O papel da engenharia na gestão de ativos de uma unidade industrial

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Manutenção

Implementação de um programa de fiabilidade de aeronaves

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Congruences on monoids of transformations preserving the orientation on a finite chain

Journal of Algebra, 321 (2009), p. 743–757

The Neogene of Portugal

After a brief historical introduction, this paper deals with the main concerned geotectonic units: the Lower Tagus and Alvalade basins, the Western and Southern borders, and their infillings. Most of the Neogene events and record concern areas South of the Iberian Central Chain, a nearly inverse situation as that of Paleogene times. In the most important of these units, the Lower Tagus basin, there are quite thick detrital series, mostly marine in its distal part near Lisboa (albeit with several continental intercalations), and mainly continental in its inner part. Sedimentological record is almost complete since Lowermost to Upper Miocene. The richness ofdata (paleontology, isotope chronology, paleoclimate, etc.) it gives and the possibility of direct marine-continental correlations render this basin one of the more interesting ones in Western Europe. Alvalade basin is separated from the previous one by a barrier of Paleozoic rocks. Two transgressions events (Upper Tortonian and Messinian in age) are recorded. Active sedimentation may be correlated to Late Miocene tectonics events. In Algarve, chiefly marine units from Lower to Upper Miocene are well developped. The Lower unit (Lagos-Portimão Formation) is best exposed in Western Algarve, but desappears eastwards. Middle Miocene is not as well known, whereas Upper Miocene main outcrops are in Eastern Algarve. Cacela Formation is remarquable for its beautiful fossils. Sedimentation as a whole refletcts the tectonic activity and in special the evolution of the Algarve flexures. There is scant evidence of post-Lower Miocene volcanism, the latest known in Portugal. Pliocene has not been recognized there beyond doubt. Miocene sediments are much less important to the North of the Central Iberian Chain. Continental beds near Leiria that yielded the well-known "Hisp anotherium fauna" are lower Middle Miocene. Pliocene corresponds to dramatic changes in paleogeography. At Setiibal Peninsula there is some evidence of a minor Lower Pliocene transgression. Continental detrital sediments, often coarse, occupy rather large areas. In Western Portugal between the Setúbal Peninsula and Pombal there is good evidence of a marine Upper Pliocene transgression, followed up by dune sands overlain by marsh clays, diatomites, lignites and boghead levels that can be partly Pleistocene in age.

Electrical ageing studies of polymeric insulation for power cables (estudo do envelhecimento eléctrico do isolante polimérico de cabos eléctricos

Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Física - Física Aplicada pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Silver coordination polymers with tri- and hexacyanoethyl-functionalized macrocyclic ligands

Tri-and hexa-cyanoethyl functionalized 17-(L-1) and 42-membered (L-2) macrocyclic compounds were obtained by [1 + 1] (for L-1) or [2 + 2] (for L-2) cyclocondensation of the corresponding dialdehyde and diethylenetriamine, followed by hydrogenation by KBH4 and subsequent cyano-functionalization with acrylonitrile. They react with silver nitrate, leading to the formation of [AgL1](NO3) (1) and of the metalorganic coordination polymers [Ag-2(NO3)(2)L-1](n) (2) and {[Ag2L2](NO3)(2)}(n) (3). The complexes were characterized by elemental analysis, H-1 NMR, C-13 NMR, IR spectroscopies, and ESI-MS; moreover, L-2, 1, 2 and 3 were also characterized by single crystal X-ray diffraction. The metal cation in 1 is pentacoordinated with a N3O2 coordination environment; in 2, the metal cations display N4O2 octahedral and N2O3 square-pyramid coordination and in 3 they are in square-planar N-4 sites. In 1, the ligand acts as a pentadentate chelator, and in the other two cases, the ligands behave as octadentate chelators in a 1 kappa N-3:kappa O-2,2 kappa N,3 kappa N,4 kappa N (in 2) or 1 kappa N-3,2 kappa N-3,3 kappa N,4 kappa N fashion (in 3). The cyanoethyl strands of the ligands are directly involved in the formation of the 2D frameworks of 2 and 3, which in the former polymer can be viewed as a net composed of hexametallic 36-membered macrocyclic rings and in the latter generates extra hexametallic 58-membered cyclic sets that form zig-zag layers. The thermal analytical and electrochemical properties of these silver complexes were also studied.

