A built-in self-test technique for high speed analog-to-digital converters

Fundação para a Ciência e a Tecnologia (FCT) - PhD grant (SFRH/BD/62568/2009)

Da assessoria ao jornalismo : análise do processo de produção de press release na era digital em Portugal

A presente dissertação pretende fazer a análise do processo de produção do press release na assessoria em Portugal, a eficácia dessa ferramenta de comunicação junto dos jornalistas e, por inerência, a evolução da figura do assessor enquanto profissional reconhecido junto da comunidade jornalística. São também objetivos, compreender a relevância de um press release, perceber se gera efeito, analisar a possível forma de melhorar esta ferramenta e, ainda, perceber se esta ferramenta sofreu algum tipo de adaptação à era digital. A investigação inicia-se com a incursão pelos contextos e história das áreas profissionais em estudo, a assessoria de comunicação em agências e o jornalismo em Portugal, no quadro da crise económica e financeira de 2008 a 2013. O enfoque deste estudo será o procedimento e a eficácia de um press release, no período considerado. A pós-produção desta ferramenta implica o contacto entre dois interlocutores, os profissionais de assessoria e os profissionais do jornalismo. Finda esta investigação com análise baseada em seis entrevistas semiestruturadas, divididas em categorias profissionais e setores de atividade: jornalistas, assessores, assessores ex-jornalistas, nas áreas de saúde e consumo. Deste estudo resulta que o press release, privilegiando-se a sua estrutura e conteúdo, é, como foi, uma ferramenta fundamental muitas vezes, e nos dias de hoje, no auxílio às negociações one to one.

Control system for actuation and sensing in digital microfluidics devices

Digital Microfluidics (DMF) is a second generation technique, derived from the conventional microfluidics that instead of using continuous liquid fluxes, it uses only individual droplets driven by external electric signals. In this thesis a new DMF control/sensing system for visualization, droplet control (movement, dispensing, merging and splitting) and real time impedance measurement have been developed. The software for the proposed system was implemented in MATLAB with a graphical user interface. An Arduino was used as control board and dedicated circuits for voltage switching and contacts were designed and implemented in printed circuit boards. A high resolution camera was integrated for visualization. In our new approach, the DMF chips are driven by a dual-tone signal where the sum of two independent ac signals (one for droplet operations and the other for impedance sensing) is applied to the electrodes, and afterwards independently evaluated by a lock-in amplifier. With this new approach we were able to choose the appropriated amplitudes and frequencies for the different proposes (actuation and sensing). The measurements made were used to evaluate the real time droplet impedance enabling the knowledge of its position and velocity. This new approach opens new possibilities for impedance sensing and feedback control in DMF devices.

RadioActive Europe: jovens, o digital e as suas comunidades

Neste artigo, apresentamos uma discussão sobre as potencialidades da rádio e dos media digitais para uma educação para os media. Esta contextualização, que inclui o contexto português relativamente ao uso da rádio como meio em contexto educativo, pretende criar o pano de fundo para a exposição da metodologia aplicada pelo investigação-ação, concentrados em formas de empoderamento que efetivamente constituam elementos de crescimento curricular dos jovens envolvidos e que possam ser usados na procura de emprego. Em seguida, estaremos em condições de expor e refletir sobre os dados preliminares de aplicação do projeto, que decorre entre 2013 e 2014 em cinco países europeus, centrando-nos em processos de ligação ao digital e de ligação à comunidade envolvente.

Indexing and active fund management: International evidence

Author's pre-print

Digital microfluidic devices: the role of the dielectric layer

Digital microfluidics (DMF) is a field which has emerged in the last decade as a re-liable and versatile tool for sensing applications based on liquid reactions. DMF allows the discrete displacement of droplets, over an array of electrodes, by the application of voltage, and also the dispensing from a reservoir, mixing, merging and splitting fluidic operations. The main drawback of these devices is due to the need of high driving volt-ages for droplet operations. In this work, alternative dielectric layers combinations were studied aiming the reduction of these driving voltages. DMF chips were designed, pro-duced and optimized according to the theory of electrowetting-on-dielectric, adopting different combinations of parylene-C and tantalum pentoxide (Ta2O5) as dielectric ma-terials, and Teflon as hydrophobic layer. With both devices’ configurations, i.e., Parylene as single dielectric, and multilayer chips combining Parylene and Ta2O5, it was possible to perform all the fluidic opera-tions in the microliter down to hundreds of nanoliters range. Multilayer chips presented significant reduction on driving voltages for droplet op-erations in silicone oil filler medium: from 70 V (parylene only) down to 30 V (parylene/Ta2O5) for dispensing; and from 50 V (parylene only) down to 15 V (parylene/Ta2O5) for movement. Peroxidase colorimetric reactions were successfully performed as proof-of-concept, using multilayer configuration devices.

The scramble for the seas : the ballad evidence of Sir Andrew Barton

The presence and importance of the sea as a factor that has helped shape the history of England since at least the Roman invasions of 55-54 BC (less successful, incidentally, than most of Caesar’s other military ventures ...) need no particular urging or demonstration. Nonetheless, a bird’s-eye view would necessarily survey the waves of invasions and settlements that, one after the other, came dashing over the centuries upon England’s shores; not to mention the requested invasion of 1688, Angles and Saxons, Scandinavians, Normans, they all crossed the whale’s path and cast anchor in England’s green and pleasant land. In the course of this retrospective voyage through the oceans of History, one would inevitably stop at the so-called ‘Discoveries’ of the 15th-16th centuries, meet their navigators, sailors and pirates extolled by Richard Hakluyt (1553?-1616), face an anonymous crowd of merchants and witness the huge expansion of trade, largely to the benefit of the ‘discovering’ countries as prescribed by the economic Gospel Adam Smith (1723-90) would later baptize as “mercantilism”.

