Advanced Materials Research Vol. 107

Abstract: A carbon molecular sieve for the purification of a gas mixtures containing O2, N2 and CO2, CH4 was produced from a waste granulated PET by means of a single carbonisation step at 973 K. Activated carbon materials presenting good adsorption capacity and some selectivity for O2/N2 and CO2/CH4 were prepared from granulated PET and cork oak with pore mouth narrowing using CVD from benzene. The diffusion coefficients of O2, N2, CO2 and CH4 in these materials were calculated and are comparable to published values determined on Takeda 3A and on a carbon molecular sieve prepared from PET textile fibres by means of carbonisation and subsequent CVD with benzene. However, the selectivities were not quite as good as those given by Takeda 3A. However, taking into account that this is a first attempt at producing CMS from PET, the results are encouraging, and it is to be expected that further development of the experimental procedure will result in new materials with improved performance.

Abstract: Manufacturing performance improvement must take into account energetic, environmental and economic considerations. Thus, when intermediate manufacturing processes are avoided, that performance is improved from the cited viewpoints. In the aeronautical industry, pre-shaped elements of UNS A92024 alloy based structural elements are machined in T3 temper state previously to be thermally treated to reach an O state in order to facilitate its posterior plastic forming process. In this work, a comparative study on the dry turning of UNS A92024 alloy in both states has been achieved in order to analyze the possibilities of eliminating the thermal treatment process, so improving the three above commented considerations. This study has been carried out on the basis of the analysis of surface finish and cutting tool wear.

Abstract: In the last decades, technologically innovative processes performed in advanced materials such as Carbon Fibre (CF) and Metal Matrix Composites (MMC) have continuously increased because of these materials find increasingly applications in the most of the industrial sectors, particularly in aeronautical industry. This is caused by their excellent relationship weight/mechanical properties. Although there is a high trend to apply and develop non-conventional technologies and methods for machining CF and MMC, other common machining processes are commonly applied for working these materials. Thus, in aeronautical industry, mechanical drilling processes are usually applied for preparing the manufactured elements to be assembled. However, drilling of CF based materials can carry on troubles related to a loss of surface finishing quality and/or quick and high tool wear. This work reports on the results about an evaluation process of the surface quality of drilled CF samples as a function of the cutting conditions and the tool materials.

Abstract: The sand exploration results in ponds, which are formed by groundwater. The supply of nutrients (especially nitrogen and phosphorus) in these environments leads to greater growth of aquatic plants – eutrophication, which can cause interference to the different uses of these ponds. This study aimed to identify the main causes of eutrophication of these environments and propose a management plan to ensure its future use and maintenance of water quality. The experiment was carried out between the cities of São José dos Campos and Jacarei (SP-Brazil) (S 23° 12" 54' e W 45° 57" 47'). The topographic map indicates the flow of water during the rainy season and the places with the greatest possibility of drag of nutrients through laminar erosion. The analysis of water showed the variation in levels of nitrogen (increase) and phosphorus (decrease). This variation occurred in the area of higher elevation to lower elevation. The climatological water balance indicated overland flow and water holding in the soil concentrated in the months of January, February, March and April. The results indicate that the water stored in soil, and environment's topography may influence on the process of eutrophication of the sand mining pool

Abstract: The aim of restoration is recompose a new vegetation structure in order to obtain benefits such as the containment of bank erosion, reestablishment of a hydric and nutrient regime, and increase the diversity of species. The present paper evaluated the development of the vegetation introduced as ciliar forest around a mining lagoon through establishing indicators based on the vegetation structure, physic-chemical characteristics of the soil and the water. Results show that the indicators of vegetation, like dying of species and the covering of top were classified as negative factors. Regarding vegetation development, it was considered positive when individuals out of inundation points were analyzed. According to soil indicators, chemical factor pH acid suggests intoxication by aluminum, iron and manganese impeding development of the vegetation in the local. Topographic factor also caused erosion and dying/extinction of species localized in declining points and carried nutrients to the inundation point and finally to the sand mining pool.

Abstract: Perhaps you have wondered, while lying on the beach or in a boat and feeling the strong pull of the waves or tides, whether it would be possible to harness all that power to produce electricity, just as we do with other elements of nature. This idea is hardly original: the first patent for wave energy was presented in France in 1799, although it was not until the early 70's of the previous century that the idea gave rise to projects funded by companies and governments like Japan and the UK. However, the slow development of technology and the enormous costs were crippling some projects that have resurfaced in the last five years. More and more governments and companies are beginning to invest in this type of energy, aware that renewable energies may be the key in helping to avoid problems such as pollution and the scarcity of energy resources, and supported by technological advances. The European Union, where the Atlantic Ocean, the North Sea and the waters surrounding the Scandinavian countries have ideal conditions, is also taking the lead in these types of projects. In fact, the Scottish island of Islay boasts the first European turbine that works with wave motion to generate power for 400 homes. Currently, there are a dozen ways to obtain electricity from wave motion at different stages of development, and with no certainty as to which may become the final one. Basically, they can be divided into two types. On the one hand, those that take advantage of the horizontal movement of the waves and that follow the same principle used in hydroelectricity: channelling the waves through structures of pipes that carry water to a tank located on land, which feeds a system of turbines that generates electric power. In the other group we can find methods based on the vertical oscillations of the waves. The energy of the tides is converted into electricity in tidal power stations, which operate like a traditional river reservoir. The tank becomes filled with the tide and the water is retained until low tide to be released later through a network of narrow channels increasing the pressure until it reaches the turbines that generate electricity. The problem is that high maintenance costs slow their proliferation. Despite these promising projects, the energy from the sea is still far from being a useful reality. WaveNet network created by the European Commission in 2000 and composed of academics, industries and research institutes from European countries, published a study explaining that the lack of public knowledge is one of the obstacles that hinder its development. The report detailed also some negative consequences that might arise in energy production, such as noise, risk of collision with ships, visual impact and possible changes in the structure of the water sediments. Consequently, the study highlighted the need for further research in order to make these technologies more competitive.

Abstract: The goal of this work is to describe the importance of environmental education in the energy conservation and energy efficiency process. Besides the various technical proposals aimed at minimizing energy waste, environmental education has been a primordial tool in the search of a more responsible character with respect to the environment. This article attempts at showing some reflections concerning the role environmental education plays in that process, as well as putting in evidence the educational actions of the National Program for Energy Conservation, with its emphases in diminishing the energy waste and pull towards its efficient use.