Improving contaminated land data communication through the developing of an environmental indicator: Desenvolvimento de um indicador ambiental para aprimorar a comunicação de dados sobre áreas contaminadas

Environment contamination is a widespread problem in all countries around the world. Contaminated sites are consequence of land use and occupation without environmental concerns, and it can cause contamination of superficial soil, subsoil, and groundwater.   This issue affects urban planning, human health as well natural resource availability. The management of contaminated land data and its communication to stakeholders is a significant driver to achieve sustainable urban planning, promoting equally sustainable cities and communities. Therefore, tools to improve comprehension of environmental quality of cities is essential to face this challenge. Here, we develop an environmental indicator to analyze contaminated land data and communicate its complexity to non-technical stakeholders. The indicator developed, adopts 15 variables and considering three parameters: polluting substance concentration, affected environmental matrices, and the environmental behavior of the polluting substance. A dataset has been elaborated containing information about 25 contaminated sites of Lapa District, the pilot area of São Paulo city, and the environmental indicator was applied, resulting in four environmental contamination levels: low, moderate, high, and remarkably high degrees, existing in an individually site

A comparative study on machine learning regression algorithms aplied to modeling gas centrifuge / Um estudo comparativo sobre algoritmos de regressão de aprendizagem de máquinas aplicado à modelagem de centrífugas a gás

The gas Centrifuge is a very hard equipment to model, because it involves a gas dynamic with many complications, such as hypersonic waves and rarefied regions combined with continuous flow areas. Therefore, data analysis regressions remain currently a very important technique to understand and describe the problem in a practical way. This paper intends to apply and compare several regression techniques using machine learning, to obtain a hydraulic and a separative power model of gas centrifuge used in enrichment plants. For this purpose, a set of normalized data composed of 134 experimental lines was used, observing the variables of interest, the separation power (dU), and the waste pressure (Pw), through the following explanatory variables: feed flow (F), cut (q), and product pressure (Pp). The comparisons were presented between the results obtained for the models generated by the following: algorithms, multivariate regression, multivariate adaptive regression splines – MARS, bootstrap aggregating multivariate adaptive regression splines – Bagging MARS, artificial neural network – ANN, extreme gradient boosting – XGBoost, support vector regression– Poly SVR, radial basis Function support vector regression – RBF SVR, K-nearest neighbors – KNN and Stacked Ensemble. That way, to avoid overfitting and provide insights about generalization of the models in unseen data, during the training phase, the k-fold cross validation approach was used.  Subsequently, the residuals were analyzed, and the models were compared by the following metrics: Root mean square error – RMSE; Mean squared error – MSE; Mean absolute error – MAE; and Coefficient of determination – R2

Functional analysis, diversity and defense-in-depth principle applied for instrumentation and control architecture in accordance with U.S.NRC / Análise funcional, diversidade e princípio da defesa em profundidade aplicado à arquitectura de instrumentação e controlo em conformidade com o U.S.NRC

According to IAEA (2020), a large number of nuclear power plants (NPP) is completing 30 to 40 years of operation, and many of them can extend the lifetime for variable periods of operation. Besides that, new applications and methods of NPP design are in direction of adopting small modular reactors (SMR) to optimize the NPP projects in relation to cost and safety (Black et al., 2021). Other way is to apply NPP in naval plants, providing efficient manners to generate energy (Freire, 2018). All these ways can make nuclear energy a viable alternative, and consequently to contribute with low carbon power demands, and stabilize the global energy matrix helping to meet climate goals in the next decades (IAEA, 2020). One of the sensing points in NPP project nowadays is the introduction of advanced digital I&C technologies (Santos, 2021). In digital I&C design based on nuclear normative basis, it is imperative to be adherent with the safety and human factors engineering (HFE) requirements. This paper proposes the formalization of a plant-level Functional Analysis (FA) methodology with Diversity and Defense-in-Depth (D3) principles, considering the U.S.NRC normative basis

Gestão da informação e crise: reflexões sobre comunicação no caso dos “terroristas brasileiros” – Olimpíadas Rio 2016: Information management and crisis: reflections on communication in the case of “brazilian terrorists” – Rio 2016 Olympics

O objetivo desse artigo é realizar uma análise crítica sobre o processo de gestão da informação a partir do caso dos “terroristas brasileiros”, ocorrido em paralelo aos preparativos para os jogos Olímpicos Rio 2016. Com base no conceito de poder proveniente da comunicação e da gestão da informação diante de situações críticas, o artigo visa analisar a conduta das autoridades brasileiras para proteger seus interesses sem afetar a relação de confiança com a sociedade, principalmente através do planejamento para tratamento e divulgação das informações

