Novas terapêuticas não farmacológicas da perturbação do pós-stress traumático

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Misturas betuminosas temperadas, do tipo SMA, com incorporação de material betuminoso reciclado e fibras celulósicas : contribuição para a sua caracterização

A crescente necessidade de reabilitação de pavimentos rodoviários tem conduzido ao aumento dos materiais resultantes das intervenções e ao consumo de quantidades significativas de energia e de novos materiais. Umas das formas de reduzir o consumo de energia decorrente da execução de trabalhos de reabilitação, e consequentemente a emissão de gases poluentes associada, é a produção de Misturas Betuminosas Temperadas. Estas são produzidas a temperaturas inferiores a 140ºC, o que permite poupar energia em relação às fabricadas a quente a uma temperatura superior a 140ºC. Por outro lado, a adição de Misturas Betuminosas Recuperadas (MBR) na produção de novas misturas, em substituição de parte dos agregados naturais e do betume novo, contribui para a diminuição do consumo de novos materiais, o que constitui uma prática ambientalmente sustentável e economicamente vantajosa. Reunindo os aspetos referidos no fabrico de misturas Stone Mastic Asphalt (SMA), caracterizadas pela sua elevada durabilidade e baixo custo de manutenção ao longo do seu ciclo de vida, pode obter-se uma mistura com inúmeras vantagens do ponto de vista económico e ambiental, destacando-se a redução do consumo e do custo de matérias-primas naturais, a redução do volume de resíduos a transportar a vazadouro, a redução do consumo de energia e a redução dos custos na manutenção e reabilitação dos pavimentos. Ao longo deste trabalho, descrevem-se as diversas tecnologias usadas para produzir misturas betuminosas temperadas, caracterizam-se as misturas do tipo Stone Mastic Asphalt, e mencionam-se os aspetos mais relevantes na incorporação de MBR na produção de novas misturas. Por último, foram realizados estudos experimentais com o intuito de investigar as propriedades volumétricas e o comportamento mecânico de misturas temperadas do tipo SMA com incorporação de MBR, contribuindo para o desenvolvimento deste tipo de misturas não tradicionais, com o objetivo de promover a sua utilização futura em trabalhos de pavimentação rodoviária.

Formulação de misturas betuminosas a quente : análise comparativa da aplicação de métodos empíricos e volumétricos

A utilização de métodos de formulação de misturas betuminosas tem como objetivo determinar a combinação de agregados e betume numa mistura, de tal modo que se obtenha um material de pavimentação tão económico quanto possível, fácil de fabricar e colocar, e que suporte os efeitos das cargas e do clima ao longo do seu ciclo de vida. As misturas colocadas nas camadas de pavimentos podem diferir no tipo de material agregado e na sua granulometria, no tipo e na quantidade de ligante, na utilização de aditivos ou agentes que modificam o betume, e na sua composição volumétrica. Os métodos empíricos de formulação de misturas betuminosas, como o método de Marshall, não permitem formular com a fiabilidade necessária misturas betuminosas com o desempenho mecânico adequado para resistir aos mecanismos de degradação a que vão ficar sujeitas nos pavimentos. Uma das alternativas ao método de Marshall é a metodologia de formulação volumétrica SUPERPAVE, desenvolvida no programa Strategic Highway Research Program(SHRP). Nesta metodologia o procedimento de seleção da percentagem ótima em betume é realizado com base nas propriedades volumétricas de provetes compactados com o compactador giratório. A percentagem ótima em betume depende da energia de compactação utilizada, sendo esta fornecida pelo número de giros a que o provete foi submetido. O equipamento geralmente usado nos ensaios é a prensa giratória de corte (PGC) que permite medir a compacidade e estimar com uma precisão suficiente a porosidade que será obtida insitu. Nestes métodos a seleção da curva granulométrica e da percentagem ótima de betume a usar é feita pela verificação da maior ou menor correspondência entre as composiçõestestadas e certos requisitos de compactabilidade pré-definidos, entendendo-se estes como uma medida da aptidão da mistura para apresentar bom comportamento no seu ciclo de vida. A prática portuguesa é a de utilizar o método de Marshall para formular misturas betuminosas convencionais e até algumas misturas não convencionais. Torna-se, assim, útil comparar os resultados de formulações obtidas por duas vias diferentes, tendo em conta que a utilização da prensa giratória de corte tem vindo a ser progressivamente integrada em várias metodologias de formulação utilizadas internacionalmente. Crê-se que os métodos baseados em PGC, mantêm alguma simplicidade de procedimentos, ao mesmo tempo que permitem amentar o nível de confiança nas composições a que se chega, no que diz respeito ao seu desempenho no seu ciclo de vida.

