Correlation between chemical and mineralogical characteristics and permeability of phyllite clays using multivariate statistical analysis

Phyllite clays are applied as a layer on a surface to be waterproofed and subsequently compacted. For this purpose, phyllite clays deposits can be grouped by their chemical and mineralogical characteristics, and these characteristics can be connected with their properties, mainly permeability, in order to select those deposits with the lowest permeability values. Several deposits of phyllite clays in the provinces of Almería and Granada (SE Spain) have been studied. The results of applying a multivariate statistical analysis (MVA) to the chemical data analysed from 52 samples determined by XRF, mineralogical analysis by XRD and permeability are reported. Permeability, a characteristic physical property of phyllite clays, was calculated using the results for experimental nitrogen gas adsorption and nitrogen adsorption-desorption permeability dependence. According to the results, permeability values differentiated two groups, i.e. group 1 and group 2, with two subgroups in the latter. The influence of chemical as well as mineralogical characteristics on the permeability values of this set of phyllite clays was demonstrated using a multiple linear regression model. Two regression equations were deduced to describe the relationship between adsorption and desorption permeability values, which support this correlation. This was an indication of the statistical significance of each chemical and mineralogical variable, as it was added to the model. The statistical tests of the residuals suggested that there was no serious autocorrelation in the residuals.Peer ReviewedPostprint (author's final draft

Sistema de consulta de notas a través de Páginas Web y de Telefonía Móvil

In this paper we are going to present a system which lets any student at Cordoba University knows what the final qualifications he has obtained in the different subjects he is registered are. The sytem lets him consult the qualifications using Internet and mobile telephony. Teachers who are reagistered in the system can upload tha qualifications without addtional software, they only need the certificate file generated by the UcoActas application. Then, all the registered students in this subject and in this service, will receive an e-mail to notify them that they can consult the qualifications. Then, they can use a Web browser or they can use a specific mobile application to consult them. Currently we are doing functionality tests with voluntary students from different courses.En este artículo se presenta un sistema que permite a cualquier alumno de la Universidad de Córdoba informarse sobre las calificaciones finales obtenidas en las asignaturas en las que está matriculado. El sistema permite consultar las notas de las actas utilizando Internet y Telefonía Móvil. Los profesores que estén dados de alta en el sistema podrán subir las notas sin necesidad de utilizar un tercer "software", directamente con el fichero de las actas generado por el programa UcoActas. Una vez subidas las notas, todos los alumnos matriculados que estén suscritos a este servicio, recibirán un e-mail con el aviso de que la consulta en la Web está disponible. Si el alumno lo desea, también podrá consultar sus notas publicadas utilizando un programa para dispositivos móviles que hará una petición segura al sistema. Actualmente se están realizando pruebas de actualización con estudiantes voluntarios de varias asignaturas

Evaluación del docente rural y multigrado de primaria. Consideraciones desde el enfoque por competencias (Original).

The objective of this article is to provide elements to evaluate rural and multigrade teachers under the competency-based approach. For this purpose, two discussion groups were organized with elementary school teachers who work in rural and multi-grade schools in Mexico in order to listen to their voices and draw on their experiences to establish competencies based on the work they have done in these contexts. The competency-based approach has been implemented in primary school since 2009 and although there have been enormous transformations in education, it continues to be basic in the curricula. Among the results, the importance given to the teacher-community relationship stands out, that is, the development of competencies to relate, coexist and work in community is proposed, in addition to including different actors (parents, students, members of the locality) to carry out evaluation tasks. It should be clarified that the approach to evaluation is formative in nature, as it seeks to provide key aspects to improve teaching practice.El objetivo de este artículo es brindar elementos para evaluar al docente rural y multigrado bajo el enfoque por competencias. Para lograrlo, se organizaron dos grupos de discusión con docentes de primaria que laboran en escuelas multigrado y rurales en México, con el propósito de escuchar sus voces y partir de sus experiencias para establecer competencias desde el trabajo que han realizado en estos contextos. El enfoque por competencias se implementa en primaria desde el 2009, y aunque en la actualidad se han vivido enormes transformaciones en materia educativa, este sigue siendo básico en los planes de estudio. Entre los resultados se destaca la importancia que se le brinda a la relación docente-comunidad, es decir, se plantea el desarrollo de competencias para relacionarse, convivir y trabajar en comunidad, además de incluir a diversos actores (padres de familia, alumnos, miembros de la localidad) para realizar tareas de evaluación. Cabe aclarar que el enfoque planteado sobre la evaluación es de carácter formativo, ya que busca proporcionar aspectos clave para mejorar la práctica docente

