Protección de carenas de embarcaciones por medio de pinturas

En esta revisión sobre el tema se consideran, en forma general, las características que deben reunir las pinturas que se emplean para la protección de la parte exterior de embarcaciones y en particular de la línea de flotación y de la carena Se describen las características de las pinturas anticorro sivas y antincrustantes para uso naval, y se relaciona su comportamiento con los problemas de diseño, de preparación de las superficies, de aplicación, etc. Para terminar se hace una breve referencia a los métodos de limpieza y carenado bajo agua. Se incluyen 44 citas bibliográficas sobre el tema.A review on this subject is presented and the characteristics of superestructure enamels, hoot-topping paints and anticorrosion and antifouling formulations are described. Ihe properties of the paints for the protection of ships' bottoms are specially considered in relation with the problem of design of naval structures, preparation of steel surfaces, application of paints, etc. The advantages and problems of underwater cleaning and painting are mentioned. Forty-four references are included

Compatibilidad de pinturas de protección temporaria ("shop primers”) con esquemas anticorrosivos para carenas

Las pinturas de protección temporaria se emplean en la industria naval para mantener el acero sin oxidación durante la etapa constructiva. Dicho fondo debe ser, además, compatible con los esquemas protectores a aplicar. Se han ensayado diferentes formulaciones de "shop-primers", exponiendo paneles a la intemperie durante un lapso de 20 meses. Productos a base de cinc y de cinc-aluminio son los que han mostrado mejores condiciones de resistencia, presentando buenas propiedades anticorrosivas. Sobre estos paneles pueden aplicarse esquemas para carena, los que cumplen con las exigencias establecidas para los ensayos en balsa.The shop-primers are employed in naval shipyards to protect the steel plates against corrosion during the construction period. These primers must be also compatible with the anticorrosion systems employed subsequently. Different formulations of shop-primers were tested by accelerated exposure tests during 20 months at La Plata. Products based on zinc dust and zinc-aluminium demonstrated good exterior resistance and anticorrosion properties. Over that panels anticorrosion marine paints were applied and submitted to raft trials in Mar del Plata’s Harbour

Pinturas anticorrosivas para la protección de carenas de barcos: VII

Se ha realizado la optimización de una serie de composiciones de pinturas anticorrosivas, ensayadas con anterioridad en balsas experimentales como etapa previa a la iniciación de experiencias sobre carenas de embarcaciones. En las formulaciones se emplean cinco pigmentos anticorrosivos (minio, silicocromato básico de plomo, sulfato de plomo-aluminio y cromatos básicos de cinc de diferente solubilidad). Los mismos fueron dispersados en un barniz de resina fenólica-aceite de tung, al cual se incorporaron diferentes proporciones de caucho clorado de 20 cP. Sistemas de pinturas aplicados sobre paneles con diferente tratamiento de superficie, fueron ensayados en línea de flotación y en carena en la balsa de Puerto Belgrano.The optimizing of a series of anticorrosion paints tested previously in experimental rafts has been done. This is a new approach to this subject, before the application of that paints on ship bottoms. Five anticorrosion pigments (lead oxide, basic lead silicochromate, basic lead sulfate-aluminium and two basic zinc chromates of different solubilities) were used in the formulations. The pigments and extenders were dispersed in a binder based in a phenolic varnish where different quantities of chlorinated rubber (20 cP) had been incorporated. The paint systems were applied on plates with different surface treatment and tested in the experimental raft at Puerto Belgrano

A pesquisa biomédica e o consentimento informado no âmbito das populações e indivíduos vulneráveis

The economical and political transnationality context inside which today's biomedical investigations take place favours the phenomenon known as life's medicalization and raises both countries' and individuals' vulnerability. If we assume that the need to protect the subjects of investigation is bioethics' accepted responsibility, and, first of all, of the most vulnerable ones, these aspects should be taken into special consideration and evaluation in order to correct them, if needed.El contexto de transnacionalidad económica y política en el que se desarrollan las actuales investigaciones biomédicas favorece el fenómeno conocido como "medicalización" de la vida y promueve la vulnerabilidad tanto de países como de individuos. Si tenemos en cuenta que es responsabilidad asumida por la bioética la preocupación por proteger al sujeto de investigación y, de manera especial, a los más vulnerables, estos aspectos deben ser objeto de una atenta consideración y evaluación que tienda hacia la corrección de los mismos. El artículo plantea también una estrategia a través de la ética del discurso y presenta objeciones a su eficacia procedimental.O contexto de transnacionalidade econômica e política em que se desenvolvem as atuais pesquisas biomédicas, favorece o conhecido fenômeno denominado medicalização" da vida e promove a vulnerabilidade, tanto dos países como dos indivíduos. Se levarmos em conta, que é responsabilidade assumida pela bioética, proteger o sujeito da pesquisa, e de maneira especial os mais vulneráveis, estes aspectos devem ser objeto de uma atenta consideração e avaliação, que vise a correção dos mesmos

