Discontinuidades estratigráficas en el Jurásico de Sierra Gorda (Subbético intnerno, Provincia de Granada)

En el Jurásico de la unidad de Sierra Gorda (Subbético interno, prov. Granada) se reconocen cinco discontinuidades estratigráficas:en el Carixiense, en la base del Dogger, en la base del Calloviense en la base del Oxfordense y en el Kimmeridgiense. En el sector septentrional de la unidad se detectan por superficies de omisión y hardgrounds, mientras que en el borde meridional muesitran gran desarrollo de diques neptúnicos

La sedimentación liásica en el sector central del Subbético medio: registro de la evolución de un rift intracontinental

Durante el Lias medio tuvo lugar el paso brusco de la sedimenta-ción carbonatada somera a la pelágica en la Zona Subbética, en relación con la evolución de un rift intracontinental. Se han podido delimitar cuatro etapas con sus sedimentos correspondientes: a) Etapa prerruptura (sedimentación marina somera). b) Inicio de la rup-tura (hardgrounds y paleokarst). c) Comienzo de la sedimentación hemipelágica (niveles de calizas  condensadas). d) Individualización del surco subbético (ritmita  calizas/margas)

Evolución de fascies abanico aluvial-fluvial-lacustre en el Plioceno de la Depresión de Guadix-Baza

El corte del Río de Gor muestra la evolución lateral de los materiales de la Fm. Guadix (fluvial) a la Fm. Gorafe-Huelago (lacustre). Desde el borde de la cuenca hacia el interior (en 6 km) se reconocen, en los materiales pliocenos, los siguientes medios sedimentarios yuxtapuestos: A. Abanico aluvial medio. B. Abanico aluvial medio. C. Ríos trenzados (braided). D. Meandriforme proximal. E. Meandriforme distal. F. Llanura lutítica. G. Medio lacustr

Activació dels músculs del tronc durant situacions que requereixen l’estabilització del raquis. Estudi de cas únic

L’objectiu d’aquest estudi va ser analitzar la intensitat de la contracció i la coordinació de 14 músculs del tronc i del muscle d’un subjecte durant la recepció i el llançament d’una pilota medicinal (acció pliomètrica), una acció d’embranzida en posició dempeus (pressió de pit horitzontal amb politja) i l’ús del Bodyblade® (barra flexible l'oscil·lació de la qual sotmet el cos a vibracions i desequilibris continus). Igualment, amb l'objecte de facilitar la discussió en relació amb l'estabilització activa del raquis, es va registrar la resposta dels músculs esmentats durant l'aplicació controlada sobre el tronc de càrregues i descàrregues desequilibrants. Els nostres resultats indiquen que l'activació dels músculs del tronc és important, tant per a estabilitzar el raquis davant pertorbacions i desequilibris sobtats, com per a l'execució d'accions on els membres superiors manegen objectes. En aquest sentit, la coactivació dels músculs del tronc va ser necessària per estabilitzar el raquis davant les oscil·lacions del Bodyblade® i davant les forces de reacció produïdes en empènyer una càrrega pesada en posició erecta. De la mateixa manera, la recepció i el llançament immediat de la pilota medicinal és una activitat relativament complexa que requereix l'acció coordinada dels músculs del tronc i de les extremitats

Influence of The Segregation Phenomenon on Structural Efficiency of Lightweight Aggregate Concretes

Lightweight aggregate concretes (LWAC) are versatile and interesting materials for projects that require greater structural efficiency. Due to the difference that exists between the densities of the materials used in these types of concrete, during transport and mainly compaction, their aggregates tend to separate from the mortar matrix, floating towards the surface, a phenomenon called segregation. Segregation in LWAC can affect its durability properties, its density, and directly affect its structural efficiency. In this work, different concrete densities (1700 kg/m3 and 1900 kg/m3) manufactured with different dosages (two different lightweight aggregates) and compaction methods (one or two layers) were analyzed to verify the impact of segregation on its structural efficiency. For this purpose, the segregation index of the LWAC was obtained by means of the image analysis technique. In addition, to obtain their structural efficiency, the density and compressive strength were obtained at different heights of the tested specimens. The results show the vibration of the samples in two layers leads to a more efficient elimination of trapped air, a reduction in the risk of segregation, and better structural efficiency.This research was funded by the University of Alicante ((GRE13‐03) and (VIGROB‐256))

