A fileira das plantas aromáticas e medicinais em Portugal

Esta comunicação insere-se no âmbito do projecto Agro nº800 “ Rede Nacional para a Conservação e Utilização de Plantas Aromáticas e Medicinais “ e pretende analisar a fileira PAM em Portugal com o objectivo de conhecer os agentes intervenientes nesta fileira, as operações técnicas realizadas, o grau de integração entre agentes, a organização interna e articulação com o exterior. Neste sentido foram efectuados inquéritos a produtores, distribuidores e transformadores de PAM e seus derivados. Relativamente aos produtores interessou-nos saber que espécies produziam, qual o peso da produção PAM na produção total, preços praticados e modalidades de escoamento da produção, nomeadamente a existência de vínculos contratuais a juzante. No sector da distribuição tentou-se analisar as quantidades e preços dos produtos transaccionados bem como as operações físicas e tecnológicas desenvolvidas por este sector e, ainda, a organização dos sistemas de comercialização e distribuição. Com o inquérito aos transformadores pretendia-se obter informações sobre a facilidade de abastecimento em matéria prima, as quantidades e preços das matérias primas e dos produtos transformados e circuitos de comercialização de produtos transformados. O tratamento da informação obtida por inquérito veio corroborar algumas das ideias pré-existentes nomeadamente a fraca organização e profissionalização da fileira PAM e fornecer elementos importantes para o conhecimento e melhoria da fileira PAM em Portugal.INIA

Water integration applied to microalgaebased systems

ABSTRACT: Microalgae-based systems have emerged as a promising solution for sustainable production of food, feed, and biofuels. However, water stress and scarcity are major challenges that limit the viability and scalability of microalgae production. To address this challenge, water integration has been proposed as a means to optimize water use efficiency and reduce the environmental impact of microalgae-based systems. This chapter reviews the current state of knowledge on water integration in microalgae-based systems, with a focus on different types of microalgae cultivation systems, process integration for water optimization, and Life Cycle Assessment (LCA) of microalgae-based systems. The chapter concludes with research gaps and future directions in water integration and LCA of microalgae-based systems.info:eu-repo/semantics/publishedVersio

Professor, I want to be oppressed!” : limit-situations and limit-acts in e professorial habitus

Esse artigo tem por objetivo apresentar e discutir episódio ocorrido no ensino superior em que estudante, tendo estudado a Pedagogia do Oprimido (Freire, 1987), demanda explicitamente a condição de ser oprimida pelo professor. O episódio registrado em diário de campo é analisado sob a ótica dos conceitos de situação-limite, inédito-viável, ambos de Paulo Freire (1992), e o de habitus, este último conceito de Bourdieu (1983). O conceito de habitus é posicionado no texto em perspectiva heurística, sendo denominado habitus professoral, nos termos de Silva (2003). O texto conclui que o pensamento freireano deve ser assumido como utopia sustentada no habitus professoral, expressando a negação do fugaz ou insatisfação momentânea e associado a movimento coletivo pela superação do estado das coisas e condições de existência desumanizadoras. _______________________________________________________________________________ ABSTRACTThe goal of this article is to present and discuss an event occurred in a higher education environment, when a student, having studied Pedagogy of the Oppressed (Paulo Freire), explicitly demands to be oppressed by the professor. The episode, recorded in field notes, is analyzed from the perspective of the concepts of limit-situations and untested feasibility, both by Paulo Freire (1992), and Bourdieu’s (1983) concept of habitus. The concept of habitus is employed in the text in a heuristic perspective, being expanded and qualified as professorial habitus, as defined in Silva (2003). The text concludes that Freire’s thought should be adopted as a utopia sustained by the professorial habitus, expressing the negation of the fugacious or of fleeting dissatisfaction and associated with a collective movement for overcoming the state of things and dehumanized conditions of existence

Inversion for subbottom sound velocity profiles in the deep and shallow ocean

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2005This thesis investigates the application of acoustic measurements in the deep and shallow ocean to infer the sound velocity profile (svp) in the seabed. For the deep water ocean, an exact method based on the Gelfand-Levitan integral equation is evaluated. The input data is the complex plane-wave reflection coefficient estimated from measurements of acoustic pressure in water. We apply the method to experimental data and estimate both the reflection coefficient and the seabed svp. A rigorous inversion scheme is hence applied in a realistic problem. For the shallow ocean, an inverse eigenvalue technique is developed. The input data are the eigenvalues associated with propagating modes, measured as a function of source-receiver range. We investigate the estimation of eigenvalues from acoustic fields measured in laterally varying environments. We also investigate the errors associated with estimating varying modal eigenvalues, analogous to the estimation of time-varying frequencies in multicomponent signals, using time-varying autoregressive (TVAR) methods. We propose and analyze two AR sequential estimators, one for model coefficients, another for the zeros of the AR characteristic polynomial. The decimation of the pressure field defined in a discrete range grid is analyzed as a tool to improve AR estimation. The nonlinear eigenvalue inverse problem of estimating the svp from a sequence of eigenvalues is solved by iterating linearized approximations. The solution to the inverse problem is proposed in the form of a Kalman filter. The resolution and variance of the eigenvalue inverse problem are analyzed in terms of the Cramer-Rao lower bound and the Backus-Gilbert (BG) resolution theory. BG theory is applied to the design of shallow-water experiments. A method is developed to compensate for the Doppler deviation observed in experiments with moving sources.I am grateful for the support of my work provided by the WHOI Academic Programs Office and the Office of Naval Research

