Design of a test bench for measuring friction force in a piston-cylinder system

In the present work, design of a first approach of a test bench prototype for measuring friction in a piston-cylinder system is presented. The bench consists of a motor, belt and pulley transmission, crank mechanism, a piston, a cylinder and a lubrication system. Friction will be determined by means of strain gages placed on the connecting rod of the mechanism. The bench also includes a phonic wheel for acquiring angular speed and angular position signals of the crank. In future research, friction will be studied for different surface finishes obtained by means of honing and plateau honing. Honing processes provide a crosshatch pattern that holds oil and helps lubrication of piston and rings. Honing conditions will be selected with the goal of minimizing friction. Friction is directly related to energy consumption of an engine and, thus, to its environmental impact. Keywords: test bench, friction, piston-cylinder system, honing, roughness.Postprint (published version

Las rocas ultrabásicas de Castriz (La Coruña) y sus posibles mineralizaciones de Cu y Ni

[Resumen] Por su posible contenido en mineralizaciones de sulfuros de Ni y Cu, se ha estudiado un sill de rocas básicas y ultrabásicas (de 4 x 1 km de extensión aproximadamente) en el que se ha realizado cartografía geo1ógica a escala 1:5.000 con apoyo petrográfico y calicatas con análisis de las rocas para Ni, Cu, 20 y Cr. En este sill se han diferenciado metagabros, peridotitas y piroxenitas, determinándose con los análisis químicos una zona de 1.000 x 70 metros con unas leyes medias de 0,17% en Cu y 0,5% en Ni.

An ab initio multiconfigurational description of core hole and shake up excited states in small molecules

In this contribution, equilibrium geometries and potential energy curves computed at the CASSCF level of theory for the core hole and shake up superexcited states of small size molecules will be presented. The effect of dynamic correlation on the description of these species will be discussed based on preliminary multireference configuration interaction energetic

First record of the genus Sernokorba Kamura, 1992 from the Iberian Peninsula with new data on Sernokorba tescorum (Simon, 1914) (Araneae: Gnaphosidae)

Se cita por primera vez para la Península Ibérica el género Sernokorba Kamura, 1992 (Araneae, Gnaphosidae). Se ilustra la distribución de la especie y se aportan datos sobre la morfología de ambos sexos, la fenología y su aparente preferencia por zonas con arbolado como son los bosques de quercíneas.The presence of the genus Sernokorba Kamura, 1992 (Araneae, Gnaphosidae) is recorded for the first time for the Iberian Peninsula. The distribution of the species is illustrated and data are provided on the morphology of both sexes, its phenology and its apparent preference for wooded areas such as Quercus forests.Estudio parcialmente financiado por el Ministerio de Economía y Competitividad (CGL2011-23658)

Linyphiidae (Araneae) en oquedades de roble en un bosque Mediterráneo: nuevas descripciones y distribución temporal de especies notables

Hollows in mature trees provide a variety of habitats for high species richness and diversity of different arthropod groups. The scarcity of samplings carried out in tree hollows, especially on spiders and on mature oaks, predict the existence of taxonomic novelties in these rich microenvironments. A total of 18 Linyphiidae species, including one species new to science, were sampled with 49 tree hollow emergence traps set in deciduous Quercus forests in the Western Iberian Peninsula. Both sexes of Scotinotylus vettonicus Barrientos & Hernández-Corral sp. nov. and the female of the endemic Iberian Pelecopsis monsantensis Bosmans & Crespo, 2010 are described and both sexes of these two species and of Centromerus succinus (Simon, 1884) are illustrated. In addition, the spatial and temporal distribution of P. monsantensis, C. succinus, Midia midas (Simon, 1884) and Lepthyphantes minutus (Blackwall, 1833) is figured. Furthermore, the checklist of Linyphiidae species recorded in Salamanca province (Spain) is updated to a total of 40 species, representing 13% of all the linyphiids occurring in the Iberian Peninsula.Las oquedades en árboles maduros proporcionan una variedad de hábitats para una alta riqueza de especies y diversidad de diferentes grupos de artrópodos. La escasez de muestreos llevados a cabo en oquedades, especialmente sobre arañas y en robles maduros, hace prever la existencia de novedades taxonómicas en estos ricos microambientes. Un total de 18 especies de Linyphiidae, incluida una especie nueva para la ciencia, fueron colectadas utilizando 49 trampas de emergencia en oquedades de bosques caducifolios de Quercus en el Oeste de la Península Ibérica. Se describen ambos sexos de Scotinotylus vettonicus Barrientos & Hernández-Corral sp. nov. y la hembra del endemismo ibérico Pelecopsis monsantensis Bosmans & Crespo, 2010, y se ilustran ambos sexos de estas dos especies y de Centromerus succinus (Simon, 1884). Además, se representa la distribución espacial y temporal de P. monsantensis, C. succinus, Midia midas (Simon, 1884) y Lepthyphantes minutus (Blackwall, 1833). Además, se actualiza la lista de especies de Linyphiidae presentes en la provincia de Salamanca (España) a un total de 40 especies, lo que representa el 13% de todos los linífidos citados en la Peninsula Ibérica.Financial support was provided by the “Ministerio de Ciencia e Innovación”, Spain (CGL2011-23658, CGL2016‐78181‐R)

Las agregaciones espaciotemporales entre especies no descartan la competencia interespecífica en los ensambles de arañas de las oquedades arbóreas

1. A community's biological diversity reflects coexistence between species. This often depends, to some extent, on whether there is competition for resources and how it is dealt with. 2. The nature of old-growth tree hollows is confined and relatively isolated, which makes them ideal for investigating the competition phenomena between their inhabitants, such as Araneae. 3. The existence of interspecific competition in the structuring of tree hollow spider assemblages in Mediterranean forests was inferred by spatial co-occurrence pattern analyses with null models at both the community and pairwise levels. The analysis included 36 spider species collected monthly with emergence traps for 1 year. The distribution of four ecological traits, body size and phenology on the resulting pattern type was discussed. 4. The analyses showed spatial segregation at the community level and spatial aggregations between species with different traits predominated at the pairwise level. Hunting strategy and body size were the main differential traits to facilitate these aggregations. In addition, only the aggregations led by Amaurobius scopolii–Scotophaeus scutulatus and Eratigena atrica–Liocranum majus also showed an overlap during their main activity period. 5. Community segregation and spatio-temporal aggregations of species with differential traits suggest that interspecific competition is a very likely structuring factor of tree hollow spider assemblages. Instead, segregations at the pairwise level seem to result from other factors, for example, habitat preferences.We are grateful to the Spanish Ministry of Economy, Industry and Competitiveness for contributing financial support to Project CGL2016-78181-R. This reserach forms part of Gerard Martínez Devesa's PhD studies granted by 'Ministerio de Universidades'(REF. FPU21/00249

DESARROLLO DE UN CÓDEC IM AF E INTEGRACIÓN EN SONIC VISUALISER

Este PFC se ha hecho en colaboración con la Queen Mary University of London, durante la estancia de Panos Kudumakis en el grupo ATIC (grupo PAIDI TIC 208)En este PFC se describe el desarrollo completo de un codificador/decodificador de IM AF (nuevo formato de audio interactivo) y su integracion en Sonic Visualiser.Andalucia Tech, Junta de Andalucía Proyecto de Excelencia Motriz P11-TIC-715