Use of nanomaterials to conserve the stone of the Roman Theatre of Cartagena

[EN] The Roman Theatre of Cartagena is an important example of the monumental architecture of Hispania. Various types of local stone were used in its construction, including a type of sandstone known as Tabaire. This paper describes the physical characteristics of Tabaire. We also identify its deterioration patterns and study its consolidation using lime nanoparticles and silicon dioxide (ethyl silicate). Initial analyses using the imaging techniques Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and X-Ray Tomography (CT) show that it is an extremely porous, soft stone. The effectiveness of the consolidating treatments was verified using non-destructive methods based on identifying dispersion and penetrability in the substrate (OM and SEM) and detecting colour variation (CIE-L*a*b*) or minimally destructive methods, such as the peeling test and Shore-D hardness, to determine their effect on the characteristics of the material.[ES] El Teatro de Cartagena es un importante exponente de la arquitectura monumental de la Hispania romana. Para su construcción fueron utilizados diversos pétreos locales, entre ellos una arenisca conocida como Tabaire. Este artículo tiene como objetivo la caracterización física del Tabaire, así como la identificación de sus formas de deterioro y el estudio de su consolidación mediante nanopartículas de cal y de dióxido de silicio (silicato de etilo). Los análisis iniciales mediante técnicas de imagen como la Microscopía Óptica (OM), Microscopía Electrónica de Barrido (SEM) y Tomografía de Rayos X (CT) muestran que es una roca de elevada porosidad y escasa dureza. La eficacia de los tratamientos consolidantes se comprobó mediante métodos no destructivos, basados en la identificación de la dispersión y penetrabilidad en el sustrato (OM y SEM) y en la detección de la variación del color (CIE-L*a*b*), o mínimamente destructivos, como el peeling test y la dureza Shore-D, para conocer su incidencia en las características del material.Navarro-Moreno, D.; Martínez-Arredondo, A.; García-Vera, VE.; Lanzón, M. (2023). Uso de nanomateriales para la conservación de la piedra del Teatro Romano de Cartagena. Loggia, Arquitectura & Restauración. (36):106-119. https://doi.org/10.4995/loggia.2023.193601061193

Combustion Recession after End of Injection in Diesel Spray

This work contributes to the understanding of physical mechanisms that control flashback, or more appropriately combustion recession, in diesel-like sprays. Combustion recession is the process whereby a lifted flame retreats back towards the injector after end-of-injection under conditions that favor autoignition. The motivation for this study is that failure of combustion recession can result in unburned hydrocarbon emissions. A large dataset, comprising many fuels, injection pressures, ambient temperatures, ambient oxygen concentrations, ambient densities, and nozzle diameters is used to explore experimental trends for the behavior of combustion recession. Then, a reduced-order model, capable of modeling non-reacting and reacting conditions, is used to help interpret the experimental trends. Finally, the reduced-order model is used to predict how a controlled ramp-down rate-ofinjection can enhance the likelihood of combustion recession for conditions that would not normally exhibit combustion recession. In general, fuel, ambient conditions, and the spray rate-of-injection transient during the end-of-injection determine the success or failure of combustion recession. The likelihood of combustion recession increases for higher ambient temperatures and oxygen concentrations as well as for higher reactivity fuels. In the transition between high and low ambient temperature (or oxygen concentration), the behavior of combustion recession changes from spatially sequential ignition to separated, or isolated, ignition sites that eventually merge. In contradistinction to typical diesel ignition delay trends where the autoignition times are longer for increasing injection pressure, the time required for combustion recession increases with injection pressure.Knox, BW.; Genzale, C.; Pickett, L.; García-Oliver, JM.; Vera-Tudela, WM. (2015). Combustion Recession after End of Injection in Diesel Spray. SAE International Journal of Fuel and Lubricants. 8(2):1-17. doi:10.4271/2015-01-0797S1178

Identification and conservation of remnant genetic resources of brown trout in relict populations from Western Mediterranean streams

This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at: https://doi.org/10.1007/s10750-012-1402-8Brown trout is a cold-adapted freshwater species with restricted distribution to headwater streams in rivers of the South European peninsulas, where populations are highly vulnerable because Mediterranean regions are highly sensitive to the global climatic warming. Moreover, these populations are endangered due to the introgressive hybridization with cultured stocks. Individuals from six remnant populations in Western Mediterranean rivers were sequenced for the complete mitochondrial DNA control region and genotyped for 11 nuclear markers. Three different brown trout lineages were present in the studied region. Significant genetic divergence was observed among locations and a strong effect of genetic drift was suggested. An important stocking impact (close to 25%) was detected in the zone. Significant correlations between mitochondrial-based rates of hatchery introgression and water flow variation suggested a higher impact of stocked females in unstable habitats. In spite of hatchery introgression, all populations remained highly differentiated, suggesting that native genetic resources are still abundant. However, climatic predictions indicated that suitable habitats for the species in these rivers will be reduced and hence trout populations are highly endangered and vulnerable. Thus, management policies should take into account these predictions to design upstream refuge areas to protect remnant native trout in the regionThis study has been supported by the Generalitat Valenciana Autonomous Government (Spain) project (2008/CI446)S