13 research outputs found

    Computer Aided Tools for Designing Plant-wide Control Structures for Large-scale Industrial Processes

    Get PDF
    In this work a systematic design procedure of a plant-wide control structure is applied to a well known benchmark problem of a large-scale pulp mill process [2]. Because of the high dimension of this system it was necessary to develop some additional computer aided tools for support calculations. It is based on the minimization of the sum of squared deviations (SSD index) [19] which is done via the use of genetic algorithm. It represents a good trade-off between achieve acceptable results with less computational effort. Previous works presented alternative solutions but using several heuristic considerations for reducing the problem dimensionality. The obtained performance with the selected control structure and the decentralized strategy presented previously [3] are compared. Several closed-loop simulations for critical set point changes are rigorously evaluated here.Sociedad Argentina de Informática e Investigación Operativ

    Spectral Graph Analysis for Process Monitoring

    Get PDF
    Process monitoring is a fundamental task to support operator decisions under ab- normal situations. Most process monitoring approaches, such as Principal Components Analysis and Locality Preserving Projections, are based on dimensionality reduction. In this paper Spectral Graph Analysis Monitoring (SGAM) is introduced. SGAM is a new process monitoring technique that does not require dimensionality reduction techniques. The approach it is based on the spectral graph analysis theory. Firstly, a weighted graph representation of process measurements is developed. Secondly, the process behavior is parameterized by means of graph spectral features, in particular the graph algebraic connectivity and the graph spectral energy. The developed methodology has been illustrated in autocorrelated and non-linear synthetic cases, and applied to the well known Tennessee Eastman process benchmark with promising results.Fil: Musulin, Estanislao. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Rosario. Centro Internacional Franco Argentino de Ciencias de la InformaciĂłn y Sistemas; Argentin

    Exploring the factors involved in the absence of parasitism of Chaetosiphon fragaefolii by generalist parasitoids in strawberry

    No full text
    Chaetosiphon fragaefolii Cockerell (Hemiptera: Aphididae) is a worldwide strawberry pest with scarce records of parasitoids for its control. The parasitization rate of two generalist parasitoids, Aphidius colemani Viereck and Aphidius matricariae Haliday, their behavior and aphid defensive behaviors were evaluated with Aphis gossypii Glover (Hemiptera: Aphididae) as a comparative host. Defensive endosymbionts were also surveyed. C. fragaefolii was never parasitized in simple-choice tests, whereas in preference tests both parasitoids chose A. gossypii over C. fragaefolii. No contacts of A. matricariae with C. fragaefolii were observed while A. colemani made more antennal contacts and “stings” on A. gossypii than on C. fragaefolii with the latter exhibiting less defensive behaviors against the parasitoid. The bacterium Acinetobacter sp. was detected in all samples of C. fragaefolii, but with an unknown function. Further research on the possible defensive role of the glandular hairs covering the body of this aphid, the role of chemical signals and the existence of defensive internal mechanisms against parasitoids could provide plausible explanations for the absence of parasitism found.Instituto de Microbiología y Zoología AgrícolaFil: Francesena, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Estudios Parasitologicos y de Vectores. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitologicos y de Vectores; Argentina.Fil: Arneodo Larochette, Joel Demian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola e Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rocca, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Estudios Parasitologicos y de Vectores. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitologicos y de Vectores; Argentina.Fil: Greco, Nancy Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Estudios Parasitologicos y de Vectores. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitologicos y de Vectores; Argentina. Provincia de Buenos Aires. Comisión de Investigaciones Científicas; Argentin

    Insights into the Cenozoic geology of North Beirut (harbour area): biostratigraphy, sedimentology and structural history

    No full text
    The biostratigraphy and sedimentology of the outcrops and bedrock recently exposed in archaeological excavations around the harbour area of Beirut (~5 km²) unlock the geological and structural history of that area, which in turn are key to understanding the hydrocarbon and hydrogeological potential of the region. A key location (Site 2) of a studied outcrop section and newly uncovered bedrock is on the northern foothill cliff of East Beirut (Achrafieh). The outcrop section of carbonates is of Eocene beds overlain by conformable Miocene beds. The excavation of the slope bordering the outcrop uncovered a bedrock section of an early Pliocene shoreline of carbonate/siliciclastic sands at its base and topped by a beach-rock structure. The early Pliocene age of the shoreline section is dated by an assemblage of planktonic foraminifera that includes Sphaeroidinellopsis subdehiscens, Sphaeroidinella dehiscens and Orbulina universa. The Eocene carbonates of Site 2 extend the coverage of the previously reported Eocene outcrops in the harbour area. They form a parasequence of thin-bedded, chalky white limestones that includes the youngest fossil fish deposits in Lebanon ( Bregmaceros filamentosus). The deposits are dated as early Priabonian by their association with the planktonic foraminiferal assemblage of Porticulasphaera tropicalis, Globigerinatheka barri, Dentoglobigerina venezuelana, Globigerina praebulloides, Turborotalia centralis and Borelis sp. The Middle Miocene carbonates that conformably overlie the early Priabonian, parasequence include a planktonic foraminiferal assemblage of Globigerinoides trilobus, Orbulina universa and Borelis melo. Elsewhere, in the harbour area, the preserved Eocene limestones are also overlain by conformable Miocene carbonate parasequences of Langhian–Serravallian age. Younger argillaceous limestone beds of the Mio/Pliocene age occur in the eastern central part of the harbour area and enclose an assemblage of Truncorotalia crassaformis, Globorotalia inflata and Orbulina universa. The three markers of old and recently raised structural blocks in the harbour area are a Lutetian/Bartonian marine terrace in the south west corner, a lower Pliocene shoreline carbonate section in the north east side and a Holocene raised beach of marine conglomerates in the north east corner of the area. The locations of these paleo-shorelines, less than 2 km apart, indicate a progressive platform narrowing of North Beirut since the Paleogene. This study underpins the geological complexity of the region and contributes to understanding the underlying geology, which will be needed for future regional archaeological, hydrocarbon and hydrogeological exploration
    corecore