One-step in situ synthesis of polyamide microcapsules with inorganic payload and their transformation into responsive thermoplastic composite materials

Well-dispersed loads of finely powdered metals, metal oxides, several carbon allotropes or nanoclays are incorporated into highly porous polyamide 6 microcapsules in controllable amounts via an original one-step in situ fabrication technique. It is based on activated anionic polymerization (AAP) of ε-caprolactam in a hydrocarbon solvent performed in the presence of the respective micro- or nanosized loads. The forming microcapsules with typical diameters of 25-50 µm entrap up to 40 wt% of load. Their melt processing produces hybrid thermoplastic composites. Mechanical, electric conductivity and magnetic response measurements show that transforming of in situ loaded microcapsules into composites by melt processing (MP) is a facile and rapid method to fabricate materials with high mechanical resistance and electro-magnetic characteristics sufficient for many industrial applications. This novel concept requires low polymerization temperatures, no functionalization or compatibilization of the loads and it is easy to scale up at industrial production levels.

Perceções dos alunos e fatores de influência sobre a escolha da Contabilidade como área de estudo

Dissertação de mestrado em Contabilidade

O procedimento relativo aos défices excessivos na União Económica e Monetária

Dissertação de mestrado em Direito da União Europeia

Sustentabilidade no Design: uma abordagem aos resíduos limpos das indústrias do calçado

Dissertação de mestrado em Design e Marketing

A vegetação na envolvente exterior dos edifícios: impactos, condicionantes e estratégias de intervenção ecoeficientes

Dissertação de mestrado integrado em Arquitectura

Acreditação e certificação em Portugal: retrato da situação portuguesa atual e comparação entre os referenciais CHKS, JCI, ACSA e ISO 9001

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

O evento levou... Comunicação de marca de uma cidade-sede

Tese de Doutoramento em Ciências da Comunicação - Especialidade em Comunicação Estratégica e Organizacional

Desenvolvimento de microcápsulas ativadas por radiação solar para aplicação em painéis cerâmicos exteriores

Dissertação de mestrado integrado em Engenharia de Materiais

Development of a model for occupational risk acceptance criteria definition in industrial settings

Doctoral Dissertation for PhD degree in Industrial and Systems Engineering

A inflação pela imaginação: Estudo dos efeitos interferentes

Tese de Doutoramento em Psicologia (Especialidade de Psicologia Experimental e Ciências Cognitivas)

Exploring the factor structure of neurocognitive measures in older individuals

Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the "best fit" model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate.

A 3D computer assisted Orthopedic Surgery Planning approach based on planar radiography

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Informática Médica)

Optimization of low-cost nutritional supplementation for lignocellulosic ethanol fermentation

[Excerpt] Bioethanol from lignocellulosic materials (LCM), also called second generation bioethanol, is considered a promising alternative to first generation bioethanol. An efficient production process of lignocellulosic bioethanol involves an effective pretreatment of LCM to improve the accessibility of cellulose and thus enhance the enzymatic saccharification. One interesting approach is to use the whole slurry from treatment, since allows economical and industrial benefits: washing steps are avoided, water consumption is lower and the sugars from liquid phase can be used, increasing ethanol concentration [1]. However, during the pretreatment step some compounds (such as furans, phenolic compounds and weak acids) are produced. These compounds have an inhibitory effect on the microorganisms used for hydrolysate fermentation [2]. To overcome this, the use of a robust industrial strain together with agro-industrial by-products as nutritional supplementation was proposed to increase the ethanol productivities and yields. (...)

Síntese e atividade de novos compostos com potencial atividade no cancro do cólon

Dissertação de Mestrado em Química Medicinal

First- and second-time parents’ couple relationship: from pregnancy to second year postpartum

First- and second-time parents’ couple relationships were studied from early pregnancy to the second year postpartum. The Relationship Questionnaire (RQ) was administered to Portuguese couples (N = 82), first- or second-time parents, at the first, second and third pregnancy trimester, childbirth, 3 and 18 months postpartum. Adverse changes in positive and negative partner relationship dimensions were reported from early pregnancy to the second year postpartum by all participants; in the same way by mothers and fathers and by first- and second-time parents. Second-time parents reported a worse couple relationship (lower RQ-positive scores) than first-time parents, but only during pregnancy. Results from the present study suggest a decline in partner relationship quality during the transition to parenthood both in mothers and fathers, as well as in first- and second-time parents.