932 resultados para vegetable oil


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We evaluated the effectiveness of diode laser trans-scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in nine patients having raised IOP following use of silicone oil (SO) for retinal detachment (RD) surgery in a retrospective observational case series. Diode laser TSCPC was applied at a power setting of 1.75 to 2.5 watts, for two sec with a maximum of 30 applications. The patients were followed up for 40 to 312 weeks. The mean pre-laser IOP was 32.06 mm Hg (SD 7.32). The mean post-laser IOP at one month, three months and six months was 17.89 mm Hg (SD 8.23), 21.89 mm Hg (SD 8.16) and 21.67 mm Hg (SD 7.55) respectively. The final IOP (at the last follow-up) was 19.56 mm Hg (SD 7.85) (P=0.021). Seven of them had undergone SO removal. In our observation, effectiveness of TSCPC in long-term control of SO-induced ocular hypertension was limited as compared to short-term control of IOP.

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Globalisation has led to a shift in world order with the rise of the corporate non-state actor. This rise has led to an assumption that Multi-National Corporations (MNCs) must assume responsibilities beyond profit maximisation for shareholders. With the rise of the MNC as a corporate non-state actor there have been discussions around the role of business with regard to human rights.

This article looks at the case of oil extraction in Nigeria. Focussing on the historical dependency of Nigeria and the evolution of the state into a resource-dependent country, it looks at the limitations of existing human rights obligations as they relate to business. This article proposes that corporate social responsibility (CSR) policies of MNCs can act as a preliminary stage in the quest for wider human rights protections. It is in motivating MNCs to design and implement effective CSR policies in dependent states like Nigeria, that the challenge lies.

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BACKGROUND AND AIM: Retinal vessel abnormalities are associated with cardiovascular disease (CVD) risk. To date, there are no trials investigating the effect of dietary factors on the retinal microvasculature. This study examined the dose response effect of fruit and vegetable (FV) intake on retinal vessel caliber in overweight adults at high CVD risk.

METHODS AND RESULTS: Following a 4 week washout period, participants were randomized to consume either 2 or 4 or 7 portions of FV daily for 12 weeks. Retinal vessel caliber was measured at baseline and post-intervention. A total of 62 participants completed the study. Self-reported FV intake indicated good compliance with the intervention, with serum concentrations of zeaxanthin and lutein increasing significantly across the groups in a dose-dependent manner (P for trend < 0.05). There were no significant changes in body composition, 24-h ambulatory blood pressure or fasting blood lipid profiles in response to the FV intervention. Increasing age was a significant determinant of wider retinal venules (P = 0.004) whereas baseline systolic blood pressure was a significant determinant of narrower retinal arterioles (P = 0.03). Overall, there was no evidence of any short-term dose-response effect of FV intake on retinal vessel caliber (CRAE (P = 0.92) or CRVE (P = 0.42)).

CONCLUSIONS: This study demonstrated no effect of increasing FV intake on retinal vessel caliber in overweight adults at high risk of developing primary CVD.

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La presente tesis está enfocada al análisis estrictamente de la combustión de un quemador de aceite (fuel oil # 6) para un caldero degeneración de vapor de agua de 300 BHP de potencia, el cual para su atomización del combustible usa aire comprimido a 40 PSI de presión y una temperatura que va desde los 15 ºC hasta los 150 ºC según nuestra particular implementación del sistema de calentamiento. El desarrollo emprende desde un marco teórico de los quemadores, sus partes consistentes, el combustible, clasificación, propiedades y características. De manera muy particular nos centramos en el proceso de combustión por cuanto es la parte medular del presente documento, así como generalidades, fundamentos, los elementos y productos, los comportamientos de éstos en la combustión. Además enfocamos conceptos básicos de tipos de combustión. En una forma analítica se establece la ecuación general de la combustión, una evaluación de la energía liberada en el proceso, en base al volumen y composición de lso productos que intervienne en la misma, yademás de la forma de cómo calibrar el equipo o sistema para obtener combustion lo más eficiente posible, sea produciendo energía calorífica más alta posible con el mínimo requerido posible de combustión. Se enfoca en el presente documento un análisis de las relaciones termodinámicas en la combustión como: la entalpía de los elementos como de los productos, las entalpías de formación de los mismos, le energía interna de los gases productos, y de la entropía o irreversibilidades del proceso total de combustión. La determinación del calor generado más la temperatura de llama adiabática son temas fundamentales en el desarrollo del tema, es por lo tanto parte importante del documento. Ya en el análisis experimental se parte del hecho de tener instalado a modo de prueba un intercambiador de calor para calentar el aire de atomización en uncaldero específico, esto es en un caldero de 300 BHP de potencia, de generación de vapor de agua de 100 PSI de presión, en la empresa Tejidos Pintex, y el análisis va enfocado a determinar la efectividad o no de calentar el aire de atomización, y de ser así cuantificar los beneficios del sistema.