Asociatividad comunal para promover el desarrollo económico y social de los productores de teja del distrito de Cajabamba – 2017

Esta investigación fue desarrollada con el objetivo de determinar si la asociatividad comunal promueve el desarrollo económico y social de los productores de teja del distrito de Cajabamba – 2017. El tipo de estudio fue no experimental y el diseño correlacional transeccional causal. Se tomó una muestra de 50 productores de teja de Cajabamba, Provincia de Cajabamba, Departamento de Cajamarca para lo cual se elaboraron dos cuestionarios confiables y validados que sirvieron para la recolección de los datos de las variables en estudio, estos fueron procesados mediante el software de estadística para ciencias sociales SPSS V23. Los resultados se presentan en tablas y figuras estadísticas. El resultado que se obtuvo de la Asociatividad comunal para promover el desarrollo económico y social de los productores de teja; haciendo uso del Coeficiente de contingencia del estadístico de prueba Tau-b de Kendall es 0.53, con nivel de significancia menor al 1% (P < 0.01); comprobándose que la asociatividad comunal promueve de forma integral y eficiente el desarrollo económico y social de los productores de teja del distrito de Cajabamba – 2017, se acepta la hipótesis y se rechaza la hipótesis nula. El mayor nivel en la variable asociatividad comunal, es el nivel débil con un 76%. Además, el mayor nivel en la variable desarrollo económico y social es el nivel bajo con un 86%. La asociatividad comunal es un elemento de actuación social que propicia el desarrollo económico y social, pues de esa forma se logra superar la crisis que atraviesa el rubro, de la teja en este caso, la que genera diversas problemáticas que les son comunes a la gran mayoría de los productores de tejas, las cuales creen poder revertir a través de la Asociación, como una organización estratégica de superación de las adversidades, la que les permita enfrentar de manera grupal, la competencia, la incorporación y mantención en el mercado, entre otras cosas

Propuesta de indicadores para los estándares de desempeño de la carrera de Técnico en Obras Civiles del Centro de Formación Técnica San Agustín de Talca bajo un modelo de competencias laborales

62 p.El trabajo a continuación expuesto surge para dar respuesta a la pregunta ¿Cuál es el vínculo entre los requerimientos técnico-laborales y la malla curricular de un Técnico en Obras Civiles en formación?, es en base a esta pregunta que se estructura el objetivo orientado a presentar una propuesta de estándares de aprendizaje para la carrera de Técnico en Obras Civiles del Centro de Formación Técnica San Agustín de Talca. El tipo de estudio por medio del cual fue recolectada la información para llevar a cabo el presente informe es un estudio cualitativo, a través de un proceso inductivo de exploración y descripción con el cuál se llevó a elaboración un producto de tipo curricular, llevando a cabo la narración de los procedimientos que llevaron a establecer los estándares de aprendizaje; estos estándares serán abordados desde la perspectiva de las competencias técnicas y competencias transversales de la carrera Técnico en Obras Civiles del Centro de Formación Técnica San Agustín de Talca

Microbiological induced carbonate (CaCO3) precipitation using clay phyllites to replace chemical stabilizers (cement or lime)

