spatial distributions at the evolving surface. To meet these challenging demands we will develop a novel multi-scale methodology relying on a multi-lattice first-principles kinetic Monte Carlo (kMC) approach. As representative example the simulations will be carried out on a PdO(101)/Pd(100) surface oxide model, but care will be taken to ensure a generalization of the multi-lattice first-principles kMC approach to other systems in which phase transformations may occur and result in a change in the surface lattice structure depending upon environmental variables.
The development of sustainable and efficient energy conversion processes at interfaces is at the center of the rapidly growing field of basic energy science. How successful this challenge can be addressed will ultimately depend on the acquired degree of molecular-level understanding. In this respect, the severe knowledge gap in electro- or photocatalytic conversions compared to corresponding thermal processes in heterogeneous catalysis is staggering. This discrepancy is most blatant in the present status of predictive-quality, viz. first-principles based modelling in the two fields, which largely owes to multifactorial methodological issues connected with the treatment of the electrochemical environment and the description of the surface redox chemistry driven by the photo-excited charges or external potentials.Successfully tackling these complexities will advance modelling methodology in (photo)electrocatalysis to a similar level as already established in heterogeneous catalysis, with an impact that likely even supersedes the one seen there in the last decade. A corresponding method development is the core objective of the present proposal, with particular emphasis on numerically efficient approaches that will ultimately allow to reach comprehensive microkinetic formulations. Synergistically combining the methodological expertise of the two participating groups we specifically aim to implement and advance implicit and mixed implicit/explicit solvation models, as well as QM/MM approaches to describe energy-related processes at solid-liquid interfaces. With the clear objective to develop general-purpose methodology we will illustrate their use with applications to hydrogen generation through water splitting. Disentangling the electro- resp. photocatalytic effect with respect to the corresponding dark reaction, this concerns both the hydrogen evolution reaction at metal electrodes like Pt and direct water splitting at oxide photocatalysts like TiO2. Through this we expect to arrive at a detailed mechanistic understanding that will culminate in the formulation of comprehensive microkinetic models of the light- or potential-driven redox process. Evaluating these models with kinetic Monte Carlo simulations will unambiguously identify the rate-determining and overpotential-creating steps and therewith provide the basis for a rational optimization of the overall process. As such our study will provide a key example of how systematic method development in computational approaches to basic energy sciences leads to breakthrough progress and serves both fundamental understanding and cutting-edge application.
Mankind is approaching a crisis in energy generation and utilization. Traditional fossil fuel reserves are diminishing and legislative issues regarding CO2 emission will make use of existing lower grade reserves unattractive. New technologies have to be developed to satisfy the ever-increasing energy demand and to maximize efficient energy usage. The materials chemist, through the design of new materials with novel properties and by controlling interfacial interactions between materials, will play a crucial role in these endeavours and in enabling the paradigm shift that is required. This project is centred around two core and inter-related issues (i) energy generation from photovoltaics using sunlight and (ii) efficient lighting devices based on light-emitting electrochemical cells (LECs) and organic light emitting diodes (OLEDs). Both of these topics are areas of intense activity world-wide. Within Europe the PIs research group is one of the leaders in the field. However, as research efforts in these areas are proving successful and proof-ofprinciple systems are being established and optimized, a new factor needs to be addressed. State of the art photovoltaic devices based upon the dye-sensitized solar cell (DSC) most frequently utilize inorganic dyes comprising ruthenium complexes of oligopyridine ligands. The projected next generation mass market OLEDs and prototype LECs are based upon iridium complexes containing cyclometallated pyridine ligands. A traditional criticism of these approaches related to the costs of the raw materials although this is in reality low compared to the costs of other components. However, the price reflects in part the availability of these metals and in this respect devices based upon ruthenium (1 ppb by atom in Earth crust) or iridium (0.05 ppb by atom in Earth crust) are unsustainable. This project is concerned with the development of complexes based upon abundant and sustainable first row transition metals to replace second and third row transition metals in these devices. Initial efforts will centre upon complexes of copper(I) and zinc(II) which have well-established photochemistry and photophysics making them suitable for such applications. The PI has already established proof-of-principle for the replacement of ruthenium by copper in DSCs and is a world leader in this technology. The work on the two projects will involve (i) materials synthesis and characterization (ii) computational modelling (iii) device construction and testing and (iv) property optimization.
