Estudo da divergência entre duas vias que curvam em sentidos contrários

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

Oxidative Leaching of metals from electronic waste with solutions based on quaternary ammonium salts

The treatment of electric and electronic waste (WEEE) is a problem which receives ever more attention. An inadequate treatment results in harmful products ending up in the environment. This project intends to investigate the possibilities of an alternative route for recycling of metals from printed circuit boards (PCBs) obtained from rejected computers. The process is based on aqueous solutions composed of an etchant, either 0.2 M CuCl2.2H2O or 0.2 M FeCl3.6H2O, and a quaternary ammonium salt (quat) such as choline chloride or chlormequat. These solutions are reminiscent of deep eutectic solvents (DES) based on quats. DES are quite similar to ionic liquids (ILs) and are used as well as alternative solvents with a great diversity of physical properties, making them attractive for replacement of hazardous, volatile solvents (e.g. VOCs). A remarkable difference between genuine DES and ILs with the solutions used in this project is the addition of rather large quantities of water. It is shown the presence of water has a lot of advantages on the leaching of metals, while the properties typical for DES still remain. The oxidizing capacities of Cu(II) stem from the existence of a stable Cu(I) component in quat based DES and thus the leaching stems from the activity of the Cu(II)/Cu(I) redox couple. The advantage of Fe(III) in combination with DES is the fact that the Fe(III)/Fe(II) redox couple becomes reversible, which is not true in pure water. This opens perspectives for regeneration of the etching solution. In this project the leaching of copper was studied as a function of gradual increasing water content from 0 - 100w% with the same concentration of copper chloride or iron(III) chloride at room temperature and 80ºC. The solutions were also tested on real PCBs. At room temperature a maximum leaching effect for copper was obtained with 30w% choline chloride with 0.2 M CuCl2.2H2O. The leaching effect is still stronger at 80°C, b ut of course these solutions are more energy consuming. For aluminium, tin, zinc and lead, the leaching was faster at 80ºC. Iron and nickel dissolved easily at room temperature. The solutions were not able to dissolve gold, silver, rhodium and platinum.

Nova metodologia de execução do ensaio SCPTu com avaliação da influência da fonte sísmica quanto à sua dimensão e afastamento

O objectivo deste trabalho consiste na determinação das Ondas de Corte, onda S, através de uma nova metodologia de ensaio do piezocone sísmico, SCPTu. A nova metodologia adoptada de aquisição de dados, consiste na aquisição da onde de corte no movimento ascendente de remoção de varas, após execução do já conhecido ensaio CPTu, ao invés da tradicional aquisição, no movimento descendente, previamente ao acréscimo de nova vara. Além da introdução de uma nova metodologia de aquisição sísmica, tentou-se avaliar a influência da dimensão da fonte geradora da onda de corte e a influência do afastamento das mesmas ao ponto de cravação, do ensaio de penetração estática mencionado. Na avaliação das influências foram usadas três fontes de madeira de secção rectangular, com uma chapa de ferro a topo e diferenciadas entre si pelas dimensões de 1m, 2m e 3m e afastamentos até 4m.

Avaliação da aptidão física funcional de idosos hipertensos da Cidade da Praia, Cabo Verde: estudo piloto

Introdução – A avaliação da aptidão física permite a identificação de níveis de incapacidade e risco de perda funcional, pelo que é extremamente útil na estruturação de programas de atividade física específicos, que constituem a primeira intervenção no que toca à intervenção não-farmacológica na Hipertensão Arterial Sistémica (HAS). Objetivo – Avaliar a aptidão física funcional e os níveis de atividade física de idosos hipertensos da Cidade da Praia – Cabo Verde. Metodologia – A flexibilidade, força e resistência muscular, resistência aeróbia e composição corporal foram avaliadas através da bateria de Fullerton e dinamometria isométrica manual. O nível de atividade física foi avaliado pelo questionário Seven Day Physical Activity Recall (7D-PAR). Resultados – Participaram 75 idosos, com idades compreendidas entre os 60 e os 99 anos, 68% dos quais eram mulheres, com índice de massa corporal (IMC) de 25,2±5,4, com diagnóstico clínico de HAS. O tempo despendido em atividades de intensidade moderada encontrava-se dentro dos valores recomendados, embora a atividade intensa se encontrasse muito abaixo do recomendado e não efetuassem qualquer exercício de força e flexibilidade. A resistência aeróbia expressa pelo Teste 6 Minutos de Marcha (T6MM) apresentou valores médios baixos (293,5±112,2m), bem como a flexibilidade e a força de preensão. Esta associação é um indicador de baixa capacidade funcional. Conclusão – Os baixos níveis de aptidão física apresentados, associados a baixos níveis de atividade física indiciam baixa capacidade funcional e justificam a necessidade urgente da inserção de programas de atividade física nesta população.

