Princ��pios orientadores da forma����o, ao n��vel do 1�� ciclo: a coopera����o Portugal/P.A.L.O.P.'s

Os Pa��ses Africanos de L��ngua Oficial Portuguesa (P.A.L.O.P.'s), tal como a grande maioria de todo o continente africano, apresentam graves defici��ncias quanto a alfabetiza����o das suas popula����es, tomando-se, assim, o ensino prim��rio uma prioridade absoluta. De entre todas as limita����es que existem ao n��vel dos respectivos sistemas educativos, talvez, a mais grave seja a fraca prepara����o cient��fica e pedag��gica que a maioria dos professores apresenta, para al��m, evidentemente, do seu reduzido n��mero. Assim, a forma����o de professores tornou-se numa das apostas mais fortes dos P.A.L.O.P.'s, no campo da educa����o. Portugal, na ��rea da coopera����o com estes pa��ses, participa num Projecto de Consolida����o dos Sistemas Educativos, no ��mbito do qual desenvolve um programa de Ac����es de Forma����o de Formadores.

Adding local priority-based dispatching mechanisms to P-NET networks: a fixed priority approach

In this paper we address the real-time capabilities of P-NET, which is a multi-master fieldbus standard based on a virtual token passing scheme. We show how P-NET���s medium access control (MAC) protocol is able to guarantee a bounded access time to message requests. We then propose a model for implementing fixed prioritybased dispatching mechanisms at each master���s application level. In this way, we diminish the impact of the first-come-first-served (FCFS) policy that P-NET uses at the data link layer. The proposed model rises several issues well known within the real-time systems community: message release jitter; pre-run-time schedulability analysis in non pre-emptive contexts; non-independence of tasks at the application level. We identify these issues in the proposed model and show how results available for priority-based task dispatching can be adapted to encompass priority-based message dispatching in P-NET networks.

Scheduling real-time communications with P-NET

In this paper we address the P-NET Medium Access Control (MAC) ability to schedule traffic according to its real-time requirements, in order to support real-time distributed applications. We provide a schedulability analysis based on the P-NET standard, and propose mechanisms to overcome priority inversion problems resulting from the use of FIFO outgoing buffers

Pre-run-time schedulability analysis of P-NET fieldbus networks

P-NET is a fieldbus industrial communication standard, which uses a Virtual Token Passing MAC mechanism. In this paper we establish pre-run-time schedulability conditions for supporting real-time traffic with P-NET. Essentially we provide formulae to evaluate the minimum message deadline, ensuring the transmission of real-time messages within a maximum time bound

Estudo da influ��ncia das concentra����es de N e P sobre o desenvolvimento de cianobact��rias em cultura mista

Ao longo de 40 anos, muitos trabalhos t��m vindo a ser desenvolvidos no ��mbito do tema da eutrofiza����o e desenvolvimento de biomassa fitoplanct��nica. Em todos eles, eram sugeridos factores respons��veis, desde a latitude, luz, temperatura, mistura da coluna de ��gua e os inputs de nutrientes. Toda a controv��rsia gerada em torno da eutrofiza����o, levou a que a in��rcia adoptada em situa����es de risco induzisse a degrada����o de muitos sistemas aqu��ticos. �� quando, al��m da degrada����o est��tica, os problemas come��am a surgir, que se compreende a necessidade de que surjam medidas de gest��o e requalifica����o das lagoas e bacias hidrogr��ficas. A tend��ncia para a ocorr��ncia de floresc��ncias de organismos como cianobact��rias, implica a necessidade de maiores cuidados nos usos das massas de ��gua, principalmente ao n��vel da produ����o de ��gua para consumo humano e do uso recreativo. Uma boa gest��o, implica um conhecimento aprofundado do comportamento destes organismos. Este trabalho, apresenta as respostas de organismos recolhidos em floresc��ncias naturais, na Lagoa das Furnas ��� ilha de S. Miguel (A��ores) em meios com diferentes teores de azoto. As diferen��as entre os resultados, permitem retirar algumas conclus��es sobre as condi����es preferenciais ao seu desenvolvimento. De um modo geral, as culturas comportaram-se da forma esperada, desenvolvendo-se mais com doses de azoto mais elevadas. Este desenvolvimento foi verificado tanto pelo aumento das part��culas ao longo de todo o ensaio, mas tamb��m pelos valores de pigmentos registados no fim deste. Por outro lado, o facto do azoto ter sido adicionado sob a forma amoniacal ou de nitratos, permite concluir que os organismos presentes nas floresc��ncias preferem assimilar as formas azotadas que impliquem um menor consumo energ��tico. Da�� que se tenham verificado desenvolvimentos mais significativos em meios em que foi adicionado azoto amoniacal. O facto de ser tratar de um trabalho baseado nas condi����es de desenvolvimento de organismos vivos, era de esperar alguma imprevisibilidade dos comportamentos. Sendo assim, ser�� recomend��vel aprofundar o conhecimento das reac����es dos organismos em cultura mista para doses diferentes de azoto, assim como a realiza����o de ensaios em que para uma dose de N fixa, se fa��am variar as concentra����es de P.

