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Detection and monitoring of algal blooms using SeaWiFS imagery

Abstract

The study presented here is a part of an attempt to improve the operational algorithm used at the Centre de Météorologie Spatiale (CMS) to calculate Sea Surface Temperature (SST) from Advanced Very High Resolution Radiometer (AVHRR) data. The errors produced by SST retrieval algorithms are analysed through two experiments: an examination of the errors calculated on a validation file and an analysis of the temperatures of oceanic cloud-free areas seen under two distinct satellite zenith angles (θ) for consecutive night-time orbits. This Letter presents the part of the study dedicated to the effect of large viewing angles on the retrieval of SST. Correction terms are proposed and compared, on the same set of data, to split window algorithms using θ dependent coefficients     

Hydraulische Charakterisierung von Störungskernzonen in kristallinen Festgesteinen am Beispiel der Talhof-Störung (Ostalpen)

The hydrogeological assessment of a rock mass can be significantly influenced by fault zones acting either as conduits, barriers, or a combined conduit-barrier system. At the Talhof-fault (Semmering-Rax, Austria) the internal structure of a core zone with respect to the hydraulic properties was investigated and compared to results of packer tests. The fault rocks are built up by cataclasites and cacirites with a planar fabric parallel to the fault zone boundaries. Samples were taken with steel pipes in three orientations with reference to a kinematic coordinate system along a scan line. The samples were analysed with respect to grain size distribution, mineralogical composition and hydraulic conductivity. The hydraulic conductivity was determined in the laboratory with tri-axial penetration cells resulting in values ranging from 1,7?10^?7 m/s to 4,2?10^?11 m/s. The analyses suggest a homogeneous and anisotropic hydraulic behaviour of the core zone despite its heterogeneous, fine layered internal structure. The hydraulic conductivity parallel to the fault plane is two orders of magnitude higher than normal to the fault plane. The results correspond well with data from packer tests also from fault rocks of the Talhof fault system and the same tectonic units, giving additional information about the fault domains within the test intervals.     

Buchbesprechungen

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Requirements and basic technologies for extended enterprises

Increased competition in global markets and accelerated technology development raise the pressure on companies to be more efficient. Higher efficiency can be achieved by the integration and automation of internal and enterprise-spanning business processes. The logically consistent further development of e-business communication leads to extended enterprises where independent enterprises join forces to be more competitive. Basic requirements for extended enterprise information technology systems are functionality, integration, usability, security and flexibility. This paper describes the approach of the European Commission supported project FLoCI-EE (Flexible Low-Cost Internet Extended Enterprise), which is based on Internet and component technologies, using J2EE, Web Services and ebXML.     

Perspectives for the production of bioethanol from wood and straw in Austria: technical, economic, and ecological aspects

Bioethanol produced from lignocellulosic resources is a promising candidate for the replacement of fossil fuels. In this study, we aim to determine the perspectives to produce lignocellulosic ethanol in Austria. Technical, environmental and economic aspects are being considered. Thirteen biotechnological production concepts using the raw materials straw and softwood were established and simulated with the steady state flowsheeting software IPSEpro. Bioethanol production cost and greenhouse gas (GHG) emissions for each system were calculated based on mass and energy balances obtained from process simulation. The emission of GHGs along the entire bioethanol process chain (“from well to wheel”) are compared to two reference systems producing the same amounts of by-products. In all concepts, process heat and considerable amounts of the by-products electricity, heat, pellets, C5 molasses, or biomethane could be obtained from residual biomass. Compared to a reference system driven by fossil energy, GHG emissions can be reduced by up to 76%. The production cost of ethanol was found to between 0.66?€ and 0.94?€ per liter of gasoline equivalent. The type and amount of by-product influence technical, economic, and environmental performance significantly. Converting all straw and softwood available in Austria to ethanol would result in an annual production of 340?kt.