Aplicación de un método matemático al análisis de direcciones volcánicas en La Palma y El Hierro (Islas Canarias)

En un área volcánica, la distribución de los puntos de emisión refleja en gran parte las pautas estructurales regionales, que condicionan esta actividad magmática; sin embargo, a veces, resulta difícil decidir sobre el terreno, basándonos únicamente en datos geológicos, cuáles de estas direcciones son aparentes y cuáles significativas. En este trabajo se aborda el problema recurriendo a un análisis matemático de todas las direcciones posibles en función del número y distribución de los centros eruptivos en un área determinada. Se realizan así mediante ordenador de barridos lineales en todas las direcciones con condiciones de selección variable. El amplio conocimiento que se tiene de estas directrices en las Islas de La Palma y El Hierro a partir de datos sobre el terreno de estudios vulcanológicos previos, permite comparar los resultados obtenidos por ambos métodos

An Automatic Programming ACO-Based Algorithm for Classification Rule Mining

In this paper we present a novel algorithm, named GBAP, that jointly uses automatic programming with ant colony optimization for mining classification rules. GBAP is based on a context-free grammar that properly guides the search process of valid rules. Furthermore, its most important characteristics are also discussed, such as the use of two different heuristic measures for every transition rule, as well as the way it evaluates the mined rules. These features enhance the final rule compilation from the output classifier. Finally, the experiments over 17 diverse data sets prove that the accuracy values obtained by GBAP are pretty competitive and even better than those resulting from the top Ant-Miner algorith

Volcanic evolution of São Vicente, Cape Verde Islands: The Praia Grande landslide

The island of São Vicente has undergone continuous volcanic activity from Pliocene to Pleistocene times. The earliest evidence of activity corresponds to some 9 million years ago when a submarine edifice of alkaline basaltic affinity had already started to develop. The island resulted from the growth of a single major edifice (the São Vicente Edifice) built up in several distinguishable growth stages. The early main stage occurred at 6.5 to 4.5 Ma giving rise to an edifice of about 10–12 km in radius and more than 2500 m in height whose centre was located south of the present city of Mindelo. Although the edifice in its earlier phase showed typical characteristics of a shield volcano (the Mindelo Formation) it adopted later on those of an ordinary composite volcano (the Madeiral–Monte Cara Formation). A giant landslide event, the Praia Grande landslide, destroyed the NE sector of the edifice and left a 10×12 km large depression that was successively refilled by nephelinitic lava flows and some associated carbonatites (the Monte Verde Formation, 4.5–3.1 Ma). The volcanic activity ceased about 3–2 Ma ago when the edifice started to be deeply eroded until disappearing about 90% of its total volume. Only in recent times (0.3 Ma) very scarce and local strombolian activity has been developed aside the São Vicente Edifice, in the eastern sector of the island

Towards a Circular Economy Development for Household Used Cooking Oil in Guayaquil: Quantification, Characterization, Modeling, and Geographical Mapping

This article belongs to the Special Issue Applications of GIS and Remote Sensing for Sustainable Development[Abstract] The objective of the present study was to quantify, geo-locate, model, and characterize domestic used cooking oil (dUCO) generation for the city of Guayaquil. For this reason, and as a prerequisite for the proper planning of municipal cooking oil waste management in the city, we carried out 14-day fieldwork involving 532 households from different parishes of Guayaquil, combined with a survey to acquire data on their demographic and socioeconomic statistics. The artisanal characterization was further executed to 40 subsamples of dUCO to determine the density, moisture, solids content, and the volatile-matter characteristics present. Additionally, the Geographic Information System (GIS) was used to map the used cooking oil generation hotspots for the city, adding the Geographical Position System (GPS) of each participating household during the data acquisition. Finally, a multiple-regression model was proposed to establish correlations between the dUCO generated and five independent variables, such as household size, socioeconomic group, tenure status, education level, and income. Results showed that the per capita daily dUCO-generation rate was found to be 4.30 g/day/c or 4.99 mL/day/c, with a density of 0.86 g/mL. Filterable solids represented 0.37% for the entire dUCO collected sample, while separable water and grease represented 1.58% and 0.014%, respectively. In addition, the percentage of the volatile matter was found to be 7.7% ± 2.1% of the filtered dUCO. Using GIS mapping, we found that the areas near tourism sites have a higher dUCO generation value, considering the household survey. Following the developed multiple-regression model developed, it was found that household size and the socioeconomic group have the maximum effect on generating used cooking oil

