Das Projekt "NANO-III-V-PIN's^Planare III-V Quantentopfstrukturen, Theoretische Modellierung" wird/wurde gefördert durch: Bundesministerium für Bildung und Forschung. Es wird/wurde ausgeführt durch: Technische Universität Berlin, Institut für Theoretische Physik.
Das Projekt "Transmutationsrelevante kernphysikalische Untersuchungen mit Einsatz moderner technologischer und numerischer Methoden, Teilvorhaben: Ultrasensitive Nachweismethoden für Radionuklide" wird/wurde gefördert durch: Bundesministerium für Bildung und Forschung. Es wird/wurde ausgeführt durch: Technische Universität München, Physik Department, E12: Lehrstuhl für Kern- und Hadronenphysik.
Das Projekt "FP4-ENV 2C, Photochemical activity and ultraviolet radiation modulation factors" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Technische Universität München, Forstwissenschaftliche Fakultät, Lehrstuhl für Bioklimatologie und Immissionsforschung.General Information: The proposed research aims in the first place at quantifying the hierarchy of UV-B modulating factors moving from stratospheric ozone to tropospheric ozone and other environmental factors such as aerosol, clouds and air quality. This project builds on recent results from EU campaigns which have shown that south-eastern Europe and particularly the Aegean sea, is experiencing enhanced background ozone up to the tropopause, with extreme gradients in the J(O1D) prevailing in the first 2 km above sea level in the region. Therefore the project in addition to quantifying with model results validated by calibrated observations the factors influencing UV transfer, it will next move on to unravel the mechanisms maintaining the high background ozone over South-eastern Europe and its interplay with UV transfer. 3-D model studies will be done in large regional and sub regional scales to understand the extend of enhanced background ozone and its sources. The tropospheric effect on UV transfer is not as large as the absorption in the stratosphere but can be important due to photon path enhancements in the presence of different types of aerosols. This synergistic effect of the aerosol burden will be separately studied, being at present an open question. The above objectives of the project will be achieved through extensive state-of-the-art campaign measurements and modelling studies. The sites selected (islands of Crete and Lampedousa)are both in central and eastern Mediterranean and provide unique environments to meet the objectives presented before. They are located in the sunniest part of Europe and are exposed to high background levels and to alternating types of aerosols (Sahara/maritime) for which the quantification of combined effects are targeted in the study. The campaign and modelling efforts include studies on the variability of aerosol in the region. The project is focusing mainly in two major objectives: (a) Quantification of UV modulating factors and validation of UV models with calibrated data sets from an extensive campaign in the Mediterranean and (b) Modelling and validation studies on the mechanisms maintaining the enhanced tropospheric ozone in the region of study and quantification of interrelationships with the UV radiation field. Prime Contractor: Aristotle University of Thessaloniki, Department of Physics, Laboratory of Atmospheric Physics; Thessalonki; Greece.
Das Projekt "Photonen-Korrelationsspektroskopie als Methode zur Untersuchung von Fluid-Partikel-Systemen" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Duisburg, Fachbereich 7 Maschinenbau, Fachgebiet Thermodynamik.Mit Hilfe der Photonen-Korrelationsspektroskopie (PCS) wurden Hydrosole und Aerosole mit kugelfoermigen Partikeln bekannter Groesse untersucht. Hierzu wurde ein Spektrometer mit Auswerteelektronik aufgebaut, das Messungen in einem bestimmten Temperatur- und Winkelbereich ermoeglicht. Im Rahmen des Forschungsprogramms werden zunaechst Streulichtmessungen an monodispersen, polydispersen und bimodalen Systemen im Ruhezustand durchgefuehrt. Hierzu werden verschiedene Auswertemethoden zur Anwendung kommen. In einer weiteren Versuchsreihe wird dann in stroemenden Fluiden die Groessenverteilung von suspendierten Partikeln mit der Photonen-Korrelationsspektroskopie untersucht. Hierbei soll geklaert werden, ob eine Analyse der Groessen bzw Groessenverteilungen von Partikeln moeglich ist.
Das Projekt "FP2-RADPROT 7C, Biophysicical models for the effectiveness of different radiations" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: GSF-Forschungszentrum für Umwelt und Gesundheit, GmbH.Objective: This project involves experimental and theoretical research towards a better understanding of the biological radiation actions of different radiation fields, with particular emphasis on low doses and low dose rates. It aims at an improvement of our present knowledge on somatic and genetic radiation risks of man and to help develop radiation protection instrumentation to measure the characteristic properties with regard to these endpoints in mixed radiation fields. In addition, the combined action of radiation and chemicals (also of those prevalent in the environment) will be investigated on a mechanistic level. General Information: This goal shall be reached by the development of new models based on: the improvement of biophysical track structure calculations for relevant radiation fields (photons, neutrons, electrons, ions) in particular by introducing structured cell geometry, condensed state cross sections, time dependency, and chemical and biological reactions; various codes of other authors will be compared in critical bench mark calculations; the analysis of such physical to chemical to biological track structures will be improved using new cluster algorithms and by testing biophysical models which will be developed; selective radiation biological experiments with soft X-rays and UV-photons will be performed, as well as with alpha-particles and gamma-rays; the biological systems will include appropriate transformational and inactivation assays, etc. The usefulness of a better understanding of radiation effects on members of the public has often been described in the radiation protection literature. This understanding is necessary also to improve the protection of workers and the public in the ALARA-sense of the IRCP, where overestimations of radiation risks might lead, for example, to a not optimum allocation of large resources. Collaboration is foreseen with other projects working on the improvements of dosimeters and on biological radiation effects. Achievements: Objectives of the project include calculation of secondary electrons produced in a water molecule and in a water cluster by proton and electron impact to investigate the influence of physical state on double differential ionization cross sections, testing of the geometry routines simulating a lymphocyte and calculation of single strand breaks (SSB), double strand breaks (DSB) and fields of dicentric chromosomes using simple models of deoxyribonucleic acid (DNA) interaction. A set of calculations of the double and single differential cross sections for secondary electron emission as a function of angle and secondary electron energy have been completed for the case of proton impact on a water molecule and a cluster of water molecules using methods developed for electron impact. ... Prime Contractor: GSF-Forschungszentrum für Umwelt und Gesundheit GmbH; Oberschleissheim; Germany.