Cantaloupe melon ( Cucumis melo L.) conservation using hydrocooling

ABSTRACT Maintaining cantaloupe melon at field temperature impairs conservation as it speeds up cell metabolism and transpiration, and, consequently, reduces shelf life. This study aimed to evaluate the conservation of Torreon hybrid cantaloupe using the hydrocooling treatment. Fruits were harvested at the commercial maturity stage (60 days after planting), in the morning, at the Nova California Farm, municipality of Mossoró-RN, in September 2007. One set of fruit was immersed in chilled water at 5 ºC for 5 min, at the packing house, while the remaining set was not hydro cooled. Then, both sets (treated and untreated with hydrocooling) were pre-cooled in air forced tunnels at 7 ºC, until the temperature in the pulp reached 10 ºC. Both fruit sets were stored for 0, 14, 21, 28 and 35 days under modified atmosphere at 3 ± 1 oC and 90 ± 5% RH. After each storage period, the fruits were incubated in an atmosphere-controlled chamber at 20 ± 2 oC and 80 ± 5% de RH, for seven days. The following characteristics were evaluated: external and internal appearance, mass loss, soluble solids, firmness and titrable acidity. The experiment was arranged in a completely randomized split-plot design with four replications of three fruits. The plots consisted of the hydrocooling conditions (with and without fruit soaking in chilled water), and the sub-plots consisted of the storage times (0, 14, 21, 28 and 35 days).The treatment with hydrocooling was efficient in keeping the firmness and soluble solids of the fruits and shortened the pre-cooling time in the cooling tunnel. However, hydrocooling did not increase fruit shelf-life.

Metamorfoses em espelho de água : identidade, perfil, contextos e mudança nas (auto)representações dos professores

RESUMO: Nos últimos trinta anos, em Portugal, ocorreram processos de democratização política e de modernização da sociedade e das instituições, tendo como impulso as vontades nacionais e as mudanças ocorridas no Mundo em globalização, lideradas, no campo da educação, por agentes como a OCDE ou o Banco Mundial, e pela integração de Portugal na União Europeia. À implementação da(s) reforma(s), correspondeu uma mudança de paradigma educativo e organizacional, a criação de uma escola para todos, a emergência de novos alunos e de novos mandatos à Escola, a contingência de novas respostas educativas. Tais reformas constituiram instrumentos de mudança das organizações escolares e do sistema educativo, mas também do que significa ser professor, reformulando o desempenho e a “performatividade” docente (Ball, 2002), induzindo uma nova “identidade social” (Bernstein, 1996 e Dubar, 2006), produzindo novos modos de “fabricação da alma dos professores” (Foucault, 1996). Neste sentido, a autora procurou analisar, numa perspectiva crítica, as representações de professores do Ensino Básico, sobre os mecanismos de (re)configuração das suas identidades/perfis profissionais, recorrendo a uma investigação qualitativa descritiva, que privilegia a análise de conteúdo dos seus discursos sobre o tema, recolhidos segundo a técnica focus group. O estudo indiciou que os alunos são factor de realização, de risco e de mudança do perfil docente, actuando como uma quinta dimensão da (re)construção identitária dos Professores, a par da formação, do associativismo, do Estado e do Mercado, constituindo factor importante a ter em conta nos estudos sobre identidade docente. ABSTRACT: In the past thirty years, in Portugal, radical changes on politics and policies have been occurring, to achive the society and its institutions democratization and modernization, led by national wills and the changes occured in the World, stimulated, in the Education area, by global agencies like OECD, or the World Bank, and the integration of Portugal in the European Union. These reforms are connected to a new educational and organizational paradigm, the creation of a school for all, the emergence of new pupils, new demands to School and teachers, the imperative of new pedagogical solutions for educational problems, and are not only changing instruments in schools and in the educational system, but are also a powerful way to change “what to be a teacher” means, to re-formulate the teaching performance and “performativity” (Ball, 2002), to recompose his/her “social identity” (Bernstein, 1996; Dubar, 2006), or, in Michel Foucault (1996) words, to produce “new ways to manufacture teachers soul”. In this sense, the author intended to analyze, on a critical perspective, the representations of portuguese teachers of basic education (K12), on the mechanisms of (re)configuration of their professional identities/profiles, appealing to a qualitative descriptive research, which privileges the analysis of content of their speeches on the subject, collected according to the focus group technique, what, in its development, was brought near a circle of culture (in the sense of Paulo Freire‟s pedagogy). At least, pupils are the most important references and motivation to teachers changes, reflecting professional satisfaction and well done, but also risk, acting like a fifth dimension of teachers identity (re)construction, together with training, associative involvement, State and Market, and they must be considered on teatching identity studies.

