29 resultados para Spray chamber


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Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

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Dissertação para obtenção do Grau de Doutor em Engenharia Física

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This paper summarises the results of the first systematic, detailed prosopographic study of the MPs – the deputados of the Lower Chamber - of the First Portuguese Republic (1910-1926). Data are presented both by legislature and for the overall period. Two kinds of background variables are explored: sociodemographic (birthplace, age, education and profession) and political (previous experience in other elite positions). Regime change in 1910 resulted in the replacement of the former political elite by homines novi. Most MPs of the Republican regime were born in small towns and communities, had carried out higher educational studies (with prevalence for law training), were mainly drawn from the professions (practising lawyers and doctors) and the Army, and were elected for the first-time at relatively young ages. Parliamentary turnover was high (two-thirds of the representatives held just one mandate) and a large proportion of MPs had a consistent connection (birth, family ties, occupation) to the constituencies to which they had been elected.

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3rd Historic Mortars Conference, 11-14 September 2013, Glasgow, Scotland

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Dissertação para obtenção do Grau de Mestre em Engenharia de Materiais

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Dissertação para obtenção do grau de Mestre em Genética Molecular e Biomedicina

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The term res publica (literally “thing of the people”) was coined by the Romans to translate the Greek word politeia, which, as we know, referred to a political community organised in accordance with certain principles, amongst which the notion of the “good life” (as against exclusively private interests) was paramount. This ideal also came to be known as political virtue. To achieve it, it was necessary to combine the best of each “constitutional” type and avoid their worst aspects (tyranny, oligarchy and ochlocracy). Hence, the term acquired from the Greeks a sense of being a “mixed” and “balanced” system. Anyone that was entitled to citizenship could participate in the governance of the “public thing”. This implied the institutionalization of open debate and confrontation between interested parties as a way of achieving the consensus necessary to ensure that man the political animal, who fought with words and reason, prevailed over his “natural” counterpart. These premises lie at the heart of the project which is now being presented under the title of Res Publica: Citizenship and Political Representation in Portugal, 1820-1926. The fact that it is integrated into the centenary commemorations of the establishment of the Republic in Portugal is significant, as it was the idea of revolution – with its promise of rupture and change – that inspired it. However, it has also sought to explore events that could be considered the precursor of democratization in the history of Portugal, namely the vintista, setembrista and patuleia revolutions. It is true that the republican regime was opposed to the monarchic. However, although the thesis that monarchy would inevitably lead to tyranny had held sway for centuries, it had also been long believed that the monarchic system could be as “politically virtuous” as a republic (in the strict sense of the word) provided that power was not concentrated in the hands of a single individual. Moreover, various historical experiments had shown that republics could also degenerate into Caesarism and different kinds of despotism. Thus, when absolutism began to be overturned in continental Europe in the name of the natural rights of man and the new social pact theories, initiating the difficult process of (written) constitutionalization, the monarchic principle began to be qualified as a “monarchy hedged by republican institutions”, a situation in which not even the king was exempt from isonomy. This context justifies the time frame chosen here, as it captures the various changes and continuities that run through it. Having rejected the imperative mandate and the reinstatement of the model of corporative representation (which did not mean that, in new contexts, this might not be revived, or that the second chamber established by the Constitutional Charter of 1826 might not be given another lease of life), a new power base was convened: national sovereignty, a precept that would be shared by the monarchic constitutions of 1822 and 1838, and by the republican one of 1911. This followed the French example (manifested in the monarchic constitution of 1791 and in the Spanish constitution of 1812), as not even republicans entertained a tradition of republicanism based upon popular sovereignty. This enables us to better understand the rejection of direct democracy and universal suffrage, and also the long incapacitation (concerning voting and standing for office) of the vast body of “passive” citizens, justified by “enlightened”, property- and gender-based criteria. Although the republicans had promised in the propaganda phase to alter this situation, they ultimately failed to do so. Indeed, throughout the whole period under analysis, the realisation of the potential of national sovereignty was mediated above all by the individual citizen through his choice of representatives. However, this representation was indirect and took place at national level, in the hope that action would be motivated not by particular local interests but by the common good, as dictated by reason. This was considered the only way for the law to be virtuous, a requirement that was also manifested in the separation and balance of powers. As sovereignty was postulated as single and indivisible, so would be the nation that gave it soul and the State that embodied it. Although these characteristics were common to foreign paradigms of reference, in Portugal, the constitutionalization process also sought to nationalise the idea of Empire. Indeed, this had been the overriding purpose of the 1822 Constitution, and it persisted, even after the loss of Brazil, until decolonization. Then, the dream of a single nation stretching from the Minho to Timor finally came to an end.

