- Allgemeine Angelegenheiten - Förderangelegenheiten - Vergabestelle - Siedlungswasserwirtschaft
Viele der Ausschreibungsverfahren der FHH werden über ein elektronisches Vergabemanagementsystem durchgeführt. Die aktuellen Ausschreibungen der Behörden, Dienststellen und Landesbetriebe finden sich in dem Hamburger Bieterportal.
Vergabestelle für Bauleistungen im Küstenschutz und Gewässern I.Ordnung Informationen zu Vergaberecht und Bauvertragsrecht. VOB A/B; VOL A/B; VOF; HOAI; VgV;
Das Projekt "Field and laboratory studies of aerosol formation from halogenated precursor gases" wird vom Umweltbundesamt gefördert und von Technische Universität Berlin, Institut für Technischen Umweltschutz durchgeführt. This project was part of the HaloProc research unit on natural halogenation processes, and explored the impact of reactive halogen species on aerosol formation in field and laboratory experiments. Field studies were focused on the Lake King salt lake area in Western Australia. New particle formation events were frequently observed and characterized by measuring the temporal evolution of the submicron aerosol size distributions, and collecting aerosol samples for subsequent chemical analysis. 9 out of 11 measurement days in 2013 showed secondary aerosol formation with particle growth rates from 2.9 to 25.4 nm h^-1. Raman spectroscopy and ultrahigh resolution mass spectrometry revealed a contribution of organohalogen compounds (mostly organochlorine) to the secondary organic aerosol, however, organosulfate and organonitrate formation seemed to play a larger role in the studied environment. Nevertheless, a new experimental approach that made use of a mobile Teflon chamber set up above the salt crust and the organic-rich mud layer of various salt lakes directly linked new particle formation to the hypersaline environment of Western Australia. For more detailed process studies, these field results provided realistic scenarios and constraints for simulation experiments in the laboratory. Salt lake conditions were successfully simulated in aerosol chamber experiments and showed secondary aerosol formation in the presence of light and organic precursor compounds. The particle formation dynamics and the chemical speciation of aerosol samples, which were collected from the chamber experiments and analyzed by Raman spectroscopy and mass spectrometry, indicated a coupling of aqueous phase chemistry and secondary aerosol formation. In particular, the Fe(II) concentrations of the simulated salt lakes were a key control for the intensity of new particle formation. In saline environments with low pH values and high solar radiation, Fe(II) might be converted to Fe(III) in the presence of organic matter in a Fenton-like reaction, which can act as a major source for highly reactive OH radicals in the aqueous phase. On the one hand, this expands the potential oxidation pathways for organic compounds, which led to a larger chemical diversity. On the other hand, Fe(II)-controlled aqueous phase chemistry competes with secondary aerosol formation in the gas phase, which led to reduced particle formation in our experiments. While it is premature to fully incorporate these findings in chemistry box models, additional laboratory studies provided experimental data that will guide the development of model parameterizations, e.g., for the organic aerosol yield from the oxidation of organic compounds by chlorine and bromine, or for reactive bromine loss due to uptake in secondary organic aerosol. In conclusion, this project bridged gaps between field studies of halogen-influenced new particle formation in the real world and laboratory experiments within the HaloProc research u
Das Projekt "Is the immune system required to adapt to flowering time change?" wird vom Umweltbundesamt gefördert und von Universität Köln, Biozentrum, Botanisches Institut durchgeführt. For effective crop improvement, breeders must be able to select on relevant phenotypic traits without compromising yield. This project proposes to investigate the evolutionary consequences of flowering time modifications on a second trait of major importance for plant breeding: immunity. This will have implications both for understanding cross-talks between flowering time and defense network and for developing efficient breeding strategies. There is clear evidence that plant maturity influences levels and effectiveness of defense. Theoretical models actually predict that changes in life-history can modulate the balance between costs and benefits of immunity. Simultaneously, actors of the immune system have often been observed to alter flowering time. Two alternative and possibly complementary hypotheses can explain this link: genetic constraints due to the pleiotropic action of players in either systems, or co-evolution, if flowering-time changes modulate the cost-benefit balance of immunity. We will conduct field assays in Arabidopsis thaliana, using constructed lines as well as recombinant inbred lines and natural accessions, to differentiate the action of the two explanatory hypotheses. Using transcriptome analyses, we will identify defense genes associating with flowering time modification (f-t-a defense genes). We will quantify their expression along the assay and test whether it varies with both flowering time and fitness. We will further test whether flowering time and immunity interact to determine yield in tomato and potato.
Das Projekt "Biological Control of Striga hermonthica in Sudan" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut) (490), Fachgebiet Agrarökologie der Tropen und Substropen (490f) durchgeführt. Striga hermonthica is a parasitic flowering plant belonging to the family Scrophulariaceae. It is a root parasite that can attack sorghum, maize, millet and several grass weeds in the semi arid Tropics. In Sudan Striga is considered as the main constraint in sorghum production, the main staple food for the majority of Sudanese people. Several means of control are used to control Striga either chemically or physically, however these means are either inefficient or very costly. The biological control is an additional recent tool for the control of parasitic weeds. Several fusarium species were isolated from Striga in Sudan and they were found to be highly efficient in controlling Striga. The main objectives of this study are to (i) test the efficacy of formulated fusarium spp. in controlling Striga under field conditions; (ii) determine the optimum dose of the mycoherbicide to be used; and (iii) identify toxins produced by these bioagents for environmental safety.
