Estudo e desenvolvimento de modelo de dispositivo controlado por temperatura no contexto de eficiência energética: potencial de aplicação para DSR-SF

Dissertação para a obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Energia

Structural stability of adenylate kinase from the sulfate-reducing bacteria Desulfovibrio gigas

Biophysical Chemistry 110 (2004) 83–92

Efficient aggregate computations in large-scale dense WSN

We focus on large-scale and dense deeply embedded systems where, due to the large amount of information generated by all nodes, even simple aggregate computations such as the minimum value (MIN) of the sensor readings become notoriously expensive to obtain. Recent research has exploited a dominance-based medium access control(MAC) protocol, the CAN bus, for computing aggregated quantities in wired systems. For example, MIN can be computed efficiently and an interpolation function which approximates sensor data in an area can be obtained efficiently as well. Dominance-based MAC protocols have recently been proposed for wireless channels and these protocols can be expected to be used for achieving highly scalable aggregate computations in wireless systems. But no experimental demonstration is currently available in the research literature. In this paper, we demonstrate that highly scalable aggregate computations in wireless networks are possible. We do so by (i) building a new wireless hardware platform with appropriate characteristics for making dominance-based MAC protocols efficient, (ii) implementing dominance-based MAC protocols on this platform, (iii) implementing distributed algorithms for aggregate computations (MIN, MAX, Interpolation) using the new implementation of the dominance-based MAC protocol and (iv) performing experiments to prove that such highly scalable aggregate computations in wireless networks are possible.

Highly scalable aggregate computations in cyber-physical systems: physical environment meets communication protocols

In this paper, we focus on large-scale and dense Cyber- Physical Systems, and discuss methods that tightly integrate communication and computing with the underlying physical environment. We present Physical Dynamic Priority Dominance ((PD)2) protocol that exemplifies a key mechanism to devise low time-complexity communication protocols for large-scale networked sensor systems. We show that using this mechanism, one can compute aggregate quantities such as the maximum or minimum of sensor readings in a time-complexity that is equivalent to essentially one message exchange. We also illustrate the use of this mechanism in a more complex task of computing the interpolation of smooth as well as non-smooth sensor data in very low timecomplexity.

Impacto da síncope na qualidade de vida: validação duma escala de avaliação em doentes submetidos a teste de inclinação em mesa basculante

Introdução e objetivos: A síncope recorrente tem um impacto significativo na qualidade de vida. O desenvolvimento de escalas de medida de fácil aplicabilidade clínica para avaliar este impacto é fundamental. O objetivo do presente estudo é a validação preliminar da escala Impact of Syncope on Quality of Life, para a população portuguesa. Métodos: O instrumento foi submetido a um processo de tradução, validação, adequação cultural e cognitive debriefing. Participaram 39 doentes com história de síncopes recorrentes (>1 ano de evolução), submetidos a teste de inclinação em mesa basculante (teste de tilt), que constitui uma amostra de conveniência, com idade de 52,1±16,4 anos (21-83; 43,5% do sexo masculino), a maioria com uma situação profissional ativa (n=18) ou reformados (n=13). A versão portuguesa resultou numa versão semelhante unidimensional à original com 12 itens agregados num único somatório, tendo passado por validação estatística, com avaliação da fidelidade, validade e estabilidade no tempo. Resultados: Em relação à fidelidade, a consistência interna da escala é de 0,9. Avaliámos a validade convergente, tendo obtido resultados estatisticamente significativos (p<0,01). Avaliámos a validade divergente tendo obtido resultados estatisticamente significativos. Relativamente à estabilidade no tempo foi efetuado um teste-reteste do instrumento aos seis meses após o teste de inclinação com 22 doentes desta amostra não submetidos a intervenção clínica, que não mostrou alterações estatisticamente significativas da qualidade de vida. Conclusões: Os resultados obtidos indicam a pertinência da utilização deste instrumento em contexto português na avaliação da qualidade de vida de doentes com síncope recorrente.

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

Dynamic adaptation of stability periods for service level agreements

A QoS adaptation to dynamically changing system conditions that takes into consideration the user’s constraints on the stability of service provisioning is presented. The goal is to allow the system to make QoS adaptation decisions in response to fluctuations in task traffic flow, under the control of the user. We pay special attention to the case where monitoring the stability period and resource load variation of Service Level Agreements for different types of services is used to dynamically adapt future stability periods, according to a feedback control scheme. System’s adaptation behaviour can be configured according to a desired confidence level on future resource usage. The viability of the proposed approach is validated by preliminary experiments.

Chemical reaction network of flavylium ions in heterogeneous media

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

The effect of metal transfer stability (spattering) on fume generation, morphology and composition in short-circuit MAG welding

The main objective of this work was to evaluate the hypothesis that the greater transfer stability leads also to less volume of fumes. Using an Ar + 25%CO2 blend as shielding gas and maintaining constant the average current, wire feed speed and welding speed, bead-on-plate welds were carried out with plain carbon steel solid wire. The welding voltage was scanned to progressively vary the transfer stability. Using two conditions of low stability and one with high stability, fume generation was evaluated by means of the AWS F1.2:2006 standard. The influence of these conditions on fume morphology and composition was also verified. A condition with greater transfer stability does not generate less fume quantity, despite the fact that this condition produces fewer spatters. Other factors such as short-circuit current, arcing time, droplet diameters and arc length are the likely governing factors, but in an interrelated way. Metal transfer stability does not influence either the composition or the size/morphology of fume particulates. (c) 2014 Elsevier B.V. All rights reserved.