The objective of the present study is to develop a biotechnological tool for a new application of clay phyllites as stabilized materials in linear works replacing chemical stabilizer (e.g. cement or lime) by natural cement, formed by precipitated calcium carbonate generated by microorganisms of the Bacillaceae family (Bacillus pasteurii). Part of the development process conducting a chemical and mineralogical characterization and an examination of physical and hydromechanical properties. The results of this study show that the effect of bacteria on clay phyllites increases the calcium carbonate content, specific surface area and plasticity values. These increased values are caused by the addition of a non-plastic component to clay phyllites resulting in a more aggregated structure through the precipitation of calcium carbonate from the bacteria, ultimately filling the pores of this material. Microbiological treatments on clay phyllites tends to aggregate the original particles, creating aggregates that are partially associated with the formation of calcium carbonate. Said process is influenced by the curing and compaction procedures conducted on samples, which also cause breakage of carbonated structures formed during treatment. As a result of this breaking process of aggregates, some compaction energy is lost and the treated samples do not reach the maximum dry density of the natural state for the same level of compaction energy applied. Treated samples display a slightly larger friction angle with no cohesion, consistent with filling properties and denser condition. Compressibility is consistently lower than that of the natural state. Comparison of collapse data shows that the occurrence and amount of collapse are controlled by the as-compacted dry density. It is also determined that higher compaction effort is even more effective than increasing the amount of bacteria introduced to stabilize the sample for the filling of pores (size ranges 3–50¿µm) with calcium carbonate. However, the post-ageing compaction destroys the initial binding/cementation effect.Peer ReviewedPostprint (author's final draft

Reducing gaps in quantitative association rules: A genetic programming free-parameter algorithm

The extraction of useful information for decision making is a challenge in many different domains. Association rule mining is one of the most important techniques in this field, discovering relationships of interest among patterns. Despite the mining of association rules being an area of great interest for many researchers, the search for well-grouped continuous values is still a challenge, discovering rules that do not comprise patterns which represent unnecessary ranges of values. Existing algorithms for mining association rules in continuous domains are mainly based on a non-deterministic search, requiring a high number of parameters to be optimised. These parameters hinder the mining process, and the algorithms themselves must be known to those data mining experts that want to use them. We therefore present a grammar guided genetic programming algorithm that does not require as many parameters as other existing approaches and enables the discovery of quantitative association rules comprising small-size gaps. The algorithm is verified over a varied set of data, comparing the results to other association rule mining algorithms from several paradigms. Additionally, some resulting rules from different paradigms are analysed, demonstrating the effectiveness of our model for reducing gaps in numerical features

Slip Partitioning in the 2016 Alboran Sea Earthquake Sequence (Western Mediterranean)

This study was supported by FEDER/MINECO projects CGL2015-67130-C2-2-R and PID2019-109608GB-I00, FEDER/Junta de Andalucia project A-RNM-421-UGR18, and is part of the research group RNM104 of the Junta de Andalucia. JA has also received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 754446 and UGR Research and Knowledge Transfer Found-Athenea3i; and by project 407141557 of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).A MW = 5.1 earthquake on January 21st, 2016 marked the beginning of a significant seismic sequence in the southern Alboran Sea, culminating in a MW = 6.3 earthquake on January 25th, and continuing with further moderate magnitude earthquakes until March. We use data from 35 seismic broadband stations in Spain, Morocco and Portugal to relocate the seismicity, estimate seismic moment tensors, and isolate regional apparent source time functions for the main earthquake. Relocation and regional moment tensor inversion consistently yield very shallow depths for the majority of events. We obtain 50 moment tensors for the sequence, showing a mixture of strike-slip faulting for the foreshock and the main event and reverse faulting for the major aftershocks. The leading role of reverse focal mechanisms among the aftershocks may be explained by the geometry of the fault network. The mainshock nucleates at a bend along the left-lateral Al-Idrisi fault, introducing local transpression within the transtensional Alboran Basin. The shallow depths of the 2016 Alboran Sea earthquakes may favor slip-partitioning on the involved faults. Apparent source durations for the main event suggest a ∼21 km long, asymmetric rupture that propagates primarily toward NE into the restraining fault segment, with fast rupture speed of ∼3.0 km/s. Consistently, the inversion for laterally variable fault displacement situates the main slip in the restraining segment. The partitioning into strike-slip rupture and dip-slip aftershocks confirms a non-optimal orientation of this segment, and suggests that the 2016 event settled a slip deficit from previous ruptures that could not propagate into the stronger restraining segment.FEDER/MINECO CGL2015-67130-C2-2-R PID2019-109608GB-I00FEDER/Junta de Andalucia project A-RNM-421-UGR18Junta de Andalucía RNM104European Union (EU) 754446German Research Foundation (DFG) 40714155