Optimal virtual cluster-based multiprocessor scheduling

Scheduling of constrained deadline sporadic task systems on multiprocessor platforms is an area which has received much attention in the recent past. It is widely believed that finding an optimal scheduler is hard, and therefore most studies have focused on developing algorithms with good processor utilization bounds. These algorithms can be broadly classified into two categories: partitioned scheduling in which tasks are statically assigned to individual processors, and global scheduling in which each task is allowed to execute on any processor in the platform. In this paper we consider a third, more general, approach called cluster-based scheduling. In this approach each task is statically assigned to a processor cluster, tasks in each cluster are globally scheduled among themselves, and clusters in turn are scheduled on the multiprocessor platform. We develop techniques to support such cluster-based scheduling algorithms, and also consider properties that minimize total processor utilization of individual clusters. In the last part of this paper, we develop new virtual cluster-based scheduling algorithms. For implicit deadline sporadic task systems, we develop an optimal scheduling algorithm that is neither Pfair nor ERfair. We also show that the processor utilization bound of us-edf{m/(2m−1)} can be improved by using virtual clustering. Since neither partitioned nor global strategies dominate over the other, cluster-based scheduling is a natural direction for research towards achieving improved processor utilization bounds.

Development of a new pultrusion equipment to manufacture thermoplastic matrix composite profiles

This paper describes the design and manufacture of a low-cost full scale pultrusion prototype equipment and discusses the production and obtained mechanical properties of polypropylene/glass (GF/PP) reinforced composite ba rs fabricated by using the prototype equipment. Three different GF/PP pre-impregnated ra w-materials, a commercial GF/PP comingled system from Vetrotex, a GF/PP powder coat ed towpreg [1-3] and, a GF/PP pre- consolidated tape (PCT) produced in our laboratorie s, were used in the production of composite bars that were subsequently submitted to mechanical testing in order to determine the relevant mechanical properties and quantify the consolidation quality. Samples of the different composite profiles were also observed und er SEM microscopy.

Growth of (Perylene)(2) [PD(MNT)(2)] crystals

The conditions for [pd(mnt)(2)]he growth of [pd(mnt)(2)]Perylene) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals either by chemical oxidation and electrochemical routes are [pd(mnt)(2)]escribed. The electrocrystallisation is limited by close [pd(mnt)(2)]roximity of [pd(mnt)(2)]he oxidation [pd(mnt)(2)]otentials of [pd(mnt)(2)]he [pd(mnt)(2)]erylene [pd(mnt)(2)]onor and [Pd(mnt) [pd(mnt)(2)]] - anion, and [pd(mnt)(2)]epending on [pd(mnt)(2)]he experimental conditions [pd(mnt)(2)]ifferent [pd(mnt)(2)]orphologies can be obtained. [pd(mnt)(2)]Per) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals obtained by elecrocrystallisation were found [pd(mnt)(2)]o be [pd(mnt)(2)]ainly of [pd(mnt)(2)]he β-polymorph with [pd(mnt)(2)]roperties comparable [pd(mnt)(2)]o [pd(mnt)(2)]he Cu, Ni and Pt analogues [pd(mnt)(2)]reviously [pd(mnt)(2)]escribed at variance with [pd(mnt)(2)]hose obtained by chemical oxidation which are [pd(mnt)(2)]ainly of [pd(mnt)(2)]he α-polymorph.