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 "Visual signals in fruits: adaptations and constraints imposed by mutualists and antagonists" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Biologie I (Zoologie) Arbeitsgruppe Evolutionsbiologie und Ökologie durchgeführt. Wir untersuchen den Einfluss von Samenverbreitern und Fruchtschädlingen auf die Kommunikation von Pflanzen und Tieren anhand von Fruchtfarben. Es ist unser Ziel, festzustellen, ob Fruchtfarben als Signale durch einen koevolutiven Prozess zwischen Tieren und Pflanzen entstehen. Mittels theoretischer Modelle zum Farbensehen von Vögeln und Primaten sowie Reflexionsmessungen von Fruchtfarben überprüfen wir, ob diese eine Adaptation an das Sehvermögen von Samenverbreitern darstellen. Indem wir Fruchtfarben manipulieren, prüfen wir, ob sie von Vögeln aufgrund ihrer Auffälligkeit als Signal selektiert werden. In einem Vergleich von 22 Arten aus neun Gattungen untersuchen wir den relativen Selektionsdruck von Samenverbreitern und Fruchtschädlingen auf verschiedenfarbige Früchte. Ziel dieser Untersuchung ist es, herauszufinden, ob Fruchtschädlinge durch direkte oder indirekte Selektion die Koevolution von Signalen zwischen Pflanzen und ihren Verbreitern beschränken. Wir überprüfen weiterhin, ob Vögel Fruchtpigmente nicht als Signal sondern als Nährstoff selektieren. Diese Versuche integrieren die Sinnes- und Ernährungsphysiologie von Samenverbreitern mit der Ökologie der Samenausbreitung in der Dreiecksbeziehung von Pflanzen, Tieren und Fruchtschädlingen.
Das Projekt "Remote Sensing of Greenhouse Gases for Carbon Cycle Modelling" wird vom Umweltbundesamt gefördert und von Universität Heidelberg, Institut für Umweltphysik durchgeführt. The proposed research aims at contributing to an improved understanding of the biogeochemical processes that control the abundances of carbon dioxide (CO2) and methane (CH4) in the Earth's atmosphere. Mitigation of adverse effects of climate change crucially depends on modelling of these processes. Such modelling, however, is hindered by the sparseness of accurate observational constraints. The goal is to overcome this limitation by remote sensing of the atmospheric CO2 and CH4 concentrations, and thereby providing observational constraints that are highly accurate and consistent among the employed retrieval, validation, and modelling methods. The proposed research group will focus on three main research topics. First, we will exploit remote sensing measurements from space-based platforms such as the Greenhouse Gases Observing SATellite (GOSAT). We will develop and evaluate methods that are able to accurately retrieve atmospheric greenhouse gas concentrations from solar backscatter measurements in the shortwave-infrared (SWIR) spectral range. Second, we will develop a ground-based grating spectrometer that is sufficiently versatile and robust to reliably measure atmospheric CO2 and CH4 concentrations under harsh conditions. Thereby, we aim at validating our satellite measurements at the optimal geolocation, providing additional constraints on sources and sinks, and proving the concept for ground-based monitoring networks and on mobile platforms. Third, we will use a carbon cycle model to assess the benefit of our remote sensing measurements for simultaneously constraining sources and sinks of CO2 and CH4. Our comprehensive approach is designed to cover observation, validation, and data interpretation for prototype case studies.
Das Projekt "Small Hydropower Systems Design for Rural Electrification" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Institut für Wasserbau und Technische Hydromechanik durchgeführt. Background: Ethiopia is a country endowed with huge hydropower potential. However, the potential has not been well exploited and the per capita consumption in the country stands as one of the lowest in the world. With this problem in mind, one of the primary objectives of the Energy policy of the government of Ethiopia has been to ensure a reliable supply of energy at the right time and at affordable prices, particularly to support the agricultural development led industrialisation strategy. While the objective is well tailored to the immediate need of rural communities, its implementation lagged much behind expectations. In order to accelerate the energy supply in Ethiopia, the government recently passed the law to allow private power developers to install and operate small to mini-hydropower plants. It is, therefore, hoped that there will be a significant number of independent power produces (IPPs) in the coming decades. While the decision to allow private investment is a good step forward, private investment alone may not produce the necessary break-through in Rural Electrification (RE) in Ethiopia. By its very nature, private investment is mainly profit-oriented which may be guaranteed by RE projects only in the long-run. This is so because the implementation of a self-standing hydropower plant for ruralenergy supply is a challenging task as it is faced by many constraints. There arises, therefore, the fear that the need for an organisation with a clear mandate and responsibility and with a substantial budget to promote RE may be obscured by the assumption that RE largely falls under the domain of private investment. The main objective of this research is, therefore, to find out if such fears are justified. The research bases itself on information on current power supply conditions in Ethiopia by taking an appropriate site for a case study. Objective of the research: The objective of this research is to give a reasonable judgement as to whether RE should be taken as part of the infrastructure development plans of the nation with strong financial support from the government or whether it should be largely left open for private investment. It is sought to find an answer to the question whether the role of RE should be undertaken by a mandated organisation with the necessary budget or whether RE should be dictated by the existing power market structure.