Desenvolvimento de solenóides para eletroválvulas hidráulicas

Os solenóides para eletroválvulas, em conjunto com outros produtos e equipamentos, permitem a automação dos sistemas de distribuição de águas não potáveis, como, por exemplo, em sistemas de rega. Deste modo é possível controlar diversos parâmetros, como o caudal e a pressão da água que passa na válvula, podendo estes ser fiscalizados à distância. Neste trabalho, foram desenvolvidos solenóides para acoplar a válvulas que se destinam à rega agrícola, comercializadas pela empresa JPrior, Fábrica de Plásticos, Lda. Para o efeito, foram definidos vários processos necessários para a criação de uma linha piloto de pré industrialização destes dispositivos. Etapas como a conceção do dispositivo, prototipagem, testes de temperatura, consumo de corrente, estabilidade eletromecânica e testes de desempenho associados a diferentes valores de pressão e de caudal de funcionamento, foram essenciais para este desenvolvimento, assim como, análises estruturais e morfológicas do material que constitui o núcleo dos solenóides. Além disso, procurou-se responder às necessidades do mercado numa perspetiva mais completa do que a existente. Para isso, foram produzidos dois tipos de solenóides de 24 V AC, com pressões máximas de funcionamento de 4 bar e de 12 bar.

O ciclo da água pluvial em meio urbano

Dissertação para obtenção do grau de Mestre em Arquitetura com Especialização em Urbanismo, apresentada na Universidade de Lisboa - Faculdade de Arquitetura.

Desenvolvimento de filtros cerâmicos impregnados com nanopartículas de prata para desinfecção de água potável

Brazil has vast amounts of hydric resources, whose quality has been deteriorating due to pollutant dumping. Household waste disposal is one of the main sources of water pollution, stimulating bacteria proliferation and introducing microorganisms, including those from fecal matter. Conventional water disinfection methods are a solution, but on the downside, they lead to the formation byproducts hazardous to human health. In this study, aiming to develop bactericidal filters for the disinfection of drinking water; silver nanoparticles were deposited on alumina foams through three routes: sputtering DC, dip coating and in situ chemical reduction of silver nitrate. The depositions were characterized through X-ray diffraction, scanning electron microscopy and EDS element mapping. The influence of the depositions on permeability and mechanical properties of the ceramic foams was assessed and, in sequence, a preliminary antibacterial efficiency analysis was carried out. Characterization results indicate that the chemical reduction routes were efficient in depositing homogeneously distributed silver particles and that the concentration of the metallic precursor salt affects size and morphology of the particles. The antibacterial efficiency analysis indicates that the chemical reduction filters have potential for water disinfection

A Hydrogeologic Evaluation of the Waterloo Area in the Upper Jefferson River Valley, Montana

The Upper Jefferson River is one of the most dewatered rivers in Montana. The river exists in an intermontane basin filled with sediment transported from the Highland Mountains to the west, the Tobacco Root Mountains to the east, and the Jefferson River from the south. The Upper Jefferson River Valley is highly dependent on the Jefferson River as the main industry in the valley is agriculture. A majority of the valley is irrigated and used to grow crops, and a good portion is also used for cattle grazing. The residents of the Upper Jefferson River Valley use the aquifer as the main source of potable water. The Jefferson River is also widely used for recreation. This study took place in the Waterloo area of the Upper Jefferson River Valley, approximately 20 miles south of Whitehall, Montana. The Waterloo area provides significant groundwater base flow to the Jefferson River, which is particularly important during the late irrigation season when the river is severely dewatered, and elevated surface-water temperatures occur, creating irrigation water shortages and poor trout habitat. This area contains two springfed streams, Willow Springs and Parson’s Slough, which discharge to the Jefferson River providing cool water in the late season as well as providing the most important trout spawning habitat in the valley. The area is bordered on both the east and west by irrigation ditches, and about 60% of the study area is irrigated. Tile drains were installed in the study area in close proximity to Parsons Slough causing some concern by neighboring residents. This study evaluated relationships between surface water, groundwater, and irrigation practices so that water managers and others can make informed management decisions about the Upper Jefferson River. Data was collected via a network of groundwater wells and surface-water sites. Additionally, water-quality samples were taken and an aquifer test was conducted to determine aquifer properties. The field data were analyzed and a groundwater budget was created in order to evaluate the aquifer. Results of the groundwater budget show that seepage from the irrigation canals and irrigation recharge have the biggest influence on recharge of the aquifer. There is significant groundwater outflow from the aquifer in the spring-fed streams as well as discharge to the Jefferson River. In comparing previous study results to this study’s results, there is no evidence of the water table decreasing due to irrigation practice changes or tile drain installation. However, given the amount of recharge irrigation practices contribute to the aquifer, if significant changes were made, they may affect groundwater elevations. Also lining the irrigation ditches would have a significant impact on the aquifer, as the amount of seepage would be greatly reduced.

