Entity

Time filter

Source Type


Rodriguez-Barcenas G.,Higher Institute of Mining and Metallurgy, Moa | Lopez-Huertas M.J.,University of Granada
Journal of the American Society for Information Science and Technology | Year: 2013

This research studied the role of knowledge organization in the process of decision making in the field of energy efficiency and rational use of energy (EERUE). Theoretical contributions to knowledge organization and decision making are stressed. We chose to work with a type of methodology known as multiple criteria decision making - Saaty's analytical hierarchies process (AHP). This made it possible to develop a detailed analysis of the decision-making process and arrive at a hierarchical model. The model provided a structure representing the studied field, where an order of priority could be given to the decision-making process. The knowledge derived may be used in other fields of study such as information retrieval and knowledge representation. © 2013 ASIS&T. Source


Gonzalez-Jimenez J.M.,Macquarie University | Proenza J.A.,University of Barcelona | Gervilla F.,University of Granada | Melgarejo J.C.,University of Barcelona | And 3 more authors.
Lithos | Year: 2011

Several chromitite bodies of variable sizes are hosted in dunite-harzburgite of the small (< 3. km) mining district of Sagua de Tánamo, in the Mayarí-Cristal ophiolitic massif, eastern of Cuba. The chromian spinel in these bodies displays a large range in Cr# (Cr/Cr + Al) atomic ratio from 0.74 to 0.45. In high-Cr chromitites, Cr# and Ti contents increase from harzburgite to dunite, to chromitite. A roughly opposite trend of variation in Cr# is observed in high-Al chromitites, although in this case Ti distributes randomly. The differences in the type of chromian spinel (i.e., high-Cr or high-Al) in the chromitite coincide with a different behavior of the platinum-group elements (PGE). Whereas high-Cr chromitites are rich in PGE and contain abundant grains of platinum-group minerals (PGM), high-Al chromitites are systematically poor in PGE and in PGM. The calculated melts in equilibrium with chromian spinel of high-Cr chromitite are island arc thoeliites (IAT) with boninitic affinity whereas those in equilibrium with chromian spinel of high-Al chromitites are back-arc basin basalts (BABB). The formation of high-Cr chromitites is interpreted as a result of the extensive reaction of harzburgite with migrating island arc tholeiite melts of boninitic affinity. Melt-rock reaction produces boninitic melts with variable composition and porous dunitic channels in which the mixing/mingling of melts promotes crystallization of mononomineralic high-Cr chromian spinel. In contrast, high-Al chromitites formed by the mixing/mingling of BABB melts within conduits not in equilibrium with dunite. Percolation of primitive BABB melts through pre-existing dunite dissolved olivine, producing melt conduits in which BABB melts mixed and formed high-Al chromian spinel. The higher PGE and PGM in high-Cr chromitites is not only a function of the degree of partial melting but is linked to interaction between the migrating melt and mantle harzburgite during the formation of the chromitite. The coexistence of both types of chromitites in one small mining district reflects the temporal and/or spatial variations of separate melt intrusions emplaced in different subarc mantle domains during the opening of a back-arc basin in a supra-subduction zone environment. © 2011 Elsevier B.V. Source


Coello Velazquez A.L.,Higher Institute of Mining and Metallurgy, Moa | Menendez Aguado J.M.,University of Oviedo | Sanchez A.B.,University of Oviedo | Rodriguez B.A.,University of Oviedo
Minerals and Metallurgical Processing | Year: 2011

The subject of this paper is particle population balance models (PBM) that describe mineral impact crushing behavior; it is mainly concerned with the selection and fragmentation distribution function due to their importance in this context. The data obtained by Datta (1999) by applying impact pendulum testing to single limestone particles, used by Austin (2002,2004a and 2004b) to obtain the principal parity of fragmentation functions, were processed in order to compare them with the results of other authors, such as Nikolov (2002 and 2004) and Vogel and Peukert (2003 and 2005) so as to increase knowledge of impact crushing. From this data it has been possible to obtain the performance models of the principal parameters of fragmentation function, thereby reducing the number of experiments necessary to model the impact crushing process. The authors also propose a simplification of the selection function model posited by Austin (2002). Copyright 2011, Society for Mining, Metallurgy, and Exploration, Inc. Source


Martinez R.D.,Higher Institute of Mining and Metallurgy, Moa
Boletin de la Sociedad Geologica Mexicana | Year: 2010

The history of gold mining in Cuba has been described in numerous published works; however, it has not been systematized in accordance with the socio-economic developments of the island. Several classifications and conceptual models have been presented on the gold metallogeny in Cuba, but they are not clear and do not plainly reflect the essential attributes that characterize gold mineralization on the island. The aforementioned circumstances justified a historical-descriptive research project based on an exhaustive literature review, and the analysis and interpretation of the available information. Gold mining on the island extends over three historical stages: colonial, neocolonial and revolutionary. Four main metallogenetic episodes for gold formation can be distinguished on the island of Cuba: (i) an Aptian-Campanian stage of mineralization with low- and high-sulfidation Au-Cu porphyries, Au skarns and Au-Ag epithermal deposits; (ii) a late Campanian-early Danian episode that hosts orogenic-type gold mineralization and listvenites; (iii) very prolific Danian-middle Eocene gold mineralization in listvenites in Central Cuba and in Palaeogene volcanic island arc rocks in the southern part of eastern Cuba; and lastly, (iv) an Oligocene-Recent mineralization stage in which surface gossans are produced by the oxidation of sulfide ores and placers. The future of gold mining in Cuba is very attractive, but at a small to medium scale. Source


Pozo A.C.,University of Information Sciences | Codorniu R.T.,Higher Institute of Mining and Metallurgy, Moa
Computacion y Sistemas | Year: 2015

In this paper we propose an online Wavelet Discrete Transform implementation scheme. Our proposal improves the execution time compared to the traditional sliding window method. Also, we modify the definition of the data window concept given in the original scheme. The experiments we performed show that the runtime cost of the proposed algorithm is better than that of the traditional sliding window method. Source

Discover hidden collaborations