Magnetized strangelets at finite temperature

The main properties of strangelets, namely their energy per baryon, radius and electric charge, are studied in the unpaired magnetized strange quark matter (MSQM) and paired magnetized colour flavour locked (MCFL) phases. Temperature effects are taken into account in order to study their stability compared to the Fe-56 isotope and nonmagnetized strangelets within the framework of the MIT bag model. We conclude that the presence of a magnetic field tends to stabilize the strangelets more, even when temperature is considered. It is also shown that MCFL strangelets are more stable than ordinary MSQM strangelets for typical gap values of the order of O(100) MeV. A distinctive feature in the detection of strangelets either in cosmic rays or in heavy-ion collider experiments could be their electric charge. We find that the electric charge is modified in the presence of the magnetic field, leading to higher (lower) charge values for MSQM (MCFL) strangelets, when compared to the nonmagnetized case.

Narrowing inequalities in infant mortality in Southern Brazil

OBJECTIVE: To determine the trends of infant mortality from 1995 to 1999 according to a geographic area-based measure of maternal education in Porto Alegre, Brazil. METHODS: A registry-based study was carried out and a municipal database created in 1994 was used. All live births (n=119,170) and infant deaths (n=1,934) were considered. Five different geographic areas were defined according to quintiles of the percentage of low maternal educational level (<6 years of schooling): high, medium high, medium, medium low, and low. The chi-square test for trend was used to compare rates between years. Incidence rate ratio was calculated using Poisson regression to identify excess infant mortality in poorer areas compared to higher schooling areas. RESULTS: The infant mortality rate (IMR) decreased steadily from 18.38 deaths per 1,000 live births in 1995 to 12.21 in 1999 (chi-square for trend p<0.001). Both neonatal and post-neonatal mortality rates decreased although the drop seemed to be steeper for the post-neonatal component. The higher decline was seen in poorer areas. CONCLUSION: Inequalities in IMR seem to have decreased due to a steeper reduction in both neonatal and post-neonatal components of infant mortality in lower maternal schooling area.

As conceções e as práticas dos gestores de topo na escola pública e privada : convergências e divergências