Objective: The prediction of biological (and in particular toxicological) impacts has, as its basic pre-requisite, the correct prediction of the sites of action and localization of the nano-particle in living organisms. We have identified the need for a paradigm shift in modelling these properties for nano-scale objects. The interactions between bare particles and organisms (cells, biological barriers) is radically different in the presence of proteins and lipids derived from the biological environment (the protein corona). The bare particle characteristic is therefore insufficient to describe the system. Similarly, nano-particles are trafficked and translocated between sites by active biological processes where traditional equilibrium principles for small molecules no longer apply. Nano-TransKinetics is firmly based on advanced high quality experimental data on the distribution of nano-particles in cells, across barriers, and (more limited) in vivo. We frame phenomenological models in a modular manner by abstracting the essential relevant principles of particle-protein (and matrix) interactions, cellular and barrier transport mechanisms of nano-particles, fitting them to experimental data. More detailed models allow for explicit checking of mechanisms and movements of individual particles into cells and across barriers. Enormous amounts of experimental data are now available to validate the models. A predictive capacity requires only simple input data on particle, corona and similar characteristics. The basis of these claims has been checked in preliminary studies, and a limited number of interactions, particles fluxes (and control parameters) between prescribed sites are sufficient to specify the system at each level of description. Resources (reaching far beyond the program itself) have been mobilised in experimental work in the Partners laboratories, and EU and US collaborations. The output will be predictive tools for use in nano-safety research and regulation and beyond.
Introduction: The United Nations Framework Convention on Climate Change classified SF6 as greenhouse gas, and the Annex I countries are obliged to publish the inventory of SF6 and to reduce emissions. However, survey data show an increasing concentration of SF6 (1), and recent evaluations demonstrate that only 30 Prozent of SF6 emissions are reported (2). Novel regulations and technical development must aim at decreasing SF6 emissions below the natural decomposition rate. For dielectric insulation applications, i.e. in situations where discharges are exceptional, it might be possible to replace SF6 by a different gas or gas mixture. No alternative gas is established, despite an extensive study of the dielectric strength of electron attaching gases in the past (3), (4). As many of the well investigated gases are covered by the Kyoto protocol, new options must be provided by fundamental research. In the present research project, the dielectric strength of alternative gases will be evaluated. There is general agreement, that mixtures of two or more gases are most suitable for replacing SF6 in dielectric insulation applications. Due to 'synergistic effects' the dielectric strength of a mixture can be higher than of pure gases (5), or at least the dielectric strength of a mixture can be higher than the linear combination of the strength of the constituents (6). Various types of synergistic effects have so far been described on the basis of the electron velocity distribution function or on the basis of ion-neutral collisions. Methods: The methods developed for investigating electron attaching gases may be classified to three groups: Phenomenological, macroscopic and microscopic methods. The research strategy of the project at hand is a combination of two established methods. In a Pulsed Townsend Discharge (PTD) experiment the macroscopic parameters of electron-ion swarms in attaching gases are measured. Synergistic effects in gas mixtures will be investigated microscopically by Monte Carlo (MC) simulations. The PTD is a traditional method and considerable experience has been gained at the HVL during the years 1980-1990 (7,8). The group of de Urquijo (Mexico) lately used a PTD for studying the alternative gas CF3I (9). In figure 1 the principle of the PTD setup is given. The swarm parameters are obtained from a fit of the analytical expression of the displacement current to the recorded current. Refer to (10) for more details on our swarm parameter experiment SParX. Recently satisfying agreement was achieved between MC simulations and data from PTD experiments (11, 12). The critical issue of these simulations is the availability of a consistent set of cross sections of electron-neutral and ion-neutral collisions. In the present study the output of SParX serves for calibrating the cross sections and the simulations. usw.
