This work aimed to investigate and compare the composition and the physicochemical properties of 18 different sources of edible vegetable oils. A systematic study on the correlation between ...composition and physical properties was performed using Fourier Transform Infrared (FTIR) Spectroscopy and fatty acid chromatographic analysis. Principal component analysis of FTIR spectra is performed to classify edible oils concerning their physical properties. The results demonstrate the potentiality of the method associated with multivariate statistics analysis as powerful, fast, and non-destructive tools for characterization and quality control of edible vegetable oils.
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•The correlation of composition and physicochemical properties of edible vegetable oils•Chromatographic and spectroscopic techniques associated with multivariate statistics analysis•Unsaturated fatty acids are related to mass density, dynamic viscosity, oxidative stability index and refractive index.•These techniques allow predicting oil properties, helping in the characterization and quality control of vegetable oils.•Direct correlation of the PCA components with the set of information about composition and physical properties of the oils
The dermatophytes are filamentous fungi that cause cutaneous fungal infections because they use keratin as a nutrient source. For this study the antidermatophyte activity of the extracts and ...derivates from leaves of Piper regnellii was analyzed. From the dichloromethane extract (EBD) neolignans such as eupomatenoid-3 and eupomatenoid-5 were obtained, and it was submitted to fractionation to remove the green residue, designated as the chloroform fraction (FF). Extracts, chloroform fraction and compounds were tested against Trichophyton rubrum ATCC 28189 to determine the minimum inhibitory concentration (MIC). The chloroform fraction was incorporated to nail lacquer that was analyzed by photoacoustic spectroscopy, in vitro assay and scanning electronic microscopy. For antifungal activity in solid medium the dichloromethane extract and chloroform fraction were used. The compounds eupomatenoid-3 and eupomatenoid-5 were less active than the dichloromethane extract against T. rubrum. EBD and FF showed moderate activity in hyphal growth inhibition in solid medium and EBD did not link to ergosterol. Nail lacquer containing the chloroform fraction showed good penetration through the nail as determined by photoacoustic spectroscopy. From in vitro studies it was observed that nail lacquer concentrations above 20 mg/mL prevented the growth of fungi, but concentrations up to 2.5 inhibited the growth. Scanning electronic microscopy was used to confirm the in vitro nail lacquer activity results. The specie P. regnellii showed great antifungal activity against T. rubrum, and nail lacquer containing its chloroform fraction has great potential to treat onychomycosis caused by these microorganisms.
O presente trabalho tem como objetivo apontar os benefícios dos jogos pedagógicos no ensino de matemática. Os jogos fazem parte de uma etapa importante na vida dos alunos. É nessa etapa que o aluno ...aprende “brincando” (jogando). O jogo é um precioso momento de construção pessoal e social, onde o aluno explora sua moralidade, afetividade perante as situações desafiadoras e significativas presentes no jogar e inerentes à produção social do conhecimento. O resgate dos jogos pedagógicos faz-se necessário no ambiente escolar. Percebemos que a cada dia que passa os alunos tem menos contato com jogos ou até mesmo brinquedos voltados ao raciocínio lógico, pois o contato maior é com o mundo virtual. Nesse contexto é fundamental conceituar e caracterizar os jogos e os benefícios dos mesmos na educação. Para a corporificação do tema versado foi imprescindível uma pesquisa bibliográfica na qual foram empregados como fontes de estudo obras de grande pertinência sobre a temática, artigos científicos, livros e revistas pedagógicas.
The nutritional composition of Spirulina platensis has been studied extensively, especially its proteins, amino acids, vitamins and mineral content. However, research on its protein properties, ...including its techno-functional properties, remains scarce. Therefore, S. platensis proteins were extracted and concentrated to produce a S. platensis protein concentrate (SpPC), which was characterized by its physicochemical and techno-functional properties. Response surface methodology (RSM) was applied to evaluate the influence of two variables, pH and SpPC concentration, on the techno-functional properties of the SpPC, instead of studying one variable at a time. The SpPC contained 75.97% proteins (dry weight); its minimum solubility was at pH 3.0, and its maximum solubility was at pH 9.0. The effects of the SpPC concentration and pH on the water absorption capacity and emulsifying and foaming properties were evaluated. The pH exhibited a positive effect on these properties, and the best conditions were far from the isoelectric point. The SpPC concentration also showed a positive effect, except water and oil absorption. Considerable concentrations of amino acids were found in the S. platensis protein concentrate; tryptophan had the highest chemical score. The most abundant secondary structure conformation was β-sheet. Consequently, the S. platensis protein concentrate may contribute technologically to food formulation, and facilitate industrial processing.
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•A protein concentrate with 76% protein and all essential amino acids was obtained.•Techno-functional properties showed higher values with the pH increase.•The highest oil absorption capacity occurred at the minor protein concentration.•The foaming properties were similar to those of egg white proteins.•According to the results, S. platensis protein concentrate may improve food systems.
The objective of this study was to investigate the color removal in a binary mixture of azo dyes from the photovoltaic electrocoagulation (EC) technique, using spectral deconvolution and the Gaussian ...fit for qualitative and quantitative determination of the physical color parameter. Initially, a conventional energy source was used to feed the EC reactor and the experimental design was conducted according to the Rotational Central Compound Design (RCCD). The spectral deconvolution method associated to the Gaussian fit aided in the description of the composition of the sample matrix, In the first step, through the Analysis of Variance, the RCCD and the three-dimensional surface response graphs, the optimized operating conditions were identified, which corresponded to 1320 A m−2 with an reaction time of 16.6 min, and an expected removal of 98.40% for Scarlet Red (SR) dye and 1160 A m−2 with a run time of 15.7 min and 97.9% removal for Turquoise Blue (TB) dye. Using the photovoltaic module as the power source of the EC reactor, a maximum removal of 97 ± 0.43% for TB dye and 98% ± 0.81 for SR was obtained. The results encourage the applicability of photovoltaic module-fed EC technology as a promising alternative for the treatment of effluents containing textile dyes, as well as the use of the spectral deconvolution method associated with the Gaussian fit, for the reliability and precision of the results.