Color and Luminescence stability of selected dental materials in vitro

To study luminescence, reflectance, and color stability of dental composites and ceramics. Materials and Methods: IPS e.max, IPS Classic, Gradia, and Sinfony materials were tested, both unpolished (as-cast) and polished specimens. Coffee, tea, red wine, and distilled water (control) were used as staining drinks. Disk-shaped specimens were soaked in the staining drinks for up to 5 days. Color was measured by a colorimeter. Fluorescence was recorded using a spectrofluorometer, in the front-face geometry. Time-resolved fluorescence spectra were recorded using a laser nanosecond spectrofluorometer. Results: The exposure of the examined dental materials to staining drinks caused changes in color of the composites and ceramics, with the polished specimens exhibiting significantly lower color changes as compared to unpolished specimens. Composites exhibited lower color stability as compared to ceramic materials. Water also caused perceptible color changes in most materials. The materials tested demonstrated significantly different initial luminescence intensities. Upon exposure to staining drinks, luminescence became weaker by up to 40%, dependent on the drink and the material. Time-resolved luminescence spectra exhibited some red shift of the emission band at longer times, with the lifetimes in the range of tens of nanoseconds. Conclusions: Unpolished specimens with a more developed surface have lower color stability. Specimens stored in water develop some changes in their visual appearance. The presently proposed methods are effective in evaluating the luminescence of dental materials. Luminescence needs to be tested in addition to color, as the two characteristics are uncorrelated. It is important to further improve the color and luminescence stability of dental materials.

Estruturas de suporte de terras executadas com pneus

O aproveitamento de pneus em fim de vida revela ser uma alternativa eficaz e promissora na indústria da construção civil, na utilização deste resíduo em muros de suporte. O presente trabalho tem como principal objetivo a apresentação de uma técnica de aproveitamento de pneus em fim de vida na execução de muros de gravidade, combinando solo e pneus. Neste sentido, tomou-se como referência um estudo realizado no Brasil por Sieira, Sayão, Medeiros e Gerscovich, para avaliar a eficiência e o custo deste tipo de estruturas, comparando-o com um muro de suporte tradicional de betão simples. Inicialmente, avaliou-se a segurança do muro de solo-pneus, de acordo com a metodologia proposta no Eurocódigo 7 (NP EN 1997-1, 2010), considerando a geometria e as características dos materiais apresentados no estudo referido e usando o programa de cálculo automático Slide, da Rocscience, para a verificação da estabilidade global. Reproduziu-se a análise numérica realizada no âmbito do caso de estudo brasileiro de referência, recorrendo também a uma formulação por elementos finitos com o programa de cálculo automático Phase2, da Rocscience. Por último, utilizando uma vez mais o programa Slide, definiu-se a geometria de um muro de betão simples cuja geometria garantisse o mesmo valor do fator de segurança à estabilidade global, obtido com o muro de solo-pneus e compararam-se os custos respetivos. O presente trabalho confirmou a eficiência e o baixo custo desta solução construtiva, sendo necessários, no entanto, estudos mais detalhados que reforcem estas conclusões.

Stability of Schistosoma mansoni progeny to antischistosomal drugs

The susceptibility of the MAP Brazilian strain (F1 to F5 progenies) of S. mansoni to four antischistosomal drugs has been reported in a previous study. In the present investigation, progeny F14 of the same strain, was tested for stability to the same 4 drugs. A new medication, Oltipraz (35,972 RP), was added to the study. Five groups of 12 mice infected with cercariae by tail immersion were treated with hycanthone, oxamniquine, niridazole, praziquantel and Oltipraz. An untreated group was used as control. Schistosomal activity was assessed by the localization of worms in the portal vein system, by oogram changes, and percentage of parasite reduction. The stability of the susceptibility of progeny F14 did not change in relation to generations F1 to F5; the progeny was resistant to hycanthone and oxamniquine; but sensitive to niridazole, praziquantel and Oltipraz. We emphasize the importance of the phenomenon of resistance of the worm in view of the fact that oxamniquine has been widely used in Brazilian areas where mansonic schistosomiasis is endemic.

Acute pulmonary histoplasmosis and first isolation of Histoplasma capsulatum from soil of Rio Grande do Sul, Brazil

A case of acute pulmonary histoplasmosis, where the clinical histoiy and epidemiological data led to the identification of H. capsulatum natural source, is described. Specimens of spleen and liver, obtained after intraperitonial inoculation in mice, grew H. capsulatum in culture from the soil of rural area of General Câmara, by the first time in Rio Grande do Sul.

Land use/ land cover change and its impact on soil erosion process in Begnas Tal Rupa Tal watershed using geospatial tools, Kaski district, Nepal

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

On sampling collection procedure effectiveness for forest soil characterization

One of the most important measures to prevent wild forest fires is the use of prescribed and controlled burning actions as it reduce the fuel mass availability. The impact of these management activities on soil physical and chemical properties varies according to the type of both soil and vegetation. Decisions in forest management plans are often based on the results obtained from soil-monitoring campaigns. Those campaigns are often man-labor intensive and expensive. In this paper we have successfully used the multivariate statistical technique Robust Principal Analysis Compounds (ROBPCA) to investigate on the sampling procedure effectiveness for two different methodologies, in order to reflect on the possibility of simplifying and reduce the sampling collection process and its auxiliary laboratory analysis work towards a cost-effective and competent forest soil characterization.