Hernandez W.,Technical University of Loja |
Maldonado-Correa J.L.,Technical University of Loja
IEEE Transactions on Energy Conversion | Year: 2017
In this letter, nonparametric statistical inference is applied to designing a simple, inexpensive method of verifying the power performance of a wind turbine. The proposed method uses the data collected by the Supervisory Control and Data Acquisition (SCADA) system and the guaranteed power curve of the turbine, and it says whether the power performance of a wind turbine differed significantly from what would be expected. © 2016 IEEE.
Donoso D.A.,University of Oklahoma |
Donoso D.A.,Technical University of Loja
Ecography | Year: 2014
Community ecology seeks to unravel the mechanisms that allow species to coexist in space. Some of the contending mechanisms may generate tractable signatures in the amount of trait and phylogenetic dispersion among co-existing species. When a community presents a pattern with reduced trait or phylogenetic dispersion, mechanisms based on ecological filters are brought into consideration. On the other hand, limiting similarity mechanisms such as competitive exclusion are proposed when communities present patterns of trait or phylogenetic even-dispersion. The strength of these mechanisms likely varies with the spatial scale of an observed sample. I surveyed species-rich tropical litter ant communities in a spatially nested design that allowed me to explore the spatial scales, fine (0.25 m2), intermediate (9 m2), and broad (361 m2) at which these mechanisms act. I then assessed the relationship between observed ant communities and potential species pools ranging in size, from plot, site, and island-wide areas. Patterns of phylogenetic dispersion within ant communities suggested that ant communities were composed of species that were more closely related than expected by a random sampling of phylogenetic pools. The magnitude of phylogenetic 'clustering' increased with the size of the species pool but was similar among communities assembled from different spatial scales. Patterns of dispersion of one ecological trait (i.e. body size) within ant communities also showed clustering of body sizes, and most communities were composed of ant species that were smaller than expected by a random sampling of trait pools. Trait clustering increased with the size of the species pool but decreased at broad spatial scales. Together, these results suggest that ecological filters, not interspecific interactions, are structuring tropical ant communities, favoring clades with small worker sizes. The larger dependency on the size of regional pools than on the spatial scale suggests that environmental heterogeneity is greater among than within the study sites. © 2013 The Author.
Onate-Valdivieso F.,Technical University of Loja |
Bosque Sendra J.,University of Alcalá
Journal of Hydrology | Year: 2010
This research studies the change in land use in a binational hydrographic basin in South America. In addition, a future perspective for land use is generated according to the trends in the development observed. A multi-temporal analysis of land use change is carried out and variables that can explain the observed transitions will be selected. The relations between changes and explicative variables are studied in order to stochastically model future land use maps. Persistence was found to be the predominant state. Higher transitions were observed in the zones of boundaries between categories. Biophysical variables had the most explicative power with a better performance of the model based on logistic regression than the one made by using neural networks. © 2010 Elsevier B.V.
Maldonado F.,Technical University of Loja |
Stashans A.,Technical University of Loja
Journal of Physics and Chemistry of Solids | Year: 2010
Changes in structural, electrical and electronic properties of zinc oxide (ZnO) due to Al doping are studied using a quantum-chemical approach based on the Hartree-Fock theory. A periodic supercell of 128 atoms has been exploited throughout the study. The atomic parameters for Zn atom were obtained by reproducing the main properties of ZnO crystal as well as the first three ionization potentials of Zn atom. The perturbation imposed by Al atom incorporation leads to the atomic relaxation, which is computed and discussed in detail. A novel effect of electron density redistribution between different atomic orbitals within the same atom has been found. This phenomenon influences atomic rearrangement near Al impurity. The Al doping generates a free electron in the conduction band, which can be considered as a large radius electron polaron increasing the n-type electrical conductivity in the crystal in agreement with the known experimental data. The obtained small increase in the band-gap width due to the impurity incorporation resolves existing experimental debates on this point. © 2010 Elsevier Ltd. All rights reserved.
Stashans A.,Technical University of Loja |
Bravo Y.,Technical University of Loja
Modern Physics Letters B | Year: 2013
First-principles calculations based on the density functional theory (DFT) within the generalized gradient approximation (GGA) have been used to study Sc-doped TiO2, rutile and anatase, crystals. Local defect microstructure, electronic and electrical properties have been obtained and discussed in the present work. Large radius hole polaron state found here points out to the possibility of p-type electrical conductivity in Sc-doped titania. © 2013 World Scientific Publishing Company.
