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Dissertação de mestrado em Design e Marketing

Processing and characterization of plates made from granulate of waste electrical cables

This article is intended to evaluate the density and the mechanical, acoustic and thermal properties of compression moulded plates composed of granulate from electrical cables wastes. Those cable wastes are the insulation part from the electric cables, and are composed of PVC, PE, EMP and PEX rubber. After these materiais lose their initial properties and cease to be useful as insulation material, due to safety requirements, it is possible to reuse them into new applications like industrial or playground floorings, as sound insulation material to be applied in walls or floors, or to dampen vibrations from equipments. Recovering electric cable waste has been a major concern to the European Commission due to its leveis of toxicity when incineration and land fill ing is the solution to dispose this material. Such as the European Commission's study for DG Xl[1] suggested that recycling may be the most favourable future waste management option.

Assessing the application of polypropylene multifilament yarns in brain phantoms

The currently available clinical imaging methods do not provide highly detailed information about location and severity of axonal injury or the expected recovery time of patients with traumatic brain injury [1]. High-Definition Fiber Tractography (HDFT) is a novel imaging modality that allows visualizing and quantifying, directly, the degree of axons damage, predicting functional deficits due to traumatic axonal injury and loss of cortical projections. This imaging modality is based on diffusion technology [2]. The inexistence of a phantom able to mimic properly the human brain hinders the possibility of testing, calibrating and validating these medical imaging techniques. Most research done in this area fails in key points, such as the size limit reproduced of the brain fibers and the quick and easy reproducibility of phantoms [3]. For that reason, it is necessary to develop similar structures matching the micron scale of axon tubes. Flexible textiles can play an important role since they allow producing controlled packing densities and crossing structures that match closely the human crossing patterns of the brain. To build a brain phantom, several parameters must be taken into account in what concerns to the materials selection, like hydrophobicity, density and fiber diameter, since these factors influence directly the values of fractional anisotropy. Fiber cross-section shape is other important parameter. Earlier studies showed that synthetic fibrous materials are a good choice for building a brain phantom [4]. The present work is integrated in a broader project that aims to develop a brain phantom made by fibrous materials to validate and calibrate HDFT. Due to the similarity between thousands of hollow multifilaments in a fibrous arrangement, like a yarn, and the axons, low twist polypropylene multifilament yarns were selected for this development. In this sense, extruded hollow filaments were analysed in scanning electron microscope to characterize their main dimensions and shape. In order to approximate the dimensional scale to human axons, five types of polypropylene yarns with different linear density (denier) were used, aiming to understand the effect of linear density on the filament inner and outer areas. Moreover, in order to achieve the required dimensions, the polypropylene filaments cross-section was diminished in a drawing stage of a filament extrusion line. Subsequently, tensile tests were performed to characterize the mechanical behaviour of hollow filaments and to evaluate the differences between stretched and non-stretched filaments. In general, an increase of the linear density causes the increase in the size of the filament cross section. With the increase of structure orientation of filaments, induced by stretching, breaking tenacity increases and elongation at break decreases. The production of hollow fibers, with the required characteristics, is one of the key steps to create a brain phantom that properly mimics the human brain that may be used for the validation and calibration of HDFT, an imaging approach that is expected to contribute significantly to the areas of brain related research.

Aplicação de celulases e xilanases na reciclagem de fibras de papel

Tese de Doutoramento em Engenharia Química e Biológica (área de conhecimento em Engenharia Enzimática e das Fermentações)

Grasses and legumes as cover crop in no-tillage system in northeastern Pará Brazil

Studies to select one or more species of coverage plants adapted to Amazonian soil and climate conditions of the Amazon are a promising strategy for the improvement of environmental quality, establishing no-till agricultural systems, and thereby reducing the impacts of monoculture farming. The aim of this study was to assess the persistence time, half-life time, macronutrient content and accumulation, and C:N ratio of straw coverage in a Ultisol in northeastern Pará. Experimental design was randomized blocks with five treatments and five replicates. Plants were harvested after 105 days, growth and biomass production was quantified. After 84 days, soil coverage was 97, 85, 52, 50, and 15% for signalgrass (Brachiaria brizantha) (syn. Urochloa), dense crowngrass (Panicum purpurascens), jack bean (Canavalia ensiformes), pearl millet (Pennisetum americanum) and sunn hemp (Crotalaria juncea,), respectively. Signalgrass yielded the greatest dry matter production (9,696 kg ha-1). It also had high C:N ratio (38.4), long half-life (86.5 days) and a high persistence in the field. Jack bean also showed high dry matter production (8,950 kg ha-1), but it had low C:N ratio (17.4) and lower half-life time (39 days) than the grasses. These attributes indicate that signalgrass and jack bean have a high potential for use as cover plants in no-till agricultural systems in the State of Pará.

