OCCASION: New Planning Tool for Optimal Climate Change Adaption Strategies in Irrigation

To sustain productive irrigated agriculture with limited water resources requires a high water use efficiency. This can be achieved by the precise scheduling of deficit irrigation systems taking into account the crops’ response to water stress at different stages of plant growth. Particularly in the light of climate change with rising population numbers and increasing water scarcity, an optimal solution for this task is of paramount importance. We solve the corresponding complex multidimensional and nonlinear optimization problem, i.e., finding the ideal schedule for maximum crop yield with a given water volume by a well tailored approach which offers straightforward application facilities. A global optimization technique allows, together with physically based modeling, for the risk assessment in yield reduction considering different sources of uncertainty (e.g., climate, soil conditions, and management). A new stochastic framework for decision support is developed which aims at optimal climate change adaption strategies in irrigation. It consists of: (1) a weather generator for simulating regional impacts of climate change; (2) a tailor-made evolutionary optimization algorithm for optimal irrigation scheduling with limited water supply; and (3) mechanistic models for rigorously simulating water transport and crop growth. The result, namely, stochastic crop-water production functions, allows to assess the impact of climate variability on potential yield and thus provides a valuable tool for estimating minimum water demands for irrigation in water resources planning and management, assisting furthermore in generating maps of yield uncertainty for specific crops and specific agricultural areas. The tool is successfully applied at an experimental site in southern France. The impacts of predicted climate variability on maize are discussed.     

HiFIT – Technische Entwicklung und Anwendung

Das Verbundprojekt REFRESH bot in den vergangenen drei Jahren eine ideale Plattform für die theoretische und experimentelle Weiterentwicklung des HiFIT (high frequency impact treatment)‐Verfahrens. So konnten sowohl die Behandlungsparameter an umfangreichen Schweißproben optimiert als auch ein industrietaugliches Gerätedesign unter Einbeziehung zahlreicher Anwendungsfälle aus der Praxis der Industriepartner entwickelt werden. Effizienz, Ergonomie und die Qualitätssicherung standen bei der Entwicklung im Vordergrund. Die Beurteilung der Anwendbarkeit des Verfahrens und die Anwendung selbst sollten im Sinne einer allgemeinen Qualitätssicherung und zur Quantifizierung des zu erwartenden Behandlungserfolgs von geschultem Personal durchgeführt werden. Letzteres gilt nicht nur im Speziellen für das HiFIT‐Verfahren, sondern generell für alle Nachbehandlungsverfahren. Hinter dem Markennamen HiFIT steht ein ganzheitliches Lösungskonzept mit rechnerischen Analysetools, Nachbehandlungswerkzeugen, Schulung und Consulting zur effizienten Steigerung der Betriebsfestigkeit neuer und bereits im Einsatz befindlicher Schweißkonstruktionen. HiFIT – Technical development and application. In the past three years the HiFIT technology for application on welded parts has been investigated in the REFRESH project. Many treatment parameters have been tested. Using prototype devices a lot of experience has been gained by treatment of several parts in cooperation with the project partners. The design of the HiFIT device is optimized for industrial application where efficiency, ergonomics and quality assurance are the main topics. An application benchmark of HiFIT and the treatment should be done only by specially trained employees. This restriction is not only HiFIT specific. The trademark HiFIT means a solution for improvement of fatigue strength of new and cyclic pre‐damaged welded structures. The solution contains assessment of fatigue strength, treatment devices, training and consulting.     

Scheme for the generation of entangled solitons for quantum communication

Abstract

Quantum-communication needs a source of entanglement which is accessible to non-local measurements. It is shown that an entangled pair of light beams may be generated from two bright amplitude squeezed beams. This is applicable to light pulses and to optical solitons in fibres. A possible experimental scheme for stroboscopic quantum teleportation is discussed.     

Influence of a wind turbine service life on the mechanical properties of the material and the blade

This paper presents results out of investigations of the DEBRA‐25 wind turbine blades. Almost unique in the history of modern wind energy, these blades were in operation for 18 years next to a weather station and were investigated afterward. Therefore, the loads experienced in the operational life could be post‐processed accurately with the measured data of the weather station and the turbine. The blades are made of materials that are similar with today's wind turbines. Furthermore, intensive laboratory tests and free field tests have been carried out, and all load assumptions and data and results are still available today. The results include experimental investigations on the moisture content of the load‐carrying material, static and fatigue behavior of the material, the relaxation of the coupling joints, the natural frequencies of the blade and a full scale static blade test. It is shown that the structural performance of the DEBRA‐25 service blades is comparable with modern wind turbine blades. Although some damage was found by visual inspection, the service blade of the DEBRA‐25 showed excellent mechanical behavior in the full scale blade test. Only small changes of the edgewise eigenfrequencies were detected. The pre‐tensioning forces of the IKEA bolts, where the two blade parts are connected, were measured and were still adequate. Copyright © 2012 John Wiley & Sons, Ltd.     

Solid State and Gas Phase NMR Studies of Immobilized Catalysts and Catalytic Active Nanoparticles

In the current study two new classes of stabile, catalytic active nanomaterials are investigated. The first class of nanoparticles consists of an inner metal core. To stabilize their structure the metal core is surrounded by organic ligands or embedded in a polymer. The second class consists of catalysts immobilized on mesoporous silica supports of SBA-3 type silica. Employing a combination of ¹H, ²H, ¹³C and ²⁹Si-solid state NMR spectroscopy the structure of the catalysts is analyzed. As a simple model for the catalytic properties of the particles, the activation of ²H₂ gas on the surface of the particles is studied. Employing ¹H and ²H gas phase NMR the kinetics of simple catalytic model reactions is studied. Employing ²H-NMR solid state NMR spectroscopy, the interaction of the metal surface with the substrate is characterized and kinetic data, which characterize the mobility of the deuterium on the surface, are extracted. For the interpretation of these data, parallel NMR studies of model η²-bound transition metal complexes are employed, which allow, owing to their simpler geometry and higher sensitivity, a quantitative modeling of the spin dynamics in the NMR experiment.     

Shape reconstruction from gradient data

We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must be calculated from the slopes by numerical integration. Existing integration techniques show drawbacks that render them unusable in many cases. Our method is based on an approximation employing radial basis functions. It can be applied to irregularly sampled, noisy, and incomplete data, and it reconstructs surfaces both locally and globally with high accuracy.     

Interferometric null test of a deep parabolic reflector generating a Hertzian dipole field

We report on interferometric characterization of a deep parabolic mirror with a depth of more than five times its focal length. The interferometer is of Fizeau type; its core consists of the mirror itself, a spherical null element, and a reference flat. Because of the extreme solid angle produced by the paraboloid, the alignment of the setup appears to be very critical and needs auxiliary systems for control. Aberrations caused by misalignments are removed via fitting of suitable functionals provided by means of ray tracing simulations. It turns out that the usual misalignment approximations fail under these extreme conditions.     

Polyphenolrückgewinnung aus Olivenölabwasser durch Einsatz von Membrantechnologie

Olive mill wastewater (OMW) is obtained as byproduct of oil production in large quantities after the olive harvest, mainly in the Mediterranean region. One problem is the high load of organic matter, such as phytotoxic polyphenols, which causes significant environmental problems. However, due to their antioxidant properties the use of these polyphenols is also popular in several industry branches, e.g. production of plastics, cosmetics and drugs. A combined wastewater treatment permits besides water purification also recovery of the polyphenolic compounds for industrial use. One possibility is membrane technology. An overview of research studies concerning polyphenol recovery from OMW using membrane technologies is given.