3,838 research outputs found
Indicators and Estimators in P-Adaptive Boundary Elements
The paper presents the possibility of implementing a p-adaptive process with the B.E.M. Although the exemples show that good results can be obtained with a limited amount of storage and with the simple ideas explained above, more research is needed in order to improve the two main problems of the method, i.e.: the criteria of where to refine and until what degree. Mathematically based reasoning is still lacking and will be useful to simplify the decission making. Nevertheless the method seems promising and, we hope, opens a path for a series of research lines of maximum interest. Although the paper has dealt only with plane potential problem the extension to plane elasticity as well as to 3-D potential problem is straight-forward
A.G. Werner (1749-1817): los objetos geológicos en el estudio científico de la tierra y su enseñanza
Wild solitary bees and their use of bee hotels in southwest Spain
There is an increasing interest in preserving and, if possible, increasing wild bee populations as evidenced by increasinginvestigations into providing supplemental nesting resources, commonly called bee hotels. The study presented herewas carried out in 2017 and 2018 with two objectives: a) to understand the role that insect refuges could have onbeneficial arthropod fauna, especially bees, and b) to evaluate different materials and which species used them. We pre-sent the preliminary results of three constructed refuges in Seville, Spain: Hymenoptera visited the refuges most fre-quently (88.7% of the visitors), of which the social wasps (Polistes dominula(Christ)) were most common, followed bybees. Bees were observed visiting bamboo canes, Arundo canes, drilled logs, and grooved boards. Drilled logs were themost used material (31.5 and 37.6% occupied in 2017 and 2018, respectively), followed by bamboo canes (14.1 and17.4% of occupied in 2017 and 2018, respectively). For drilled logs, holes of 4.9–6.5mm (2017) and 7.0–9.2 mm (2018)were preferred, whilst diameters of 2.6/2.7–4.9/5.0 mm (both 2017 and 2018) were preferred for bamboo canes. Forgrooved boards, holes of 5.0 mm (only 2018) were preferred. The bee species most frequently nesting in bamboo caneswereCeratina cucurbitina(Rossi) andCeratina dentiventrisGerstacker, whereas in drilled logsHoplitis lepeletieri(P erez)was most common, butHoplitis adunca(Panzer) was also recorded. Their abundance throughout the study period variedbetween species, and their role in biodiversity and sustaining wild flora is discussed
Análisis del comportamiento a compresión de un laminado [0,90,0,90] de tejido no ondulado mediante un modelo 3D de elementos finitos
VI CONGRESO NACIONAL DE MATERIALES COMPUESTOS. Celebrado en Valencia, 27-29 de junio de 2005.El presente trabajo está dedicado al análisis numérico del comportamiento a compresión
de un laminado [0, 90]a de tejido no ondulado o non-crimp fabric (NCF). Para ello se ha
realizado un modelo tridimensional de elementos finitos del laminado a nivel
mesoscópico en el que se han modelado los constituyentes del material, mazos de fibras
y paquetes de resina, como entes homogéneos, sin considerar la microestructura que
caracteriza a cada uno de ellos. Los resultados obtenidos con este modelo muestran que
el mecanismo de fallo a compresión de un laminado de NCF está asociado a la
curvatura que presentan los mazos de fibras en este tipo de materiales compuestos,
como consecuencia del curado. En efecto, en la zona en que dicha curvatura es máxima
aparecen deformaciones tangenciales de diferente signo cuya diferencia crece a medida
que la carga de compresión aplicada aumenta hasta que llega un momento en que el
material no es capaz de soportarlo y se produce el fallo.Unión Europea (FALCOM) G4RD-CT- 0069
Mentiras: historias ciertas en medios con prestigio social
Las más prestigiosas publicaciones del mundo difunden informaciones falsas... de vez en cuando. La cantidad de veces que esto se ha producido en los últimos tiempos empieza a inquietar a la profesión y a la sociedad. El texto relata casos relevantes en los que medios de comunicación o publicaciones científicas han publicado informaciones que, posteriormente, se demostraron falsas
Report on fisheries mangement in international deep sea water and its biodiversity conservation
It is a repport on the FAO "Analysis and guide for the implementation of international and policy instruments related to deep sea fisheries and biodiversity conservation in ABJN (Areas Beyond National Jurisdiction)” of 27th June 2016
Prehistoria de la matemática y mente moderna : pensamiento matemático y recursividad en el Paleolítico franco-cantábrico
En este artículo, en primer lugar, se repasan de forma general distintos tipos de registros simbólicos realizados por los grupos prehistóricos desde los más remotos y probables orígenes de la mente humana moderna. A continuación, se revisan algunas de las más destacadas piezas de la Prehistoria relacionadas con el registro matemático, destacando la importancia (por cantidad y calidad), no suficientemente valorada, de las piezas de este tipo de la región franco-cantábrica. La información anterior, finalmente, nos da pie a destacar la tremenda importancia en este contexto de cuatro plaquitas de hueso hioides de caballo de la Cueva de Altamira, datadas en el Solutrense Superior (c. 18.500 años). Estas plaquitas, al ser un conjunto coherente de elementos interrelacionados, se proponen aquí como la representación de una recursividad, cualidad ésta que se ha considerado como propia y exclusiva del lenguaje humano
Characterization of fimbriae extracts from porcine enterotoxigenic Escherichia coli strains carrying F6 (987P) antigen
Fimbrial extracts from porcine enterotoxigenic Escherichia coli (ETEC) strains carrying F6 (987P) intestinal colonization factor antigen were obtained using the thermal shock method. The extracts were analyzed by SDSPAGE and immunoblotting using different fimbriae-specific antisera. Two major protein bands with molecular masses of 17.5 and 21.9 kDa were detected. The 21.9-kDa band was identified as the major subunit of F6 fimbrial antigen in strains of serogroups O9 and O141. The 17.5-kDa band was associated with porcine strains of serogroups O9 and O20. [Int Microbiol 2006; 9(4):241-246
Field measurements of angular motions of a vessel at berth: Inertial device application
[Abstract]: The study and characterization of the oscillations of a moored vessel has a major importance in port operational efficiency, not only in the design of mooring and anchoring systems, but also in order to prevent the movement of the cargo, minimize ship and dock damage and optimizing the operations which have to take place while the ship is moored.The dynamic behavior of a vessel moored in waves has been mathematically described and interactions between ships and environmental loads such as waves, wind, currents and ice are commonly tested for different docks and mooring systems in scale models. However, field data studies of the behavior moored ships have not been properly addressed so far.This paper proposes a novel application of Inertial Measurement Units to estimate the angular movements (roll, pitch and yaw) of a moored vessel. The proposed technique has been validated in laboratory conditions and the behavior of the ship Urania Mella in the Outer Port of Punta Langosteira (A Coruña, Spain), has been analyzed, obtaining very promising results.This research was funded by the Spanish Ministry of Economy, Industry and Competitiveness, R&D National Plan, within the project BIA2017-86738-
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