Litterfall production in intact and selectively logged forests in southern of Amazonia as a function of basal area of vegetation and plant density

Nutrient recycling in the forest is linked to the production and decomposition of litter, which are essential processes for forest maintenance, especially in regions of nutritionally poor soils. Human interventions in forest such as selecttive logging may have strong impacts on these processes. The objectives of this study were to estimate litterfall production and evaluate the influence of environmental factors (basal area of vegetation, plant density, canopy cover, and soil physicochemical properties) and anthropogenic factors (post-management age and exploited basal area) on this production, in areas of intact and exploited forest in southern Amazonia, located in the northern parts of Mato Grosso state. This study was conducted at five locations and the average annual production of litterfall was 10.6 Mg ha-1 year-1, higher than the values for the Amazon rainforest. There were differences in litterfall productions between study locations. Effects of historical logging intensity on litterfall production were not significant. Effects of basal area of vegetation and tree density on litterfall production were observed, highlighting the importance of local vegetation characteristics in litterfall production. This study demonstrated areas of transition between the Amazonia-Cerrado tend to have a higher litterfall production than Cerrado and Amazonia regions, and this information is important for a better understanding of the dynamics of nutrient and carbon cycling in these transition regions.

Technical requirements for the use of C&DW recycled aggregates in municipal and rural roads and trenches

The use of construction and demolition waste (C&DW) in the construction industry is an important contribution to attain sustainability in the sector. The roads are among the civil engineering works which can use larger quantities of C&DW recycled aggregates. In Portugal, the limit values for the properties of C&DW recycled aggregates that can be used in the roads of Portuguese Road Network are defined by two Laboratório Nacional de Engenharia Civil (LNEC) technical specifications (TS), in accordance to Portuguese Decree-law no. 46/2008 of May 12th. Municipal and rural roads and trenches have specific characteristics that can enable the use of C&DW of lower quality than those required by existing LNEC TS, and even then ensuring an adequate performance. However, given the absence of specific regulation for those applications, the Portuguese Environment Agency requires compliance with the existing LNEC TS, which represents an obstacle to recycling a significant part of the C&DW, in particular at a local government level. This paper presents guidelines for the recycling of C&DW in municipal and rural roads and in trenches, which could be considered in a new forthcoming LNEC TS. In the preparation of the guidelines, the bibliography collected and analysed, the information gathered from the application of C&DW in a municipal and rural roads of a Portuguese municipality and in the roadways of a Portuguese resort, and the results of laboratory tests carried out on samples collected in the Portuguese municipality were taken into consideration.

Degradação fotocatalítica de petróleo e seus derivados através da utilização de nanopartículas de dióxido de titânio puro e misturado com óxido de grafeno reduzido

Dissertação de mestrado integrado em Engenharia de Materiais

Integração no laboratório da Lameirinho e controlo aos tecidos acabados

Dissertação de mestrado em Técnicas de Caraterização e Análise Química

A review of sustainable approaches in transport infrastructure geotechnics

Transportation geotechnics associated with constructing and maintaining properly functioning transportation infrastructure is a very resource intensive activity. Large amounts of materials and natural resources are required, consuming proportionately large amounts of energy and fuel. Thus, the implementation of the principles of sustainability is important to reduce energy consumption, carbon footprint, greenhouse gas emissions, and to increase material reuse/recycling, for example. This paper focusses on some issues and activities relevant to sustainable earthwork construction aimed at minimising the use of energy and the production of CO2 while improving the in-situ ground to enable its use as a foundation without the consumption of large amounts of primary aggregate as additional foundation layers. The use of recycled materials is discussed, including steel slag and tyre bales, alongside a conceptual framework for evaluating the utility of applications for recycled materials in transportation infrastructure.

