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

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

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

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

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(CH2)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.Centro de Investigación y Desarrollo en Tecnología de Pintura

Strain measurements of cylinder magnetostrictive samples by interferometer readings

Magnetoelastic materials are utilized in applications under variable stress in presence of a magnetic field excitation. An accurate characterization of the material behaviour needs of magnetic and strain measurements on the material specimen, usually performed on a dynamic test machine equipped with a magnetic excitation core. Strain measurements are usually made by means of a strain gauge glued on the specimen. This method has some limitations: it requires a bonding of strain gauge for each specimen. Moreover, the strain gauge performs a local strain measurement, which is significant if the magnetization of the sample is uniform. To overcome the above-mentioned limitations of strain gauges in this application, an interferometer with a differential optical setup has been designed and tested onto a measuring machine. The design makes use of symmetric and differential paths by the reference and moving arms of the interferometer, thus compensating for drifts and dead-path of linear set-ups. The interferometer reading is zeroed or corrected afterwards by pre-registering strain of the loading cylinders at the same loading curve to be used for testing the sample. Preliminary results highlight a good repeatability of measured strain. Some further steps are envisaged by suitable control of the strain test runs