Strategy Lab Experiences: Bathtub Dynamics

As the world changes ever faster, managers increasingly recognize the complexity and turbulence of the business systems in which they are embedded. The management problems are dynamic, while the dynamic complexity comes frequently from few variables with circle and delays interrelations that introduce nonlinearities.The present paper describes a research conducted in Portugal with two different groups - one, academic; the other, professional - where we explored the subjects’ understanding of some basic systems thinking concepts such as stock-flow relationship, feedback processes and time delays.

Representações coloniais no feminino: o oriente de Isabel Tamagnini

O Diário de uma Viagem a Timor (1882-1883) descreve o itinerário de Isabel Pinto da França Tamagnini entre Singapura e Díli. O Diário oferece uma representação peculiar da cultura asiática e das suas mulheres, através do olhar de uma europeia cuja formação e mundividência em pouco ultrapassavam a esfera doméstica e religiosa. A escrita de Tamagnini reflecte a sensibilidade de um estrato privilegiado da sociedade, que considerava a escrita feminina como um passatempo tolerável de senhoras prendadas. Logo nas primeiras linhas do Diário, Tamagnini afirma claramente que a sua produção e recepção devem restringir-se ao círculo da família e amigos, pois ela mesma o considera um texto recreativo e impressionista. Mas é precisamente esta característica que faz do Diário de Tamagnini um documento da sociedade colonial portuguesa de finais do século xix. Tamagnini compõe uma representação subjectiva de uma realidade ‘exótica’ e dos seus actores, recordando a noção de ‘orientalismo’ de Edward Said. O olhar de Tamagnini é dominado pela pertença a uma elite etnocêntrica e produz um texto crítico, simultaneamente confessional e moralizador. Tamagnini parece viajar através de espaços de socialização aristocrática, mais do que através de geografias e culturas. Mas o espaço urbano é progressivamente substituído pelo território ‘selvagem’, à medida que a viagem se aproxima do destino. E aqui o Diário funciona como texto paradigmático, se bem que por vezes irreverente, de uma representação etnocêntrica da colónia, dos agentes coloniais e ‘seus’ colonizados, com especial atenção à descrição dos ‘tipos’ femininos observados ao longo desta Viagem a Timor.

Evaluation of intermolecular interactions in thioxanthone derivatives: substituent effect on crystal diversity

A family of 9H-thioxanthen-9-one derivatives and two precursors, 2-[(4-bromophenyl) sulfanyl]-5-nitrobenzoic acid and 2-[(4-aminophenyl) sulfanyl]-5-nitrobenzoic acid, were synthesized and studied in order to assess the role of the different substituent groups in determining the supramolecular motifs. From our results we can conclude that Etter's rules are obeyed: whenever present the -COOH head to head strong hydrogen bonding dimer, R-2(2)(8) synthon, prevails as the dominant interaction. As for -NH2, the best donor when present also follows the expected hierarchy, an NH center dot center dot center dot O(COOH) was formed in the acid precursor (2) and an NH center dot center dot center dot O(C=O) in the thioxanthone (4). The main role played by weaker hydrogen bonds such as CH center dot center dot center dot O, and other intermolecular interactions, pi-pi and Br center dot center dot center dot O, as well as the geometric restraints of packing patterns shows the energetic interplay governing crystal packing. A common feature is the relation between the p-p stacking and the unit cell dimensions. A new synthon notation, R`, introduced in this paper, refers to the possibility of accounting for intra- and intermolecular interactions into recognizable and recurring aggregate patterns.