Schistosomiasis mansoni: evidence for a milder response in germfree mice

Germfree (GF and conventional (CV) mice were infected intraperitoneally with GF cercariae of Schistosoma mansoni and kept for six weeks. Twenty four hours before killing, they were injected with [³H]-thymidine. Schistosoma worms, harvested after perfusion of portal system, were counted as well as eggs from liver and intestines. Liver was also used for DNA, protein, and collagen determinations. [³H] -Thymidine incorporation and collagen determinations were used to establish the indices given by the difference between their contents in infected and control animals and expressed per thousand eggs in liver. The recovery of worms in GF mice was around twice as much as in CV ones, and the total number of eggs was higher in the liver of GF animals. No hypertrophy of liver cells was observed by the ratio protein/DNA, but [³H]-thymidine incorporation into DNA was higher than in controls in both GF and CV infected animals. The [³H]-thymidine and collagen indices were lower in GF animals which indicate a more discrete cellular replication and smaller collagen content in relation to the number of eggs present in livers of these mice. It was concluded that the disease seems to be less severe in GF animals.

American trypanosomiasis (Chagas' disease) in conventional and germfree rats and mice

Germfree (GF) and conventional (CV) CFW (LOB) mice and Wistar and Sprague-Dawley rats were infected with Trypanosoma cruzi. The disease was more severe in the GF than in the CV animals as revealed by: (1) an earlier and more intense parasitemia; (2) a more precocious mortality; (3) a twice enlarged spleen: (4) a more intense cell and tissue parasitism; (5) visceral signs of cardiac failure.

UltramicroELISA para la deteccion de anticuerpos IgM al Mycobacterium leprae utilizando muestras de sangre seca

En este trabajo se establecen las condiciones optimas para la detección de anticuerpos IgM al glicolipido fenólico-I (GF-I) en muestras de sangre en papel de filtro utilizando el UltramicroELISA HANSEN y la tecnologia SUMA. Se estudiaron 300 donantes de sangre y 58 pacientes leprosos. Para estas dos poblaciones se compararon los resultados de muestras de sangre seca colectadas en papel de filtro SS-2992 con los de suero, y se obtuvo una correlación de 0.919 para donantes de sangre, 0.969 para pacientes y 0.954 para el total de las dos poblaciones. Se obtuvo una coincidencia de 98% en pacientes y 96% en donantes. En la población de pacientes la sensibilidad fue de 93% y la especificidad de 100% para las muestras de sangre seca evaluadas por el UMELISA HANSEN, con respecto a las muestras de suero analizadas por esta misma tecnica.

Genetic diversity of arginine catabolic mobile element in Staphylococcus epidermidis

PLos One, 4(11): ARTe7722

INFLUENCE OF DIETARY PROTEIN CONTENT ON Trypanosoma cruzi INFECTION IN GERMFREE AND CONVENTIONAL MICE

Germfree (GF) and conventional (CV) mice were fed on diets containing 4.4, 13.2 or 26.4% of protein (weight/weight). CV mice fed on low protein diet did not gain weight during four weeks, whereas the protein deficient diet did not affect the growth of GF mice. After four weeks on these diets, the mice were inoculated with 5x103 trypomastigotes of Trypanosoma cruzi. The protein deficiency affected less the GF than the CV mice, according to the following parameters: weight gain, hemoglobin, plasma protein and albumin levels and water and protein contents of the carcass. Infection with T. cruzi produced a significant decrease in hemoglobin levels, red blood cell count, and water and protein contents in the carcass. This decrease was more pronounced in the GF mice. Histopathologically, there was no difference between the treatments in animals with the same microbiological status (GF or CV). However, the disease was more severe in the GF than in the CV mice.