Factores determinantes de la variabilidad espacial de anchoveta peruana (Engraulis ringens) en el Pacífico Sudoriental

Los modelos de nicho ecológico permiten estudiar el efecto del ambiente sobre la distribución de las especies, relacionando datos de su distribución con información ambiental. El objetivo del presente estudio fue estimar el nicho ecológico y describir la variabilidad en la distribución espacial de la anchoveta (Engraulis ringens) mediante el uso de modelos estadísticos de nicho ecológico. Se trabajó con dos enfoques de análisis: por stocks (norte, centro y sur) en el Pacífico Sudoriental (PSO) y por estadios de desarrollo (pre-reclutas, reclutas y adultos) en la costa peruana. El modelo de nicho ecológico utilizó modelos aditivos generalizados, estimaciones georeferenciadas de presencia y ausencia de anchoveta e información de cuatro variables ambientales (temperatura superficial del mar, salinidad superficial del mar, concentración de clorofila a superficial y la profundidad de la oxiclina) entre los a˜nos 1985 y 2008. Se encontró que no existen diferencias en los nichos ecológicos de los tres stocks de anchoveta siendo los modelos que utilizaron la información de la anchoveta en todo el PSO los que lograron modelar el nicho de manera correcta. Respecto al análisis por estadios, se evidenció que cada estadio de desarrollo tiene distintas tolerancias a las variables ambientales consideradas en este trabajo, siendo los nichos de estadios menos desarrollados los que estuvieron incluidos dentro de los estadios más desarrollados. Se recomienda realizar estudios separados para cada estadio de desarrollo, lo cual permita comprender mejor las relaciones ecológicas encontradas en los resultados del nicho ecológico. Además se recomienda realizar simulaciones con modelos de nicho que incluyan más variables ambientales, las cuales puedan mejorar los mapas de distribución espacial de la anchoveta para los dos enfoques de análisis.

Desenvolvimento de pastas cimentantes contendo nanossílica como material estendedor para aplicação em fases iniciais, de poços petrolíferos, submetidas à baixa temperatura (5°c ± 3ºc)

The improved performance of hydraulic binders, the base of Portland cement, consists in the careful selection and application of materials that promote greater durability and reduced maintenance costs There is a wide variety of chemical additives used in Portland cement slurries for cementing oil wells. These are designed to work in temperatures below 0 ° C (frozen areas of land) to 300 ° C (thermal recovery wells and geothermal); pressure ranges near ambient pressure (in shallow wells) to greater than 200 MPa (in deep wells). Thus, additives make possible the adaptation of the cement slurries for application under various conditions. Among the materials used in Portland cement slurry, for oil wells, the materials with nanometer scale have been applied with good results. The nanossílica, formed by a dispersion of SiO2 particles, in the nanometer scale, when used in cement systems improves the plastic characteristics and mechanical properties of the hardened material. This dispersion is used commercially as filler material, modifier of rheological properties and / or in recovery processes construction. It is also used in many product formulations such as paints, plastics, synthetic rubbers, adhesives, sealants and insulating materials Based on the above, this study aims to evaluate the performance of nanossílica as extender additive and improver of the performance of cement slurries subjected to low temperatures (5 ° C ± 3 ° C) for application to early stages of marine oil wells. Cement slurries were formulated, with densities 11.0;12.0 and 13.0 ppg, and concentrations of 0; 0.5, 1.0 and 1.5%. The cement slurries were subjected to cold temperatures (5 ° C ± 3 ° C), and its evaluation performed by tests rheological stability, free water and compressive strength in accordance with the procedures set by API SPEC 10A. Thermal characterization tests (TG / DTA) and crystallographic (XRD) were also performed. The use of nanossílica promoted reduction of 30% of the volume of free water and increased compression resistance value of 54.2% with respect to the default cement slurry. Therefore, nanossílica presented as a promising material for use in cement slurries used in the early stages of low-temperature oil wells

