Optical frequency tripling with improved suppression and sideband selection

Journal Article, Impact factor:3.749A novel optical dispersion tolerant millimetre-wave radio-over-fibre system using optical frequency tripling technique with enhanced and selectable sideband suppression is demonstrated. The implementation utilises cascaded optical modulators to achieve either an optical single sideband (OSSB) or double sideband-suppressed carrier (DSB-SC) signal with high sideband suppression. Our analysis and simulation results indicate that the achievable suppression ratio of this configuration is only limited by other system factors such as optical noise and drifting of the operational conditions. The OSSB transmission system performance is assessed experimentally by the transport of 4 WiMax channels modulating a 10 GHz optical upconverted RF carrier as well as for optical frequency doubling and tripling. The 10 GHz and tripled carrier at 30 GHz are dispersion tolerant resulting both in an average relative constellation error (RCE) of -28.7 dB after 40 km of fibre. (C)2011 Optical Society of AmericaFundação para a Ciência e Tecnologi

Border cities in Portugal-Spain and territorial development trends

Portugal and Spain share what is one of the oldest unchanged national borderlines in the World. It has remained practically unchanged for 800 years. As a result, the formal cross-border cooperation process between the two Iberian countries was only engaged, with significant formal partnerships, after the 1990s, following the implementation of the EU INTERREG-A Communitive Initiative. As time progressed, this Initiative, later on transformed into a EU Cohesion Policy goal (European Territorial Cooperation) contributed to an exponential growth of cross-border cooperation processes, translated into the creation of more than 100 cross-border entities across the Portuguese-Spanning border. These included not only Euroregions, and later on European Groupings of Territorial Cooperation (EGTCs), but also several Eurocities close to the border. Indeed, in a context in which the Portuguese-Spanish border region faces, in vast areas, a dramatic depopulation process, the role of border cities is particularly relevant to retain population and economic activities in the border area. As such, this chapter will analyse the border cities in the Portuguese-Spanish border region and their contribution to the territorial development of this border region. A more detailed analysis will be done to the case of the Eurocity Elvas (PT) - Badajoz (ES).info:eu-repo/semantics/acceptedVersio

Non-Chern-Simons Topological Mass Generation in (2+1) Dimensions

By dimensional reduction of a massive BF theory, a new topological field theory is constructed in (2+1) dimensions. Two different topological terms, one involving a scalar and a Kalb-Ramond fields and another one equivalent to the four-dimensional BF term, are present. We constructed two actions with these topological terms and show that a topological mass generation mechanism can be implemented. Using the non-Chern-Simons topological term, an action is proposed leading to a classical duality relation between Klein-Gordon and Maxwell actions. We also have shown that an action in (2+1) dimensions with the Kalb-Ramond field is related by Buscher's duality transformation to a massive gauge-invariant Stuckelberg-type theory.Comment: 8 pages, no figures, RevTE

How impactful are public policies on environmental sustainability? Debating the Portuguese case of PO SEUR 2014–2020

Sustainable development is a key feature of national, European Union and global development strategies. The main research goal is to provide evidence on how impactful public policies on environmental sustainability in Portugal are at the regional level, in various policy areas. In this context, this paper analyses the main impacts of the Portuguese Operational Programme for Sustainability and Efficient Use of Resources (PO SEUR 2014–20). The research uses a territorial impact assessment (TIA) methodology (TARGET_TIA) to assess these impacts in five analytic dimensions (economy with low emissions, adaptation to climate change, risk prevention and management, environmental protection and resource efficiency) in the five mainland Portuguese NUTS 2. It concludes that, in overall terms, PO SEUR produced low to moderate positive impacts in all NUTS II and analysed dimensions, but it was particularly positive in measures fostering adaptation to climate change, and less impactful in measures supporting an economy with low emissions and resource efficiency in Portugal. Despite data limitations, the research provided adequate evidence that key public policies supporting environmental sustainability in Portugal are largely ineffective and inefficient in view of their policy goals and allocated funding. To turn this scenario around, the process of project selection needs to undergo significant improvements to better adjust the regional needs on environmental sustainability-related issues to the available funding. Moreover, on a policy strategic level, there needs to be support for a prosperous, modern, competitive and climate-neutral economy in Portugal via concrete actions exploring environmental capital and a green economy in urban areas.info:eu-repo/semantics/publishedVersio

Does rotation of B stars depend on metallicity? preliminary results from GIRAFFE spectra

We show the vsini distribution of main sequence B stars in sites of various metallicities, in the absolute magnitude range -3.34 < Mv < -2.17. These include Galactic stars in the field measured by Abt et al. (2002), members of the h & chi Per open clusters measured by North et al. (2004), and five fields in the SMC and LMC measured at ESO Paranal with the FLAMES-GIRAFFE spectrograph, within the Geneva-Lausanne guaranteed time. Following the suggestion by Maeder et al. (1999), we do find a higher rate of rapid rotators in the Magellanic Clouds than in the Galaxy, but the vsini distribution is the same in the LMC and in the SMC in spite of their very different metallicities.Comment: 2 pages, 1 figure, poster presented at the ESO/Arcetri Workshop on "Chemical abundances and mixing in stars in the Milky Way and its satellites", 13-17 Sept. 200

Distribuicao e frequencia mensal do estro de caprinos SRD e anglo-nubiano no municipio de Oeiras-Piaui.

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Prevalência, intensidade de infecção e variação estacional de helmintos em caprinos no estado do Piauí.

No periodo de julho/77 a agosto/79, estudou-se a epidemiologia das helmintoses em 52 caprinos sem raça definida (SRD) criados extensivamenteno municipio de Valença do Piaui, atraves do exame de ovos por grama de ovos por grama de fezes (OPG), coprocultura e necropsias mensais em animais infectados naturalmente sendo 26 com idade de 3 a 6 meses e 26 com 9 a 12 meses. Os helmintos identificados foram: Heamonchus contortus, Trichostrongylus colubriformis, T. axei, Cooperia curticei, C. punctata, C. pectinata, Strongyloides papillosus, Oesophagostomum columbianum, Trichuris ovis, Trichyris sp., Moniezia expansa e Cysticercus tenuicollis. Os helmintos que ocorreram, em media, com maior intensidade e frequencia foram, respectivamente: H. contortus (697, 6 e 92, 3%,T. colubrifromis (340,5 e 86,4%) e O. columbianum (53,7 e 96,1%). Os dados de OPG indicaram aumento do nivel de infecção por Strongyloidea durante a época chuvosa. As necropsias revelaram que os caprinos são parasitados por helmintos durante todo o ano e, mais especificamente na epoca chuvosa

Verminose em ovinos e seu controle.

Helmintos identificados - principais espécies; Época de ocorrência; Ciclo de vida do Haemonchus contortus; Sintomas; Controle; Anti-helmínticos recomendados; Práticas de manejo recomendadas.bitstream/item/35646/1/CIT19.pd