Assessment of zinc salicylate as antifouling product for marine coatings

The present research deals with the assessment of a new bioactive product obtained from salicylic acid, zinc salicylate (ZnSal), to be employed in antifouling coatings. ZnSal was obtained in the laboratory and the procedure to precipitate it was described. Preliminary assays were carried out in the laboratory to assess its potential use in an antifouling formulation. The bioactivity of ZnSal was assessed by means of the Artemia larvae test. In a second stage soluble matrix paints were prepared with two different binders: rosin/oleic acid and rosin/styrene-acrylate copolymer. Previous to the immersion in natural environments, the coatings leaching rate in artificial seawater was monitored. Finally, the antifouling efficiency of experimental coatings was evaluated at Mar del Plata harbor, in Argentina. The coating with ZnSal and rosin/oleic acid binder proved to have an acceptable efficiency for more than 12 months.Fil: Bellotti, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Tecnología de Pinturas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Romagnoli, Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Tecnología de Pinturas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Assessment of zinc salicylate as antifouling product for marine coatings

The present research deals with the assessment of a new bioactive product obtained from salicylic acid, zinc salicylate (ZnSal), to be employed in antifouling coatings. ZnSal was obtained in the laboratory and the procedure to precipitate it was described. Preliminary assays were carried out in the laboratory to assess its potential use in an antifouling formulation. The bioactivity of ZnSal was assessed by means of the Artemia larvae test. In a second stage soluble matrix paints were prepared with two different binders: rosin / oleic acid and rosin / styrene-acrylate copolymer. Previous to the immersion in natural environments, the coatings leaching rate in artificial sea water was monitored. Finally, the antifouling efficiency of experimental coatings was evaluated at Mar del Plata harbor, in Argentina. The coating with ZnSal and rosin / oleic acid binder proved to have an acceptable efficiency for more than twelve months.Facultad de Ingenierí

Complex networks and public funding: the case of the 2007-2013 Italian program

In this paper we apply techniques of complex network analysis to data sources representing public funding programs and discuss the importance of the considered indicators for program evaluation. Starting from the Open Data repository of the 2007-2013 Italian Program Programma Operativo Nazionale 'Ricerca e Competitivit\`a' (PON R&C), we build a set of data models and perform network analysis over them. We discuss the obtained experimental results outlining interesting new perspectives that emerge from the application of the proposed methods to the socio-economical evaluation of funded programs.Comment: 22 pages, 9 figure

A particle classification system for the PAMELA calorimeter

Abstract In this paper we propose a particle classification system for the imaging calorimeter of the PAMELA satellite-borne experiment. The system consist of three main processing phases. First, a segmentation of the whole signal detected by the calorimeter is performed to select a Region of Interest (RoI); this step allows to retain bounded and space invariant portions of data for the following analysis. In the next step, the RoIs are characterized by means of nine discriminating variables, which measure event properties useful for the classification. The third phase (the classification step) relies on two different supervised algorithms, Artificial Neural Networks and Support Vector Machines. The system was tested with a large simulated data set, composed by 40 GeV/c momentum electrons and protons. Moreover, in order to study the classification power of the calorimeter for experimental data, we have also used biased simulated data. A proton contamination in the range 10 −4 –10 −5 at an electron efficiency greater than 95% was obtained. The results are adequate for the PAMELA imaging calorimeter and show that the approach to the classification based on soft computing techniques is complementary to the traditional analysis performed using optimized cascade cuts on different variables

