RESUMEN
The effects of impurities on reaction precursors for metal-organic framework (MOF) synthesis have not been studied in extensive detail. The impact of these impurities can be an important factor while considering scale-up of these materials. In this work, we study the apparently positive impact of the presence of manganese ions for the synthesis of a Co-based MOF, Massey University Framework-16 (MUF-16). The presence of a trace amount of manganese in the reaction mixture led to consistently high CO2 uptake across multiple batches. Characterization including X-ray diffraction, scanning electron microscopy, Fourier transform infrared-attenuated total reflectance, ultraviolet-visible spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure spectroscopy led us to hypothesize that the differences in CO2 adsorption among materials with differing synthesis routes arise from variations in the local environment around the cobalt metal center. Aided by density functional theory calculations, we speculate that manganese ions get inserted into the structure during crystallization and act as catalysts for ligand substitution, improving the possibility for octahedral coordination of cobalt with the ligand, thus leading to Co-based pristine structures with higher CO2 uptakes.
RESUMEN
Este trabalho teve como objetivo analisar as propriedades psicométricas do Questionário de Apoio às Necessidades Psicológicas Básicas (QANPB) com estudantes portugueses. A amostra foi constituída por 445 estudantes do sexo masculino e feminino, com idades compreendidas entre os 12 e os 16 anos. Inicialmente, a escala foi traduzida para o português, para posteriormente se realizar uma análise das propriedades psicométricas. Os resultados comprovaram que o QANPB se apresentava como um instrumento com evidências de validade (fatorial e nomológica) e confiabilidade, que permite analisar a percepção dos alunos sobre o apoio do professor à autonomia, competência e relações sociais nas aulas de Educação Física. (AU)
The purpose of this study was to analyze the psychometric properties of the Basic Psychological Needs Questionnaire (BPNQ) with Portuguese students. The sample was composed of 445 male and female students, ranging in age from 12 to 16 years. Initially, the scale was translated into Portuguese, and later, an analysis of the psychometric properties was done. Results emphasized that the BPNQ is a valid (factorial and nomological) and reliable instrument to measure students' perception of autonomy, competence and relatedness support in Physical Education classes. (AU)