11 research outputs found

    Wideband Propagation Measurements and Modeling in Indoor Environment

    No full text
    This paper presents the results of wideband measurements of an indoor wireless radio channel at 1.8 GHz. Propagation measurements were carried out in an indoor environment at the Technical University of Athens with a network analyzer. From the measured impulse response (IR) profiles collected, mean excess delay τm and root mean square of delay spread τrms have been estimated. Statistical analysis of delay spread and amplitude fading has been performed. Comparison with simulation results extracted from SIRCIM Simulator package has also been made

    Hydrocarbon prospectivity in the Hellenic trench system: organic geochemistry and source rock potential of upper Miocene–lower Pliocene successions in the eastern Crete Island, Greece

    No full text
    Results of the current and already published studies suggest that the Tortonian in age deposits could serve a major source rocks (for both oil and gas) beneath the Messinian evaporites in the Hellenic trench system. Additionally, the strong terrestrial input in Pliocene deposits could lead to the production of biogenic gas, similar to the Po basin in Adriatic Sea (Italy). In the current study, fourteen samples from late Miocene Faneromeni section and twelve samples from the early Pliocene Makrilia section in eastern Crete were collected in order to evaluate their hydrocarbon generation potential. For this purpose, Rock-Eval analysis and characterization of the organic matter were performed. The results document a clear distinction between the two sections. Faneromeni section contains organic matter of kerogen type III, whereas the Makrilia section contains organic matter of kerogen type IV. The HI/TOC plot diagram, in both sections, indicates poor oil generating potential, with the exception of several samples showing fair to good gas and oil potential. Although thermal maturities of the samples from the two successions are similar, according to the Tmax values, samples from Faneromeni succession exhibit higher hydrogen index values, indicating a better quality of organic matter in terms of hydrocarbon generation. Very low obtained concentrations of bitumen (mg/g of rock), as well as the predominance of NSO compounds, compared to the saturates and aromatics, indicate low maturation level. The n-alkanes profiles exhibit a bimodal distribution, indicating a mixed origin (marine and terrestrial) of the organic matter in both areas. Terrestrial organic matter input is more pronounced in Makrilia section. The analysis of saturated biomarkers indicates that Faneromeni deposits were accumulated under constant organic matter input in an environment influenced by cyclic changes (from marine to lagoon origin and vice versa). Faneromeni section corresponds to a restricted basin during Tortonian, with quick and often sea-level fluctuations just before the Messinian crisis, while Makrilia section represents a very restricted intramontane basin with strong terrestrial influence. © 2015, Springer-Verlag Berlin Heidelberg

    Preliminary results based on geochemical sedimentary constraints on the hydrocarbon potential and depositional environment of a Messinian sub-salt mixed siliciclastic-carbonate succession onshore Crete (Plouti section, eastern Mediterranean)

    No full text
    corecore