Estudo da incorporação de resíduos de perfuração para aplicação em cimentação de poços de petróleo

During the drilling of oil and natural gas are generated solid waste, liquid and gaseous. These solid fragments, which are known as cuttings, are carried to the surface through the drilling fluid. Furthermore, this fluid serves to cool the bit, keeping the internal pressure of the well, and others. This solid residue is very polluting, because it has incorporated beyond the drilling fluid, which has several chemical additives harmful to the environment, some heavy metals that are harmful to the environment, such as lead. To minimize the residue generated, are currently being studied numerous techniques to mitigate the problems that such waste can cause to the environment, like addition of cuttings in the composition of soil cement brick masonry construction, addition of cuttings on the clay matrix for the manufacture of solid masonry bricks and ceramic blocks and coprocessing of the cuttings in cement. So, the main objective of this work is the incorporation of cuttings drilling of oil wells, the cement slurry used in the cementing operation of the well. This cuttings used in this study, arising from the formation Pendências, was milled and separated in a sieve of 100 mesh. After grinding had a mean particle sike in order of 86 mm and crystal structure containing phases of quartz and calcite type, characteristic of the Portland cement. Were formulated and prepared slurries of cement with density 13 lb / gal, containing different concentrations of gravel, and realized characterization tests API SPEC 10A and RP 10B. Free water tests showed values lower than 5.9% and the rheological model that best described the behavior of the mixtures was the power. The results of compressive strength (10.3 MPa) and stability (Dr <0.5 lb / gal) had values within the set of operational procedures. Thus, the gravel from the drilling operation, may be used as binders in addition to Portland cement oil wells, in order to reuse this waste and reduce the cost of the cement paste.

Desenvolvimento de novos biolubrificantes hidráulicos derivados dos óleos de maracujá e de moringa in natura e epoxidados

With the increasing environmental awareness, maximizing biodegradability and minimizing ecotoxicity is the main driving force for new technological developments. Thus, can be developed new biodegradable lubricants for use in environmentally sensitive areas. The aim of this study was to obtain new bio-lubricants from passion fruit (Passiflora edulis Sims f. flavicarpa Degener) and moringa (Moringa oleifera Lamarck) epoxidized oils and develop a new additive package using experimental design for their use as a hydraulic fluid. In the first stage of this work was performed the optimization of the epoxidation process of the oils using fractional experimental design 24-1 , varying the temperature, reaction time, ratio of formic acid and hydrogen peroxide. In the second step was investigated the selectivity, thermodynamics and kinetics of the reaction for obtaining the two epoxides at 30, 50 and 70 °C. The result of the experimental design confirmed that the epoxidation of passion fruit oil requires 2 hours of reaction, 50 °C and a ratio H2O2/C=C/HCOOH (1:1:1). For moringa oil were required 2 hours reaction, 50 °C and a ratio of H2O2/C=C/HCOOH (1:1:1.5). The results of the final conversions were equal to 83.09% (± 0.3) for passion fruit oil epoxide and 91.02 (±0,4) for moringa oil epoxide. Following was made the 23 factorial design to evaluate which are the best concentrations of corrosion inhibitor and anti-wear (IC), antioxidant (BHA) and extreme pressure (EP) additives. The bio-lubricants obtained in this step were characterized according to DIN 51524 (Part 2 HLP) and DIN 51517 (Part 3 CLP) standards. The epoxidation process of the oils was able to improve the oxidative stability and reduce the total acid number, when compared to the in natura oils. Moreover, the epoxidized oils best solubilized additives, resulting in increased performance as a lubricant. In terms of physicochemical performance, the best lubricant fluid was the epoxidized moringa oil with additives (EMO-ADI), followed by the epoxidized passion fruit oil with additives (EPF-ADI) and, finally, the passion fruit in natura oil without additives (PFO). Lastly, was made the investigation of the tribological behavior under conditions of boundary lubrication for these lubricants. The tribological performance of the developed lubricants was analyzed on a HFRR equipment (High Frequency Reciprocating Rig) and the coefficient of friction, which occurs during the contact and the formation of the lubricating film, was measured. The wear was evaluated through optical microscopy and scanning electron microscopy (SEM). The results showed that the addition of extreme pressure (EP) and anti-wear and corrosion inhibitor (CI) additives significantly improve the tribological properties of the fluids. In all assays, was formed a lubricating film that is responsible for reducing the coefficient of metal-to-metal wear. It was observed that the addition of EP and IC additives in the in natura vegetable oils of passion fruit and moringa did not favor a significant reduction in wear. The bio-lubricants developed from passion fruit and moringa oils modified via epoxidation presented satisfactory tribological properties and shown to be potential lubricants for replacement of commercial mineral-based fluids.