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This thesis reports the work performed in the optimization of deposition parameters of Multi – Walled Carbon Nanotubes (MWCNT) targeting the development of a Field Effect Transistors (FET) on paper substrates. The CNTs were dispersed in a water solution with sodium dodecyl sulphate (SDS) through ultrasonication, ultrasonic bath and a centrifugation to remove the supernatant and have a homogeneous solution. Several deposition tests were performed using different types of CNTs, dis-persants, papers substrates and deposition techniques, such as spray coating and inkjet printing. The characterization of CNTs was made by Scanning Electron Microscopy (SEM) and Hall Effect. The most suitable CNT coatings able to be used as semiconductor in FETs were deposited by spray coat-ing on a paper substrate with hydrophilic nanoporous surface (FS2) at 100 ºC, 4 bar, 10 cm height, 5 second of deposition time and 90 seconds of drying between steps (4 layers of CNTs were deposited). Planar electrolyte gated FETs were produced with these layers using gold-nickel gate, source and drain electrodes. Despite the small current modulation (Ion/Ioff ratio of 1.8) one of these devices have p-type conduction with a field effect mobility of 1.07 cm2/V.s.

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In the context of this dissertation several studies were developed resulting in submission and publication “Evaluation of mechanical soft-abrasive blasting and chemical cleaning methods on alkyd-paint graffiti made on calcareous stones” to Journal of Cultural Heritage. (http://dx.doi.org/10.101 /j.culher.2014.10.004)

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Neste trabalho trabalho produziram-se micropartículas de polissacarídeos contendo um fármaco anticancerígeno, o 5-Fluorouracil, ou um anti-inflamatório, a Prednisolona, utilizando como matrizes encapsulantes o quitosano e o FucoPol. As micropartículas foram produzidas pelo método de secagem por atomização (spray-drying). Foram estudados vários reticulantes biocompatíveis: o ácido glutâmico; o ácido cítrico e a lisina. As micropartículas produzidas foram caracterizadas em termos de morfologia, tamanho, propriedades químicas, propriedades térmicas, cristalinidade e eficiência de encapsulamento recorrendo a técnicas como microscopia electrónica de varrimento (SEM), Espectro de infravermelho por transformada de Fourier (FT-IR), calorimetria diferencial de varrimento (DSC), difracção de raios-X (XRD) e espectroscopia UV. Os perfis de concentração foram obtidos realizando ensaios de libertação em dois meios distintos, em Suco Gástrico Simulado (pH=1,2) e Suco Intestinal Simulado (pH=6,8) e foram calculadas as velocidades de libertação para cada ensaio. Verificou-se que os ensaios com o fármaco modelo Prednisolona em matrizes de quitosano em meio ácido, pH=1,2, apresentam uma libertação mais lenta. Os reticulantes mais adequados para o quitosano são o ácido glutâmico para a libertação no estômago, a pH=1,2, e o ácido cítrico para a libertação no intestino, a pH=6,8. Em relação ao FucoPol, a concentração de reticulante mais adequada para ambos os meios de libertação revelou ser a de 50% em massa de lisina relativamente à massa de FucoPol.

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This thesis explores the development and employment of microfluidic devices as a tool for studying the effect of the surrounding environment on embryonic stem cells during the migration phenomena. Different single-cell microchips were designed and manufactured to study mouse embryonic fibroblasts (MEFs) migration towards an environmental variation (increase of serum concentration in the culture medium) that was expected to function as a motility stimuli. Considering the experimental, cells were injected into the microchips chambers and individually isolated by dedicated cell traps with view to a single-cell analysis. Once fribroblasts were attached to the surface, culture medium with an increased serum level was subsequently injected in an adjacent chamber to promote the formation of a serum concentration gradient. The gradient established between the chambers could be sensed by the fibroblasts and thus triggered the cells mobilization towards and in the direction of the richer serum medium. Additionally, the experiment allowed the observation of MEFs’ structural reorganization when migrating through micro-tunnels containing widths below the cell size, suggesting a cytoskeleton rearrangement on account of the nutritional stimulus introduced. Furthermore, results indicate that fibronectin promotes MEFs adhesion to the substrate and that MEFs migration is characterized as haptotactic.