Hydrogeophysical Characterization of Anisotropy in the Biscayne Aquifer Using Geophysical Methods

The anisotropy of the Biscayne Aquifer which serves as the source of potable water for Miami-Dade County was investigated by applying geophysical methods. Electrical resistivity imaging, self potential and ground penetration radar techniques were employed in both regional and site specific studies. In the regional study, electrical anisotropy and resistivity variation with depth were investigated with azimuthal square array measurements at 13 sites. The observed coefficient of electrical anisotropy ranged from 1.01 to 1.36. The general direction of measured anisotropy is uniform for most sites and trends W-E or SE-NW irrespective of depth. Measured electrical properties were used to estimate anisotropic component of the secondary porosity and hydraulic anisotropy which ranged from 1 to 11% and 1.18 to 2.83 respectively. 1-D sounding analysis was used to models the variation of formation resistivity with depth. Resistivities decreased from NW (close to the margins of the everglades) to SE on the shores of Biscayne Bay. Porosity calculated from Archie's law, ranged from 18 to 61% with higher values found along the ridge. Higher anisotropy, porosities and hydraulic conductivities were on the Atlantic Coastal Ridge and lower values at low lying areas west of the ridge. The cause of higher anisotropy and porosity is attributed to higher dissolution rates of the oolitic facies of the Miami Formation composing the ridge. The direction of minimum resistivity from this study is similar to the predevelopment groundwater flow direction indicated in published modeling studies. Detailed investigations were carried out to evaluate higher anisotropy at West Perrine Park located on the ridge and Snapper Creek Municipal well field where the anisotropy trend changes with depth. The higher anisotropy is attributed to the presence of solution cavities oriented in the E-SE direction on the ridge. Similarly, the change in hydraulic anisotropy at the well field might be related to solution cavities, the surface canal and groundwater extraction wells.

Climate variability of the last 1000 years in the NW Pacific: high resolution, multi-biomarker records from Lake Toyoni

The East Asian Monsoon (EAM) is an active component of the global climate system and has a profound social and economic impact in East Asia and its surrounding countries. Its impact on regional hydrological processes may influence society through industrial water supplies, food productivity and energy use. In order to predict future rates of climate change, reliable and accurate reconstructions of regional temperature and rainfall are required from all over the world to test climate models and better predict future climate variability. Hokkaido is a region which has limited palaeo-climate data and is sensitive to climate change. Instrumental data show that the climate in Hokkaido is influenced by the East Asian Monsoon (EAM), however, instrumental data is limited to the past ~150 years. Therefore down-core climate reconstructions, prior to instrumental records, are required to provide a better understanding of the long-term behaviour of the climate drivers (e.g. the EAM, Westerlies, and teleconnections) in this region. The present study develops multi-proxy reconstructions to determine past climatic and hydrologic variability in Japan over the past 1000 years and aid in understanding the effects of the EAM and the Westerlies independently and interactively. A 250-cm long sediment core from Lake Toyoni, Hokkaido was retrieved to investigate terrestrial and aquatic input, lake temperature and hydrological changes over the past 1000-years within Lake Toyoni and its catchment using X-Ray Fluorescence (XRF) data, alkenone palaeothermometry, the molecular and hydrogen isotopic composition of higher plant waxes (δD(HPW)). Here, we conducted the first survey for alkenone biomarkers in eight lakes in the Hokkaido, Japan. We detected the occurrence of alkenones within the sediments of Lake Toyoni. We present the first lacustrine alkenone record from Japan, including genetic analysis of the alkenone producer. C37 alkenone concentrations in surface sediments are 18µg C37 g−1 of dry sediment and the dominant alkenone is C37:4. 18S rDNA analysis revealed the presence of a single alkenone producer in Lake Toyoni and thus a single calibration is used for reconstructing lake temperature based on alkenone unsaturation patterns. Temperature reconstructions over the past 1000 years suggest that lake water temperatures varies between 8 and 19°C which is in line with water temperature changes observed in the modern Lake Toyoni. The alkenone-based temperature reconstruction provides evidence for the variability of the EAM over the past 1000 years. The δD(HPW) suggest that the large fluctuations (∼40‰) represent changes in temperature and source precipitation in this region, which is ultimately controlled by the EAM system and therefore a proxy for the EAM system. In order to complement the biomarker reconstructions, the XRF data strengthen the lake temperature and hydrological reconstructions by providing information on past productivity, which is controlled by the East Asian Summer monsoon (EASM) and wind input into Lake Toyoni, which is controlled by the East Asian Winter Monsoon (EAWM) and the Westerlies. By combining the data generated from XRF, alkenone palaeothermometry and the δD(HPW) reconstructions, we provide valuable information on the EAM and the Westerlies, including; the timing of intensification and weakening, the teleconnections influencing them and the relationship between them. During the Medieval Warm Period (MWP), we find that the EASM dominated and the EAWM was suppressed, whereas, during the Little Ice Age (LIA), the influence of the EAWM dominated with time periods of increased EASM and Westerlies intensification. The El Niño Southern Oscillation (ENSO) significantly influenced the EAM; a strong EASM occurred during El Niño conditions and a strong EAWM occurred during La Niña. The North Atlantic Oscillation, on the other hand, was a key driver of the Westerlies intensification; strengthening of the Westerlies during a positive NAO phase and weakening of the Westerlies during a negative NAO phase. A key finding from this study is that our data support an anti-phase relationship between the EASM and the EAWM (e.g. the intensification of the EASM and weakening of the EAWM and vice versa) and that the EAWM and the Westerlies vary independently from each other, rather than coincide as previously suggested in other studies.