A gest��o do conhecimento como estrat��gia de internacionalização da marca wines of Portugal

Mestrado em Gest��o e Empreendedorismo

Synthesis, characterization and reactivity of new cobalt, palladium and nickel complexes bearing ��-diimines and P, O ligands

This work describes the synthesis and characterization of a series of new ��-diimine and P,O, ��-keto and acetamide phosphines ligands, and their complexation to Ni(II), Co(II),Co(III) and Pd(II) to obtain a series of new compounds aiming to study their structural characteristics and to test their catalytic activity. All the compounds synthesized were characterized by the usual spectroscopic and spectrometric techniques: Elemental Analysis, MALDI-TOF-MS spectrometry, IR, UV-vis, 1H, 13C and 31P NMR spectroscopies. Some of the paramagnetic compounds were also characterized by EPR. For the majority of the compounds it was possible to solve their solid state structure by single crystal X-ray diffraction. Tests for olefin polymerization were performed in order to determine the catalytic activity of the Co(II) complexes. Chapter I presents a brief introduction to homogenous catalysis, highlighting the reactions catalyzed by the type of compounds described in this thesis, namely olefin polymerization and oligomerization and reactions catalyzed by the complexes bearing ��-diimines and P,O type ligands. Chapter II is dedicated to the description of the synthesis of new ��-diimines cobalt (II) complexes, of general formula [CoX2(��-diimine)], where X = Cl or I and the ��-diimines are bis(aryl)acenaphthenequinonediimine) (Ar-BIAN) and 1,4-diaryl-2,3-dimethyl-1,4-diaza-1,3-butadiene (Ar-DAB). Structures solved by single crystal X-ray diffraction were obtained for all the described complexes. For some of the compounds, X-band EPR measurements were performed on polycrystalline samples, showing a high-spin Co(II) (S = 3/2) ion, in a distorted axial environment. EPR single crystal experiments on two of the compounds allowed us to determine the g tensor orientation in the molecular structure. In Chapter III we continue with the synthesis and characterization of more cobalt (II)complexes bearing ��-diimines of general formula [CoX2(��-diimine)], with X = Cl or I and ��-diimines are bis(aryl)acenaphthenequinonediimine) (Ar-BIAN) and 1,4-diaryl-2,3-dimethyl- 1,4-diaza-1,3-butadiene (Ar-DAB). The structures of three of the new compounds synthesized were determined by single crystal X-ray diffraction. A NMR paramagnetic characterization of all the compounds described is presented. Ethylene polymerization tests were done to determine the catalytic activity of several of the Co(II) complexes described in Chapter II and III and their results are shown. In Chapter IV a new rigid bidentate ligand, bis(1-naphthylimino)acenaphthene, and its complexes with Zn(II) and Pd(II), were synthesized. Both the ligand and its complexes show syn and anti isomers. Structures of the ligand and the anti isomer of the Pd(II) complex were solved by single crystal X-ray diffraction. All the compounds were characterized by elemental analysis, MALDI-TOF-MS spectrometry, and by IR, UV-vis, 1H, 13C, 1H-1H COSY, 1H-13C HSQC, 1H-13C HSQC-TOCSY and 1H-1H NOESY NMR when necessary. DFT studies showed that both conformers of [PdCl2(BIAN)] are isoenergetics and can be obtain experimentally. However, we can predict that the isomerization process is not available in square-planar complex, but is possible for the free ligand. The molecular geometry is very similar in both isomers, and only different orientations for naphthyl groups can be expected. Chapter V describes the synthesis of new P, O type ligands, ��-keto phosphine, R2PCH2C(O)Ph, and acetamide phosphine R2PNHC(O)Me, as well as a series of new cobalt(III) complexes namely [(��5-C5H5)CoI2{Ph2PCH2C(O)Ph}], and [(��5- C5H5)CoI2{Ph2PNHC(O)Me}]. Treating these Co(III) compounds with an excess of Et3N, resulted in complexes ��2-phosphinoenolate [(��5-C5H5)CoI{Ph2PCH���C(���O)Ph}] and ��2- acetamide phosphine [(��5-C5H5)CoI{Ph2PN���C(���O)Me}]. Nickel (II) complexes were also obtained: cis-[Ni(Ph2PN���C(���O)Me)2] and cis-[Ni((i-Pr)2PN���C(���O)Me)2]. Their geometry and isomerism were discussed. Seven structures of the compounds described in this chapter were determined by single crystal X-ray diffraction. The general conclusions of this work can be found in Chapter VI.