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Os biocombustíveis têm estado na linha da frente das políticas energéticas mundiais visto que as suas vantagens conseguem colmatar as incertezas e resolver alguns dos problemas associados aos combustíveis fósseis. O biodiesel tem provado ser um combustível muito fiável, alternativo ao petrodiesel. É uma mistura de ésteres alquílicos produzidos a partir de óleos vegetais e gorduras animais através de uma reacção de transesterificação. Como combustível, o biodiesel é economicamente viável, socialmente responsável, tecnicamente compatível e ambientalmente amigável. O principal desafio associado ao seu desenvolvimento tem a ver com a escolha de matéria-prima para a sua produção. Nos países do terceiro mundo, óleos alimentares são mais importantes para alimentar pessoas do que fazer funcionar carros. Esta tese tem como objectivos produzir/processar biodiesel a partir de recursos endógenos de Timor-Leste e medir/prever as propriedades termodinâmicas do biodiesel, a partir das dos esteres alquílicos. A síntese do biodiesel a partir dos óleos de Aleurites moluccana, Jatropha curcas e borras de café foram aqui estudados. As propriedades termodinâmicas como densidade, viscosidade, tensão superficial, volatilidade e velocidade do som também foram medidas e estimadas usando modelos preditivos disponíveis na literatura, incluindo as equações de estado CPA e soft-SAFT. Timor-Leste é um país muito rico em recursos naturais, mas a maioria da população ainda vive na pobreza e na privação de acesso a serviços básicos e condições de vida decentes. A exploração de petróleo e gás no mar de Timor tem sido controlado pelo Fundo Petrolífero. O país ainda carece de electricidade e combustíveis que são cruciais para materializar as políticas de redução da pobreza. Como solução, o governo timorense criou recentemente o Plano Estratégico de Desenvolvimento a 20 anos cujas prioridades incluem trazer o desenvolvimento do petróleo do mar para a costa sul de Timor-Leste e desenvolver as energias renováveis. É neste último contexto que o biodiesel se insere. O seu desenvolvimento no país poderá ser uma solução para o fornecimento de electricidade, a criação de empregos e sobretudo o combate contra a pobreza e a privação. Para ser usado como combustível, no entanto, o biodiesel deve possuir propriedades termodinâmicas coerentes com as especificadas nas normas da ASTM D6751 (nos Estados Unidos) ou EN 14214 (na Europa) para garantir uma adequada ignição, atomização e combustão do biodiesel no motor.

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The ability of microorganisms to use oil hydrocarbons as a source of carbon and energy is crucial for environmental oil detoxification. However, there is still a lack of knowledge on fundamental aspects of this process on specific habitats and under different climate scenarios. In the first phase of this work, the culturable fraction of the oil hydrocarbon (OH) degrading bacteria from the sea surface microlayer (SML) of the estuarine system Ria de Aveiro was characterized. In the second phase, the impact of oil contamination on the active bacterial community was studied under climate change scenarios. Pseudomonas emerged as the prevailing genera among OH degrading bacteria in the SML. Moreover, culture-independent methods revealed that the relative abundance and diversity of Gammaproteobacteria, in which Pseudomonas is included, varies along an estuarine gradient of contamination. In order to access the impact of oil contamination on microbial communities under climate change scenarios, an experimental life support system for microcosm experiments (ELLS) was developed and validated for simulation of climate change effects on microbial communities. With the ELSS it is possible to simulate, in controlled conditions, fundamental parameters of the dynamics of coastal and estuarine systems while maintaining community structure in terms of the abundance of the most relevant members of the indigenous bacterial community. A microcosm experiment in which the independent and combined impact of ultraviolet radiation, ocean acidification and oil contamination on microbial communities was conducted. The impact on bacterial communities was accessed with a 16S RNA (cDNA) based barcode pyrosequencing approach. There was a drastic decrease of Desulfobacterales relative abundance after oil contamination under the reduced pH value estimated for 2100, when compared to present values. Since members of this order are known OH degraders, such a significant decrease may have consequences on OH detoxification of contaminated environments under the pH levels of the ocean expected for the future. Metagenome predictions based on the 16S RNA database indicated that several degradation pathways of OH could be affected under oil contamination and reduced water pH. Taken together, the results from this work bring new information on the dynamics of OH degrading bacteria in coastal and estuarine environments under present and future climate scenarios.