Digital microfluidics on paper

This thesis is one of the first reports of digital microfluidics on paper and the first in which the chip’s circuit was screen printed unto the paper. The use of the screen printing technique, being a low cost and fast method for electrodes deposition, makes the all chip processing much more aligned with the low cost choice of paper as a substrate. Functioning chips were developed that were capable of working at as low as 50 V, performing all the digital microfluidics operations: movement, dispensing, merging and splitting of the droplets. Silver ink electrodes were screen printed unto paper substrates, covered by Parylene-C (through vapor deposition) as dielectric and Teflon AF 1600 (through spin coating) as hydrophobic layer. The morphology of different paper substrates, silver inks (with different annealing conditions) and Parylene deposition conditions were studied by optical microscopy, AFM, SEM and 3D profilometry. Resolution tests for the printing process and electrical characterization of the silver electrodes were also made. As a showcase of the applications potential of these chips as a biosensing device, a colorimetric peroxidase detection test was successfully done on chip, using 200 nL to 350 nL droplets dispensed from 1 μL drops.

Web Design como ferramenta de Comunicação Digital

WEB DESIGN COMO FERRAMENTA DE COMUNICAÇÃO DIGITAL: DESIGN E DESENVOLVIMENTO DE SITES, UTILIZANDO O GESTOR DE CONTEÚDOS WORDPRESS; DESIGN DE CONTEÚDOS VISUAIS PARA O FACEBOOK DE UMA MARCA

A model to screen and improve business potential of micro and small enterprises in developing countries: Evidence from the Island of Mozambique

Programmes supporting micro and small enterprises in developing countries have been showing that capital is not enough to allow business success: survival and growth. Literature does not provide comprehensive and practical tool to support business development in this context, but allowed the collection of forty-nine success variables that were studied in a sample of successful and unsuccessful businesses in the Island of Mozambique to discover what were the key factors affecting those businesses’ performance. Empirical data gave the insights for the development of a model to screen and improve business potential of micro and small enterprises in this context.

Predictability of stock market returns: Evidence from Eurozone's banking sectors

This paper analyzes the in-, and out-of sample, predictability of the stock market returns from Eurozone’s banking sectors, arising from bank-specific ratios and macroeconomic variables, using panel estimation techniques. In order to do that, I set an unbalanced panel of 116 banks returns, from April, 1991, to March, 2013, to constitute equal-weighted country-sorted portfolios representative of the Austrian, Belgian, Finish, French, German, Greek, Irish, Italian, Portuguese and Spanish banking sectors. I find that both earnings per share (EPS) and the ratio of total loans to total assets have in-sample predictive power over the portfolios’ monthly returns whereas, regarding the cross-section of annual returns, only EPS retain significant explanatory power. Nevertheless, the sign associated with the impact of EPS is contrarian to the results of past literature. When looking at inter-yearly horizon returns, I document in-sample predictive power arising from the ratios of provisions to net interest income, and non-interest income to net income. Regarding the out-of-sample performance of the proposed models, I find that these would only beat the portfolios’ historical mean on the month following the disclosure of year-end financial statements. Still, the evidence found is not statistically significant. Finally, in a last attempt to find significant evidence of predictability of monthly and annual returns, I use Fama and French 3-Factor and Carhart models to describe the cross-section of returns. Although in-sample the factors can significantly track Eurozone’s banking sectors’ stock market returns, they do not beat the portfolios’ historical mean when forecasting returns.

Spinoffs and other entrants: Evidence from Portugal

This thesis studies the prevalence and survival of spinoff entrants in Portugal from 1987 to 2008. Information on worker flows is used to identify them at a population level, providing evidence on other operations such as mergers and acquisitions. We show that the number of spinoffs has been increasing at a higher rate than other entrants of comparable size. Studying the determinants of their exit suggests that the most important predictor is whether the spinoff was motivated by the failure of the parent firm. The effect of industry specific knowledge and previous experience of the founders from working together in the parent firm is seemingly negligible, with only weak evidence supporting the latter.

Mental health and the crisis: Evidence from share

Mental health constitutes a significant share of the global burden of disease. It is shaped to a great extent by socioeconomic factors and is vulnerable to external shocks. The recent financial crisis brought about stressors prone to trigger and aggravate mental illnesses. This project presents a micro analysis of the effect of the economic crisis on mental health in eleven European countries, through the estimation of individual health production functions accounting for socioeconomic controls and macroeconomic indicators. We find that mental health has deteriorated since 2007, even though the development of depression episodes is unchanged. Additionally, his variation can be partially attributed to economic recession and budgetary cuts in health spending.

Is low worker mobility evidence for monopsony power?

Major in Competition and Regulation

Do the psychological impacts of war cause poverty?: Evidence from Mozambique

This paper evaluates the extent to which war-related psychological distress causes poverty. The endogeneous nature of mental distress is addressed by using exposure to the civil war in Mozambique as an instrument. It is found that exposure to war has a significant and positive long-lasting impact on mental distress. Furthermore, the causal impact of war-related psychological distress on income and wealth is shown to be significant, negative, and nonnegligible. One standard deviation increase in mental distress decreases income by half a standard deviation. These findings are robust to alternative specifications, including the use of an alternative database on the incidence of PTSD in Mozambique.