Dynamic power- and failure-aware cloud resources allocation for Sets of independent tasks

Cloud computing is increasingly being adopted in different scenarios, like social networking, business applications, scientific experiments, etc. Relying in virtualization technology, the construction of these computing environments targets improvements in the infrastructure, such as power-efficiency and fulfillment of users’ SLA specifications. The methodology usually applied is packing all the virtual machines on the proper physical servers. However, failure occurrences in these networked computing systems can induce substantial negative impact on system performance, deviating the system from ours initial objectives. In this work, we propose adapted algorithms to dynamically map virtual machines to physical hosts, in order to improve cloud infrastructure power-efficiency, with low impact on users’ required performance. Our decision making algorithms leverage proactive fault-tolerance techniques to deal with systems failures, allied with virtual machine technology to share nodes resources in an accurately and controlled manner. The results indicate that our algorithms perform better targeting power-efficiency and SLA fulfillment, in face of cloud infrastructure failures.

Inserção no mercado de trabalho de jovens com baixas qualificações escolares: o caso de um bairro social do concelho de Ribeira Grande

Dissertação de Mestrado, Sociologia, 31 de Março de 2014, Universidade dos Açores.

HACCP numa indústria corticeira: implementação, identificação de pontos críticos e proposta de acções correctivas

Mestrado em Engenharia Química

Biaxial Nematic Order in the Hard-boomerang Fluid

We consider a fluid of hard boomerangs, each composed of two hard spherocylinders joined at their ends at an angle Psi. The resulting particle is nonconvex and biaxial. The occurence of nematic order in such a system has been investigated using Straley's theory, which is a simplificaton of Onsager's second-virial treatment of long hard rods, and by bifurcation analysis. The excluded volume of two hard boomerangs has been approximated by the sum of excluded volumes of pairs of constituent spherocylinders, and the angle-dependent second-virial coefficient has been replaced by a low-order interpolating function. At the so-called Landau point, Psi(Landau)approximate to 107.4 degrees, the fluid undergoes a continuous transition from the isotropic to a biaxial nematic (B) phase. For Psi not equal Psi(Landau) ordering is via a first-order transition into a rod-like uniaxial nematic phase (N(+)) if Psi > Psi(Landau), or a plate-like uniaxial nematic (N(-)) phase if Psi < Psi(Landau). The B phase is separated from the N(+) and N(-) phases by two lines of continuous transitions meeting at the Landau point. This topology of the phase diagram is in agreement with previous studies of spheroplatelets and biaxial ellipsoids. We have checked the accuracy of our theory by performing numerical calculations of the angle-dependent second virial coefficient, which yields Psi(Landau)approximate to 110 degrees for very long rods, and Psi(Landau)approximate to 90 degrees for short rods. In the latter case, the I-N transitions occur at unphysically high packing fractions, reflecting the inappropriateness of the second-virial approximation in this limit.

Shear-induced lamellar phase of an ionic liquid crystal at room temperature

The phase behaviour of a number of N-alkylimidazolium salts was studied using polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction. Two of these compounds exhibit lamellar mesophases at temperatures above 50 degrees C. In these systems, the liquid crystalline behaviour may be induced at room temperature by shear. Sheared films of these materials, observed between crossed polarisers, have a morphology that is typical of (wet) liquid foams: they partition into dark domains separated by brighter (birefringent) walls, which are approximately arcs of circle and meet at "Plateau borders" with three or more sides. Where walls meet three at a time, they do so at approximately 120 degrees angles. These patterns coarsen with time and both T1 and T2 processes have been observed, as in foams. The time evolution of domains is also consistent with von Neumann's law. We conjecture that the bright walls are regions of high concentration of defects produced by shear, and that the system is dominated by the interfacial tension between these walls and the uniform domains. The control of self-organised monodomains, as observed in these systems, is expected to play an important role in potential applications.