Very high temperature reactor (VHTR) - a proposal to generation IV reactors / Reactor a temperatura muito elevada (VHTR) - uma proposta para reactores da geração IV

The Generation IV reactors depict a revolution in terms of electricity supply for the future. The proof of concept originated in the Generation IV forum, which listed six possible technological routes for a future of nuclear generation based on fissile material, which includes safety requirements, nuclear energy efficiency and less waste generation. These are the very high temperature reactor (VHTR); supercritical water-cooled reactor (SCWR); molten salt reactor (MSR); gas-cooled fast reactor (GFR); sodium cooled fast reactor (SFR); and lead-cooled fast reactor (LFR). The present study explored the possibilities, the obstacles, as well as the challenges to be overcome, for the Very High Temperature Reactor (VHTR). VHTR technology seems to be versatile; it originates on the advancement of another type, the High Temperature Reactor (HTR). USA, Germany and UK were main countries in this avant-garde research. In addition to generating electrical energy, VHTR can provide heat for industrial sectors and other applications. Like any nuclear technology, challenges regarded to safety and the environment are key points in the implementation of the system. VHTR was here prospected, with its “pros and cons”; as a promising way to a safe nucleoelectric energy. Summarizing, VHTR is shown as a possible alternative, as long as studies of high-strength materials go ahead. In short, the reactor becomes a viable source of thermonuclear generation, also associated with hydrogen production

Characterization of polyacrylonitrile thermal stabilization process for carbon fiber production using intelligent algorithms

Composite materials have widened their application range in recent years. The polymeric composite reinforced with carbon fibers can be described as a high-performance structural material which merges two important features: low weight and mechanical stability. Carbon fiber production which uses polyacrylonitrile as precursor is composed of many stages such as polymerization, spinning, thermal stabilization, carbonization, and surface treatment. Thermal stabilization is the critical stage of this production process, during which aromatic rings are generated, and therefore the main factor for the carbon fiber structure definition and thus for this material quality. A thermal stabilization model using intelligent algorithms was developed aiming a possible optimization of the production process and consequent cost reduction. This work was based on real experimental data obtained from a composite material production pilot plant. A qualitative analysis was initially performed using Self-Organizing Maps trained with variables of fiber production reagents and process. Thereafter, a supervised training with feedforward backpropagation neural network was used for a quantitative analysis. Based on this quantitative analysis, the carbon fiber thermal stabilization process was simulated, obtaining 2.98% and 2.48% mean errors relative to experimental results of Volumetric Density and FTIR Conversion index, respectively

Repositórios institucionais como fonte de dados para pesquisas: um estudo sobre o formato de apresentação das dissertações do programa de Pós-graduação do Instituto de Pesquisas Energéticas e Nucleares.

Os trabalhos científicos apresentados na academia devem estar de acordo com padrões estéticos para serem submetidos a banca examinadora, que avaliam conteúdo e forma, sendo necessário seu depósito em repositórios institucionais de modo que a produção intelectual das instituições sejam disseminadas. Como isso, o presente artigo tem por objetivo apresentar a capacidade dos repositórios institucionais como fonte de dados para pesquisas, propondo ainda avaliar as dissertações depositadas no Repositório Digital da Produção Técnico-Científica do Instituto de Pesquisas Energéticas e Nucleares quanto ao formato, verificando sua adequação às normas de apresentação propostas pelo Insituto e comparando a adesão dos trabalhos às normas entre alunos que cursaram e alunos que não cursaram a disciplina de Metodologia da Pesquisa Científica ofertada pelo programa. Este estudo é descritivo, exploratório e Survey, realizado diretamente nas dissertações depositadas no repositório do instituto. A amostra foi de 172 dissertações. Os resultados do estudo apontaram para a predominância de trabalhos muito adequado em todas as variáveis avaliadas nos dois grupos. Na aplicação dos testes estatísticos, observou-se que, 5 variáveis categóricas apresentaram-se com resultados significativos na comparação entre os 2 grupos da pesquisa (alunos que cursaram a disciplina de Metodologia da Pesquisa Científica e alunos que não cursaram). Foi possível evidenciar a importância e alcance dos repositórios institucionais como fonte de dados de pesquisa e a contribuição do guia de normas e da disciplina de Metodologia da Pesquisa Científica na apresentação geral das dissertações