Agency: European Commission | Branch: FP7 | Program: CSA | Phase: INFRA-2007-1.2.3;INFRA-2007-1.2-03 | Award Amount: 5.11M | Year: 2008
EELA-2 aims to build, on the current EELA e-Infrastructure, a high capacity, production-quality, scalable Grid Facility providing round-the-clock, worldwide access to distributed computing, storage and network resources for a wide spectrum of applications from European and Latin American scientific communities. The project will provide an empowered Grid Facility with versatile services fulfilling application requirements and ensure the long-term sustainability of the e-Infrastructure beyond the term of the project. The specific EELA-2 objectives are: - Build a Grid Facility by: Expanding the current EELA e-Infrastructure to consist of more production sites mobilising more computing nodes and more storage space, at start of the project and to further grow storage over the duration of the project; Providing, in collaboration with related projects (e.g. EGEE), the full set of Grid Services needed by all types of scientific applications; Supporting applications various types (from classical off-line data processing up to control and data acquisition of scientific instruments), selected against well defined criteria (including grid added value, suitability for Grid deployment, outreach/potential impact); - Ensure the Grid Facility sustainability: Through the already established and new contacts with policy/decision makers, collaborating with RedCLARA and NRENs and supporting the ongoing creation of e-Science Initiatives and/or National Grid initiatives (NGI). Building the support of the e-Infrastructure to provide a complete set of Global Services from a Central Operation Centre and to pave the way for the creation of Regional Operation Centres in Latin America: Attracting new applications; Making available knowledge of EELA-2 Grid Facility to all potential users, developers, and decision makers through an extensive Training and Dissemination program; Creating knowledge repositories federated with the EGEE ones.
University of Arkansas and Technical University of Loja | Date: 2014-09-15
Plant extracts, compositions, pharmaceutical compositions and methods of making and using the same are provided herein. The compositions comprise -tocotrienol (GT3) and -tocotrienol (DT3) in ratios wherein the DT3 is predominate. The compositions are useful for radioprotection and radiomitigation in subjects in need thereof.
Quispe L.E.,Technical University of Loja |
Galan L.M.,Polytechnic University of Mozambique
Expert Systems with Applications | Year: 2014
A mobile Ad Hoc network (MANET) is a collection of wireless mobile nodes that can dynamically configure a network without a fixed infrastructure or central administration. This makes it ideal for emergency and rescue scenarios, where sharing information is essential and should occur as soon as possible. This article discusses which of the routing strategies for mobile MANETs: proactive, reactive or hierarchical, has a better performance in such scenarios. By selecting a real urban area for the emergency and rescue scenario, we calculated the density of nodes and the mobility model needed for the validation study of AODV, DSDV and CBRP in the routing model. The NS2 simulator has been used for our study. We also show that the hierarchical routing strategies are better suited for this type of scenarios. © 2013 Published by Elsevier Ltd.
Tovar E.,Technical University of Madrid |
Piedra N.,Technical University of Loja
IEEE Transactions on Education | Year: 2014
Open Educational Resources (OER) provide a strategic opportunity to improve the quality of education as well as facilitate policy dialog, knowledge sharing, and capacity building. One of the fundamental concepts of OER is 'the ability to freely adapt and reuse existing pieces of knowledge.' Reuse of educational resources by both individuals and organizations may have significant creative and economic benefit for the educational environment. This Special Issue editorial introduces six interesting experiences, representative of the use of OER in engineering education in important areas such as the production of open content at various scales, reuse of contents, institutional open Web site initiatives, and technological applications to support the exploitation of OER, all at different degrees of maturity. Since some readers will be unfamiliar with prior work on OER, this Special Issue also outlines the hot topics in OER and the critical factors for success when joining the Open Educational Movement. Finally, the editorial provides a set of recommendations and examples offered by the Special Issue editors from their over 6 years of experience leading a research group in semantic Web technologies applied to Open Education. A key requirement, in their opinion, is to improve the metadata interoperability between various collections of open material, so as to facilitate the discoverability and subsequent combining, remixing, or adapting OER; that is, OER data should be easily accessible to any user. © 1963-2012 IEEE.
Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: KBBE-2008-1-4-08 | Award Amount: 3.85M | Year: 2009
VALORAM aims at exploring and valorizing Andean soil microbial diversity for the development of alternative, efficient technologies and crop management practices to improve the sustainability and productivity of Andean cropping systems benefiting rural farming households. The project will focus on potato because of its global importance for small-scale farmers in the central Andean highlands. The participants will use metagenomic, genomic, proteomic and metabolomic analysis to identify novel traits of microorganisms and characterize beneficial soil microbial communities, to achieve the objective. The project specific aims are to (1) explore the agro-ecosystem functions of soil microbes in potato-based cropping systems and preserve the components of this microflora in international culture collections, (2) elucidate the role of rhizosphere microorganisms and communities in promoting plant growth, suppressing soil borne disease and priming plant biotic defenses, developing eco-efficient technologies/products for sustainable crop production systems, (3) develop applied technologies and knowledge-based systems to improve the sustainability and resilience of potato based cropping systems for the benefit of the indigenous farmers and (4) promote the exchange of scientific knowledge and technologies among partners and the LA scientific community to impulse research in this area and support the continuous development of crop production technologies. The strategy for VALORAM implementation is to engage LA and EU partners in developing and further stengthening collaborative research activities in order to sustainably improve potato-based systems. This is supported by a multidisciplinary team of experts with highly complementary skills and based on a robust management structure with an efficient workshop and communication programme. The results will directly benefit the local partners and may also contribute to increase the productivity of organic potato production in the EU.