Estudo do comportamento da sinterização de compactos de cavacos de um aço SAE 1050 obtidos sob alta pressão

From an economic standpoint, the powder metallurgy (P/M) is a technique widely used for the production of small parts. It is possible, through the P/M and prior comminution of solid waste such as ferrous chips, produce highly dense sintered parts and of interest to the automotive, electronics and aerospace industries. However, without prior comminution the chip, the production of bodies with a density equal to theoretical density by conventional sintering techniques require the use of additives or significantly higher temperatures than 1250ºC. An alternative route to the production of sintered bodies with high density compaction from ferrous chips (≤ 850 microns) and solid phase sintering is a compression technique under high pressure (HP). In this work, different compaction pressures to produce a sintered chip of SAE 1050 carbon steel were used. Specifically, the objective was to investigate them, the effect of high pressure compression in the behavior of densification of the sintered samples. Therefore, samples of the chips from the SAE 1050 carbon steel were uniaxially cold compacted at 500 and 2000 MPa, respectively. The green compacts obtained were sintered under carbon atmosphere at 1100 and 1200°C for 90 minutes. The heating rate used was 20°C/min. The starting materials and the sintered bodies were characterized by optical microscopy, SEM, XRD, density measurements (geometric: mass/volume, and pycnometry) and microhardness measurements Vickers and Rockwell hardness. The results showed that the compact produced under 2000 MPa presented relative density values between 93% and 100% of theoretical density and microhardness between 150 HV and 180 HV, respectively. In contrast, compressed under 500 MPa showed a very heterogeneous microstructure, density value below 80% of theoretical density and structural conditions of inadequate specimens for carrying out the hardness and microhardness measurements. The results indicate that use of the high pressure of ferrous chips compression is a promising route to improve the sinterability conditions of this type of material, because in addition to promoting greater compression of the starting material, the external tension acts together with surface tension, functioning as the motive power for sintering process. Additionally, extremely high pressures allow plastic deformation of the material, providing an intimate and extended contact of the particles and eliminating cracks and pores. This tends to reduce the time and / or temperature required for good sintering, avoiding excessive grain growth without the use of additives. Moreover, higher pressures lead to fracture the grains in fragile or ductile materials highly hardened, which provides a starting powder for sintering, thinner, without the risk of contamination present when previous methods are used comminution of the powder.

Revestimento decorativo monocamada pigmentado, com resíduo de vidro temperado, para aplicação em fachadas

Although efficient from a technical point of view, mortar layers that make up the traditional masonry coating (slurry mortar, plaster and plaster) have to be in contradiction with the new construction technologies and more efficient methods of consumption and work rationalization. From an environmental point of view, the recovery of waste into new composites for the building has been a growing strand of studies in the scientific community, may prove to be a cost-effective solution in some cases. Thus, this research proposes the development of a mortar Decorative Coating Monolayer (RDM), for use in facades, produced on site, incorporating tempered glass waste (RVT) in the cement matrix, as a partial substitute for aggregate. Therefore, we adopted the binder respect / aggregate of 1: 6 (by volume), consistency index 250mm ± 20, sand substitution levels of glass waste 20%, 50% and 80% and relative water / cement varied in many traits. Two additives were used, a polymer, styrene-butadiene-based, and other chemical, besides mineral and silica fume inorganic pigment in colors red, yellow and blue. Mechanical tests were carried out on fresh pasta and hardened, as well as for the applied coating on masonry, so as to demonstrate the feasibility of the material. In addition, it verified the adequacy of the RDM built environment by means of thermal tests. The results demonstrated the feasibility of the proposed RDM with significantly higher values when compared to norms, especially the dash-added replacement content of 20% and addition of pigment in red. Therefore, the study shows the scientific community as an incentive to the use of technological innovations in construction, increasing the range of alternatives available for housing production, with the proposition of a material that achieves the desired functionality and obtain environmental gain, and may be adopted on construction sites as an alternative industrialized mortars.

