Aproximações e distanciamentos

UID/ELT/00657/2013 SFRH/BPD/115279/2016A propósito do papel do teatro na tomada de consciência de si, Delfim Santos discordou veementemente de Ortega e da sua visão do teatro como ‘distração’.publishersversionpublishe

Filter Bank Multi-Sub-Band Transmission for Optical Systems with Mode Multiplexing

Mode-multiplexed optical transmission is subject to mode coupling and potentially large differential mode delays. In most recent implementations, these effects are compensated for at the receiver by complex adaptive multiple-input multiple-output (MIMO) equalizers. Although frequency-domain MIMO equalization requires a moderate complexity compared to time-domain equalization, the long required fast Fourier transforms may face implementation issues. In this paper, we evaluate an alternative transceiver architecture based on sub-band partitioning, implemented by filter banks, which enables concurrent time-domain equalization. Single-carrier (SC) and multi-sub-band (MSB) mode division multiplexing transmission are simulated using frequency-domain equalization and time-domain equalization, respectively. Their performance is compared in terms of static transmission performance, channel tracking capability, phase noise tolerance, and computational complexity. The results indicate that compared with an equivalent SC solution, the MSB architecture provides a high degree of parallelism at the cost of a penalty of 0.7-1.3 dB for a laser linewidth of 25-100 kHz and a moderate increase in complexity

HEI teaching mobility: looking for dynamics in a seven-year period

Higher Education Institutions are currently embracing mobility as an imperative goal, particularly and most impressively in the European Union countries where programs such as Erasmus+ strongly encourage students and staff to participate. This exploratory research aims to characterize teaching mobility in one university, identify facilitators, determine outcomes of repeated mobility, and provide clues on mobility dynamics over time. Qualitative and quantitative data were collected from application forms and final reports submitted by 107 outgoing and 58 incoming teachers in one university between 2009 and 2016. It was observed that teaching mobility covers diversified profiles (e.g., gender, seniority, and fields of study). 23 out of 71 outgoing teachers participated in more than one mobility program during that period. A deeper analysis on the mobility champions reveals both individual and team initiatives. The results provide some interesting data on facilitators and consequences of teaching mobility.publishe

Evaluating the impact of extreme temperature based indices in the 2003 heatwave excessive mortality in Portugal

This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men’s excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r = 0.79 for women and a poorer adjustment (r = 0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement

Termite resistance, chemical and mechanical characterization of paulownia tomentosa wood before and after heat treatment

The introduction of new species in forest management must be undertaken with a degree of care, to help prevent the spread of invasive species. However, new species with higher profitability are needed to increase forest products value and the resilience of rural populations. Paulownia tomentosa has an extremely fast growth. The objective and novelty of this work was to study the potential use of young Paulownia trees grown in Portugal by using heat treatment to improve its properties, thereby allowing higher value applications of the wood. The average chemical composition of untreated and heat-treated wood was determined. The extractive content was determined by successive Soxhlet extraction with dichloromethane (DCM), ethanol and water as solvents. The composition of lipophilic extracts was performed by injection in GC-MS with mass detection. Insoluble and soluble lignin, holocellulose and α-cellulose were also determined. Physical (density and water absorption and dimensional stability) and mechanical properties (bending strength and bending stiffness) and termite resistance was also determined. Results showed that extractive content increased in all solvents, lignin and α-cellulose also increased and hemicelluloses decreased. Compounds derived from the thermal degradation of lignin were found in heat-treated wood extractions. Dimensional stability improved but there was a decrease in mechanical properties. Resistance against termites was better for untreated wood than for heat-treated wood, possibly due to the thermal degradation of some toxic extractives.info:eu-repo/semantics/publishedVersio

On the Levi-Civita solutions with cosmological constant

The main properties of the Levi-Civita solutions with the cosmological constant are studied. In particular, it is found that some of the solutions need to be extended beyond certain hypersurfaces in order to have geodesically complete spacetimes. Some extensions are considered and found to give rise to black hole structure but with plane symmetry. All the spacetimes that are not geodesically complete are Petrov type D, while in general the spacetimes are Petrov type I.Comment: Typed in Revtex, including two figures. To appear in Phys. Rev.

Genetic characterization of the red algae Asparagopsis armata and Asparagopsis taxiformis (Bonnemaisoniaceae) from the Azores

info:eu-repo/semantics/publishedVersio

Assessing antimicrobial potential of agroindustrial byproducts' extracts produced through solid state fermentation in marine fish

[Excerpt] Sustainability is definitely the 21st century word. The future global food provision is dependent on fish and on sustainable expansion of aquaculture production. For that, alternative nutritional strategies for aquaculture disease management are required, reducing the use of synthetic drugs. Agroindustrial byproducts(brewery, winery and olive oil industry) constitute a circular and ecofriendly potential source of add-value bioactive compounds. Solid state fermentation(SSF) is a biotechnological low cost process that may be applied to these byproducts to effectively increase bioavailability of their bioactive compounds and so their antimicrobial potential against fish pathogens. The aim of this study was to evaluate antibacterial properties of agroindustry(beer, wine and oil processing industries) byproducts' extracts produced through SSF with Aspergillus ibericus. [...]SPO3(ref.POCI-01-0145-FEDER-030377;FCT) & InovFeed(ref. MAR-02.01.01-FEAMP0111;Mar2020)info:eu-repo/semantics/publishedVersio

Structural characterisation of adaptive facades in Europe \u2013 Part I: Insight on classification rules, performance metrics and design methods

Adaptive facades are increasingly used in modern buildings, where they can take the form of complex systems and manifest their adaptivity in several ways. Adaptive envelopes must meet the requirements defined by structural considerations, which include structural safety, serviceability, durability, robustness and fire safety. For these novel skins, based on innovative design solutions, experimentation at the component and / or assembly level is required to prove that these requirements are fulfilled. The definition of appropriate metrics is hence also recommended. A more complex combination of material-related, kinematic, geometrical and mechanical aspects should in fact be properly taken into account, compared to traditional, static facades. Accordingly, specific experimental methods and regulations are required for these novel skins. As an outcome of the European COST Action TU1403 \u2018Adaptive facades network\u2019 - \u2018Structural\u2019 Task Group, this paper collects some recent examples and design concepts of adaptive systems, specifically including a new classification proposal and the definition of some possible metrics for their structural performance assessment. The aim is to provide a robust background and detailed state-of-the-art information for these novel structural systems, towards the development of standardised and reliable procedures for their mechanical and thermo-physical characterisation

Novel luminescent materials based on silica doped with an europium(III) complex of 2,6-dihydroxybenzoic acid: the crystal structure of [(nBu4N)2[Eu(2,6-Hdhb)(5)(H2O)(2)]

Novel luminescent materials were prepared by introducing a new Eu3+ complex of 2,6-dihydroxybenzoic acid (2,6-H2dhb) into a silica gel made by the sol–gel method. The crystal structure of the resulting complex [nBu4N]2[Eu(2,6-Hdhb)5(H2O)2] was determined using single-crystal X-ray diffraction. The compound was further characterised using FTIR, FT-Raman and elemental analysis. Photoluminescence measurements were performed for the isolated Eu(III) 2,6-dihydroxybenzoate complex and also for the related silica composite material