Morfologia urbana e qualidade do ar: uma proposição metodológica aplicada em caso empíricono Rio de Janeiro

Considerando a importância das cidades como fontes emissoras de poluentes e polos de concentração de população, o trabalho investigapossíveis impactos de aspectos da forma urbana nas concentrações de poluentes. O artigo discute o estado da artesobre as interações entre a qualidade do ar e indicadoresda forma urbana, compara e testa diferentes indicadores da forma urbana, incluindo um indicador de compacidadetridimensional proposto. O artigo sugere uma forma de modelagem e avaliação dessas relações, e apresenta, por fim, um estudo de caso na cidade do Rio de Janeiro, envolvendo métodos estatísticos aplicados a poluentes (SO2, CO e PI), variáveis morfológicas (taxa de ocupação e percentagem de verticalização) e meteorológicas (vento – direção e velocidade -, precipitação pluvial e temperatura do ar). Os resultados apontam para graus de influência das variáveis taxa de ocupação e verticalização na concentração dos poluentes considerados.Considering the importance of cities as pollutants emission sources and population hubs, the work researches possible impacts of the urban form aspects on pollutants concentrations. The paper discussesthe state of art of interactions between air quality and urban form indexes, compares and tests different indicators of urban form, including a proposed tridimensional compacity index. It.s suggested a way of modeling and testing these relations andpresented a case study in Rio de Janeiro city, involving statistical methods applied to pollutants (SO2, CO e PI), morphological variables (ground space index and verticalization) and meteorological (wind . direction and speed - , rainfall and air temperature). Results point to gradesof influenceof the ground space index and verticalizationon concentrations of considered pollutants

Influence of different protecting groups on the regioselectivity of the hydrotelluration reaction of hydroxy alkynes

The influence of protecting groups on the synthesis of regio- and stereodefined vinyl tellurides derived from the reaction of BuTeNa and propargylic- or homo-propargylic alcohols showed that TIPS silyl ether is useful as a regiodirecting group. The application of the methodology to the synthesis of a fragment of (±)-Seselidiol, a natural product, demonstrated the applicability of the new methodology

Fast decellularization process using supercritical carbon dioxide for trabecular bone

Decellularization is a process that consists on the removal of immunogenic cellular material from a tissue, so that it can be safely implanted as a functional and bioactive scaffold. Most decellularization protocols rely on the use of harsh chemicals and very long washing processes, leading to severe changes in the ultrastructure and loss of mechanical integrity. To tackle these challenges, supercritical carbon dioxide (scCO2) is herein proposed as an alternative methodology for assisting decellularization of porcine trabecular bone tissue and is combined, for the first time, with Tri(n-butyl) phosphate (TnBP). Histological and DNA analysis revealed that both TnBP and scCO2 were able to extract the DNA content from the scaffolds, being this effect more pronounced in treatments that used TnBP as a co-solvent. The combined protocol led to a decrease in DNA content by at least 90%, demon- strating the potential of this methodology and opening new possibilities for future optimizations.info:eu-repo/semantics/publishedVersio

Glatiramer Acetate Treatment Increases Stability Of Spinal Synapses And Down Regulates Mhc I During The Course Of Eae.

The recent discovery that the major histocompatibility complex of class I (MHC I) expression has a role in the synaptic elimination process, represented an insight into understanding the cross talk between neurons. In the present study, the possibility that glatiramer acetate (GA) treatment influences the MHC class I expression and the synaptic plasticity process in the spinal cord during the course of EAE was investigated. C57BL/6J mice were induced to EAE and submitted to treatment either with a placebo solution or with GA (0.05 mg/animal, subcutaneously, on a daily basis). All the animals were sacrificed at the peak disease (14 days after induction) or at the point of recovery of the clinical signs (21 days after induction). The spinal cords were removed and submitted to immunohistochemical examination, Western blotting and transmission electron microscopy analysis. The results showed that GA treatment was able to decrease synaptic loss during the course of EAE, which correlates with the downregulation of the MHC I complex. The present results reinforce the neuroprotective role of GA treatment, by reducing synaptic loss during the course of the disease. Such action may be associated with the recently described role of MHC I regulation during the synaptic plasticity process.71188-20

Rapid synthesis of MCM-41 and SBA-15 by microwave irradiation: promising adsorbents for CO2 adsorption

