Browsing by Issue Date, starting with "2009-10"
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- Toxicity of Ashes Produced During the Combustion and Co-combustion of Coal and Meat and Bone Meal in a Fluidized- Bed ReactorPublication . Barbosa, Rui; Lapa, Nuno; Lopes, Helena; Gulyurtlu, Ibrahim; Mendes, BenildeThe replacement of fossil fuels by renewable fuels can contribute to improve the environmental performance of the power production and to move forward in the sustainability way. The experience has shown that the availability of alternative fuels can be an obstacle for its extensive use for energy production, since biomass is not always available. The use of non-hazardous wastes may be a good alternative to biomass, mainly if they are economically unattractive for recycling or if they present a high cost for land-filling. The co-firing of non-hazardous wastes with coal is, therefore, a subject of great interest for the sustainability of energy production and the reduction of the emissions of fossil greenhouse gases. The use of these wastes for energy is promising if they combine well with other fuels during the conversion process for energy production and have no negative effect on the combustion system, on the ash quality and on the gaseous emissions.
- Evaluation of the toxicity of char residues produced in the co-pyrolysis of different wastesPublication . Bernardo, Maria; Lapa, Nuno; Gonçalves, Maria Margarida; Barbosa, Rui; Mendes, Benilde; Pinto, FilomenaThe high amounts of solid waste produced in industrial installations and in urban centers is a complex problem of today's society. The traditional strategies for solid waste transformation and disposal include and filling or incineration. Other approaches are being exploited namely waste selective collection and recycling on the energetic valorization of solid wastes through pyrolysis. In the pyrolytic process, the wastes are converted into a gaseous and liquid phase that can be used in energy production or as feedstock in chemistry industries. A solid residue (char) is also produced in a proportion that depends on the pyrolysis conditions. Even when the operating condiions are optimized in order to minimize the solid fraction, a resonable amount of chars are obtained. Those chars are mainly composed of a carbon-rich matrix that contains the mineral matter initially present in the wastes as well as components of the liquid fraction. Therefore, these solid residues have a toxicity potential due to the presence of heavy metals or organic compounds that must be assessed in order to define their safe reutilization or disposal. In the present study, the chars produced in the co-pyrolysis of plastics, pine biomass and tyres were characterized through chemical and ecotoxicological tests. A fraction of the solid chars was treated by extraction with dichloromethane. Different volatibility groups of compounds present in the extracted and non extracted char were evaluated. A selected group of heavy metals was determined in both chars. Chars were subjected to the leaching test ISO/TS 21268-2 and the resulting eluates were further characterized by determining a group of inorganic and organic parameters. An ecotoxicological characterization was performed by using he bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were compared and analysed according to the council Decision 2003/33/CE and the Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). The results of the chemical characterization indicate that the extraction of the char residues with an appropriate organic solvent allows the sufficient elimination of the volatile organic contaminants thus decreasing the potential toxicity of these chars. The semi-volatile and non-volatile fractions were not, apparently, affected by this pre-treatment. Regarding the release of heavy metals from extracted and non-extracted chars during the leaching tests, a strong contamination with Zn was found in both eluates, which contribute to a classification of the corresponding chars as hazardous and ecotoxic materials. Also the results of the ecotoxicological characterization of the eluates led to a classification of these chars as ecotoxic materials.
- Study of the slow batch pyrolysis of mixtures of plastics, tyres and forestry biomass wastes. Effect of experimental conditions in the liguid compoundsPublication . Paradela, Filipe; Pinto, Filomena; Ramos, Ana M.; Gulyurtlu, Ibrahim; Cabrita, IsabelIn this work was studied the effect of experimental conditions in the production of liquid compounds from slow batch pyrolysis of mixtures of plastics, tires and pines wastes. The major compounds formed were toluene, ethylbenzene, and linear alkanes from C5 to C10 (each reaching yields around 5% w/w of the initial waste mixture). The pyrolysis reaction time and temperature improved the production of those species, while decreasing heavier alkanes formation. An increase of plastics content in waste mixture seemed to favour the production of lighter alkanes, although this effect was not as notorious as the ones just mentioned. The styrene production decreased regularly with the decrease of tyres content in the mixture. Autoclave initial pressure variation did not seem to affect significantly the formation of the major compounds.
