4,354 research outputs found
Some colored travertines from the Betic Range (SE Iberian Peninsula): their geological setting and petrophysical properties
En la zona Bética Externa, se encuentran depósitos de travertinos coloreados de valor como rocas ornamentales cuyas características petrofísicas son poco conocidas. Están en relación con fallas activas. Las canteras de travertino se sitúan en Alhama de Almería, Albox (Almería) y Baños de Mula (Murcia). Estos travertinos forman parte de la última etapa del relleno de las cuencas terciarias postectónicas béticas (Pleistoceno) y generalmente aparecen espacialmente asociados a episodios tobáceos. El objetivo de este trabajo es definir las facies de estos travertinos y las características petrofísicas que presentan con vistas a su utilización como roca ornamental. Predominan en ellos las facies bandeadas (1 - 10 cm). Su porosidad es variable (5 - 15%) consistente en una microporosidad bastante homogénea, con moda (0.005-0.05 μm) ligada al carbonato micrítico, y una familia de poros menos seleccionada entre 0.05-2 μm asociada a cristales de mayor tamaño. La macroporosidad de tamaño y disposición variable es un rasgo característico de estos travertinos. El coeficiente de absorción capilar es muy anisótropo y varía mucho en los diferentes travertinos estudiados. El valor mínimo encontrado en travertinos comercializados ha sido de 1.42 (g/m2s0.5) en dirección oblicua a la estructura en el travertino Rojo Alhama y el máximo de 10.71(g/m2s0.5) en dirección paralela a la estructura en el travertino de Albox. Su resistencia es notablemente anisótropa, encontrando valores de resistencia a compresión que pueden llegar a alcanzar 68 MPa en dirección perpendicular al bandeado. Cortados en dicha dirección constituyen una roca ornamental de buena calidad dentro de la categoría de mármoles comerciales.The Betic Range contains several colored travertine deposits which were formed during the last stage of the post-tectonic Tertiary-Quaternary (Pleistocene) basin refill. Associated with active faults, these travertines are quarried in Alhama de Almería, Albox (Almería) and Baños de Mula (Murcia) for subsequent use as ornamental stone. The aim of this study was to characterize their facies and physical properties in order to establish their suitability for use as an ornamental stone. The main facies was banded (1-10 cm), and the travertines presented variable porosity ranging from 5-15%. Porosity is related to travertine texture: a) fairly homogeneous microporosity, with a mode between 0.005 and 0.05 μm, is linked to micritic carbonate; and b) a porosity mode varying widely from 0.05 to 2 μm is associated with larger crystals. A characteristic feature of these travertine deposits was their macroporosity of variable size and distribution. The coefficient of capillary absorption was highly anisotropic and presented very different magnitudes in the different travertines studied. A minimum value of 1.42 (g/m2 s0.5) was observed in the commercial Red Alhama travertine, in an oblique direction to the structure, while the maximum value of 10.71 (g/m2 s0.5) was found in Albox travertine deposits, in a parallel direction to the structure. Strength was markedly anisotropic, attaining compressive strength values as high as 68 MPa in the direction perpendicular to the bedding planes. When cut in this direction, the travertines studied yield good quality ornamental stone within the category of commercial marble.Este trabajo ha contado con la ayuda del MEC: Proyecto CGL2006-05027y de la Comunidad de Madrid: Proyectos Geomateriales (S2009/Mat-1629 y S2023/MIT 2914)
Drawing the Architectural Heritage on the Coast of the Mediterranean (1936-39)
During the civil war (1936-39) was built a network of defensive settlements on the coast in anticipation of attacks enemies, forming the so-called 'wall Mediterranean', because of its similarity with the Wall Atlantic of the World War II. These enclaves were composed of groups of batteries, bunkers and buildings. This communication comes to inventory and draw the remains of more than 50 architectures that are located in the Valencian South Coast (from Denia to Torrevieja), documenting the first ruins of hormigion armed with our history. It's a set of military settlements anti-aircraft, mostly scattered coastal rural, which are a great heritage and landscape value, and from which planes haven't been preserved. It is to lift current state record of them all, proceeding to its typological classification, in order to contribute to its assessment and protection on the grounds that they constitute a legacy of architectural heritage that increases our cultural memory.history
A Petal of the Sunflower: Photometry of the Stellar Tidal Stream in the Halo of Messier 63 (NGC 5055)
We present surface photometry of a very faint, giant arc feature in the halo
of the nearby spiral galaxy NGC 5055 (M63) that is consistent with being a part
of a stellar stream resulting from the disruption of a dwarf satellite galaxy.
