Influence of public policies on the diffusion of wind and solar PV sources in Brazil and the possible effects of COVID-19

Renewable energy is crucial to achieving carbon neutrality and supporting sustainable development, but its success depends on effective policies. This study aims to evaluate public policies and their influences on the use and diffusion of wind and solar PV into the Brazilian electricity grid and to understand if, and how, the two renewable sources could be affected by the post-COVID-19 pandemic scenario. This work plays an important role in the decarbonization of the electricity sector, highlights the need to modernize the Brazilian industrial park, and addresses new barriers to the development of renewable sources in the country. To carry out the analysis and answer the research questions, a mixed methodological approach was adopted covering the quantitative and qualitative aspects, led by a rigorous systematic review of the literature and semi-structured interviews with Brazilian stakeholders. The results revealed that 1/4 of the policies, characterized by socio-economic drives, were responsible for the growth of the share of wind and solar PV supply in the electrical mix, contributing to the decarbonization of the Brazilian energy mix. The results also suggest that new policies will be needed to ensure a greater presence of both sources in the electricity mix. The findings of the study reveal unpublished and valuable information capable of supporting policymakers and stakeholders in the diffusion of renewable sources. Further studies are needed to highlight other aspects, such as the need to modernize the “distribution” network and storage system for renewable technologies

Manejo integrado das plantas infestantes no cafezal.

O trabalho verifica a necessidade de aplicação do manejo integrado das plantas infestantes na lavoura cafeeira, cuja utilização combinada e rotativa de diversos recursos alternativos de controle, proporcionarão maior rentabilidade da cultura, com diminuição dos custos e melhor conservação ambiental.bitstream/item/72104/1/0000004037-ct69-cafe.pd

Global priorities for conservation across multiple dimensions of mammalian diversity

Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity-taxonomic, phylogenetic, and traits-and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts

Entropy, non-ergodicity and non-Gaussian behaviour in ballistic transport

Ballistic transportation introduces new challenges in the thermodynamic properties of a gas of particles. For example, violation of mixing, ergodicity and of the fluctuation-dissipation theorem may occur, since all these processes are connected. In this work, we obtain results for all ranges of diffusion, i.e., both for subdiffusion and superdiffusion, where the bath is such that it gives origin to a colored noise. In this way we obtain the skewness and the non-Gaussian factor for the probability distribution function of the dynamical variable. We put particular emphasis on ballistic diffusion, and we demonstrate that in this case, although the second law of thermodynamics is preserved, the entropy does not reach a maximum and a non-Gaussian behavior occurs. This implies the non-applicability of the central limit theorem.Comment: 9 pages, 2 figure

A systematic comparison of supervised classifiers

Pattern recognition techniques have been employed in a myriad of industrial, medical, commercial and academic applications. To tackle such a diversity of data, many techniques have been devised. However, despite the long tradition of pattern recognition research, there is no technique that yields the best classification in all scenarios. Therefore, the consideration of as many as possible techniques presents itself as an fundamental practice in applications aiming at high accuracy. Typical works comparing methods either emphasize the performance of a given algorithm in validation tests or systematically compare various algorithms, assuming that the practical use of these methods is done by experts. In many occasions, however, researchers have to deal with their practical classification tasks without an in-depth knowledge about the underlying mechanisms behind parameters. Actually, the adequate choice of classifiers and parameters alike in such practical circumstances constitutes a long-standing problem and is the subject of the current paper. We carried out a study on the performance of nine well-known classifiers implemented by the Weka framework and compared the dependence of the accuracy with their configuration parameter configurations. The analysis of performance with default parameters revealed that the k-nearest neighbors method exceeds by a large margin the other methods when high dimensional datasets are considered. When other configuration of parameters were allowed, we found that it is possible to improve the quality of SVM in more than 20% even if parameters are set randomly. Taken together, the investigation conducted in this paper suggests that, apart from the SVM implementation, Weka's default configuration of parameters provides an performance close the one achieved with the optimal configuration