- Evaluation of the environmental hazard of char residues produced in the co-pyrolysis of different wastes :chemical and ecotoxicological characterizationPublication . Bernardo, Maria; Lapa, Nuno; Gonçalves, Maria Margarida; Barbosa, Rui; Mendes, Benilde; Pinto, Filomena; Gulyurtlu, IbrahimChar residues produced in co-pyrolysis of different wastes were characterized through chemical and toxicity tests. A fraction of the solid chars was treated by extraction with dichloromethane. Different volatilit fractions present in the extracted and non extrated char were evaluated. A selected group of heavy metals was determined in both chars. Chars were subjected to the leaching test ISO/TS 21268-2 and resulting eluates were further characterized by determining a group of inorganic parameters and concentrations of several organic contaminants. An ecotoxicological characterization was performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological characterization led to a classification on the chars as ecotoxic
- Standards on social responsibilityPublication . Sousa Rocha, Cristina
- Pesquisa de propriedades anti-inflamatórias da planta Prunus lusitanica = Search anti-inflammatory properties of the plant Prunus lusitanicaPublication . Duarte, P. Gonçalves; Costa, Maria do Céu; Rosado, Catarina; Teixeira, Adriano; Rodrigues, A. L.As formulações actuais para aplicação na pele devem satisfazer requisitos de eficácia elevada, compatibilidade cutânea e atracção estética. É geralmente aceite que o desempenho de um produto cosmético está relacionado com a tecnologia de todas as etapas da formulação. Assim, uma forma galénica óptima é um pré-requisito tão necessário para sucesso no mercado como a incorporação dos ingredientes activos adequados. O objectivo de formulações tópicas pode ser classificado em duas áreas principais: modular ou suportar a função de barreira da pele e actuar como sistema de libertação para ingredientes activos. Além disso, a possibilidade de utilizar uma formulaçáo galénica patenteada torna-se progressivamente mais importante como instrumento de marketing. Este trabalho constitui a primeira fase do desenvolvimento de conceitos de formulação galenicamente interessantes e utilizados em produtos dermocosméticos na actualidade. Conhecida popularmente em Portugal como "ginjeira brava" ou "loureiro de Portugal", a Prunus lusitanica L. nunca foi estudada de forma “bioconduzida” nem valorizada como fonte de fármacos de origem natural, apesar do seu enorme potencial devido a um elevado conteúdo em terpenos. Até ao momento, apenas existem 34 artigos na literatura mencionando a planta e apenas um estudo da sua composição química (1). Este refere o isolamento e identificação de triterpenos: aldeído ursólico, ácido ursólico e friedelina (2,3). A estas substâncias estão já atribuídas propriedades antimicrobianas (4), propiedades anti-inflamatórias (8) e são conhecidas como promotoras da permeação transcutânea (6). Ambas são plenamente justificadoras da sua inclusão em formulações para aplicação sobre a pele.
- Recolha de dados sobre consumo de medicamentos e/ou suplementos à base de plantas medicinais numa amostra da população de Lisboa e Vale do TejoPublication . Palma, L.; Martins, A. P.; Santos, A. C.; Oliveira, S.; Águas, S.; Monteiro, C.; Costa, Maria do CéuEste trabalho pretende dar sequência a um estudo anteriormente realizado na Escola de Saúde Pública ERISA, onde se concluiu que a maioria dos inquiridos nunca sentiu ou desconhece ter sentido reacções adversas associadas a medicamentos à base de plantas medicinais. Segundo o referido estudo, os produtos à base de plantas são procurados como medicamentos maioritariamente por mulheres, em particular as estudantes, tendo como objectivo o emagrecimento. Os estudos sobre os hábitos de consumo de produtos à base de plantas são extremamente importantes, uma vez que existem poucos dados sobre estes consumos em Portugal, e a população de um modo geral não tem noção dos riscos associados a uma adesão contínua, indiscriminada de medicamentos e/ou suplementos à base de plantas medicinais não acompanhada por profissionais de saúde.
- Antioxidant activity of two abietane diterpenoids from Plectranthus spp.Publication . Rijo, P.; Chumbo, J.; Oliveira, A.; Costa, Maria do Céu; Rodriguez, B.; Simões, M. F.
- Promoting small scale anaerobic digestion systemsPublication . Di Berardino, Santino; Chatzimpiros, Alexis; Bourka, Olga
- Quality control and productivity in oak timber - from forest to the primary processingPublication . Carvalho, João P. F.; Santos, José António dos; Santos, JoanaOak timber is valuated for its beauty, good mechanical properties and natural durability and may have multiple uses. An understanding of the factors that affect oak timber quality is essential. It is important to have quality control of physical, mechanical and technological wood characteristics in order to define the better primary processing and end-use. Silviculture may significantly impact wood quality and final stand value. Specific prescriptions will depend on species, site conditions, desired end product and management options. An appropriate silviculture with optimized technological operations allows a well use of wood even with small diameters. Adequate wood classification is required in order to optimize industrial processes and improve product quality. Quality criteria and procedures for round and sawtimber are referenced.