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•The EC achieved a color removal efficiency of 98%.•Spectral deconvolution method viable for the separation of the absorption bands•Use the CCRD essential to obtain the optimum independent variables•The photovoltaic module supplies sustainable energy to the electrochemical processes.
Jogos no processo de ensino de matemática Ariza, Josefa Fernanda; Sehn, Elizandra
Revista Eletrônica Científica Inovação e Tecnologia,
10/2017, Letnik:
8, Številka:
19
Journal Article
Odprti dostop
Esta pesquisa deseja analisar e compreender a contribuição dos jogos infantis no processo de desenvolvimento das crianças em séries iniciais do ensino fundamental. Constata-se que através do lúdico ...pode se trabalhar a interdisciplinaridade, a fim de melhorar suas habilidades manuais, motoras e intelectuais. Esse estudo tem como objetivo mostrar a importância dos jogos no processo de ensino de matemática. Os dados foram coletados a partir de um questionário com os professores de uma escola pública, contendo perguntas abertas e fechadas. Os jogos são vistos por muitos pesquisadores aqui citados, como processo de ensino, na qual permite a integração social, cultural e cognitiva no âmbito escolar. Os mesmos ratificam que os jogos podem tornar a aprendizagem mais prazerosa, ressaltando a importância de atribuí-los não no contexto educacional. Os resultados obtidos nos mostram a importância de inserirmos novos métodos e técnicas de ensino, para propiciar aos alunos a apropriação do conceito.
Este trabalho é um requisito para conclusão do curso de Educação: Métodos e Técnicas de Ensino que têm como objetivo avaliar a importância dos jogos e brincadeiras como estratégias de ensino de ...matemática no ensino fundamental. Considerando os projetos de aperfeiçoamento para os docentes da educação criados pelo governo federal, como o Pacto Nacional pela Alfabetização na Idade Certa (PNAIC) que tem como principal desafio garantir que todas as crianças brasileiras até oito anos sejam alfabetizadas plenamente. Neste contexto, o trabalho expõe as principais teorias e práticas existentes na literatura, relacionadas ao uso dos jogos matemáticos no Ciclo de Alfabetização.
A realização do trabalho ocorreu a partir da importância do conhecimento matemático para o aprendizado de disciplinas de ciências exatas. O entendimento de conceitos matemáticos pode favorecer o ...desenvolvimento de ferramentas intelectuais no aluno, permitindo o entendimento de conteúdos lógicos de diversas disciplinas. Um dos principais motivos para a dificuldade de aprendizagem dos alunos pode estar relacionada a metodologia adotada pelo professor, que geralmente apresenta os conteúdos de forma bastante teórica, sendo necessária uma constante capacitação dos professores, de forma a garantir que busquem novas maneiras de apresentar os conteúdos. A pesquisa verificou que esta formação é importante principalmente pelo fato que 70% dos professores de exatas analisados possui formação em nível de bacharelado ou engenharia, não tendo uma formação pedagógica satisfatória. Dentreos professores analisados 80% considera que os alunos possuem um desempenho suficiente ou regular em suas disciplinas. Os professores também consideram que o conhecimento matemático possui influência no entendimento dos conteúdos de suas disciplinas, onde a grande maioria dos alunos que possui dificuldade de aprendizado também apresenta dificuldade em matemática. Por fim os professores acreditam que outras disciplinas que também apresentam influência no ensino de exatas são Física, Português, Química e Sociologia.
Laser-induced wavefront distortion is detectable by several techniques based on the photothermal effect. The effect is probed by monitoring the phase shift caused by the bulging of the heated area, ...the photoelastic effects, and the spatial distribution of the refractive index within the sample and in the fluid surrounding it. A simple analytical solution for the wavefront distortion was only possible for low absorbing materials, with the assumption that the stresses obey either the thin-disk or the long-rod type distributions. Recently, a unified theoretical description for the laser-induced optical path change was proposed to overcome part of this limitation for weakly absorbing materials, regardless of its thickness. In this work, we perform an experimental investigation taking the sample–fluid heat coupling effect into account using the thermal lens technique. The experimental investigation presented here validates the unified model. In addition, we show that the heat-coupling model provides an alternative method to obtain physical properties of non-absorbing fluid by using a reference solid sample.
The international public health emergency related to COVID‐19 caused by the SARS‐CoV‐2 virus has altered several production and registration criteria for sanitary products, including alcohol‐based ...hand sanitizers. In this work, we investigate the concentration of alcohol in sanitizers presented in gel form applying the principal component regression method on measurements using Infrared and Raman spectroscopic methods. The chemometric calibration is performed using isopropanol or ethanol as active agents, and the method is used to characterize several commercial samples. Furthermore, the results of the prediction of alcohol concentration, obtained by applying the principal component regression and partial least squares methods, in the spectroscopic techniques, were compared with each other and with the results provided by nuclear magnetic resonance. Our results show that spectroscopic techniques coupled with principal component regression are fast, low‐cost, and safe tools for the determination of alcohol concentration, regardless the gelling agent used.
The association between chemometrics and spectroscopy in the determination of alcohol in sanitizing products in the form of a gel allows for a quick, low‐cost measurement without subjective treatment of the spectroscopic analysis results.
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