A design of experiments to assess phosphorous removal and crystal properties in struvite precipitation of source separated urine using different Mg sources

Supplementary data associated with this article can be found, in the online version, at: http://dx.doi.org/10.1016/j.cej.2016.03.148.

Acabamentos funcionais têxteis aplicados por estamparia digital em substratos têxteis ativados por plasma

Tese de Doutoramento em Engenharia Têxtil

Optimização do processo de recolha de resíduos: desenvolvimento de ferramentas de investigação operacional para o problema de orientação de equipas com multi-restrições

Tese de Doutoramento em Engenharia Industrial e de Sistemas.

Sustentabilidad productiva de pequeños rumiantes en áreas desfavorecidas (SUPPRAD). Estudios de genética animal

Este proyecto se ubica dentro del programa SUPPRAD que trabaja en red a lo largo del país en áreas desfavorecidas y con pequeños productores. En el contexto del uso sustentable de los recursos naturales y de promoción del desarrollo, el mejoramiento genético es una herramienta fundamental porque aporta beneficios a ambos componentes. Por eso se ha tomado para este proyecto como objetivos generales estudiar las estrategias de implementación de programas de mejoramiento genético de fibra en rumiantes menores y Camélidos en las áreas desfavorecidas donde actúa el programa. Se pretende aquí identificar genotipos de mayor eficiencia productiva en fibra en rumiantes menores y Camélidos y aplicar los conocimientos adquiridos en programas de mejoramiento productivo que tiendan a mejorar el ingreso del pequeño productor para finalmente contribuir al desarrollo de producciones sustentables en distintas regiones del país. Esto se va a desarrollar a través de estudios de estructura poblacional a nivel de pequeños productores de Llamas de la provincia de Jujuy, Córdoba, La Pampa y Río Negro; productores trashumantes de caprinos criollos con aptitud de fibra del área noroeste de Neuquén; pequeños productores de la pampa de Olaen (Córdoba). Por otra parte y a partir de los planteles experimentales establecidos en los campos de productores se organiza la toma de registros de las distintas variables a describir genéticamente: peso de vellón, peso de parche de vellón (predictor del peso de vellón), diámetro medio de las fibras, coeficientes de variación, frecuencia de rizos, rinde al descerdado (vellones mixtos), frecuencias y diámetro de tipos de fibra y tipos de folículos en cortes de piel. Por otra parte se diseñarán objetivos de mejoramiento para las distintas especies a partir de la información genética generada en este proyecto y la información económica recopilada a partir de informaciones de mercado y de los resultados de ensayos de textiles específicos. Como resultado final se pretende elaborar estrategias de abordajes de los mejoramientos productivos de las distintas áreas en estudio y de los distintos tipos de productores involucrados.

Desarrollo de tecnología textil para el procesamiento de la fibra de camélidos, caprinos y ovinos Merino superfino

En este proyecto se pretende abordar el problema de la comercialización de la fibra de Camélidos sudamericanos, caprinos de Angora y de Cachemira y de ovinos Merinos superfino, apuntando a desarrollar tecnologías no disponibles o cuyos detalles aun no están claros, para poder brindar a través de una planta textil propia un servicio de procesamiento textil a los productores interesados e integrados a Programas de Desarrollo, a los fines de obviar los problemas de mercado y comercialización de la fibra en bruto. Para esto, se van a realizar ensayos textiles de diversa índole, con gran énfasis en el desarrollo de una tecnología de separación no convencional del “guard hair” y el “down” de las fibras de Camélidos y Caprinos, minimizando las roturas de fibras y obteniendo un producto final con un porcentaje de “guard hair” no superior al 2%, que es lo se ajusta a las normas de calidad más exigentes. Por otra parte, el procesamiento convencional (sistemas “worsted” y “woollen”) requiere ajustes para obtener hilos puros de estas fibras y para hilar lanas superfinas que ya no se producían en el país. Se trabajará en relación con el convenio interinstitucional entre la Facultad y la Fundación Habitat. Se utilizará como materia prima para los ensayos fibra proveniente de todos los proyectos integrados al SUPPRAD.