O papel crucial da escola na sociedade e o exercício da atividade profissional como docente, com um olhar atento sobre o traçar das políticas educativas, motivou a elaboração deste trabalho de investigação, que tem como objeto de estudo os papéis desempenhados pelos diretores das escolas estatais e não estatais e como objetivos específicos estudar o impacto da legislação emanada pela tutela, nas escolas públicas e privadas e analisar as convergências e divergências nas conceções e práticas dos seus diretores. As dimensões analíticas exploradas no estudo abrangem as conceções gestionárias dos diretores quanto aos modelos de gestão, às práticas de autonomia, ao serviço educativo e à prestação de contas. Este trabalho de natureza qualitativa foca o olhar sobre um grupo restrito de atores educativos que foram escolhidos devido ao papel que desempenham na organização educativa e porque a publicação do Decreto- Lei 75/ 2008 de 22 de abril, trouxe alterações à escola pública. A tradição de direção colegial que vigorava nas organizações educativas estatais foi quebrada. O presidente do conselho diretivo é doravante substituído pelo diretor que passa a delegar competências, a designar equipas e a prestar contas à tutela e comunidade educativa à semelhança do diretor da escola privada. O estudo de caso apresentado foi realizado em três escolas públicas e em três colégios privados com recurso a entrevistas semiestruturadas e à análise documental. As conclusões deste trabalho remetem para a existência de muitos pontos de convergência entre a opinião dos diretores da escola pública e privada. As temáticas relativas à autonomia, escolha do pessoal docente e prestação de contas, são olhadas pela mesma perspetiva. A autonomia é vista como “uma miragem”; uma “terra prometida” (Lima e Afonso, 1995). A prestação de contas é exigida aos diretores do ensino estatal e do privado através de instrumentos próximos. As principais divergências situam-se ao nível do menor interesse demonstrado, por parte da direção da escola privada, pela oferta de cursos profissionais e pelo menor investimento em estratégias para a prevenção do abandono escolar, que é considerado pouco significativo na escola não estatal. A defesa da escolha de escola e da modalidade de cheque ensino são outros dos pontos que marcam a divergência entre estes diretores. Abstract: This investigative paper - whose objective is the study of the role of the school directors, both State and non-state, and the impact of legislation on both State and private schools, as well as the analysis of the convergent and divergent conceptions and practices of these directors – is motivated by the crucial role played by schools in our society and by the professional activity of the teacher, with an attentive look at the educational practices. The analytical dimension explored in this study includes the various concepts of management of the school director as models of management, as well as practices in self-sufficiency, budget control and educational service to the community. This study has a qualitative nature and focuses on a small group of individuals who were chosen for the role they play in the whole educational structure, considering that the Decree nº 75/2008, published on April the 22nd, determined alterations to the public school system. The traditional method of control of the public school system has, henceforth, been changed. The headmaster is now substituted by a director who delegates his functions, makes up work teams and elaborates the school budget which is presented to the respective governmental ministry and the community, much like as what happens in private schools. The present study encompasses three public schools and three private schools, the methods of study being semi-structured interviews as well as the consultation of documentation. The conclusions point to many convergent opinions of the school directors of both the public and the private sector. The school directors of both public and private schools used in this study share the same opinion as to the factors involved in the selection of teachers, the elaboration of the school budget and the implementation of self-sufficiency policies. These self-sufficiency policies are seen as a “mirage” or a “promised land” (Lima and Afonso, 1995). The school budget and its management practices are implemented in both public and private schools through similar instruments. The principal differences are noted on smaller, less interesting points, on the part of the direction of the private schools, and result from the elaboration of professional courses and minor investment in the strategies, oriented to the prevention of school drop-outs, which is considered of little significance in the private school sector. The other factors of divergence result from the right to choose the type of school desired and the type of teaching implemented.

Economia social, pilar de um novo modelo de desenvolvimento económico sustentável

Dissertação apresentada ao Instituto Superior de Contabilidade para a obtenção do Grau de Mestre em Auditoria Orientada por Dr.ª Alcina Portugal Dias

Dual source/dual energy-renal applications

Development of Dual Source Computed Tomography (Definition, Siemens Medical Solutions, Erlanger, Germany) allowed advances in temporal resolution, with the addition of a second X-ray source and an array of detectors to the TCM 64 slices. The ability to run exams on Dual Energy, allows greater differentiation of tissues, showing differences between closer attenuation coefficients. In terms of renal applications, the distinction of kidney stones and masses become one of the main advantages of the use of dual-energy technology. This article pretends to demonstrate operating principles of this equipment, as its main renal applications.

Paul Auster and the music of change: building new stories

In the work of Paul Auster (Newark, 1947 - ), we find two main themes: the sense of loss and existential drift and the loneliness of the individual fully committed to the work of writing, as if he had been confined to the book that commands his life. However, this second theme is clearly the dominant one because the character's space of solitude may include its own wandering, because this wandering is also often performed inside the four walls of a room, just like it is narrated inside the space of the page and the book. Both in his poetry, essays and fiction, Auster seems to face the work of writing as an actual physical effort of effective construction, as if the words that are aligned in the poem-text were stones to place in a row when building a wall or some other structure in stone.