Supply chain optimization of residual forestry biomass for bioenergy production: the case study of Portugal

Within a large set of renewable energies being explored to tackle energy sourcing problems, bioenergy can represent an attractive solution if effectively managed. The supply chain design supported by mathematical programming can be used as a decision support tool to the successful bioenergy production systems establishment. This strategic decision problem is addressed in this paper where we intent to study the design of the residual forestry biomass to bioelectricity production in the Portuguese context. In order to contribute to attain better solutions a mixed integer linear programming (MILP) model is developed and applied in order to optimize the design and planning of the bioenergy supply chain. While minimizing the total supply chain cost the production energy facilities capacity and location are defined. The model also includes the optimal selection of biomass amounts and sources, the transportation modes selection, and links that must be established for biomass transportation and products delivers to markets. Results illustrate the positive contribution of the mathematical programming approach to achieve viable economic solutions. Sensitivity analysis on the most uncertain parameters was performed: biomass availability, transportation costs, fixed operating costs and investment costs. (C) 2015 Elsevier Ltd. All rights reserved.

Detection of hepatitis B virus DNA by the polymerase chain reaction in anti-HBE positive chronic hepatitis B patients

Detection of HBV-DNA by PCR was compared with other serological markers (HBsAg, HBeAg and anti-HBe) in a series of49 Chronic Hepatitis B patients, including 12 with a spontaneous clearance of HBsAg. None of these HBsAg negative cases were PCR positive, but 33/37 (89.2%) HBsAg positive cases were PCR positive (p < 0.0001). Among HBsAg positive samples, nine cases were HBeAg positive and anti-HBe negative, all of them PCR positive. Other 3 patients were HBeAg and anti-HBe positive and these cases were also found PCR positive. A third group included 21 patients anti-HBe positive and HBeAg negative: 19 of them were PCR positive and 2 were PCR negative. The last 4 cases were HBeAg and anti-HBe negative, two of them were PCR positive. The detection of anti-HBe viremic cases in the present series suggest that preC variants could occur in our country. In conclusion, the integrated phase o f chronic hepatitis B seems to be less frequent than it was assumed, when only HBeAg or dot blot hybridization techniques were used. The new term "low replication phase" might favorably replace the former "integrated phase".

Novel coordination polymers with (Pyrazolato)-based tectons: catalytic activity in the peroxidative oxidation of alcohols and cyclohexane

Coupling five rigid or flexible bis(pyrazolato)based tectons with late transition metal ions allowed us to isolate 18 coordination polymers (CPs). As assessed by thermal analysis, all of them possess a remarkable thermal stability, their decomposition temperatures lying in the range of 340-500 degrees C. As demonstrated by N-2 adsorption measurements at 77 K, their Langmuir specific surface areas span the rather vast range of 135-1758 m(2)/g, in agreement with the porous or dense polymeric architectures retrieved by powder X-ray diffraction structure solution methods. Two representative families of CPs, built up with either rigid or flexible spacers, were tested as catalysts in (0 the microwave-assisted solvent-free peroxidative oxidation of alcohols by t-BuOOH, and (ii) the peroxidative oxidation of cydohexane to cydohexanol and cydohexanone by H2O2 in acetonitrile. Those CPs bearing the rigid spacer, concurrently possessing higher specific surface areas, are more active than the corresponding ones with the flexible spacer. Moreover, the two copper(I)-containing CPs investigated exhibit the highest efficiency in both reactions, leading selectively to a maximum product yield of 92% (and TON up to 1.5 x 10(3)) in the oxidation of 1-phenylethanol and of 11% in the oxidation of cydohexane, the latter value being higher than that granted by the current industrial process.

Congruences on monoids of order-preserving or order-reversing transformations on a finite chain

Glasgow Mathematical Journal, nº 47 (2005), pg. 413-424

Presentations for some monoids of injective partial transformations on a finite chain.

