Advanced Materials Research Vol. 107

Abstract: Industrial residues generated by the modern society constitute an environmental problem and are harmful both to the health and to the environment (greenhouse effect). In addition, they can give place to leaching pollutants [1,2] more concretely in the European area; it tends to the politics of them 3R, recovery, recycling and reutilization. It is, in this frame, where the present work is included. On the other hand, like result of environmental regulations, bricks of clay are going to be demanded by an increase in the insulating capacity. A way of increasing the insulating capacity of the bricks is to generate porosity in the counterfoil of clay.

Abstract: In the aeronautical industrial sector, the control of the manufacturing process allows to fit the results to the conditions of design of pieces. This manufacturing process conditions the functional behaviour of pieces. In this work are presented the preliminary results of a study conducing to obtain the influence of machining parameters in the response to corrosion of aerospace aluminium alloys in seawater. This results show a high influence of feed, and a minor influence of cutting speed.

Abstract: This article involves computer simulation and surface analysis by nuclear techniques, which are non-destructive. The “energy method of analysis” for nuclear reactions and elastic scattering is used. Energy spectra are computer simulated and compared with experimental data, giving target composition and concentration profile information. The method is successfully applied to depth profiling of 18O and 12C nuclei in thick targets through the 18O(p,α0)15N and 12C(d,p0)13C reactions, respectively. Similarly, elastic scattering of (4He)+ ions is applied to determination of concentration profiles of O and Al for a thick target containing a thin film of aluminium oxide.

Abstract: The main motivation for the present work was the idea to project and build a car, with a hybrid source of power, based on an electric engine, a group of batteries and a source of energy that can be a combustion engine with an electric generator, a fuel-cell or other. The main use of this vehicle was on an urban circuit, but allowing it to make broader circuits. The purpose of this task was to select, with a sustained study, what are the solutions for the source of energy for that kind of vehicle, considering the environmental, energetic and economical perspectives. The main project idea was to make a hybrid vehicle, with a higher autonomy than a simple electric vehicle, with a lower consumption as possible, and as cleaner and quiet as an electric vehicle can be. With this idea in mind, the future user can have an economic vehicle, with lower pollution emissions which can be used also in other voyages, because it has higher autonomy and can be refuelled more easily. In order to achieve the objectives of this work, it was made a research about the life cycle impacts considering several possible energetic choices. Based in three different international studies it was tried to make the proper connection to the Portuguese reality. This involved the extrapolation of the results obtained for other possibilities not mentioned as, for instance, the impact of the electricity production, based in the Portuguese data. For the energetic analysis, several scenarios were made, based on the higher heating value of the different fuels possibilities and on the thermal efficiency of different technologic arrangements. It was made a consumption determination, and a comparative analysis could be done for the several hypotheses that were at stake. Assuming a typical urban vehicle, with places for four persons, and taking into account the actual vehicles reality, the determination of the fuel consumption of that kind of vehicle were made, with similar weight and dimensions characteristics. This evaluation gives the total energy necessary for a vehicle of this kind and the percentage of electric energy that can be saved and also the percentage that has to be used. This can give the quantity of energy that has to be produced to assure that the car can move in urban and extra-urban typical journeys. Considering the energy consumption and how much it costs and the market price for engines, it is possible to make an economical analysis for the several possibilities. Taken into account the several results obtained, for the different choices that were object of the present study, it could be concluded about the choice for better source of energy to generate electric energy for propulsion to the hybrid vehicle.

Abstract: In this work, Stereoscopic Optical Microscopy (SOM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) have been applied for analyzing the evolution of tool wear during the dry turning process of aerospace Al-Cu alloys. The results derived from this analysis have revealed that secondary adhesion is the main tool wear mechanism that takes place in such process. So, in the first instants of the machining process, a Built-Up Layer (BUL) is developed onto the tool rake face by thermomechanical causes, promoting the conditions for developing a Built-Up Edge (BUE) which grows to a critical size. Starting from it, BUE is extruded giving rise to secondary BUL-BUE effects. When these are removed, tool particles are dragged out provoking the tool wear.

Abstract: The risks associated to uranium mining and milling wastes require the radiological surveillance of the areas with these residues and the assessment of the radiation risk to the populations living in the region. This radiological surveillance is based on an environmental monitoring programme implemented by ITN. Annually, soils, water, and plants including horticulture products from the uranium mine areas are sampled and analyzed for radioactivity. As part of this programme, analyses of soils, irrigation waters, agriculture products (lettuce), green pasture, and cheese were performed in samples collected in the area of the old Urgeiriça uranium mine and milling facilities near Viseu, Centre-North of Portugal, in order to assess the transfer of uranium series radionuclides to man. In the Urgeiriça area, some soils and vegetables display radionuclide concentrations higher than in reference areas 226Ra was the radionuclide more concentrated by vegetables. Through ingestion of these products 226Ra may be the main contributor to the increment of radiation dose received by local population. The solutions implemented for environmental remediation of tailings piles and mining waste dumps in Urgeiriça and in other old uranium mine sites, with time are expected to render safe these areas and to allow the release of old mining concession areas for other uses by the public without radiation risks.

Abstract: Radioactive ore mining for the production of radium and uranium in Portugal did span over most of the 20th century and ceased in 2001. It was performed mostly before the development of environmental legislation and radiation protection standards. Environmental remediation of the mining and milling sites is currently underway. Rehabilitated and non-rehabilitated sites require also radioactivity monitoring whose costs are covered by the State. The likely re start of uranium mining, in Portugal as well as elsewhere in Europe, reminds that uranium mining shall be managed under the mine “life cycle approach” in order to include decommissioning and environmental rehabilitation costs in the ore pricing.