Synthesis of Integrated Polymers for Soil Stabilization

In this work, the synthesis of vinylpyrrolidone- (VP), vinyl acetate- (VA) and acrylamide- (AM) based polymers and copolymers was developed with a view to their application as drilling fluids. P(VP-co-VA), P(AM-co-VA) and P(AM-co-VP) were synthesized with different monomer ratio (87-13%, 75-25% and 50-50%) in water with the aim of obtaining a copolymer which is: (1) water soluble in a ratio of 1 g per liter of water (2) and able to exhibit a viscosity value ≥ 55 s/quart. The material fulfilling these requirements may be applied as (i) a main compound or as (ii) an additive for drilling fluids. All viscosity measurements were performed in a Marsh funnel as preliminary tests to select which was the best candidate polymer for the previous objectives. The chemical composition of all polymers and copolymers was investigated by FTIR-ATR or/and solid state 13C NMR to ensure the success of polymerization. Polymers and copolymers which achieved the previously mentioned requisites (1) and (2) were characterized by scanning electron microscopy (SEM), zeta potential and their molecular weight was determined in an Ubbelohde type I Capillar viscometer. Partially hydrolyzed P(AM-co-VA) with a weight monomer ratio of 75-25% of acrylamide and VP, respectively, and partially hydrolyzed P(AM-co-VP) with a weight monomer ratio of 87-13% of acrylamide and VP, respectively, showed a viscosity of 56 s/quart in water, gathering all needed conditions to be evaluated according to suspension and settling tests with soil. These suspension and settling tests were performed with clay in distilled-deionized and tap water. P(AM-co-VA) were not able to suspend clay neither as main viscosifier nor as additive. P(AM-co-VP) did not reveal suspending clay capacity as main viscosifier, but when 1g of copolymer is added to one liter of PolyMud® solution (1 g/L) comprising distilled-deionized water, 100% of soil suspension was reached over a period of 24 hours. When tap water was used, P(AM-co-VP) exhibited the best performance by keeping in suspension 90% of the total clay present in solution over 24 hours. In addition, PVP was successfully used as additive to a PolyMud® solution (1 g/L), comprising distilled-deionized water, exhibiting in suspension capacity of 90% of the total clay during 24 hours

Evolution of microstructure, texture and grain boundary character distribution of potassium doped tungsten fibers annealed at variable temperatures

The effect of the annealing temperature on the microstructure and grain boundary character distribution of potassium doped tungsten fibers made of drawn wire was investigated by Electron Backscatter Diffraction. Samples, with a diameter of 148.7 μm, in the as-received condition and annealed at 1300, 1600, 1900, 2100 and 2300 °C were analyzed at the center of the transversal sections. Up to 1900 °C, a uniform microstructural coarsening and primary recrystallization followed by normal grain growth was observed. Between 1900 and 2100 °C abnormal grain growth took place. The strong texture (<110> parallel to the drawing axis) remained present in all conditions. With increasing the annealing temperature, the low angle grain boundary fraction increased at the expense of high angle grain boundaries while the amount of coincidence site lattice boundaries reached its maximum at 1600 °C. At this temperature, the most resistant configuration of triple junctions against intergranular crack propagation was obtained

Ser estudante no ensino superior: as respostas institucionais à diversidade de públicos

Textos selecionados a partir de comunicações apresentadas no 2º Seminário “Ser Estudante no Ensino Superior: As respostas institucionais à diversidade de públicos”, realizado pelo ObservatoriUM - Observatório dos Percursos Académicos dos Estudantes da UMinho (Campus de Gualtar, 9 de setembro de 2016).info:eu-repo/semantics/publishedVersio

Perceptions of obstacles to creativity with university students from different subject areas and grade levels