Capital structure of medium and large companies in the Portuguese manufacturing industry: the impact of the financial crisis

This study analyses the Capital Structure of Medium and Large companies in the Portuguese Manufacturing industry along the period 2007-2017. This is a particularly interesting period since the Global Financial Crisis deeply affected offer and demand for credit and consequently the Capital Structure of Portuguese firms. In our analysis, we address the following key questions: How do explanatory variables of debt ratios perform along this period? What conclusions can we draw concerning the challenges that decision makers had to face during this period? What are the main differences in the explanatory variables when comparing the Pre-Crisis period (2007-2008) and the Crisis period (2009-2017), where the crisis had its full impact? The research also tries to verify hypotheses elaborated for the explanatory variables according to the main Capital Structure theories – The Trade-Off theory and the Pecking Order theory. The study considers three debt ratios: Total Debt ratio, Short-Term Debt ratio, Long-Term Debt ratio, and six explanatory variables: Size, Profitability, Growth, Asset Structure, Non-Debt Tax Shield and Liquidity. The determinants show a relevant explanatory capacity. Size, Profitability, Asset Structure and Non-Debt Tax Shield are important explaining the Long-Term Debt ratio while Size, Asset Structure and Liquidity are important to explain Short-Term Debt ratio. Total Debt ratio is mostly explained by Profitability and Liquidity. Size, Profitability and Liquidity show relevant explanatory differences for the two periods considered. Although the results are more consistent with the arguments supporting the Pecking Order theory, we also found evidence that supports the arguments behind the Trade-Off theory.O estudo analisa a Estrutura de Capital das Médias e Grandes empresas na indústria Transformadora Portuguesa no período 2007-2017. Neste período, a Crise Financeira Global afetou profundamente a oferta e procura de crédito e consequentemente a Estrutura de Capital das empresas Portuguesas. Abordamos as seguintes questões: Como é que as variáveis explicativas dos rácios de dívida se comportaram? Que conclusões podemos tirar relativamente aos desafios que os responsáveis tiveram que enfrentar? Quais são as principais diferenças entre as variáveis explicativas quando comparando o período Pré-crise (2007-2008) com o período Crise (2009-2017)? A dissertação tenta também verificar as hipóteses elaboradas para as variáveis explicativas, de acordo com as principais teorias da Estrutura de Capital – a teoria de Trade-Off e de Pecking Order. Este estudo considera três rácios de dívida: rácio de Dívida Total, rácio de Dívida de Curto-prazo, rácio de Dívida de Longo-prazo e seis variáveis explicativas: Dimensão, Rentabilidade, Crescimento, Tangibilidade, Custos Fiscalmente Dedutíveis Excluindo Dívida e Liquidez. Os determinantes mostram uma capacidade explicativa relevante. Dimensão, Rentabilidade, Tangibilidade e Custos Fiscalmente Dedutíveis Excluindo Dívida são importantes a explicar o rácio de Dívida de Longo-prazo enquanto que Dimensão, Tangibilidade e Liquidez são importantes a explicar o rácio de Dívida de Curto-prazo. O rácio de Dívida Total é maioritariamente explicado pela Rentabilidade e Liquidez. Dimensão, Rentabilidade e Liquidez apresentam diferenças relevantes para os dois períodos. Apesar dos resultados serem mais consistentes com os argumentos que suportam a teoria Pecking Order, também encontramos evidência que suporta os argumentos por detrás da teoria de Trade-Off

Taming hot-spots in DHT inverted indexes

DHT systems are structured overlay networks capable of using P2P resources as a scalable platform for very large data storage applications. However, their efficiency expects a level of uni- formity in the association of data to index keys that is often not present in inverted indexes. Index data tends to follow non- uniform distributions, often power law distributions, creating in- tense local storage hotspots and network bottlenecks on specific hosts. Current techniques like caching cannot, alone, cope with this issue. We propose a new distributed data structure based on a decen- tralized balanced tree to balance storage data and network load more uniformly across all hosts. The approach is stackable with standard DHTs and ensures that the DHT storage subsystem re- ceives an uniform load by assigning fixed sized, or low variance, blocks

Search optimizations in structured peer-to-peer systems

DHT systems are structured overlay networks capable of using P2P resources as a scalable platform for very large data storage applications. However, their efficiency expects a level of uniformity in the association of data to index keys that is often not present in inverted indexes. Index data tends to follow non-uniform distributions, often power law distributions, creating intense local storage hotspots and network bottlenecks on specific hosts. Current techniques like caching cannot, alone, cope with this issue. We propose a distributed data structure based on a decentralized balanced tree to balance storage data and network load more uniformly across hosts. The results show that the data structure is capable of balancing resources, in particular when performing multiple keyword searches