Manutenção do solo em olivais de Trás-os-Montes

O artigo discute alternativas de manutenção do solo em olival de sequeir

Regime mapping and the role of the intermediate region in wall-coated microreactors

Operation of a wall-coated microreactor can occur in several mass transfer-reaction regimes. We define these regimes analytically in several planes of a multi-parametric map, taking into account the different degrees of concentration profile development, as well as the influence of non-unity orders of reaction and reactant inhibition in the kinetic law. It was found that the regions where conversion can be calculated from simplified mass transfer models are not discriminated by common results for entrance-length. We also illustrate the trade-offs that exist across this operating map concerning the catalyst design (costs associated with loading and volume) and overall system performance (evaluated in terms of reactant conversion, flow efficiency and microreactor effectiveness). It is shown that under certain conditions, the existence of moderate mass transfer resistance can be advantageous (even if internal limitations cannot be avoided), clarifying the role of the intermediate transport-reaction region

A poda não aumenta a produção da oliveira

A poda tem sido vista como um meio indispensável de melhorar a produção do olival. A primeira referência escrita à importância da poda em olival terá sido de Columella (nascido em 4 a. C. ), um dos agrónomos reconhecidos do império romano. Columella citava um provérbio já antigo à época que dizia: quem lavra o olival pede-lhe fruto; quem o estruma pede-lhe com muita insistência; quem o poda obriga-o a dar azeitona (Foster e Heffner, 1941. ). Os autores modernos que têm escrito sobre poda são também, de uma maneira geral, unânimes na opinião de que a poda é determinante para aumentar e regular as produções (Gucci e Cantini, 2000; Tombesi e Tombesi, 2007; Vossen e Devarenne, 2007; Garcia-Ortíz et al., 2008; Gregoriou 2009; Therios, 2009).info:eu-repo/semantics/publishedVersio

New Features to Look at Natural Phenomena

Proceeding of the 3rd International Conference on Fractional Systems and Signals, at Ghent, BelgiumThe paper focuses the patterns seen in the number of victims from natural catastrophic phenomena. We consider the number of victims of storms from 1900 up to 2013 in 11 countries and study the distributions of the events with more than 30 deadly victims. The similarities among events across the 11 countries are analysed using agglomerative hierarchical clustering. Countries belonging to the same cluster are similar with respect to fatalities. Power laws and hierarchical clustering provide comparable results for the data. Future work is needed in order to explore these numerical tools in more countries and in victims of other hazards

A review of power laws in real life phenomena

Power law distributions, also known as heavy tail distributions, model distinct real life phenomena in the areas of biology, demography, computer science, economics, information theory, language, and astronomy, amongst others. In this paper, it is presented a review of the literature having in mind applications and possible explanations for the use of power laws in real phenomena. We also unravel some controversies around power laws

Efeito da manutenção do solo na produção e crescimento das árvores em olival de sequeiro

Durante oito anos consecutivos estudou-se o efeito de sistemas de manutenção do solo em dois olivais de sequeiro localizados nas proximidades de Bragança e Mirandela em Trás-os-Montes. O olival de Bragança, que estava gerido com uma pastagem natural em 2001, foi dividido em três parcelas onde se implementaram os sistemas de manutenção do solo: pastagem; mobilização; e herbicida não selectivo aplicado em Abril. O olival de Mirandela, que estava gerido com mobilização em 2001 recebeu os tratamentos: mobilização; herbicida não selectivo; e herbicida com componente de acção residual aplicado no fim de Fevereiro

Double power laws, fractals and self-similarity

Power law (PL) distributions have been largely reported in the modeling of distinct real phenomena and have been associated with fractal structures and self-similar systems. In this paper, we analyze real data that follows a PL and a double PL behavior and verify the relation between the PL coefficient and the capacity dimension of known fractals. It is to be proved a method that translates PLs coefficients into capacity dimension of fractals of any real data

Design Concepts for Peel-Dominant Adhesive Joints in Aeronautic Applications

The adhesive bonding technique is employed from the aeronautical/aerospace industry to current house products. To comply with the requirements of distinct applications, different joint configurations are available to the designer. While single-lap joints (SLJ) are the most common in application and research, double-lap joints, scarf joints and T-joints find specific applications. T-joints are seldom studied in the literature, but these are used, for instance, in aircraft to bond the stiffener beams to the skin, or in the cars between the B-pillar and the rocker. Due to the high stress concentrations, T-joints often fail under average stresses much lower than the adhesive strengths, giving rise to the necessity for proper design and strength improvement methodologies. This work initially aims to validate the cohesive zone modelling (CZM) technique with experiments, and then use it to numerically evaluate and optimize the performance of T-joints subjected to peel loads. CZM is nowadays regarded as the most powerful strength prediction tool for adhesive joints, and can be a valuable tool to improve T-joints. Different features are addressed for a complete analysis: adhesive type, geometrical parameters, dual-adhesive technique for strength improvement, and composite joints. The evaluated geometrical parameters are the base adherend thickness (a), T-part thickness (t), overlap or bonding length (l) and curvature radius (r). As a result of this work, the model was successfully validated, and clear design guidelines were provided to define the ideal geometric and material (adhesive) conditions for best performance

A poda (limpa) do olival tradicional

A poda do olival é uma prática ancestral, ainda que a forma de intervir nas árvores tenha evoluído ao longo dos tempos e varie substancialmente entre diferentes regiões produtoras. Apesar da poda ser uma prática generalizada entre olivicultores nem sempre se sabe muito bem porque se poda e, frequentemente, discute- -se e duvida-se da melhor forma de podar. Tende ainda a avaliar-se a qualidade do podador pela estética com que deixa a árvore, tal como acontece com os podadores de árvores e arbustos ornamentais dos jardins públicos e privados. Aliás, a poda foi no passado um trabalho especializado, só executada por trabalhadores experimentados. Este aspeto tem perdido significado pela extrema falta de mão-de-obra no meio rural que obriga a que todas as mãos disponíveis possam ser chamadas a podar de forma mais ou menos independente da sua experiência.info:eu-repo/semantics/publishedVersio