This faint feature was first detected in early photographic studies by van der
Kruit (1979); more recently by Mart\'inez-Delgado et al. (2010) and as
presented in this work, the loop has been realized to be the result of a recent
minor merger through evidence obtained by deep images taken with a telescope of
only 0.16 m aperture. The stellar stream is confirmed in additional images
taken with the 0.5 m of the BlackBird Remote Observatory and the 0.8 m of the
McDonald Observatory. This low surface brightness structure around the disk of
the galaxy extends ~29 kpc from its center, with a projected width of 3.3 kpc.
The stream's morphology is consistent with that of the visible part of a
"great-circle" stellar stream originating from the accretion of a ~10^8 M_sun
dwarf satellite in the last few Gyr. The progenitor satellite's current
position and fate are not conclusive from our data. The color of the stream's
stars is consistent with Local Group dwarfs and is similar to the outer regions
of M63's disk and stellar halo. We detect other low surface brightness
"plumes"; some of these may be extended spiral features related to the galaxy's
complex spiral structure and others may be tidal debris associated with the
disruption of the galaxy's outer stellar disk as a result of the accretion
event. We differentiate between features related to the tidal stream and faint,
blue features in the outskirts of the galaxy's disk previously detected by the
GALEX satellite. With its highly warped HI gaseous disk (~20 deg), M63
represents one of several examples of an isolated spiral galaxy with a warped
disk showing strong evidence of an ongoing minor merger.Comment: 16 pages, 10 figures, 3 tables, Accepted for publication in The
Astronomical Journa
Active learning based laboratory towards engineering education 4.0
Universities have a relevant and essential key role to ensure knowledge and development of competencies in the current fourth industrial revolution called Industry 4.0. The Industry 4.0 promotes a set of digital technologies to allow the convergence between the information technology and the operation technology towards smarter factories. Under such new framework, multiple initiatives are being carried out worldwide as response of such evolution, particularly, from the engineering education point of view. In this regard, this paper introduces the initiative that is being carried out at the Technical University of Catalonia, Spain, called Industry 4.0 Technologies Laboratory, I4Tech Lab. The I4Tech laboratory represents a technological environment for the academic, research and industrial promotion of related technologies. First, in this work, some of the main aspects considered in the definition of the so called engineering education 4.0 are discussed. Next, the proposed laboratory architecture, objectives as well as considered technologies are explained. Finally, the basis of the proposed academic method supported by an active learning approach is presented.Postprint (published version
Travertine of Baños de Mula. A stone with sedimentological and archaeological interest
Los travertinos coloreados de Baños de Mula fueron utilizados como roca dimensional entre otros sitios, en el Teatro Romano de Cartagena (Travertino Rojo de Mula). Esta roca tiene buenas propiedades mecánicas y buen comportamiento hídrico. Estas propiedades presentan fuerte anisotropía, relacionada con su característica estructura bandeada definida visualmente por cambios en la coloración y en la distribución de los poros. Sus características texturales, muestran el predominio de niveles constituidos por cristales fibrosos y fibroso-radiados, con una fase cementante tardía de oxihidróxidos de Fe, así como morfologías micríticas del tipo de colonias bacterianas. Ambos rasgos pueden relacionarse con actividad bacteriana. Todos estos datos apuntan a favor de una génesis relacionada con aguas termales. Este hidrotermalismo está en relación con fallas activas y se mantiene activo en la actualidad (Balneario de Baños de Mula).The coloured travertine of the Baños de Mula,were used as dimensional stone among other sites in the Roman Theatre in Cartagena (Red Mula Travertine). This rock has good mechanical properties and water behavior. These properties show strong anisotropy related to the characteristic bedding planes visually defined by changes in the color intensity and pore distribution. Their textural features show the prevalence of layers consisting of fibrous and fibrous-radiated crystals with a late stage cementing Fe oxyhydroxides and micritic aggregates following colonial bacterial morphologies. Both features may be related to bacterial activity. All these data point in favor of a genesis related upwelling of thermal waters. These hydrothermal processes are connected with hydrothermal circulation along the active faults, and are manifested at present in the hot springs of Baños de Mula.Este trabajo ha sido parcialmente subvencionado por el proyecto Geomateriales (P2009/MAT-1629) de la Comunidad de Madrid