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O transporte marítimo e o principal meio de transporte de mercadorias em todo o mundo. Combustíveis e produtos petrolíferos representam grande parte das mercadorias transportadas por via marítima. Sendo Cabo Verde um arquipelago o transporte por mar desempenha um papel de grande relevância na economia do país. Consideramos o problema da distribuicao de combustíveis em Cabo Verde, onde uma companhia e responsavel por coordenar a distribuicao de produtos petrolíferos com a gestão dos respetivos níveis armazenados em cada porto, de modo a satisfazer a procura dos varios produtos. O objetivo consiste em determinar políticas de distribuicão de combustíveis que minimizam o custo total de distribuiçao (transporte e operacões) enquanto os n íveis de armazenamento sao mantidos nos n íveis desejados. Por conveniencia, de acordo com o planeamento temporal, o prob¬lema e divido em dois sub-problemas interligados. Um de curto prazo e outro de medio prazo. Para o problema de curto prazo sao discutidos modelos matemáticos de programacao inteira mista, que consideram simultaneamente uma medicao temporal cont ínua e uma discreta de modo a modelar multiplas janelas temporais e taxas de consumo que variam diariamente. Os modelos sao fortalecidos com a inclusão de desigualdades validas. O problema e então resolvido usando um "software" comercial. Para o problema de medio prazo sao inicialmente discutidos e comparados varios modelos de programacao inteira mista para um horizonte temporal curto assumindo agora uma taxa de consumo constante, e sao introduzidas novas desigualdades validas. Com base no modelo escolhido sao compara¬das estrategias heurísticas que combinam três heur ísticas bem conhecidas: "Rolling Horizon", "Feasibility Pump" e "Local Branching", de modo a gerar boas soluçoes admissíveis para planeamentos com horizontes temporais de varios meses. Finalmente, de modo a lidar com situaçoes imprevistas, mas impor¬tantes no transporte marítimo, como as mas condicões meteorológicas e congestionamento dos portos, apresentamos um modelo estocastico para um problema de curto prazo, onde os tempos de viagens e os tempos de espera nos portos sao aleatórios. O problema e formulado como um modelo em duas etapas, onde na primeira etapa sao tomadas as decisões relativas as rotas do navio e quantidades a carregar e descarregar e na segunda etapa (designada por sub-problema) sao consideradas as decisoes (com recurso) relativas ao escalonamento das operacões. O problema e resolvido por um metodo de decomposto que usa um algoritmo eficiente para separar as desigualdades violadas no sub-problema.