Economic Interplay Forecasting Business Success

A startup ecosystem is a dynamic environment in which several actors, such as investors, venture capitalists, angels, and facilitators, are the protagonists of a complex interplay. Most of these interactions involve the flow of capital whose size and direction help to map the intricate system of relationships. This quantity is also considered a good proxy of economic success. Given the complexity of such systems, it would be more desirable to supplement this information with other informative features, and a natural choice is to adopt mathematical measures. In this work, we will specifically consider network centrality measures, borrowed by network theory. In particular, using the largest publicly available dataset for startups, the Crunchbase dataset, we show how centrality measures highlight the importance of particular players, such as angels and accelerators, whose role could be underestimated by focusing on collected funds only. We also provide a quantitative criterion to establish which firms should be considered strategic and rank them. Finally, as funding is a widespread measure for success in economic settings, we investigate to which extent this measure is in agreement with network metrics; the model accurately forecasts which firms will receive the highest funding in future years

AFM Measurements and Tip Characterization of Nanoparticles with Different Shapes

Unambiguous identification of the measurement methodologies is fundamental to reduce the uncertainty and support traceability of particle shape and size at the nanoscale. In this work, the critical aspects in atomic force microscopy measurements, that is, drawbacks on sample preparation, instrumental parameters, image pre-processing, size reconstruction, and tip enlargement, are discussed in reference to quantitative dimensional measurements on different kinds of nanoparticles (inorganic and biological) with different shapes (spherical, cylindrical, complex geometry). Once the cross-section profile is extracted, top-height measurements on isolated nanoparticles of any shape can be achieved with sub-nanometer accuracy. Lateral resolution is affected by the pixel size and shape of the probe, causing dilation in the atomic force microscopy image. For the reconstruction of critical sizes of inorganic non-spherical nanoparticles, a geometric approach that considers the nominal shape because of the synthesis conditions is presented and discussed

AFM Measurements and Tip Characterization of Nanoparticles with Different Shapes

Unambiguous identification of the measurement methodologies is fundamental to reduce the uncertainty and support traceability of particle shape and size at the nanoscale. In this work, the critical aspects in atomic force microscopy measurements, that is, drawbacks on sample preparation, instrumental parameters, image pre-processing, size reconstruction, and tip enlargement, are discussed in reference to quantitative dimensional measurements on different kinds of nanoparticles (inorganic and biological) with different shapes (spherical, cylindrical, complex geometry). Once the cross-section profile is extracted, top-height measurements on isolated nanoparticles of any shape can be achieved with sub-nanometer accuracy. Lateral resolution is affected by the pixel size and shape of the probe, causing dilation in the atomic force microscopy image. For the reconstruction of critical sizes of inorganic non-spherical nanoparticles, a geometric approach that considers the nominal shape because of the synthesis conditions is presented and discussed

Quaternary Ammonium “Tannate” for Antifouling Coatings

The undesirable accumulation of a wide variety of marine organisms (biofouling) on ship hulls can lead to significantly increased costs, principally by increased fuel consumption to maintain cruising speed. Generally, these coatings have bioactive compounds, called biocides. In this sense, this paper deals with the assessment of the antifouling properties of a natural product derivative obtained from "quebracho" tannin and a quaternary ammonium salt (hexadecyltrimethylammonium bromide ([CH3(CH 2)15N(CH3)3]Br). Two derivatives were obtained depending on the precipitation pH (4 and 8). The bioactivity of these derivatives was assessed by means of the Artemia test. Furthermore, soluble matrix paints were prepared with two different binders: rosin/oleic acid and rosin/styrene-acrylate copolymer. The leaching of "quebracho" tannin derivatives from coatings in artificial seawater was monitored until constant values were obtained, previous to the immersion in natural environments. Finally, the antifouling activity of coatings pigmented with the "quebracho" tannin derivative was evaluated in Mar del Plata harbor (38°08′17″S-57 31′18″W). The coating obtained with the derivative obtained at pH 4 and rosin/oleic acid as binder proved to have an acceptable efficiency for 10 months.Fil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: del Amo, Delia Beatriz. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Romagnoli, Roberto. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentin

Strategic management of technology in the chemicals/materials industry : policy recommendations for Brazil

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1994.Includes bibliographical references (leaves 169-170).by Paulo Roberto Bellotti.M.S