Uma teoria da justiça libertarista: contribuições de Nozick e Steiner

Dissertação de mestrado em Filosofia Política

Project scheduling and cost minimization with multiple availability constrained resources under stochastic conditions

The authors propose a mathematical model to minimize the project total cost where there are multiple resources constrained by maximum availability. They assume the resources as renewable and the activities can use any subset of resources requiring any quantity from a limited real interval. The stochastic nature is inferred by means of a stochastic work content defined per resource within an activity and following a known distribution and the total cost is the sum of the resource allocation cost with the tardiness cost or earliness bonus in case the project finishes after or before the due date, respectively. The model was computationally implemented relying upon an interchange of two global optimization metaheuristics – the electromagnetism-like mechanism and the evolutionary strategies. Two experiments were conducted testing the implementation to projects with single and multiple resources, and with or without maximum availability constraints. The set of collected results shows good behavior in general and provide a tool to further assist project manager decision making in the planning phase.

New control algorithm for single-phase series active power filter

This paper presents a single-phase Series Active Power Filter (Series APF) for mitigation of the load voltage harmonic content, while maintaining the voltage on the DC side regulated without the support of a voltage source. The proposed series active power filter control algorithm eliminates the additional voltage source to regulate the DC voltage, and with the adopted topology it is not used a coupling transformer to interface the series active power filter with the electrical power grid. The paper describes the control strategy which encapsulates the grid synchronization scheme, the compensation voltage calculation, the damping algorithm and the dead-time compensation. The topology and control strategy of the series active power filter have been evaluated in simulation software and simulations results are presented. Experimental results, obtained with a developed laboratorial prototype, validate the theoretical assumptions, and are within the harmonic spectrum limits imposed by the international recommendations of the IEEE-519 Standard.

Which soft lens power is better for piggyback in keratoconus? Part II

Purpose: To evaluate how soft lens power affects rigid gas-permeable (RGP) lens power and visual acuity (VA) in piggyback fittings for keratoconus. Methods: Sixteen keratoconus subjects (30 eyes) were included in the study. Piggyback contact lens fittings combining Senofilcon-A soft lenses of −6.00, −3.00, +3.00 and +6.00 D with Rose K2 RGP contact lenses were performed. Corneal topography was taken on the naked eye and over each soft contact lens before fitting RGP lenses. Mean central keratometry, over-refraction, RGP back optic zone radius (BOZR) and estimated final power as well as VA were recorded and analyzed. Results: In comparison to the naked eye, the mean central keratometry flattened with both negative lens powers (p < 0.05 in all cases), did not change with the +3.00 soft lens power (p = 1.0); and steepened with the +6.00 soft lens power (p = 0.02). Rigid gas-permeable over-refraction did not change significantly between different soft lens powers (all p > 0.05). RGP’s BOZR decreased significantly with both positive in comparison with both negative soft lens powers (all p < 0.001), but no significant differences were found among negative- or positive-powers separately (both p > 0.05). Estimated RGP’s final power increased significantly with positive in comparison with negative lens powers (all p < 0.001), but no significant differences were found among negative or positive lens powers separately (both p > 0.05). Visual acuity did not change significantly between the different soft lens powers assessed (all p > 0.05). Conclusion: The use of negative-powered soft lenses in piggyback fitting reduces RGP lens power without impacting VA in keratoconus subjects.

Development of a methodology to incorporate risk and uncertainty in electricity power planning

Dissertação de mestrado em Engenharia Industrial

Performance assessment of electrically small antennas for implantable microsystems with wireless power and communications

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

Repository power: how repositories can support Open Access mandates

Many funding agencies have Open Access mandates in place, but how often are scientific publications as outputs linked to funding details? The benefits of linking funding information to publications as part of the deposit workflow can assist in adhering to Open Access mandates. This paper examines how OpenAIRE – Open Access Infrastructure for Research in Europe – can ease monitoring Open Access and reporting processes for funders, and presents some results and opportunities. It also outlines how it relies on cleaned and curated repository content, a vital cog in the ever turning wheel of the global scholarly landscape, and the benefits it brings.

