6 resultados para Meso-tetrakis porphyrins
em Universidade do Minho
Resumo:
The main objective of this work is to evaluate, by non-destructive techniques, seven old Chestnut beams. For that, after the geometric assessment and the detailed visual inspection that allowed to strength grade the beams, a series of non-destructive tests was setup. In a first step, non-destructive bending tests, under the elastic limit, were performed to quantify the modulus of elasticity in bending (MoE) of the seven beams. Then, Resistograph® and Pilodyn® tests were done to assess the superficial decay and to have aclearer idea of the voids dimensions. Then, two beams were tested in bending until failure to evaluate the bending strength. In a second step, end parts were cut from the beams, one per end of the beams, to perform Resistograph®, Pilodyn® and ultrasound tests, to quantify the density of the beams and to extract meso-specimens to be used in tension parallel to the grain tests
Resumo:
Multiarm star polymers are attractive materials due to their unusual bulk and solution properties. They are considered analogues of dendrimers with a wide range of applications, such as drug delivery, membranes, coatings and lithography.1 The advent of controlled polymerization made possible the existence of this unique class of organic nanoparticles (ONPs).2 Two major synthetic strategies are usually employed in the preparation of star polymers, the core-first and arm-first approaches. The core-first approach involves a controlled living polymerization using a multiarm initiator core while the arm-first methodology is based in the quenching of living polymers with multifunctional coupling agent or bifunctional vinyl compounds. Herein, we present the synthesis and characterization of a new star polymer, the multiarm star poly(2-hydroxyethyl methacrylate). The tetra-armed star polymer was prepared by reversible addition fragmentation chain-transfer (RAFT) polymerization using the core-first approach. The RAFT chain-transfer agent (RAFT CTA) pentaerythritol tetrakis[2-(dodecylthiocarbonothioylthio)-2-methylpropionate] was used as multiarm initiator core were 2-hydroxyethyl methacrylate (HEMA) was polymerized using AIBN as radical initiator. Structural characterization was performed by 1H NMR and FTIR. The new polymer is able to uptake large quantities of organic solvents, forming gels. The rheological behavior of these gels was also investigated.
Resumo:
Tese de Doutoramento em Ciência e Engenharia de Polímeros e Compósitos
Resumo:
Dissertação de mestrado integrado em Engenharia Civil
Resumo:
Relatório de estágio de mestrado em Ensino de Inglês e de Espanhol no 3ºciclo do Ensino Básico e Ensino Secundário
Resumo:
This study is in line with the analyses of university and working career in their interaction in relation with conditioning factors. It comprises two central issues: the issue of identity bound to the issue of professionalization within the domain of training and employment. Nowadays, professionalization of the individuals, inside a troubled occupational world, demands the implementation of mechanisms favoring the development of both the individuals and the institution in which they work. All this has an impact at the local, regional and even national levels. Three levels of analysis interplay from a sui generis perspective: macro-meso-micro-macro (Aparicio, 2005; 2007a; 2007b, 2013a, 2014, 2015 b, d – See the Three- Dimensional Spiral of Sense Theory). The aim was to be aware of the doctors’ representations regarding the value of such degree under the present “degree devaluation”, and its impact on the professional future as well as on the core issues of the labor market which need urgent measures with a view to a belter interaction between the two systems. The methodology used was quanti-qualitative (semi-structured questionnaires, interviews, and hierarchical evocations). The population consisted of doctors (2005-2012) from the National University of Cuyo, in Argentina. The results helped us understand the nucleus of such representations and the peripheral aspects by career and institution, thus revealing professional and disciplinary identities. The professional identities show the situated needs in terms of professionalization within the different contexts and, particularly, within the labor market.