Marine-friendly antifouling coating based on the use of a fatty acid derivative as a pigment

This study was devoted to examining the application of copper dodecanoate as a non-contaminant antifouling pigment due to its low copper content and fatty acid nature. For this purpose, antifouling paints with mono-component epoxy resin and rosin matrixes were formulated, and their antifouling efficiency was evaluated. Before its incorporation into the different formulations, the synthesized pigment was characterized. Immersion tests in a marine environment were carried out for 12 months to evaluate the antifouling efficiency of the developed paints; the results were compared with those from a commercial paint. The antifouling efficiency of the new epoxy formulation was found to be considerably higher than that of the rosin formulation and very similar to that of the commercial paint. Most importantly, the release of copper from the epoxy paint formulated with copper dodecanoate was 73.5% lower than that of the commercial paint, suggesting prolonged activity of the developed paint.Peer ReviewedPostprint (published version

Multiply Folded Graphene

The folding of paper, hide, and woven fabric has been used for millennia to achieve enhanced articulation, curvature, and visual appeal for intrinsically flat, two-dimensional materials. For graphene, an ideal two-dimensional material, folding may transform it to complex shapes with new and distinct properties. Here, we present experimental results that folded structures in graphene, termed grafold, exist, and their formations can be controlled by introducing anisotropic surface curvature during graphene synthesis or transfer processes. Using pseudopotential-density functional theory calculations, we also show that double folding modifies the electronic band structure of graphene. Furthermore, we demonstrate the intercalation of C60 into the grafolds. Intercalation or functionalization of the chemically reactive folds further expands grafold's mechanical, chemical, optical, and electronic diversity.Comment: 29 pages, 10 figures (accepted in Phys. Rev. B

“We the people”: interpretaciones actuales sobre el fenómeno del populismo

Abstract  Populism has become a political phenomenon of special interest due to the proliferation of organizations, leaders or movements that are ascribed to such an elusive political category. However, it has been uncritically assumed that it has been more closely linked to journalistic uses than to studies of various spheres of knowledge such as the discipline of history or political science. For this reason, this article aims to focus on the validation of the concept as an axis of analysis of historical political experiences. To this end, the numerous problems in conceptualizing the phenomenon will be highlighted first and the evolution of the successive attempts will be presented. After that, the three predominant interpretative frameworks will be presented, and finally the concluding observations will be laid out. Keywords  Populism, historiography, concepts, interpretations, political strategyResumen El populismo se ha convertido en un fenómeno político de especial interés debido a la proliferación de organizaciones, líderes o movimientos que son adscritos a tan escurridiza categoría política. No obstante, se ha asumido de forma acrítica un significado más ligado a los usos periodísticos que a los estudios de diversas esferas del conocimiento como la disciplina histórica o las ciencias políticas. Por dicha razón, este artículo pretende poner el foco en la validez del concepto como eje de análisis de experiencias políticas históricas. Para ello, en primer lugar se destacarán los numerosos problemas a la hora de conceptualizar al fenómeno y se presentará la evolución de los sucesivos intentos. Tras ello, serán presentados los tres marcos interpretativos predominantes en la actualidad, para, finalmente, exponer las observaciones finales. Palabras clave Populismo, historiografía, conceptos, interpretaciones, estrategia polític

Determination of parasite resistance status to anthelmintics through the larval development test.

The control of gastrointestinal nematodes of small ruminants has been carried out through intense and indiscriminate use of anthelmintics.Boletim de Indústria Animal, v. 74

Three-dimensional printed polycaprolactone-microcrystalline cellulose scaffolds

Microcrystalline cellulose (MCC) is proposed in this study as an additive in polycaprolactone (PCL) matrices to obtain three-dimensional (3D) printed scaffolds with improved mechanical and biological properties. Improving the mechanical behavior and the biological performance of polycaprolactone-based scaffolds allows to increase the potential of these structures for bone tissue engineering. Different groups of samples were evaluated in order to analyze the effect of the additive in the properties of the PCL matrix. The concentrations of MCC in the groups of samples were 0, 2, 5, and 10% (w/w). These combinations were subjected to a thermogravimetric analysis in order to evaluate the influence of the additive in the thermal properties of the composites. 3D printed scaffolds were manufactured with a commercial 3D printer based on fused deposition modelling. The operation conditions have been established in order to obtain scaffolds with a 0/90° pattern with pore sizes between 450 and 500 µm and porosity values between 50 and 60%. The mechanical properties of these structures were measured in the compression and flexural modes. The scaffolds containing 2 and 5% MCC have higher flexural and compression elastic modulus, although those containing 10% do not show this reinforcement effect. On the other hand, the proliferation of sheep bone marrow cells on the proposed scaffolds was evaluated over 8 days. The results show that the proliferation is significantly better (p < 0.05) on the group of samples containing 2% MCC. Therefore, these scaffolds (PCL:MCC 98:2) have suitable properties to be further evaluated for bone tissue engineering applications

Fractal Topological Analysis for 2D Binary Digital Images

Fractal dimension is a powerful tool employed as a measurement of geometric aspects. In this work we propose a method of topological fractal analysis for 2D binary digital images by using a graph-based topological model of them, called Homological Spanning Forest (HSF, for short). Defined at interpixel level, this set of two trees allows to topologically describe the (black and white) connected component distribution within the image with regards to the relationship “to be surrounded by”. This distribution is condensed into a rooted tree, such that its nodes are connected components determined by some special sub-trees of the previous HSF and the levels of the tree specify the degree of nesting of each connected component. We ask for topological auto-similarity by comparing this topological description of the whole image with a regular rooted tree pattern. Such an analysis can be used to directly quantify some characteristics of biomedical images (e.g. cells samples or clinical images) that are not so noticeable when using geometrical approaches.Ministerio de Economía y Competitividad TEC2016-77785-PMinisterio de Economía y Competitividad MTM2016-81030-

Horizontes neoliberais na subjetividade

O texto de Jorge Alemán intitulado “Horizontes neoliberais na subjetividade” foi publicado em 2016 como capítulo de um livro homônimo, além de uma série de textos centralizados nesta temática tão atual. O debate proposto por Alemán aponta principalmente para a especificidade do neoliberalismo, já que seria o primeiro regime histórico a tentar atingir o simbólico. Ao disputar o campo do sentido, busca capturar o sujeito pela palavra que é sua dependência estrutural. Sua novidade é promover um modelo de subjetividade que se configura pelo paradigma empresarial, competitivo e gerencial, ou seja, o indivíduo empreendedor de si mesmo. Esta nova subjetividade, marcada pelo imperativo do ilimitado, espolia qualquer possibilidade de um legado simbólico ou história a decifrar sobre a subjetividade particular de cada um. Tentando promover assim uma heterogeneidade, que se reduz ao circuito da forma mercadoria. Nesse sentido, a contribuição de Alemán passa pelo reconhecimento dessa impossibilidade, já que nem tudo é apropriável pelo Capital, como exemplificado pela categoria de sujeito, que se constitui como aquilo que possibilita a abertura para a diferença, para a não-totalização