It is known that the world scenario is one of constant search for sustainable technologies that can reduce the emission of carbon dioxide (CO2) in the atmosphere. This is because CO2 is seen as the main responsible for the increase in the generation of greenhouse gases, which leads to global warming and climate change. The development of efficient adsorbents for CO2 capture is a current challenge. MCM-41 and SBA-15 were synthesized in a microwave reactor and used as adsorbents in this work. Microwave irradiation presents itself as an easy synthesis strategy with less preparation time and energy requirement. The silica synthesis period was extremely reduced (1 h) at a temperature of 60 and 80 °C in the microwave reactor, obtaining silica with good textural and chemical properties. The CO2 adsorption isotherms were performed at 0, 25, and 40 °C at 1 bar. The MCM-41 and SBA-15 present favorable results for CO2 capture processes, showing that pure silica synthesized by microwave already obtains promising results, reaching a maximum adsorption capacity of 2.16 mmol g−1 (1 bar—0 °C) and a good fit for the Langmuir, DsL and Toth models. Furthermore, to increase CO2 adsorption, the mesoporous silica was also modified via impregnation with branched polyethylene diamine (PEI) or tetraethylenepentamine (TEPA). It is worth mentioning that microwave irradiation reduced the synthesis steps and improved the properties and adsorption capacity of the silica. This work opens new opportunities in the efficient preparation of materials that require optimizing the adsorbent synthesis process.The authors thank you to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, National Council for Scientific and Technological Development, Brazil) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Higher Education Personnel Improvement Coordination, Brazil, CAPES—financing code 001) for financial support. This research was also funded by the Ministry of Science, Innovation and Universities (Spain), Grants Nos. RTI2018-099668-B-C22 and PID2021-126235OB-C32, and projects UMA18-FEDERJA-126 and P20_00375 of Junta de Andalucía and FEDER funds. // Funding for open access publishing: Universidad Málaga/CBUA

Refletindo sobre desafios à inserção didática da história e filosofia da ciência em oficina de formação docente

O presente artigo apresenta uma pesquisa empírica realizada em oficina de formação docente. A intervenção realizada buscou a sensibilização quanto à utilização didática de episódios históricos para a abordagem da temática Natureza da Ciência. Entre outros aspectos, foram abordados desafios previstos na inserção didática da História da Ciência e discutidos exemplares de intervenções didáticas. Finalizadas discussões iniciais, os grupos de participantes se engajaram em tentativa de elaborar propostas didáticas a partir de um texto de subsídio sobre a História do Vácuo. A listagem de desafios previstos serviu como referência para a cunhagem de critérios que nortearam a avaliação dessas propostas. A análise qualitativa buscou identificar a possível materialização de desafios, se os participantes tentaram ou não enfrentá-los, dentre outros aspectos. Os resultados podem colaborar para iniciativas de formação docente. Adicionalmente, contribuem com avanços no que diz respeito a referenciais para avaliar a formação de professores visando o uso de abordagens histórico-filosóficas na escola básica

Influência do teor de molibdênio em catalisadores de cobalto e molibdênio suportado em óxido de magnésio para a produção de nanotubos de carbono

O desenvolvimento dos processos de produção de nanotubos de carbono é amplamente estudado com o objetivo de melhorar a produção, pureza e qualidade do produto. Entre os processos de produção de nanotubos, a deposição química em fase vapor sobre catalisadores é o método mais empregado para produção em larga escala, pois este permite controlar, de modo eficiente, os parâmetros reacionais. Catalisadores de CoMo/MgO com baixa concentração de cobalto, 5% em massa, e três diferentes concentrações de molibdênio, 5, 10 e 20%, foram preparados pelo método de impregnação seca para estudar o efeito do molibdênio na síntese de nanotubos de carbono. As caracterizações dos catalisadores e dos nanotubos puderam demonstrar as relações entre as propriedades catalíticas e as características dos nanotubos. Os catalisadores com maior concentração de molibdênio apresentaram maior formação de espécies CoMoO4 e MgMoO4 indicando maior interação do cobalto e do suporte com o molibdênio. A elevada concentração de molibdênio nos catalisadores prejudicou a taxa de formação dos nanotubos e a menor grau de grafitização.Palavras-chave: nanotubos de carbono, cobalto, molibdênio, deposição química de vapor

Surface tension implementation for Gensmac 2D

In the present work we describe a method which allows the incorporation of surface tension into the GENSMAC2D code. This is achieved on two scales. First on the scale of a cell, the surface tension effects are incorporated into the free surface boundary conditions through the computation of the capillary pressure. The required curvature is estimated by fitting a least square circle to the free surface using the tracking particles in the cell and in its close neighbors. On a sub-cell scale, short wavelength perturbations are filtered out using a local 4-point stencil which is mass conservative. An efficient implementation is obtained through a dual representation of the cell data, using both a matrix representation, for ease at identifying neighbouring cells, and also a tree data structure, which permits the representation of specific groups of cells with additional information pertaining to that group. The resulting code is shown to be robust, and to produce accurate results when compared with exact solutions of selected fluid dynamic problems involving surface tension