Corrosion performance of nanocomposite coatings in moist SO2 environment.

This paper presents a study of corrosion behavior of electrodeposited Ni, Ni-Al2O3, Ni-ZrO2, and Ni-Graphene (Gr) coatings in moist SO2 environment. Nanocomposite coatings were deposited on steel substrate by pulse electrodeposition technique with an average thickness of 9 ± 1 μm. Coatings were characterized by using nanoindentation and scratch tests to measure their mechanical properties prior to conducting corrosion tests. The corrosion resistance of coatings was evaluated according to G87-02 Method B, employing SO2 cyclic spray in the presence of moisture followed by drying. The results indicated that the addition of nanoparticles is beneficial both for enhancing mechanical properties and improving the corrosion resistance of these coatings. Higher surface corrosion resistance was observed for Ni-Gr coating. Corrosion behavior of coating was also quantified by open circuit potential measurement in 0.5 M H2SO4 environment. The results suggest that the nanocomposite Ni coatings have improved corrosion resistance compared to pure Ni coating. This work will bring significant impacts in terms of industrial applications such as architectural, automotive and marine industries in the presence of S-pollutants because it can cause corrosion either due to acid rain or by the reaction of moisture with dry deposition of Sulfur

Synergistic Wear-Corrosion Analysis and Modelling of Nanocomposite Coatings.

This paper presents analysis and modelling of synergistic wear-corrosion performance of Nickel-Graphene (Ni/GPL) nanocomposite coating and compares it with un-coated steel 1020 under reciprocating-sliding contact. A novel synergistic wear-corrosion prediction model incorporating Archard description with nano-mechanics and electrochemistry was developed for Ni/GPL and steel 1020. The model is equally applicable to any kind of nanocomposite coating and bulk material like metals. For various nanocomposite coatings; their respective mechanical parameters should be used as inputs such as poisons ratio (v), Elastic Modulus (E), Hardness (H), Coefficient of Thermal Elastic mismatch (CTE) and intrinsic grain size (Do). The synergistic wear-corrosion effects were significantly-prominent in steel compared to Ni/GPL especially under contaminated lubricating oil conditions. This behaviour of Ni/GPL attributes to compact, refined grain structure leading to minimal grain pull-out during wear cycles which was also assured by less severe micro-ploughing in Ni/GPL compared to severe micro-cutting in steel. The predictions and experimental results were in good-agreement. Modelling of synergistic effects of wear-corrosion applied to nano-composite coatings have never been presented prior to this research. The significance of this work in terms of precision based wear-corrosion synergistic analysis, modelling and predictive techniques is evident from various industrial applications. This work will bring impacts for both in-situ and remote sensor based condition monitoring techniques to automotive, locomotive, aerospace, precision manufacturing and wind turbine industries

The Brazilian Developments On The Regional Atmospheric Modeling System (brams 5.2): An Integrated Environmental Model Tuned For Tropical Areas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS), in which different previous versions for weather, chemistry, and carbon cycle were unified in a single integrated modeling system software. This new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. The description of the main model features includes several examples illustrating the quality of the transport scheme for scalars, radiative fluxes on surface, and model simulation of rainfall systems over South America at different spatial resolutions using a scale aware convective parameterization. Additionally, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America, are shown. Atmospheric chemistry examples show the model performance in simulating near-surface carbon monoxide and ozone in the Amazon Basin and the megacity of Rio de Janeiro. For tracer transport and dispersion, the model capabilities to simulate the volcanic ash 3-D redistribution associated with the eruption of a Chilean volcano are demonstrated. The gain of computational efficiency is described in some detail. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near-surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding both its functionalities and skills are discussed. Finally, we highlight the relevant contribution of this work to building a South American community of model developers. © Author(s) 2017.1011892222014/01563-1, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2014/01564-8, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2015/10206-0, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo306340/2011-9, Conselho Nacional de Desenvolvimento Científico e TecnológicoFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Compressed Pairings

Pairing-based cryptosystems rely on bilinear non-degenerate maps called pairings, such as the Tate and Weil pairings defined over certain elliptic curve groups. In this paper we show how to compress pairing values, how to couple this technique with that of point compression, and how to benefit from the compressed representation to speed up exponentiations involving pairing values, as required in many pairing based protocols