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Salt marshes are highly productive intertidal habitats that serve as nursery grounds for many commercially and economically important species. Because of their location and physical and biological characteristics, salt marshes are considered to be particularly vulnerable to anthropogenic inputs of oil hydrocarbons. Sediment contamination with oil is especially dangerous for salt marsh vegetation, since low molecular weight aromatic hydrocarbons can affect plants at all stages of development. However, the use of vegetation for bioremediation (phytoremediation), by removal or sequestration of contaminants, has been intensively studied. Phytoremediation is an efficient, inexpensive and environmental friendly approach for the removal of aromatic hydrocarbons, through direct incorporation by the plant and by the intervention of degrading microbial populations in the rhizosphere (microbe-assisted phytoremediation). Rhizosphere microbial communities are enriched in important catabolic genotypes for degradation of oil hydrocarbons (OH) which may have a potential for detoxification of the sediment surrounding the roots. In addition, since rhizosphere bacterial populations may also internalize into plant tissues (endophytes), rhizocompetent AH degrading populations may be important for in planta AH degradation and detoxification. The present study involved field work and microcosms experiments aiming the characterization of relevant plant-microbe interactions in oilimpacted salt marshes and the understanding of the effect of rhizosphere and endosphere bacteria in the role of salt marsh plants as potential phytoremediation agents. In the field approach, molecular tools were used to assess how plant species- and OH pollution affect sediment bacterial composition [bulk sediment and sediment surrounding the roots (rhizosphere) of Halimione portulacoides and Sarcocornia perennis subsp. perennis] in a temperate estuary (Ria de Aveiro, Portugal) chronically exposed to OH pollution. In addition, the 16S rRNA gene sequences retrieved in this study were used to generate in silico metagenomes and to evaluate the distribution of potential bacterial traits in different microhabitats. Moreover, a combination of culture-dependent and -independent approaches was used to investigate the effect of oil hydrocarbons contamination on the structure and function of endophytic bacterial communities of salt marsh plants.Root systems of H. portulacoides and S. perennis subsp. perennis appear to be able to exert a strong influence on bacterial composition and in silico metagenome analysis showed enrichment of genes involved in the process of polycyclic aromatic hydrocarbon (PAH) degradation in the rhizosphere of halophyte plants. The culturable fraction of endophytic degraders was essentially closely related to known OH-degrading Pseudomonas species and endophytic communities revealed sitespecific effects related to the level of OH contamination in the sediment. In order to determine the effects of oil contamination on plant condition and on the responses in terms of structure and function of the bacterial community associated with plant roots (rhizosphere, endosphere), a microcosms approach was set up. The salt marsh plant Halimione portulacoides was inoculated with a previous isolated Pseudomonas sp. endophytic degrader and the 2-methylnaphthalene was used as model PAH contaminant. The results showed that H. portulacoides health and growth were not affected by the contamination with the tested concentration. Moreover, the decrease of 2-methylnaphthalene at the end of experiment, can suggest that H. portulacoides can be considered as a potential plant for future uses in phytoremedition approaches of contaminated salt marsh. The acceleration of hydrocarbon degradation by inoculation of the plants with the hydrocarbon-degrading Pseudomonas sp. could not, however, be demonstrated, although the effects of inoculation on the structure of the endophytic community observed at the end of the experiment indicate that the strain may be an efficient colonizer of H. portulacoides roots. The results obtained in this work suggest that H. portulacoides tolerates moderate concentrations of 2-methylnaphthalene and can be regarded as a promising agent for phytoremedition approaches in salt marshes contaminated with oil hydrocarbons. Plant/microbe interactions may have an important role in the degradation process, as plants support a diverse endophytic bacterial community, enriched in genetic factors (genes and plasmids) for hydrocarbon degradation.

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Gilthead seabream is the most important farmed species in the Mediterranean, and knowledge on how common farming practices impact its quality is limited. As such, this Thesis aimed to evaluate how gilthead seabream flesh quality is affected by some of these practices. In Chapter 2, the influence of nutritional factors was evaluated, specifically the high replacement of traditional marine-derived ingredients, both fishmeal and fish oil, with vegetable sources. We have seen that the vegetable-based diets tested did not greatly impact seabream flesh quality, although some alterations were seen in the fatty acid profile of the muscle. However, and despite having caused no alterations in flesh texture, vegetable ingredients reduced the amount of sulphated glycosaminoglycans in the extracellular matrix, affected muscle pH and reduced the activity of proteolytic enzymes. Throughout this Thesis, we measured for the first time the activity of proteolytic enzymes in seabream muscle, and cathepsin B was found to play a pivotal role in post-mortem muscle degradation. In Chapter 3, we evaluated the effect of harvesting and slaughter stress on seabream quality, and contrary to what is seen in most farmed species, our results show that gilthead seabream muscle structure is highly resistant to changes caused by stressful events. Nonetheless, considering that welfare is an increasingly important quality criterion, the use of a zero-withdrawal anaesthetic as a rested harvest technique or even slaughter method could prove valuable to the industry. In Chapter 4, we used maslinic acid as a dietary supplement, to modulate the muscle’s energetic status pre-mortem. As a finishing strategy, maslinic acid failed to increase levels of glycogen and ATP in the muscle. However, supplementation resulted in higher muscle fibre diameter and lower cathepsin B activity, and maslinic acid is likely to be useful to promote growth in this species. In general our Thesis has generated new knowledge to a major challenge facing the aquaculture industry, which is to find a compromise between the trends towards intensive rearing and consumer demand for healthy, high quality seafood being ethically acceptable and having a low impact on the environment.

