results are presented for compression ratios of 16:1 and 20:1.

No abstract

In Arequipa -Peru, tailings produced from the gold cyanidation process are deposited in tailings dumps. This accumulation creates the need for large spaces, high maintenance costs, and a negative impact on the environment. The present study aims to develop a process for reusing gold mine tailings as a raw material for the manufacture of bricks. This study deals with important aspects of the mining industry involved in sustainable development, namely the transformation of an environmental liability into an environmental asset. This work will seek to address two problems related to environmental damage: the buildup of toxic solid wastes at mining sites, and the over-exploitation of natural resources in the brick production process. The proposed process has been divided into three stages: (I) thickening and molding; (II) filtering, mixing and neutralizing; and (III) drying and sintering. The development and validation of the process and the evaluation of the final featured products allow defining the process as "recycling" (collection, processing, trading, and use of materials considered wastes). Standard procedures in brick manufacture analyzed physical and mechanical quality from bricks produced. Results showed that the bricks comply with current regulations for materials in compression resistance, maximum absorption, and dimensional variation tests. It is concluded that the enormous environmental liability represented by mining tailings can be used as a raw material within the construction materials industry.

The power generation, used to promote comfort, mobility and others continually grows. To solve this growing demand, efforts have been directed towards the development of new energy sources, preferably renewable, and better ways of energy conversion by increasing the processes efficiencies. A good example of this is the gradual shift from conventional and highly inefficient vehicles, being replaced by hybrids or purely electrics. But even with gradual migration for more efficient energy use, we will continue depending of traditional fuels therefore it is necessary to develop more efficient and less polluting ways to use these sources. Thus, this work aims to study alternative ways of converting energy contained in fuels used in internal combustion engines by use of combustion mode RCCI, two fluids with different cetane numbers are introduced into the combustion chamber at different times with the purpose of burning the fuel with lower cetane number. Therefore, for combustion mode RCCI, the SOI of fuel with lower enthalpy of vaporization and the start of combustion must be determined to determine the ignition delay. The results show the ignition delays for the different techniques of injection of fuels with compression ratios of 16:1 and 20:1.

No abstract

Currently, several transport and fuel production sectors are aiming to develop new technologies that can replace traditional fossil fuels by fuels produced from renewable sources, most of them dubbed as Biofuels. In the particular case of n-butanol, an additive widely used in the blend with diesel oil, it has achieved considerably good results; however, the dependence on fossil fuels still remains present. In this investigation, in order to replace diesel oil in CI engines; n-butanol was tested as an ignition improver when blended with ethanol (Biofuel) as energy source. For this purpose, a rapid compression machine (RCM) was used under different test conditions, such as compression ratio from 16:1 to 24:1. The combustion process of Ethanol / n-butanol blend (10% w/w) was compared to a diesel S10 (as baseline fuel) and with mixture of ethanol / polyethylene-glycol 400 (13% w/w) and showed interesting results. These results were discussed and showed the necessity of several modification in the fuel and the compression ignition system in order to burn the mixture of Ethanol / n-butanol.

No abstract

The power generation, used to promote comfort, mobility and others continually grows. To solve this growing demand, efforts have been directed towards the development of new energy sources, preferably renewable, and better ways of energy conversion by increasing the processes efficiencies. A good example of this is the gradual shift from conventional and highly inefficient vehicles, being replaced by hybrids or purely electrics. But even with gradual migration for more efficient energy use, we will continue depending of traditional fuels therefore it is necessary to develop more efficient and less polluting ways to use these sources. Thus, this work aims to study alternative ways of converting energy contained in fuels used in internal combustion engines by use of combustion mode RCCI, two fluids with different cetane numbers are introduced into the combustion chamber at different times with the purpose of burning the fuel with lower cetane number. Therefore, for combustion mode RCCI, the SOI of fuel with lower enthalpy of vaporization and the start of combustion must be determined to determine the ignition delay. The results show the ignition delays for the different techniques of injection of fuels with compression ratios of 16:1 and 20:1.