Influence of design parameters on the mechanical behavior and porosity of braided fibrous stents

In spite of all innovations in stent design, commonly used metallic stents present several problems such as corrosion, infection and restenosis, leading to health complications or even death of patients. In this context, the present paper reports a systematic investigation on designing and development of 100% fiber based stents, which can eliminate or minimize the problems with existing metallic stents. For this purpose, braided stents were produced by varying different materials, structural and process parameters such as mono-filament type and diameter, braiding angle and mandrel diameter. The influence of these design parameters on mechanical behavior as well as stent's porosity was thoroughly investigated, and suitable parameters were selected for developing a stentwith mechanical characteristics and porosity matching with the commercial stents. According to the experimental results, the best performance was achieved with a polyester stent designed with 0.27 mm monofilament diameter, braiding angle of 35° and mandrel diameter of 6 mm, providing similar properties to commercial Nitinol stents.

A violência entre pares na adolescência: desenvolvimento e implementação de um programa de prevenção

Tese de Doutoramento em Psicologia (área de especialização em Psicologia da Justiça).

Tribunais nacionais e tutela jurisdicional efetiva: da cooperação à integração judiciária no contencioso da união europeia

Tese de Doutoramento em Ciências Jurídicas (área de especialização em Ciências Jurídicas Públicas).

Design de superfície biomimética para aplicação em atividades desportivas

Tese de Doutoramento Engenharia Têxtil.

Mechanical, fatigue and wear properties of sintered Carbon Nanotube-based functionally graded materials

Tese de Doutoramento Engenharia Mecânica

Os estereótipos de gênero na publicidade televisiva. Uma comparação entre spots publicitários brasileiros e portugueses

Tese de Doutoramento em Ciências da Comunicação (área de especialização em Comunicação Estratégica e Organizacional).

Biochemical and physical surface functionalization of polycaprolactone as a key mediator of osteogenic differentiation and vascularized tissue morphogenesis

Tese de Doutoramento em Engenharia de Tecidos, Medicina Regenerativa e Células Estaminais.

O Display da morte na ficção de José Saramago

Tese de Doutoramento em Ciências da Literatura (área de especialização em Literatura Portuguesa).

Estudo de materiais fibrosos para aplicação em modelos cerebrais

Neste trabalho, multifilamentos ocos de polipropileno foram estudados com o objetivo de construir um fantoma cerebral adequado à validação e controlo de qualidade de uma modalidade de imagem clínica inovadora: High-Definition Fiber Tractography. Foram investigadas e discutidas a análise à secção transversal e a redução da área de multifilamentos ocos de polipropileno, através de estiramento. De acordo com os resultados experimentais, a dimensão da secção transversal dos multifilamentos é proporcional à massa linear dos mesmos, existindo uma irregularidade, relativamente, à forma deste tipo de materiais.

Angular distributions in tt¯H(H→bb¯) reconstructed events at the LHC

The associated production of a Higgs boson and a top-quark pair, tt¯H, in proton-proton collisions is addressed in this paper for a center of mass energy of 13TeV at the LHC. Dileptonic final states of tt¯H events with two oppositely charged leptons and four jets from the decays t→bW+→bℓ+νℓ, t¯→b¯W−→b¯ℓ−ν¯ℓ and h→bb¯, are used. Signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed by applying a kinematic fit. New angular distributions of the decay products as well as angular asymmetries are explored in order to improve discrimination of tt¯H signal events over the dominant irreducible background contribution, tt¯bb¯. Even after the full kinematic fit reconstruction of the events, the proposed angular distributions and asymmetries are still quite different in the tt¯H signal and the dominant background (tt¯bb¯).

Pultrusion of fibre reinforced thermoplastic pre-impregnated materials

Fibre reinforced thermoplastic pre impregnated materials produced continuously by diverse methods and processing conditions were used to produce composites using pultrusion. The processing windows used to produce these materials and composites profiles were optimized by using the Taguchi / DOE (Design of Experiments) methods. Composites were manufactured by pultrusion and compression moulding and subsequently submitted to mechanical testing and microscopy analysis. The obtained results were compared with the expected theoretical ones predicted from the Rule of Mixtures (ROM) and with those of similar engineering conventional available materials. The results obtained shown that produced composites have adequate properties for applications in common and structural engineering markets.

Aquisição de verbos da língua portuguesa, no primeiro ciclo de escolaridade, por crianças bilingues luso-alemãs e crianças monolingues alemãs

Tese de Doutoramento em Ciências da Linguagem (área de especialização em Linguística Aplicada).

Off-line simulation inspires insight: a neurodynamics approach to efficient robot task learning

There is currently an increasing demand for robots able to acquire the sequential organization of tasks from social learning interactions with ordinary people. Interactive learning-by-demonstration and communication is a promising research topic in current robotics research. However, the efficient acquisition of generalized task representations that allow the robot to adapt to different users and contexts is a major challenge. In this paper, we present a dynamic neural field (DNF) model that is inspired by the hypothesis that the nervous system uses the off-line re-activation of initial memory traces to incrementally incorporate new information into structured knowledge. To achieve this, the model combines fast activation-based learning to robustly represent sequential information from single task demonstrations with slower, weight-based learning during internal simulations to establish longer-term associations between neural populations representing individual subtasks. The efficiency of the learning process is tested in an assembly paradigm in which the humanoid robot ARoS learns to construct a toy vehicle from its parts. User demonstrations with different serial orders together with the correction of initial prediction errors allow the robot to acquire generalized task knowledge about possible serial orders and the longer term dependencies between subgoals in very few social learning interactions. This success is shown in a joint action scenario in which ARoS uses the newly acquired assembly plan to construct the toy together with a human partner.

O espaço do lazer infantil e as suas cores, formas e texturas

Given the high significance of playing on achildren's life, the existence of spaces for the same becomes essential. However, there are elements that should not be overlooked during its conception. In order for the space to become of the child, he must establish with it three relationships: with the space, with the objects in the room and with the other children. This article describes a part of the first empirical phase of an investigation. This phase of the project observed 14 children's play areas inserted in different environments, from the point of view of one of the main visual elements of design: colour. The aim is to understand which colours are the most used in the spaces and how the colour combination is performed. Thus, by crossing the observed colours and their meaning it is possible to determine what kind of space environments are intended to be created.

Active magneto-optical control of spontaneous emission in graphene

We investigate the spontaneous emission rate of a two-level quantum emitter near a graphene-coated substrate under the influence of an external magnetic field or strain induced pseudo-magnetic field. We demonstrate that the application of the magnetic field can substantially increase or decrease the decay rate. We show that a suppression as large as 99$\%$ in the Purcell factor is achieved even for moderate magnetic fields. The emitter's lifetime is a discontinuous function of $|{\bf B}|$, which is a direct consequence of the occurrence of discrete Landau levels in graphene. We demonstrate that, in the near-field regime, the magnetic field enables an unprecedented control of the decay pathways into which the photon/polariton can be emitted. Our findings strongly suggest that a magnetic field could act as an efficient agent for on-demand, active control of light-matter interactions in graphene at the quantum level.