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Com o crescimento económico e populacional, as necessidades energéticas globais aumentam diariamente. Juntamente com a percepção de que os combustíveis fósseis são finitos e com uma progressiva consciência ambiental, os biocombustíveis são vistos como a alternativa a seguir. A produção de biodiesel a partir da transesterificação de óleos vegetais aumenta a deflorestação e o custo de bens alimentares. Como alternativa, surgem os óleos de origem microbiana – single cell oil (SCO) - acumulados principalmente como triacilgliceróis, a mesma forma dos óleos vegetais, podendo ser utilizados para biodiesel ou como lípidos de alto valor acrescentado. Contudo, a utilização de microrganismos para síntese de lípidos está limitada pelos custos associados ao processo de produção. Este bioprocesso torna-se economicamente mais favorável quando resíduos obtidos a baixo custo são utilizados como fonte de carbono. Assim, o objectivo deste trabalho foi estudar a possibilidade de utilização de subprodutos de diversas indústrias (glicerol bruto e banha de porco) e glicerol puro na produção de SCO, utilizando a levedura Yarrowia lipolytica. Foram realizados ensaios em batch em matraz de 500 mL, matraz de 1000 mL e biorreator de 2 L, de modo a estudar qual o melhor substrato e concentração para produção de SCO. Verificou-se que a banha é o substrato mais eficaz para a acumulação de gordura pela estirpe Y. lipolytica W29, seguida do glicerol bruto, enquanto o glicerol puro mostrou ser a fonte de carbono menos adequada. Encontrou-se um intervalo de concentração de glicerol bruto para produção de SCO, enquanto que a concentração de banha no meio não afeta a acumulação de gordura pelas células. Os ácidos gordos preferencialmente acumulados pelas células em meio com banha e glicerol bruto foram o ácido oleico e o linoleico, respetivamente. Nos meios com glicerol puro e bruto observou-se a produção de ácido cítrico, o que não se verificou em meio com banha.

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Tese de doutoramento, Ciências do Mar, da Terra e do Ambiente (Modelação), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014

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The Malaysian palm oil industry is well known for the social, environmental and sustainability challenges associated with its rapid growth over the past ten years. Technologies exist to reduce the conflict between national development aims of economic uplift for the rural poor, on the one hand, and ecological conservation, on the other hand, by raising yields and incomes from areas already under cultivation. But the uptake of these technologies has been slow, particularly in the smallholder sector. In this paper we explore the societal and institutional challenges that influence the investment and innovation decisions of micro and small enterprise (MSE) palm oil smallholders in Sabah, Malaysia. Based on interviews with 38 smallholders, we identify a number of factors that reduce the smallholders' propensity to invest in more sustainable practices. We discuss why more effective practices and innovations are not being adopted using the concepts of, firstly, institutional logics to explore the internal dynamics of smallholder production systems, including attitudes to sustainability and innovation; and, secondly, institutional context to explore the pressures the smallholders face, including problems of access to land, labour, capital, knowledge and technical resources. These factors include limited access to global market information, corruption and uncertainties of legal title, weak economic status and social exclusion. In discussing these factors we seek to contribute to wider theoretical debates about the factors that block innovation and investment in business improvements in marginal regions and in marginalised groups.

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The present paper shows preliminary results of an ongoing project which one of the goals is to investigate the viability of using waste FCC catalyst (wFCC), originated from Portuguese oil refinery, to produce low carbon blended cements. For this purpose, four blended cements were produced by substituting cement CEM I 42.5R up to 20% (w/w) by waste FCC catalyst. Initial and final setting times, consistency of standard paste, soundness and compressive strengths after 2, 7 and 28 days were measured. It was observed that the wFCC blended cements developed similar strength, at 28 days, compared to the reference cement, CEM I 42.5R. Moreover, cements with waste FCC catalyst incorporation up to 15% w/w meet European Standard EN 197-1 specifications for CEM II/A type cement, in the 42.5R strength class.