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Microbial electrolysis cells (MECs) are an innovative and emerging technique based on the use of solid-state electrodes to stimulate microbial metabolism for wastewater treatment and simultaneous production of value-added compounds (such as methane). This research studied the performance of a two-chamber MEC in terms of organic matter oxidation (at the anode) and methane production (at the cathode). MEC‟s anode had been previously inoculated with an activated sludge, whereas the cathode chamber inoculum was an anaerobic sludge (containing methanogenic microorganisms). During the experimentation, the bioanode was continuously fed with synthetic solutions in anaerobic basal medium, at an organic load rate (OLR) of around 1 g L-1 d-1, referred to the chemical oxygen demand (COD). At the beginning (Run I), the feeding solution contained acetate and subsequently (Run II) it was replaced with a more complex solution containing soluble organic compounds other than acetate. For both conditions, the anode potential was controlled at -0.1 V vs. standard hydrogen electrode, by means of a potentiostat. During Run I, over 80% of the influent acetate was anaerobically oxidized at the anode, and the resulting electric current was recovered as methane at the cathode (with a cathode capture efficiency, CCE, accounting around 115 %). The average energy efficiency of the system (i.e., the energy captured into methane relative to the electrical energy input) under these conditions was over 170%. However, reactor‟s performance decreased over time during this run. Throughout Run II, a substrate oxidation over 60% (on COD basis) was observed. The electric current produced (57% of coulombic efficiency) was also recovered as methane, with a CCE of 90%. For this run the MEC‟s average energy efficiency accounted for almost 170 %. During all the experimentation, a very low biomass growth was observed at the anode whereas ammonium was transferred through the cationic membrane and concentrated at the cathode. Tracer experiments and scanning electron microscopy analyses were also carried out to gain a deeper insight into the reactor performance and also to investigate the possible reasons for partial loss of performance. In conclusion, this research suggests the great potential of MEC to successfully treat low-strength wastewaters, with high energy efficiency and very low sludge production.

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A soldadura é o processo mais utilizado na ligação de materiais. Os efeitos na saúde dos trabalhadores expostos a fumos de soldadura estão normalmente associados a danos pulmonares agudos e crónicos, mas também a outras condições médicas e doenças. O principal objectivo deste estudo foi correlacionar as emissões de macro e nanopartículas libertadas durante o processo de soldadura MIG/MAG de aços inoxidáveis com diferentes gases de protecção. Usando diferentes misturas gasosas utilizadas industrialmente com diferentes entregas térmicas, determinaram-se taxas de formação de fumos e áreas superficiais de nanopartículas com capaciade de deposição alveolar por volume pulmonar. Verificou-se como os diferentes modos de transferências e tipos de protecção gasosa, em particular, a percentagem de elementos activos na composição química do gás, afectam a quantidade de fumos gerados bem como a existência de nanopartículas com uma elevada capacidade de deposição alveolar. O modo de transferência por spray apresenta sempre valores superiores de área de superfície das partículas por volume pulmonar, ao contrário da taxa de formação de fumos. A mistura 82% Ar + 18% gera maiores emissões de nanopartículas bem como de fumos formados. A extracção na fonte e a regeneração do ar ambiente são a solução mais segura e eficiente de controlo das emissões de macro e nanopartículas em soldadura.

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The main purpose of this report is to present the work developed during the curricular internship on the Commercial Arbitration Centre of the Portuguese Chamber of Commerce and Industry. It is structured in two parts. The first, in which i´ll present the CAC, its organic structure and its activities. In this part I will also show the work I´ve done during the internship, as well as i´m going to identified, and comment, the tasks performed. The second part presents a study on arbitration awards that aimed to determine the amount “split the baby awards”, that is to say those that condemn in (approximately) half of the request. In addition to these data, I collected from sentences other, such as the duration of the cases, the number of foreign persons in each process, the number of foreign arbitrators, the language of proceedings etc. What is expected with this paperwork is to be able to clarify, and make known, some aspects on Arbitration in Portugal, thus contributing to the strengthening of the role of the Arbitration and Arbitral Justice.