Adição de policloreto de alumínio e remoção de peixes bentívoros como técnicas de restauração de lagos rasos do semiárido brasileiro

Eutrophication is the most common cause of water quality degradation in the world. This process occurs by excessive nutrients inputs, nitrogen and phosphorus, to the aquatic systems resulting in algal and cyanobacterial blooms. In shallow lakes these effects are pronounced due to the higher interaction of the lake with watershed, air and sediment. There are innumerous restoration techniques of eutrophied lakes with a range of successful results but there is only one case of successful lake restoration in Brazil: Paranoá Lake in Brasília city. The Brazilian semiarid region has many artificial lakes, named açudes, which are mostly eutrophic and shallow lakes. The eutrophication in these lakes is reported and the phytoplankton community is dominated by potentially toxic cyanobacteria species, mainly Cylindrospermopsis raciborskii. The aim of this thesis is to test techniques for water quality management which can be easily applied in Brazilian semiarid lakes. Results from a laboratory experiment suggest that the addition of a phosphorus sorbent clay associated with an aluminium based coagulant is an effective technique in removing soluble reactive phosphorus and reducing C. raciborskii growth rate – cyanobacteria potentially toxic dominant in reservoirs of Brazilian semiarid – but this effect is dependent on the biomass in the application moment. Results from a field experiment in mesocosm in a eutrophied lake showed that the addition of aluminium based coagulant and removal of benthivorous fish is more efficient in removing total phosphorus and chlorophyll-a from water column than the isolated application of one of the techniques. Lastly, laboratory tests showed that aluminium based coagulant exhibited good performance in removing turbidity and total phosphorus from water of six reservoirs but the efficiency was reduced by algal biomass and pH. The results of this study showed that the improvement in water quality of eutrophied reservoirs in semiarid region is possible through internal loading control by phosphorus precipitation and inactivation in sediments or inhibition of phosphorus release by benthivorous fishes, and also that these results show are additives in water quality improvement.

Adição de policloreto de alumínio e remoção de peixes bentívoros como técnicas de restauração de lagos rasos do semiárido brasileiro

Eutrophication is the most common cause of water quality degradation in the world. This process occurs by excessive nutrients inputs, nitrogen and phosphorus, to the aquatic systems resulting in algal and cyanobacterial blooms. In shallow lakes these effects are pronounced due to the higher interaction of the lake with watershed, air and sediment. There are innumerous restoration techniques of eutrophied lakes with a range of successful results but there is only one case of successful lake restoration in Brazil: Paranoá Lake in Brasília city. The Brazilian semiarid region has many artificial lakes, named açudes, which are mostly eutrophic and shallow lakes. The eutrophication in these lakes is reported and the phytoplankton community is dominated by potentially toxic cyanobacteria species, mainly Cylindrospermopsis raciborskii. The aim of this thesis is to test techniques for water quality management which can be easily applied in Brazilian semiarid lakes. Results from a laboratory experiment suggest that the addition of a phosphorus sorbent clay associated with an aluminium based coagulant is an effective technique in removing soluble reactive phosphorus and reducing C. raciborskii growth rate – cyanobacteria potentially toxic dominant in reservoirs of Brazilian semiarid – but this effect is dependent on the biomass in the application moment. Results from a field experiment in mesocosm in a eutrophied lake showed that the addition of aluminium based coagulant and removal of benthivorous fish is more efficient in removing total phosphorus and chlorophyll-a from water column than the isolated application of one of the techniques. Lastly, laboratory tests showed that aluminium based coagulant exhibited good performance in removing turbidity and total phosphorus from water of six reservoirs but the efficiency was reduced by algal biomass and pH. The results of this study showed that the improvement in water quality of eutrophied reservoirs in semiarid region is possible through internal loading control by phosphorus precipitation and inactivation in sediments or inhibition of phosphorus release by benthivorous fishes, and also that these results show are additives in water quality improvement.