Wetting behaviour of femtosecond laser textured Ti-6Al-4V surfaces

The aim of the present work was to investigate the wetting behaviour of biomedical grade Ti-6Al-4V alloy surfaces textured by a femtosecond laser treatment. The material was treated in ambient atmosphere using an Yb: KYW chirped-pulse-regenerative amplification laser with a wavelength of 1030 nm and a pulse duration of 500 fs. Four main types of surface textures were obtained depending on the processing parameters and laser treatment method. These textures consist of: (1) nanoscale laser-induced periodic surface structures (LIPSS); (2) nanopillars; (3) a bimodal roughness distribution texture formed of LIPSS overlapping microcolumns; (4) a complex texture formed of LIPSS overlapping microcolumns with a periodic variation of the columns size in the laser scanning direction. The wettability of the surfaces was evaluated by the sessile drop method using distilled-deionized (DD) water and Hank's balanced salt solution (HBSS) as testing liquids. The laser treated surfaces present a hydrophilic behaviour as well as a high affinity for the saline solution, with equilibrium contact angles in the ranges 24.1-76.2. for DD water and 8.4-61.8. for HBSS. The wetting behaviour is anisotropic, reflecting the anisotropy of the surface textures. (c) 2012 Elsevier B.V. All rights reserved.

Determinação da tensão interfacial do sistema Água - Tolueno - Acetona

Mestrado em Engenharia Química. Ramo de Optimização Energética na Indústria Química

Embedded platform for ECG biometric recognition

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Electrónica e Telecomunicações

PPO Reaction Scale-up

O óxido de polifenileno com a marca comercial PPO® é uma das resinas principais produzidas na SABIC IP e o ingrediente principal do plástico de engenharia com a marca registada, Noryl®. A equipa de tecnologia de processo de PPO® desenvolve uma série de novos produtos em reactores de pequena escala, tanto em Selkirk como em Bergen op Zoom. Para se efectuar uma transição rápida da escala laboratorial para a fábrica, é necessário um conhecimento completo do reactor. O objectivo deste projecto consiste em esboçar linhas gerais para o scale-up de novos produtos de PPO1, do laboratório para a escala industrial, baseado no estudo de um tipo de PPO, PPO 803. Este estudo pode ser dividido em duas fases. Numa primeira fase, as receitas e os perfis da reacção são comparados, de onde se retiram as primeiras conclusões. Posteriormente, com base nestas conclusões, é realizado um planeamento experimental. O estudo inicial sugeriu que a receita, a temperatura inicial do reactor e a velocidade do agitador poderiam influenciar o tempo da reacção bem como a queda da velocidade intrínseca do polímero (IV drop). As reacções experimentais mostraram que a receita é o principal factor que influencia, tanto o tempo de reacção, como a queda de viscosidade intrínseca. O tempo de reacção será tanto maior quanto menor a agitação devido à má dispersão do oxigénio na mistura. O uso de temperaturas iniciais elevadas conduz a uma queda maior da viscosidade intrínseca devido à desactivação do catalisador. O método experimental utilizado no laboratório de Bergen op Zoom é um bom exemplo, simulador, do procedimento utilizado na fábrica.

Global material analysis on phosphorus flows, supply horizon and impact assessment on phosphorus depletion

Different problems are daily discuss on environmental aspects such acid rain, eutrophication, global warming and an others problems. Rarely do we find some discussions about phosphorus problematic. Through the years the phosphorus as been a real problem and must be more discussed. On this thesis was done a global material flow analysis of phosphorus, based on data from the year 2004, the production of phosphate rock in that year was 18.9 million tones, almost this amount it was used as fertilizer on the soil and the plants only can uptake, on average, 20% of the input of fertilizer to grow up, the remainder is lost for the phosphorus soil. In the phosphorus soil there is equilibrium between the phosphorus available to uptake from the plants and the phosphorus associate with other compounds, this equilibrium depends of the kind of soil and is related with the soil pH. A reserve inventory was done and we have 15,000 million tones as reserve, the amount that is economical available. The reserve base is estimated in 47,000 million tones. The major reserves can be found in Morocco and Western Sahara, United Sates, China and South Africa. The reserve estimated in 2009 was 15,000 million tone of phosphate rock or 1,963 million tone of P. If every year the mined phosphate rock is around 22 Mt/yr (phosphorus production on 2008 USGS 2009), and each year the consumption of phosphorus increases because of the food demand, the reserves of phosphate rock will be finished in about 90 years, or maybe even less. About the value/impact assessment was done a qualitative analysis, if on the future we don’t have more phosphate rock to produce fertilizers, it is expected a drop on the crops yields, each depends of the kind of the soil and the impact on the humans feed and animal production will not be a relevant problem. We can recovery phosphorus from different waste streams such as ploughing crop residues back into the soil, Food processing plants and food retailers, Human and animal excreta, Meat and bone meal, Manure fibre, Sewage sludge and wastewater. Some of these examples are developed in the paper.