Chiroptical and emissive properties of a calix[4]arene-containing chiral poly (P-phenylene ethynylene) with enantioselective recognition ability

Supramolecular chirality was achieved in solutions and thin films of a calixarene-containing chiral aryleneethynylene copolymer. The observed chiroptical activity, which is primarily allied with the formation of aggregates of high molecular weight polymer chains, is the result of a combination of intrachain and interchain effects. The former arises by the adoption of an induced helix-sense by the polymer main-chain while the latter comes from the exciton coupling of aromatic backbone transitions. The co-existence of bulky bis-calixKlarene units and chiral side-chains on the polymer skeleton prevents efficient pi-stacking of neighbouring chains, keeping the chiral assembly highly emissive. In contrast, for a model polymer lacking calixarene moieties, the chiroptical activity is dominated by strong interchain exciton couplings as a result of more favourable packing of polymer chains, leading to a marked decrease of photoluminescence in the aggregate state. The enantiomeric recognition abilities of both polymers towards (R)- and (S)-alpha-methylbenzylamine were examined. It was found that a significant enantiodiscrimination is exhibited by the calixarene-based polymer in the aggregate state.

Cultura da (in) seguran��a nos contextos de trabalho em enfermagem: o caso do Hospital do Esp��rito Santo de ��vora - E.P.E.

Mestrado em Interven����o S��cio-Organizacional na Sa��de - ��rea de especializa����o: Pol��ticas de Administra����o e Gest��o de Servi��os de Sa��de

Aplica����es SIG no apoio aos processos de licenciamento na ARH do Alentejo, I.P.: o caso das capta����es de ��gua

Disserta����o apresentada como requisito parcial para obten����o do grau de Mestre em Ci��ncia e Sistemas de Informa����o Geogr��fica

A percep����o dos profissionais de sa��de sobre o trabalho em equipa no contexto do Hospital do Esp��rito Santo de ��vora, E.P.E.

Mestrado em Interven����o S��cio-Organizacional na Sa��de - ��rea de especializa����o: Pol��ticas de Administra����o e Gest��o de Servi��os de Sa��de

Com��rcio eletr��nico em Angola: impacto e desafio face �� internacionalização de uma empresa de transporte a��reo - caso TAAG

Disserta����o apresentada ao Instituto Superior de Contabilidade e Administra����o do Porto para a obten����o do Grau de Mestre em Empreendedorismo e Internacionalização Orienta����o pela Professora Doutora: Ana Azevedo Manuela Patr��cio

Esquemas de controlo de acesso ao meio para sistemas CSMA/CA p-persistente

Disserta����o apresentada para obten����o do Grau de Mestre em Engenharia Electrot��cnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ci��ncias e Tecnologia

Substituted P-Phenylene Ethynylene trimers as fluorescent sensors for nitroaromatic explosives

New sensory materials based on p-phenylene ethynylene trimers integrating calix[4]arene receptors (CALIX-PET) and tert-butylphenol (TBP-PET) moieties have been synthesized and their sensitivity and selectivity for the detection of nitroaromatic compounds (NACs) such as nitrobenzene (NB), 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT) and picric acid (PA) investigated in fluid phase and solid-state. It was found that both fluorophores displayed high sensitivities toward NACs detection in solution as evaluated by the Stern-Volmer formalism. For all the tested explosives, the ratio of fluorescence intensities (F-0/F) is a linear function of the quencher concentration only after appropriate correction of fluorescence quenching data for inner-filter effects. The quenching efficiencies for CALIX-PET and TBP-PET follow the order PA >> TNT > DNT > NB, which correlate well with the quenchers electron affinities as evaluated from their LUMOs energies thereby suggesting a photoinduced electron transfer as the dominant mechanism of fluorescence quenching. The selectivity of these sensors was checked against exemplar interferents possessing differentiated electronic properties (benzoic acid, 2,4-dichlorophenol and benzoquinone) and reduced quenching activity was detected. The quenching efficiencies and response times of the two fluorophores in the solid-state toward NB, 2,4-DNT and TNT vapors were evaluated through steady-state fluorescence quenching experiments with the materials dispersed in polymeric matrices or as neat films. The most significant fluorescence quenching responses were achieved for drop-casted films of TBP-PET upon exposure to nitroaromatics.

Generalized models from Beta(p,2) densities with strong allee effect: dynamical approach

A dynamical approach to study the behaviour of generalized populational growth models from Bets(p, 2) densities, with strong Allee effect, is presented. The dynamical analysis of the respective unimodal maps is performed using symbolic dynamics techniques. The complexity of the correspondent discrete dynamical systems is measured in terms of topological entropy. Different populational dynamics regimes are obtained when the intrinsic growth rates are modified: extinction, bistability, chaotic semistability and essential extinction.