How foam-like is the shear-induced lamellar phase of an ionic liquid crystal?

Philosophical Magazine Letters Volume 88, Issue 9-10, 2008 Special Issue: Solid and Liquid Foams. In commemoration of Manuel Amaral Fortes

Assigning real-time tasks on heterogeneous multiprocessors with two unrelated types of processors

A preliminary version of this paper appeared in Proceedings of the 31st IEEE Real-Time Systems Symposium, 2010, pp. 239–248.

In-situ X-ray diffraction studies during growth of Ni-Ti shape memory alloy films and their complementary ex-situ characterization

Shape Memory Alloy (SMA) Ni-Ti films have attracted much interest as functional and smart materials due to their unique properties. However, there are still important issues unresolved like formation of film texture and its control as well as substrate effects. Thus, the main challenge is not only the control of the microstructure, including stoichiometry and precipitates, but also the identification and control of the preferential orientation since it is a crucial factor in determining the shape memory behaviour. The aim of this PhD thesis is to study the optimisation of the deposition conditions of films of Ni-Ti in order to obtain the material fully crystallized at the end of the deposition, and to establish a clear relationship between the substrates and texture development. In order to achieve this objective, a two-magnetron sputter deposition chamber has been used allowing to heat and to apply a bias voltage to the substrate. It can be mounted into the six-circle diffractometer of the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, enabling an in-situ characterization by X-ray diffraction(XRD) of the films during their growth and annealing. The in-situ studies enable us to identify the different steps of the structural evolution during deposition with a set of parameters as well as to evaluate the effect of changing parameters on the structural characteristics of the deposited film. Besides the in-situ studies, other complementary ex-situ characterization techniques such as XRD at a laboratory source, Rutherford backscattering spectroscopy(RBS), Auger electron spectroscopy (AES), cross-sectional transmission electron microscopy (X-TEM), scanning electron microscopy (SEM), and electrical resistivity (ER) measurements during temperature cycling have been used for a fine structural characterization. In this study, mainly naturally and thermally oxidized Si(100) substrates, TiN buffer layers with different thicknesses (i.e. the TiN topmost layer crystallographic orientation is thickness dependent) and MgO(100) single crystals were used as substrates. The chosen experimental procedure led to a controlled composition and preferential orientation of the films. The type of substrate plays an important role for the texture of the sputtered Ni-Ti films and according to the ER results, the distinct crystallographic orientations of the Ni-Ti films influence their phase transformation characteristics.

The utilization bound of static-priority preemptive partitioned multiprocessor scheduling is 50%

This paper studies static-priority preemptive scheduling on a multiprocessor using partitioned scheduling. We propose a new scheduling algorithm and prove that if the proposed algorithm is used and if less than 50% of the capacity is requested then all deadlines are met. It is known that for every static-priority multiprocessor scheduling algorithm, there is a task set that misses a deadline although the requested capacity is arbitrary close to 50%.

Chiroptical and emissive properties of a calix[4]arene-containing chiral poly (P-phenylene ethynylene) with enantioselective recognition ability

Supramolecular chirality was achieved in solutions and thin films of a calixarene-containing chiral aryleneethynylene copolymer. The observed chiroptical activity, which is primarily allied with the formation of aggregates of high molecular weight polymer chains, is the result of a combination of intrachain and interchain effects. The former arises by the adoption of an induced helix-sense by the polymer main-chain while the latter comes from the exciton coupling of aromatic backbone transitions. The co-existence of bulky bis-calixKlarene units and chiral side-chains on the polymer skeleton prevents efficient pi-stacking of neighbouring chains, keeping the chiral assembly highly emissive. In contrast, for a model polymer lacking calixarene moieties, the chiroptical activity is dominated by strong interchain exciton couplings as a result of more favourable packing of polymer chains, leading to a marked decrease of photoluminescence in the aggregate state. The enantiomeric recognition abilities of both polymers towards (R)- and (S)-alpha-methylbenzylamine were examined. It was found that a significant enantiodiscrimination is exhibited by the calixarene-based polymer in the aggregate state.