Amorphous silicon e 3D sensors applied to object detection

Nowadays, existing 3D scanning cameras and microscopes in the market use digital or discrete sensors, such as CCDs or CMOS for object detection applications. However, these combined systems are not fast enough for some application scenarios since they require large data processing resources and can be cumbersome. Thereby, there is a clear interest in exploring the possibilities and performances of analogue sensors such as arrays of position sensitive detectors with the final goal of integrating them in 3D scanning cameras or microscopes for object detection purposes. The work performed in this thesis deals with the implementation of prototype systems in order to explore the application of object detection using amorphous silicon position sensors of 32 and 128 lines which were produced in the clean room at CENIMAT-CEMOP. During the first phase of this work, the fabrication and the study of the static and dynamic specifications of the sensors as well as their conditioning in relation to the existing scientific and technological knowledge became a starting point. Subsequently, relevant data acquisition and suitable signal processing electronics were assembled. Various prototypes were developed for the 32 and 128 array PSD sensors. Appropriate optical solutions were integrated to work together with the constructed prototypes, allowing the required experiments to be carried out and allowing the achievement of the results presented in this thesis. All control, data acquisition and 3D rendering platform software was implemented for the existing systems. All these components were combined together to form several integrated systems for the 32 and 128 line PSD 3D sensors. The performance of the 32 PSD array sensor and system was evaluated for machine vision applications such as for example 3D object rendering as well as for microscopy applications such as for example micro object movement detection. Trials were also performed involving the 128 array PSD sensor systems. Sensor channel non-linearities of approximately 4 to 7% were obtained. Overall results obtained show the possibility of using a linear array of 32/128 1D line sensors based on the amorphous silicon technology to render 3D profiles of objects. The system and setup presented allows 3D rendering at high speeds and at high frame rates. The minimum detail or gap that can be detected by the sensor system is approximately 350 μm when using this current setup. It is also possible to render an object in 3D within a scanning angle range of 15º to 85º and identify its real height as a function of the scanning angle and the image displacement distance on the sensor. Simple and not so simple objects, such as a rubber and a plastic fork, can be rendered in 3D properly and accurately also at high resolution, using this sensor and system platform. The nip structure sensor system can detect primary and even derived colors of objects by a proper adjustment of the integration time of the system and by combining white, red, green and blue (RGB) light sources. A mean colorimetric error of 25.7 was obtained. It is also possible to detect the movement of micrometer objects using the 32 PSD sensor system. This kind of setup offers the possibility to detect if a micro object is moving, what are its dimensions and what is its position in two dimensions, even at high speeds. Results show a non-linearity of about 3% and a spatial resolution of < 2µm.

Avaliação do desempenho hidráulico de agregados reciclados de escórias de aciaria e RCD à água e ao lixiviado de RSU e sua comparação com basalto e calcário

As atuais políticas de gestão de resíduos estão mais focadas na reciclagem e na reutilização dos resíduos do que na sua eliminação em aterros de resíduos. Nos casos em que o resíduo não é perigoso para o ambiente, não existe nenhuma razão para que esse material não seja utilizado em obras de construção e de engenharia civil, desde que garanta um desempenho equivalente, no mínimo, ao dos materiais naturais. De forma a contribuir para a valorização dos resíduos, estudou-se o comportamento hidráulico de um Agregado Siderúrgico Inerte para a Construção (ASIC), proveniente de escórias de aciaria de Forno de Arco Elétrico (FAE), e de um agregado reciclado de betão, proveniente de resíduos de construção e demolição (RCD), à água de abastecimento público e a um lixiviado recolhido num aterro de resíduos sólidos urbanos (RSU). Pretendeu-se avaliar a viabilidade técnica da sua aplicação em estruturas de drenagem de obras geotécnicas e infraestruturas de transporte, em particular na camada de drenagem e recolha dos lixiviados dos aterros de resíduos. Efetuaram-se ensaios de permeabilidade sobre duas frações granulométricas diferentes: areia (0,25-2mm) e “brita” (2-20mm), considerando que no nosso país é habitual aquela camada ser composta por um nível de areia, com 0,2m de espessura, sobre um nível de brita, com 0,3m espessura. Seguindo o procedimento adotado para o estudo dos dois agregados reciclados, também se ensaiaram dois agregados naturais, basalto e calcário, utilizados como materiais de referência.

Estrutura da floresta equatorial úmida da estação experimental de silvicultura tropical do INPA

Analisam a estrutura da floresta equatorial úmida próxima a Manaus, introduzindo a qualidade de fuste na. análise. Utilizam 8 amostras de 20m x 500m para indivíduos com DAP > 20cm, 24 subamostras de 10m x 100m para. indivíduos com DAP entre 5cm e 20cm e 120 subamostras de 2m x 10m para indivíduos com DAP < 5cm. Determinam valores mínimos de 2,6 e 22 amostras para composição florística é de 6,18 e 80 para a abundância em cada fração da floresta. Concluem que a floresta é muito heterogênea, com 324 espécies, 173 gêneros e 57 fiamílias e com grande diferença entre a regeneração e o povoamento adulto. Eschweilera odora, Corythophora alta., Protium apiculatum e Radlkoferella sp. são as espécies mais importantes. A floresta em geral apresenta a estrutura diamétrica regular esperada para florestas nativas devido às espécies do estrato inferior e sub-bosque.