Personality Traits and Aggression as Explanatory Variables of Cyberbullying in Spanish Preadolescents
There is a growing interest in preventing cyberbullying in youth. However, multiple questions remain as to the relationship between cyberbullying and psychosocial variables. This study examines the relationship between personality traits, aggression and cyberbullying (victims, bullies, victimized bullies and not involved) in 548 Spanish students aged 10 to 13 (50.2% boys). To do so, the Screening of Peer Harassment, the Big Five Questionnaire for Children and the Aggression Questionnaire were used. Logistic regression analyses indicated that the extraversion trait is an explanatory factor for being a victim and openness is a protective factor against being a cyberbully. Agreeableness was found to be a positive predictor of being a cyberbullying victim. Only verbal aggression and anger were included as explanatory factors of being a victim and a victimized bully, respectively. The results are discussed, suggesting their potential implications in the development of preventive programs.This research was funded by the Regional Ministry of Culture, Education and Sport of Region of Valencia (Spain), grant number GV/2015/111, with Beatriz Delgado as the Principal Researcher
Relationship between Cyberbullying, Motivation and Learning Strategies, Academic Performance, and the Ability to Adapt to University
Cyberbullying has become a frequent relational problem among young people, which has made it necessary to evaluate and prevent it in the university setting. The aim of this study is to examine the relationship between cyberbullying, motivation and learning strategies, the ability to adapt to university, and academic performance. A sample of 1368 Spanish university students (64% female) was administered a battery consisting of the European Bullying Intervention Project Questionnaire, the Learning and Study Strategies Inventory Short version, and the Student Adaptation to College Questionnaire, with their academic performance also being studied. The results found that the victimized bullies have greater difficulties in their organization and planning for study and exams, have fewer control and consolidation strategies, and are less able to adapt to university. Logistic regression analyses show that the greater the difficulties in organization and planning, and the greater the difficulties experienced in exams, the greater the probability of a person being a victim and a victimized bully. In addition, students are less likely to be victims, bullies, and victimized bullies as their ability to adapt to university increases. The findings have been discussed and it has been noted that there is a need to address academic adjustment and the ability to adapt to the university environment as a preventive measure for cyberbullying in university students
Red para la elaboración de materiales docentes en el análisis y tratamiento de datos geoquímicos y petrológicos
El trabajo realizado por esta red docente tiene por objetivo el desarrollo de materiales docentes específicos para el análisis y tratamiento de datos geoquímicos y petrológicos dentro de las asignaturas enmarcadas en el tercer curso del Grado en Geología: Petrología Ígnea y Metamórfica, Petrología Sedimentaria y Geoquímica y Prospección Geoquímica. El trabajo se ha centrado en la definición de las actividades a realizar por el estudiante, haciendo especial hincapié en la coordinación de los contenidos y distribución temporal entre las asignaturas anteriormente mencionadas. Los resultados obtenidos durante los cursos precedentes han mostrado la necesidad de desarrollar manuales, páginas webs y videos que permitan el autoaprendizaje del alumno. Una de las principales debilidades encontradas durante el tratamiento de datos radica en el conocimiento de los diferentes pasos intermedios que se realizan, las suposiciones que se consideran y los errores derivados de ellas. La gran parte del material y software docente existente solo proporciona el resultado final del tratamiento de los datos obtenidos en el estudio geoquímico y petrológico de las muestras naturales. Por lo tanto, el material desarrollado para solventar dichos problemas docentes incluye colecciones de problemas y prácticas, videos-tutoriales y el desarrollo de software propio o utilizando software libre
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