As características da atualidade exigem que se seja criativo e inovador. Todo o indivíduo pode rentabilizar intencionalmente seu potencial criativo, podendo e devendo a universidade ter um papel importante nesse desenvolvimento. Porém, observam-se perceções de barreiras à expressão criativa em alunos universitários, apesar de existir muito pouca investigação acerca do tema. Neste estudo, quis-se então analisar perceções de barreiras à criatividade em estudantes universitários portugueses, tomando 582 alunos de três áreas curriculares (Artes e Humanidades; Ciências e Tecnologias; Ciências Sociais e Humanas) e dois níveis de graduação (licenciatura e mestrado). Usou-se o Inventário de Barreiras Pessoais à Expressão Criativa, adaptado à realidade portuguesa. Foram avaliadas diferenças, considerando os fatores do inventário, mas também os seus itens numa análise mais detalhada. Encontraram-se diferenciações nos fatores para a área curricular e, no caso dos itens, para as duas variáveis estudadas. Algumas reflexões são feitas no sentido de repensar práticas no quotidiano académico.The current features require to be creative and innovative. Everyone can intentionally develop their creative potential and the university should play an important role in this development. However, there are perceptions of barriers to creative expression in university students, although there is very little research about this subject. This study, wants to analyze perceptions of barriers to creativity in Portuguese university students, and were considered 582 students from three subject areas (Arts and Humanities; Science and Technology; Social Sciences and Humanities) and from graduation and post-graduation levels. It was used the Inventory of Personal Barriers to Creative Expression, adapted to the Portuguese reality. Differences were evaluated considering the dimensions of the inventory, but also its items in a more detailed analysis. Significant statistical differences were found in the inventory dimensions for the subject area; in the case of items, they were found for both variables. Some reflections are appointed in order to reconsider practices in the academic daily life

“Eu seria mais criativo se...”: barreiras à expressão criativa percebidas segundo o gênero dos universitários

Creativity has become essential to the innovation that is demanded today. In this context, the university is fundamental in promoting creative skills and, thus, meeting such demand. Despite the lack of research concerning what college students think about creativity, these students perceive barriers to their creative expression. A total of 582 Portuguese college students were analyzed in the present study regarding their perceived barriers to the expression of creativity, using an inventory concerning psychological and social dimensions. Gender differences were assessed, not only considering the inventory’s factors, but also items independently. Statistically signifi cant differences were found in both analyses. These results are the starting point to a debate about the role of university in students’ development, which should be not only professional, but also social and personal, besides the importance of fi nding place to creativity in their daily academic lives.Research Center on Education (CIEd, Centro de Investigação em Educação), projects UID/CED/1661/2013 e UID/CED/1661/2016, Institute of Educação, Universidade de Minho, trough national funds of FCT/MCTES-PT.info:eu-repo/semantics/publishedVersio

Productive Structure and Income Distribution: the Brazilian Case.

This study deals with the impacts of structural changes on income distribution in Brazil in the period 1992-2002. A Pure Leontief Model and a Leontief-Miazawa Model were utilized to portray the structure of the economy in both years, and to perform counterfactual simulations on some important changes occurring during the period. The methodology allowed for the identification of the high and low inequality sectors in both years, and to their contribution to the increasing inequality during the period. It is interesting to notice that some sectors with low internal inequality ended-up provoking increased global inequality through their interaction pattern with other sectors in the economy,and through the consumption structure. The results also indicate that the change in sectoral shares in the period contributed to diminishing inequality. Therefore, the causes for increasing inequality remains within the distribution of wages within the sectors.

Criatividade e cognição: diferenciação de desempenhos criativos extremos

[Resumo] Este estudo focalizou-se na' pesquisa da manifestação criativa no Ensino Superior. Especificamente, trabalhou-se com estudantes universitários de cursos diferentes (Artes e Letras), tomando dimensoes cognitivas usualmente associadas a criatividade (variáveis independentes) e dois tipos de realizac;ao criativa - a elaboração de textos e de posters (variáveis dependentes). O principal objectivo foi o de investigar diferenças, em termos cognitivos, entre estudantes avaliados como muito e muito pouco criativos. Consequentemente, tais diferenças poderiam indicar contribuições da cognição para uma realização criativa elevada. Os resultados encontrados viriam, entao, a revelar uma conjugação particular de variáveis significativa na distinção dos grupos extremos avaliados e semelhante para ambos os tipos de produção criativa. Os principais contornos da condução deste estudo, assim como a caracterizac;ao e interpretação da conjugação cognitiva encontrada, serao o conteúdo deste trabalho. Tentarse- á ainda reflectir aplicac;oes dos resultados encontrados para o contexto educativ

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