The 2016 seismic series in the south Alboran Sea: Seismotectonics, Coulomb Failure Stress changes and implications for the active tectonics in the area

The Southern Alboran Sea, particularly the area offshore Al Hoceima Bay, presents moderate but continuous seismic activity since the Mw 6.0 1994 Al Hoceima earthquake. The maximum magnitude occurred in the area was a Mw 6.3 earthquake in the 2004 Al Hoceima – Tamasint seismic series. Since then, the seismicity in the Al Hoceima area has been usual, with maximum seismic magnitudes around 4. An increase in the seismic rate was registered during 2015, especially from May, culminating in the seismic series in January 2016. The mainshock occurred on January 25th 2016 with a magnitude Mw 6.3 and it was preceded by a Mw 5.1 foreshock on January 21st. The seismic series took place at the western end of the Alboran Ridge. Towards the northeast the Alboran Ridge bends, and seems to be connected with the NW-SE right-lateral transtensional Yusuf Fault. The recorded seismicity is mainly located in the Alboran Ridge area and along the N-S Al-Idrisi Fault that seems to continue southwards, towards the Al Hoceima Bay. The focal mechanisms calculated previously in the area showed a leftlateral strike-slip faulting with some normal component in the Alboran Ridge; but always within a complex system of diffuse deformation and high rupture type variability. We have used 41 computed focal mechanisms of this seismic series to analyze its seismotectonics and structural characteristics. To group the focal mechanisms we used a clustering algorithm using the spatial distribution of the events and also the type of rupture mechanism. For each cluster we have obtained the composed focal mechanism, associating it to a particular fault or family of structures. We have tested the mechanical compatibility of these structures by Coulomb Failure Stress transfer modeling. The mainshock of the series occurred in the Al Idrisi Fault intersecting the western Alboran Ridge. This event triggered aftershocks and independent series in left-lateral strike-slip faults associated with the Al Idrisi Fault System towards the south, but also in near pure reverse faults in the fault zone bounding the the Alboran Ridge. Both types of faults and rupture-mechanisms coexist, linked mechanically by stress transfer, being coeval the uplift of the Alboran Ridge and its northwestward displacement due to the left-lateral motion of the Al-Idrisi Fault. It is also discussed how the contrasting faulting processes and seismic ruptures are developed in two differentially oriented fault zones in the context the current NW-SE plate convergence between the African and Eurasian plates in the Westernmost Mediterranean

Shaking earth: Non-linear seismic processes and the second law of thermodynamics: A case study from Canterbury (New Zealand) earthquakes

We would like to express our gratitude to GeoNet for making available the data used in this work. This work was partially sup-ported by the RNM104 and RNM194 (Research Groups belonging to Junta de Andalucia, Spain) , the Spanish National Projects [grant project PID2019-109608GB-I00] , and the Junta de Andalucia Project [grant project A-RNM-421-UGR18] . English language editing was performed by Tornillo Scientific.Earthquakes are non-linear phenomena that are often treated as a chaotic natural processes. We propose the use of the Second Law of Thermodynamics and entropy, H, as an indicator of the equilibrium state of a seismically active region (a seismic system). In this sense, in this paper we demonstrate the exportability of first principles (e.g., thermodynamics laws) to others scientific fields (e.g., seismology). We suggest that the relationship between increasing H and the occurrence of large earthquakes reflects the irreversible transition of a system. From this point of view, a seismic system evolves from an unstable initial state (due to external stresses) to a state of reduced stress after an earthquake. This is an irreversible transition that entails an increase in entropy. In other words, a seismic system is in a metastable situation that can be characterised by the Second Law of Thermodynamics. We investigated two seismic episodes in the Canterbury area of New Zealand: the 2010 Christchurch earthquake (M = 7.2) and the 2016 Kaikoura earthquake (M = 7.8). The results are remarkably in line with our theoretical forecasts. In other words, an earthquake, understood as an irreversible transition, must results in an increase in entropy.Research Groups belonging to Junta de Andalucia, Spain RNM104- RNM194Spanish National Projects PID2019-109608GB-I00Junta de Andalucia A-RNM-421-UGR1