Sintomatologia depressiva e (in)satisfação escolar

Trabalho apresentado em XIII Congreso Internacional Galego-Portugués de Psicopedagoxía, Área 5 Familia, Escuela y Comunidad. Universidad da Coruña, 2 de Setembro de 2015.

Aproveitamento energético num sistema de distribuição de água

Dissertação de Mestrado, Engenharia e Gestão de Sistemas de Água, 9 de Novembro de 2015, Universidade dos Açores.

Recuperação de calor dos efluentes da tinturaria

Foram utilizados como elemento principal de estudo, os efluentes líquidos dos processos industriais da ENDUTEX, Tinturaria e Acabamento de Malhas, S. A. localizada no município de Caldas de Vizela, distrito de Braga. O estudo foi realizado na empresa devido ao interesse da mesma em poder reaproveitar o calor libertado nos efluentes para aquecimento de parte da água captada no rio de Vizela. O objectivo do trabalho consiste no dimensionamento de um permutador de calor que permita satisfazer o interesse da empresa, assim como, um estudo económico relativo aos custos envolventes. Com o intuito de concretizar os objectivos propostos foram realizadas visitas semanais à empresa para se proceder ao levantamento de dados e para a realização de amostragens do efluente para posterior caracterização. Depois de efectuado o dimensionamento do permutador de placas para diferentes caudais e temperaturas dos fluidos, frio (água do rio) e quente (efluentes), concluiu-se que as condições mais rentáveis correspondiam a um caudal de fluido frio de 17 m3/h em que a temperatura de entrada e de saída no permutador seria de 14 ºC e 48 ºC, respectivamente. O caudal de fluido quente seria de 20 m3/h, sendo a temperatura de entrada e de saída no permutador de 62 ºC e 33,1 ºC, respectivamente. Como resultado do dimensionamento obteve-se um permutador de placas com 167 placas em que o coeficiente global de transferência de calor (U) é de 726,9 W/m2ºC, a área projectada de 55,7 m2 e a queda de pressão de 0,904 KPa. Foi consultada a empresa ARSOPI-THERMAL para verificação das características dos permutadores existentes no mercado. No entanto, para as mesmas condições foi sugerido um permutador com 31 placas em que o coeficiente global de transferência de calor (U) é de 6267 W/m2ºC, a área projectada de 7,39 m2 e a queda de pressão de 76 KPa. A diferença verificada nos resultados apresentados pode ter origem na utilização de diferentes expressões no cálculo do coeficiente pelicular de transferência de calor (h) e pelo facto da ARSOPI desprezar o factor de sujamento no seu dimensionamento Na análise económica do projecto é de referir que para o arranque do projecto foi feito o levantamento das necessidades de investimento, situando-se este num valor total de 9640€, sendo o investimento financiado apenas por capitais próprios. O prazo de recuperação do investimento (Pay Back Period) é de cerca de 2 meses.

Capillary bridging and long-range attractive forces in a mean-field approach

When a mixture is confined, one of the phases can condense out. This condensate, which is otherwise metastable in the bulk, is stabilized by the presence of surfaces. In a sphere-plane geometry, routinely used in atomic force microscope and surface force apparatus, it, can form a bridge connecting the surfaces. The pressure drop in the bridge gives rise to additional long-range attractive forces between them. By minimizing the free energy of a binary mixture we obtain the force-distance curves as well as the structural phase diagram of the configuration with the bridge. Numerical results predict a discontinuous transition between the states with and without the bridge and linear force-distance curves with hysteresis. We also show that similar phenomenon can be observed in a number of different systems, e.g., liquid crystals and polymer mixtures. (C). 2004 American Institute of Physics.