Climate projections and trend analysis of historical data suggest that precipitation and temperature changes can dramatically alter the supply of and the demand for water in the human- and eco-systems. Moreover, anthropogenic landscape changes are occurring at unprecedented scales and rates given the societal needs for various (and often competing) ecosystem goods and services (food, energy, and water). How stable or resilient are the human- and eco- systems to climatic and anthropogenic perturbations remain a major societal concern. Of these concerns, hydrologic cycle changes, water resources availability and related management rank among the highest because of their importance in regulating human and ecological sustainability and climate feedbacks. A number of recent studies suggest that continental runoff increased throughout the 20th century despite a rapid increase in water consumption by humans and their activities. Scope of the project: The goal of this research program is on the overall impact of such changes on rainfall (the source of water) and concomitant replenishment of usable water supplies (e.g. ground- and stream- water) given their high priority to any future water resource planning. Even within this restricted scope, the barriers to scientific progress are numerous necessitating an inter-disciplinary approach that combines principles from eco-hydrology, hydraulics and fluid mechanics, soil physics, plant physiology, stochastic processes, dynamical systems theory, and water resources management. This project aims to build a network of researchers with complementary talents to begin progress on these fronts. Moreover, this network of researchers will be actively engaged in preparing the next generation of international scientists (via graduate student exchanges) who will be trained to approach such interdisciplinary societal problems and progress on them by adopting trans-disciplinary approaches now emerging from complex systems science.
Objectives: The project aims on developing a dry CO2 capture system for atmospheric and pressurized fluidized bed boilers. The atmospheric option will be developed towards a pilot plant application. For the pressurized option the project seeks for a proof of principle to determine if the advantages of a pressurized capture system can balance the problems known from existing PFBC systems. The quantifiable objectives are: - Low CO2 capture costs (less than 20 Euro/t for atmospheric, less than 12 Euro/t for pressurized sy stems) - Acceptable efficiency penalty for CO2 capture (less than about equal to 6 percent nel). - greater than 90 percent carbon capture for new power plants and greater than 60 percent for retrofitted existing plants - A purge gas stream containing greater than 95 percent CO2 - A solid purge usable for cement production - Sim ultaneous sulphur and CO2 removal with sulphur recovery option Approach: Limestone is a CO2 carrier. The CO2 can be released easily in a conventional calcination process, well known in the cement and lime industry. By integrating a closed carbonation/calc ination loop in the flue gas of a conventional CFB-boiler, the CO2 in the flue gas can be removed. The heat required for calcination is released during carbonation and can be utilised efficiently (high temperature) in the steam cycle of the boiler. Concent rated CO2 can be generated when using oxygen blown calcination. Because the fuel required for supplying heat for calcination is only a fraction of the total fuel requirements, the required oxygen is only about 1/3 of the oxygen required for oxyfuel process es. The work programme: 1.Definition of the technical and economic boundary conditions 2.Selection and improvement of sorbent materials 3.Lab scale and semi-technical scale process development (experimental work) 4.Technical and economic evaluation 5.Des ign of a 1 MWth Pilot plant.
Water repellency (WR) plays a significant role in a large number of soils all over the world. In many regions global warming will lead to drier land surfaces and thus, increasing the likeliness of actual water repellency for such soils. The hydrological effects of WR (surface runoff, water erosion, preferential flow) have been relatively well investigated in the last decades. However, its effect on the energy balance between soil and atmosphere has not been studied yet. We postulate that global warming does not only lead to an increase in WR of soils, but WR has an impact on the energy balance and thus, will lead to a feedback on global warming. In order to test our hypothesis, we want to determine all components of the energy- and water balance between soil and atmosphere for a strongly water repellent soil. As a reference we want to repeat the same measurements for the same soil, at which the WR has been suspended by application of a surfactants. While the laboratory studies aim to give insight into more principle processes, the lysimeter (bare and with plants) and field scale studies shall give information about integrated complex natural processes. The gained knowledge shall be implemented into a numerical simulation tool for modeling water and energy balances in order to predict the effects of WR under different atmospheric conditions and physical soil properties.
| Organisation | Count |
|---|---|
| Bund | 29 |
| Wissenschaft | 8 |
| Type | Count |
|---|---|
| Förderprogramm | 29 |
| License | Count |
|---|---|
| Offen | 29 |
| Language | Count |
|---|---|
| Deutsch | 2 |
| Englisch | 28 |
| Resource type | Count |
|---|---|
| Keine | 22 |
| Webseite | 7 |
| Topic | Count |
|---|---|
| Boden | 23 |
| Lebewesen und Lebensräume | 28 |
| Luft | 20 |
| Mensch und Umwelt | 28 |
| Wasser | 21 |
| Weitere | 29 |