Communications in Algebra, 33 (2005), p. 587-604

The cardinal and the idempotent number of various monoids of transformations on a finite chain

Bulletin of the Malaysian Mathematical Sciences Society, 2, 34 (1),(2011), p. 79–85

Ligação Adesiva de Polímeros Particularmente Difíceis de Colar

As ligações adesivas têm sido cada vez mais utilizadas nos últimos anos em detrimento de outros métodos tais como a soldadura, ligações aparafusadas e ligações rebitadas. Os plásticos de Engenharia têm um papel cada vez mais preponderante na indústria, devido às suas excelentes propriedades. Neste trabalho foram considerados três polímeros diferentes, o Policloreto de Vinilo (PVC) e o Polipropileno (PP) dado o seu baixo custo e peso e a superfície quimicamente inerte e o Politetrafluoretileno (PTFE) devido às suas boas propriedades químicas e excelentes propriedades de deslizamento. No entanto, estes materiais possuem uma baixa energia de superfície e, por isso, são muito difíceis de colar com mais relevância para o PTFE. Assim, após um estudo preliminar foi escolhido, para realizar as colagens necessárias, um adesivo da Tamarron Technology “Tam Tech Adhesive”, próprio para este tipo de substratos difíceis de colar. Posteriormente foi efetuada a sua caraterização através de ensaios de provetes maciços à tração. O principal objetivo deste trabalho foi estudar juntas de sobreposição simples de materiais poliméricos difíceis de colar tais como o PTFE, PP e PVC com recurso a um adesivo que não necessitasse de preparação de superfície. Foram fabricadas juntas de sobreposição simples (JSS) segundo os métodos Lap Shear (LS) e Block Shear (BS) dos três materiais referidos anteriormente e realizados os respetivos ensaios para avaliar o comportamento mecânico das ligações adesivas. Os materiais utilizados como substratos foram também submetidos a ensaios de tração com a finalidade de obter o módulo de elasticidade e as suas propriedades de resistência. Os substratos envolvidos nas juntas adesivas não sofreram qualquer preparação especial das superfícies. Na maioria dos casos consistiu apenas numa limpeza das superfícies com álcool etílico. Contudo, para o PTFE também se experimentou a preparação por abrasão com lixa e por chama. Foi também efetuado um trabalho de simulação numérica por elementos finitos utilizando um modelo de dano coesivo triangular. As resistências ao corte obtidas são superiores em BS comparativamente a LS, exceção feita aos substratos de PTFE aonde os resultados são similares. O tratamento por chama melhorou a resistência mecânica das juntas. Verificou-se também que o modelo numérico simulou adequadamente o comportamento das juntas principalmente das LS.

Detection and identification of dengue virus isolates from Brazil by a simplified reverse transcription - polymerase chain reaction (RT-PCR) method

We show here a simplified RT-PCR for identification of dengue virus types 1 and 2. Five dengue virus strains, isolated from Brazilian patients, and yellow fever vaccine 17DD as a negative control, were used in this study. C6/36 cells were infected and supernatants were collected after 7 days. The RT-PCR, done in a single reaction vessel, was carried out following a 1/10 dilution of virus in distilled water or in a detergent mixture containing Nonidet P40. The 50 µl assay reaction mixture included 50 pmol of specific primers amplifying a 482 base pair sequence for dengue type 1 and 210 base pair sequence for dengue type 2. In other assays, we used dengue virus consensus primers having maximum sequence similarity to the four serotypes, amplifying a 511 base pair sequence. The reaction mixture also contained 0.1 mM of the four deoxynucleoside triphosphates, 7.5 U of reverse transcriptase, 1U of thermostable Taq DNA polymerase. The mixture was incubated for 5 minutes at 37ºC for reverse transcription followed by 30 cycles of two-step PCR amplification (92ºC for 60 seconds, 53ºC for 60 seconds) with slow temperature increment. The PCR products were subjected to 1.7% agarose gel electrophoresis and visualized by UV light after staining with ethidium bromide solution. Low virus titer around 10 3, 6 TCID50/ml was detected by RT-PCR for dengue type 1. Specific DNA amplification was observed with all the Brazilian dengue strains by using dengue virus consensus primers. As compared to other RT-PCRs, this assay is less laborious, done in a shorter time, and has reduced risk of contamination

Organização e disposição dos armazéns

Relatório de Estágio Curricular apresentado ao Instituto Superior de Contabilidade e Administração do Porto para obtenção do Grau de Mestre em Logística Orientado pelo Doutor Júlio Faceira Guedes Coorientado pelo Engenheiro Ricardo Costa Moreira