DESLAZAMIENTOS EN LA CUENCA DEL RIO BANANO, UNA CONSECUENCIA DEL TERREMOTO DE ABRIL DE 1991

En la región Caribe algunas cuencas se vieron afectadas en su comportamiento hidrológico, como consecuencia del terremoto de abril de 1991.Un ejemplo evidente de lo anterior es la cuenca del rio Banano, que es la fuente principal del agua potable para la provincia de Limón, y que se presenta un comportamiento de rio aluvial acelerado como consecuencia de cerca de 40 millones de m3 de material deslizado. Los deslizamientos  característicos en la cuenca son deslizamientos de roca (rockslide), aunque puede observarse uno de tipo rotacional (rotational slump); además existen flujos de detritos ( debris flow). Este comportamiento acelerado origina inundaciones en poblados como Aguas Zarcas, Quitaría, Beverly; Polonia, Bomba y María Luisa. Con el fin de minimizar las consecuencias de estas inundaciones se establece una zonificación de áreas inundables para la parte baja de la cuenca en tres clases. Además, en la cuenca se registra un aporte significativo de material en suspensión, lo cual podrá alterar la posibilidad del agua. ABSTRACTThe April 1991 earthquake in Costa Rica caused changes in the hydrological characteristics of several watersheds in the Caribbean region of country.Evidence of these changes was observer in the rio Banano, the principal source of potable water for the province de Limon. The behavior of the alluvial river accelerated as a consequence of nearly 40 million cubic meters of material that moved within the watershed as a result of the earthquake. The characteristical landslides were rockslides, althoung rotational slump and debris flow slides were also observed. The accelerated hydrological changes in the river have caused flooding in populated areas such as Aguas Zarcas, Quitará, Beverly, Polonia, Bomba and Maria Luisa. In order to minimize the consequences of the flooding, the lower part of the watershed was classified in three categories according to flooding susceptibility.The river has also shown an increase in suspended material, which could affect the potability of the water.

Agua potable y saneamiento ambiental en América Latina, 1981-1990 = Drinking water supply and sanitation in Latin America, 1981-1990

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Necesidades financieras del Decenio Internacional del Agua Potable y del Saneamiento Ambiental en América Latina = Financial demands of the International Drinking Water Supply and Sanitation Decade in Latin America

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Suministro de servicios de agua potable y saneamiento a la población rural de América Latina = Provision of drinking water and sanitation services to the rural population of Latin America

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Decenio Internacional del Agua Potable y del Saneamiento Ambiental: la situación en América Latina al comenzar el Decenio y las perspectivas para el futuro = International Drinking Water Supply and Sanitation Decade: the situation in Latin America on the eve of the decade and the prospects for the future

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Avances hacia el logro de los objetivos del Decenio Internacional del Agua Potable y del Saneamiento Ambiental, 1980-1983 = Progress towards achievement of the goals of the International Drinking Water Supply and Sanitation Decade (IDWSSD), 1980-1983

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Aprovechamiento de los recursos hídricos: progresos realizados en la aplicación del Plan de Acción de Mar del Plata y el Decenio Internacional del Agua Potable y del Saneamiento Ambiental en América Latina y el Caribe = Water resource development: progress in the implementation of the Mar del Plata Action Plan and the International Drinking Water Supply and Sanitation Decade in Latin America and the Caribbean

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Abastecimiento de agua potable y saneamiento ambiental en América Latina y el Caribe con posterioridad a la Carta de Punta del Este = Drinking water supply and sanitation in Latin America and the Caribbean since Punta del Este

Incluye Bibliografía