A parallel algorithm for solving the incompressible Navier-Stokes problems

AbstractWe introduce and analyze a parallel algorithm for solving the Navier-Stokes equations based on the splitting of the two main difficulties involved, the presence of nonlinear terms and the zero divergence condition. The numerical results obtained by using the proposed algorithm are quite consistent with those furnished by other known algorithms. Numerical results are discussed, as well as the advantages of this new algorithm

Características composicionales del Complejo Volcánico Sur I de Fuerteventura (Islas Canarias)

The Southern Volcanic Complex I consists mainly of basalts with scarce felsic members. On the basis of chemical and mineralogical compositional features two groups could be considered. 80th groups are alkaline, the first normal alkaline (in the Cofete Area) and the second one more alkaline (in the Mungía Area). When the proportions of crystallizing phases are estimated, these two groups show different behaviour. The first group is controlled by olivine and c1ynopiroxene and the second one by these two phases plus plagioclase and magnetite. These two different evolution paths culminate with also two different more differentiated members. The basic rocks in the Cofete Area are related to the trachytes of Montaña Azufrá whilst these in the Mungía Area are connected to the felsic rocks of Cofete Islet

Edad de los domos sálicos de la isla de La Gomera

The new radiometric data from felsic domes on La Gomera allow to separate two different felsic both intrusive and extrusive episodes on the island. The early one, upper Miocene in age, includes the domes on the eastern sector of the island as well as the radial and the conical dikes cropping out on the north. Within this early episode of felsic magmatism, the domes on the eastern sector and the so called eastern radial dike-swarm seem to be contemporaneous and slightly older (8.6-7.9 Ma) than the western radialdike swarm and the con e-sheet complex, a structure which also includes some related domes (7.5-6.4 Ma). A later felsic episode, lower Pliocene in age (4.5-3.9 Ma),includes all the rest of existent domes on La Gomera which are less alkaline and peralkaline than the older ones

Discriminación de bosques de Araucaria araucana en el Parque Nacional Conguillío, centro-sur de Chile, mediante datos Landsat TM

Martin, JS (San Martin, Jose). Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, ChileAraucaria forests (Araucaria araucana) have a tremendous ecological relevance; however, the information concerning their spatial distribution is still insufficient. They have only been classified according to small management scales, using satellite photos and images processed through conventional methods. The present study had as its objective to discriminate and characterize types of A. araucana forests in the Conguillio National Park, located in the Southern-Center Chile, through data derived from the Landsat-5 TM satellite and geographic information systems. The normalized difference vegetation index (NDVI) was satisfactorily related with variables corresponding to crown coverage and the diameter at breast height; thus, these index values were incorporated to the classification process. Using the digital elevation model and the NDVI, the effect provoked by the shadow was minimized. Seven types of forests, between dense and semi-dense-open, were discriminated in accordance with the accompanying species. The global reliability of the classification was 83.8 %. The greatest reliability for the producer was for the medium crown density forest of A. araucana - N. dombeyi (B1) (87.5 %); and for the consumer, for the high crown density forests of A. araucana - N. dombeyi (B1) and also for those of medium density (B2) (93 %). It is concluded that incorporating NDVI values and data derived from the digital elevation model to the satellite classification process, it is possible to discriminate araucaria forests with satisfactory reliability in areas of rough relief, which is very useful information for the management of these forestry ecosystems