Contribución al estudio del comportamiento de las pinturas antiincrustantes

Se ha estudiado, mediante ensayos en balsa de 18 meses de duración, el comportamiento de pinturas antiincrustantes elaboradas en base a compuestos orgánicos de estaño: TBTO, TBTF, TPTF y TBTS. Los mismos se usaron solos, asociados con óxido cuproso y con TPLA. Las pinturas se prepararon empleando caucho clorado o resinas vinílicas para la formulación de los correspondientes vehículos. Sólo tres de las pinturas preparadas exclusivamente con TBTF, TPTF o TBTS se mantienen sin fouling durante un período de 12 a 15 meses. Los mejores resultados se logran cuando estos compuestos están asociados al óxido cuproso. Lo mismo ocurre en el caso del TPLA.By means of raft tests we have studied the antifouling properties of paints prepared with TBTO, TBTF, TPTF and TBTS. That substances were employed alone or associated with cuprous oxide and TPLA. The samples were prepared with chlorinated rubber and vinyl binders. After a immersion period of 15 months, only three of the paints with TBTF, TPTF or TBTS gave good results. The best antifouling activity correspond to the organotin cornin' pounds, associated with cuprous oxide. TPLA is a good reinforcement toxic for paints based on cuprous oxide or in organotins

Assessing Tolerance to Heavy-Metal Stress in Arabidopsis thaliana Seedlings

The deposited book chapter is a post-print version and has been submitted to peer review.The deposited book chapter version contains attached the supplementary materials within the pdf.This publication hasn't any creative commons license associated.The deposited book chapter is part of the book series: "Environmental Responses in Plants: Methods and Protocols" (pp.197-208) published by Springer.Heavy-metal soil contamination is one of the major abiotic stress factors that, by negatively affecting plant growth and development, severely limit agricultural productivity worldwide. Plants have evolved various tolerance and detoxification strategies in order to cope with heavy-metal toxicity while ensuring adequate supply of essential micronutrients at the whole-plant as well as cellular levels. Genetic studies in the model plant Arabidopsis thaliana have been instrumental in elucidating such mechanisms. The root assay constitutes a very powerful and simple method to assess heavy-metal stress tolerance in Arabidopsis seedlings. It allows the simultaneous determination of all the standard growth parameters affected by heavy-metal stress (primary root elongation, lateral root development, shoot biomass, and chlorophyll content) in a single experiment. Additionally, this protocol emphasizes the tips and tricks that become particularly useful when quantifying subtle alterations in tolerance to a given heavy-metal stress, when simultaneously pursuing a large number of plant lines, or when testing sensitivity to a wide range of heavy metals for a single line.Fundação para a Ciência e a Tecnologia grants: (EXPL/AGR-PRO/1013/2013, SFRH/BPD/44640/2008); GREEN-it "Bioresources for Sustainability": (UID/Multi/04551/2013).info:eu-repo/semantics/publishedVersio

Long-term field metal extraction by pelargonium:phytoextraction efficiency in relation to plant maturity

The long length of periods required for effective soil remediation via phytoextraction constitutes a weak point that reduces its industrial use. However, these calculated periods are mainly based on short-term and/or hydroponic controlled experiments. Moreover, only a few studies concern more than one metal, although soils are scarcely polluted by only one element.In this scientific context, the phytoextraction of metals and metalloids (Pb, Cd, Zn, Cu,and As) by Pelargonium was measured after a long-term field experiment. Both bulk and rhizosphere soils were analyzed in order to determine the mechanisms involved in soil-root transfer. First, a strong increase in lead phytoextraction was observed with plant maturity, significantly reducing the length of the period required for remediation. Rhizosphere Pb, Zn, Cu, Cd, and As accumulation was observed (compared to bulk soil), indicating metal mobilization by the plant, perhaps in relation to root activity. Moreover, metal phytoextraction and translocation were found to be a function of the metals’ nature. These results, taken altogether, suggest that Pelargonium could be used as a multi-metal hyperaccumulator under multi-metal soil contamination conditions, and they also provide an interesting insight for improving field phytoextraction remediation in terms of the length of time required, promoting this biological technique

Use of manganese oxides recovered from spent batteries in electrocatalysis of oxygen reduction reaction in alkaline medium

The oxygen reduction reaction was studied in alkaline media using manganese oxides obtained from spent batteries as electrocatalysts. Three processes were used to recover manganese oxides from spent batteries. The particles obtained were in the range from 8 to 11 nm. The electrochemical experiments indicated a good electrocatalytic activity toward oxygen reduction using the different samples and showing approximately a direct transference of 4 electrons during the process. Even though all the processes were efficient, the best result was observed for the prepared sample using reactants of low cost.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)UFAB