Importance of contact lens power and thickness in oxygen transmissibility

PURPOSE: The aim of this work was to study the central and peripheral thickness of several contact lenses (CL) with different powers and analyze how thickness variation affects CL oxygen transmissibility. METHODS: Four daily disposable and five monthly or biweekly CL were studied. The powers of each CL were: the maximum negative power of each brand; -6.00 D; -3.00 D; zero power (-0.25 D or -0.50 D), +3.00 D and +6.00 D. Central and peripheral thicknesses were measured with an electronic thickness gauge. Each lens was measured five times (central and 3mm paracentral) and the mean value was considered. Using the values of oxygen permeability given by the manufacturers and the measured thicknesses, the variation of oxygen transmissibility with lens power was determined. RESULTS: For monthly or biweekly lenses, central thickness changed between 0.061 ± 0.002 mm and 0.243 ± 0.002 mm, and peripheral thickness varied between 0.084 ± 0.002 mm and 0.231 ± 0.015 mm. Daily disposable lenses showed central values ranging between 0.056 ± 0.0016 mm and 0.205 ± 0.002 mm and peripheral values between 0.108 ± 0.05 and 0.232 ± 0.011 mm. Oxygen transmissibility (in units) of monthly or biweekly CL ranged between 39.4 ± 0.3 and 246.0 ± 14.4 and for daily disposable lenses the values range between 9.5 ± 0.5 and 178.1 ± 5.1. CONCLUSIONS: The central and peripheral thicknesses change significantly when considering the CL power and this has a significant impact on the oxygen transmissibility. Eyecare practitioners must have this fact in account when high power plus or minus lenses are fitted or when continuous wear is considered.

Controlador com FPGA para um motor-in-wheel CA de fluxo axial

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e de Computadores

Roteiro metodológico para o estudo dos moinhos e aproveitamentos hidráulicos no concelho de Lousada

A Agência Portuguesa do Ambiente é possuidora de um valioso arquivo, resultante da atividade centenária desenvolvida pelos diferentes organismos com tutela sobre a gestão da água e o planeamento dos recursos hídricos, que importa conhecer e divulgar. O Arquivo Histórico dos Serviços Hidráulicos é um dos mais ricos acervos locais do País, reunindo um conjunto de milhares de documentos, que vão do século XIX à atualidade, constituindo um repositório documental com características ímpares e um testemunho da identidade, memória e história dos Serviços Hidráulicos. Os processos arquivados contam casos de estudo que percorrem os usos das águas públicas para diferentes fins e as modalidades da sua utilização, das quais queremos destacar os aproveitamentos hidráulicos e a laboração de moinhos. Com este artigo, pretendemos apresentar um roteiro metodológico para o estudo das formas de organização dos processos existentes no arquivo sobre os moinhos e aproveitamentos hidráulicos, no concelho de Lousada, no que respeita aos documentos e peças anexas, bem como aos modelos administrativos subjacentes.

Quantifying, generating and mitigating radio interference in Low-Power Wireless Networks

Doctoral Programme in Telecommunication - MAP-tele

Aproveitamento de energia em sistemas de abastecimento de água

Dissertação de mestrado integrado em Engenharia Civil

Listening to the public: enacting power : citizen access, Standing and influence in public participation discourses

Public participation in environmental governance is typically associated with citizen access to power despite many closures and limitations having been identified in participatory processes. This article proposes an analytical framework to analyse discursive practices involved in public consultation processes. Critical Discourse Analysis is used to examine and appraise citizens’ access, standing and influence. We apply that framework to a ‘notice and comment’ process on a hydroelectric power plan in Portugal and show that it was discursively managed to justify the decision of constructing 10 large dams and to reject critical or alternative views. Citizens’ access, standing and influence were constrained through diverse discursive practices which (re)produced very unequal power relationsbetween policy proponents and participating individuals. More generally, the article illustrates the potential of Critical Discourse Analysis to assess voice(s) in policy processes. Focusing on argumentative, interactional and rhetorical levels, and how they are interwoven in public consultation discourses, the proposed framework is conceivably applicable in other studies.

Potenciar a competência comunicativa e sociocultural através de documentos audiovisuais na aula de espanhol língua estrangeira

Relatório de estágio de mestrado em Ensino de Português no 3º Ciclo do Ensino Básico e Ensino Secundário e de Espanhol nos Ensinos Básico e Secundário

A gestão do desempenho como prática de implementação participada de um plano estratégico: o caso do Banco de Moçambique

Dissertação de Mestrado em Políticas Desenvolvimento dos Recursos Humanos