Concrete Swelling in Existing Dams

Several chemical reactions are able to produce swelling of concrete for decades after its initial curing, a problem that affects a considerable number of concrete dams around the world. Principia has had several contracts to study this problem in recent years, which have required reviewing the state-of-the-art, adopting appropriate mathematical descriptions, programming them into user routines in Abaqus, determining model parameters on the basis of some parts of the dams’ monitored histories, ensuring reliability using some other parts, and finally predicting the future evolution of the dams and their safety margins. The paper describes some of the above experience, including the programming of sophisticated non-isotropic swelling models, that must be compatible with cracking and other nonlinearities involved in concrete behaviour. The applications concentrate on two specific cases, an archgravity dam and a double-curvature arch dam, both with a long history of concrete swelling and which, interestingly, entailed different degrees of success in the modelling effort

Trace fossil characterization during Termination V and MIS 11 at the western Mediterranean: Connection between surface conditions and deep environment

This study was supported by the predoctoral FPU contract FPU17/03349 awarded to A. Gonzalez-Lanchas by the Spanish Ministry of Sci-ence, Innovation and Universities. The research by JD was funded through the Juan de la Cierva Program (IJC2019-038866-I) by the Spanish Ministry of Science and Innovation. Essential financial infra-structure was provided by the programs RTI2018-099489-B-100 of the Spanish Ministry of Science, Innovation and Universities granted to GGO (Grupo de Geociencias Oceanicas de la Universidad de Salamanca) and CGL2015-66835-P and PID2019-104625RB-100 of the Spanish Ministry of Science, Innovation and Universities and B-RNM-072-UGR18, P18-RT-4074 of the Andalusian Government granted to Ichnology and Palaeoenvironment RG (University of Granada) . We thank Alessandra Negri and the two anonymous reviewers, whose comments contributed to improve this manuscript.Trace fossil assemblages are studied at Ocean Discovery Program (ODP) Site 977 to characterize the response of the macrobenthic trace maker community to deep paleoenvironmental conditions during the Termination V (TV) and interglacial Marine Isotope Stage (MIS) 11 at the western Mediterranean Alboran Sea. An assemblage composed of Chondrites, Planolites, Scolicia, Thalassinoides and Zoophycos is identified, showing notable variations in ichnodiversity, abundance and Bioturbation Index, that were analyzed in detail. The integration of ichnological information with sediment color and high-resolution coccolithophore records from Site 977, evidenced that variations in macrobenthic trace maker community are primarily controlled by oxygen availability and surface organic productivity patterns. During TV, high surface organic productivity by intense Alboran Upwelling System enhanced the deep organic accumulation that, together with reduced deep-water removal, resulted in a decrease of bioturbation and the formation of an Organic Rich Layer. Moderate and stable surface production through MIS 11c reduced deep food availability, resulting in an oligotrophic and stable deep environment. This is reflected by relatively abundant trace fossils in lighter sediments. Intra-interglacial increase in surface organic production at ~405 ka is evidenced by increased organic matter preservation. Minor impact of western Mediterranean circulation on deep-water removal, but a plausible stronger control by Bernoulli aspiration intensities in the region, is, in overall, observed during these intervals. During the Heinrich-type (Ht) events 3 and 2, increased trace fossil diversity and ameliorated oxygenation is driven by limited surface organic production, but intense western Mediterranean deep-water circulation and enhanced regional deep-water removal.Spanish Government FPU17/03349Juan de la Cierva Program by the Spanish Ministry of Science and Innovation IJC2019-038866-ISpanish Government RTI2018-099489-B-100 CGL2015-66835-P PID2019-104625RB-100Andalusian Government B-RNM-072-UGR18 P18-RT-407

Investigar la Comunicación en el Departamento de Administración de Empresas y Marketing de la Universidad de Sevilla

Este trabajo recoge las principales investigaciones sobre comunicación llevadas a cabo por los profesores del Departamento de Administración de Empresas y Marketing. Se ha hecho una revisión de las publicaciones de los últimos 20 años y se han extraído y agrupado por tópicos los trabajos de investigación realizados. Se ha tenido en cuenta la pertenencia a las dos áreas específicas del Departamento “Organización de Empresas” y “Marketing”. Este estudio pone de manifiesto la importancia de la comunicación en la investigación de administración de empresas y la involucración del profesorado adscrito a la Facultad de Comunicación, que centran parte de su labor investigadora en los conocimientos específicos que se imparten en el centro

Laboratorio Web para prototipado y verificación de sistemas hardware/software

Versión electrónica de la ponencia presentada en Jornadas de Computación Reconfigurable y Aplicaciones, celebrado en Madrid en 2003En este trabajo se presenta un laboratorio Web basado en plataformas reconfigurables. El usuario sólo necesita un ordenador personal con acceso a Web para implementar un prototipo de un sistema digital, siendo posible además verificar su funcionamiento. El entorno permite trabajar en remoto con las herramientas de síntesis e implementación de un diseño digital en un circuito FPGA desde una descripción VHDL. También es posible la compilación en remoto de código fuente descrito en C para ser ejecutado en el procesador embebido de la plataforma. El laboratorio se ha probado con éxito para complementar los contenidos teóricos de un curso de postgrado. Los experimentos incluyen la realización de sistemas especializados que involucran: el estudio de la interface de los componentes hardware específicos y el procesador con el que intercambian datos, la verificación de un prototipo de procesador implementado en FPGA y el desarrollo de módulos hardware para aplicaciones en robótica. En todos los casos el usuario consigue una implementación de un prototipo del sistema completamente operativo para su utilización directa en aplicaciones prácticas.Este trabajo ha sido parcialmente financiado por los proyectos TIC2000-0464 y TIC2001- 2688-C03-03 y del Ministerio de Ciencia y Tecnología

MicroBlaze en sistemas embebidos para aplicaciones criptográficas

En este trabajo se presenta un estudio sobre el “Soft Core Processor” MicroBlaze como microprocesador en sistemas embebidos para aplicaciones que involucran algoritmos de criptografía. Se analiza el rendimiento alcanzado para un conjunto representativo de los algoritmos simétricos más empleados: DES, 3DES, IDEA, BLOWFISH y AES. Se proponen diferentes arquitecturas del sistema que aprovechen mejor los recursos internos del microprocesador. Se estudia la mejora de rendimiento asociada con cada variación de la arquitectura interna, y se compara con la integración en el sistema de un core de cifrado específico, implementado en el hardware reconfigurable. Los resultados obtenidos permiten concluir que MicroBlaze puede ser considerado un serio candidato para este tipo de aplicaciones.Trabajo financiado por los proyectos 07T/0052/2003-3 de la Consejería de Educación de la CAM y TIC2001-2688-C03-03 del Ministerio de Ciencia y Tecnología de España

Effect of fermented, hardened, and dehulled of chickpea (Cicer arietinum) meals in digestibility and antinutrients in diets for tilapia (Oreochromis niloticus)

Among the most typical feed sources for tilapia, plants represent a low-cost source in substituting for traditional high-cost feed ingredients. Fermentation, hardening and dehulling are common grains processing techniques to make plant nutrients available and more digestible to fish. Apparent digestibility coefficients (ADC) of dry matter and protein, and antinutrients (phytic acid and tannins) in fermented, hardened and dehulled chickpea (Cicer arietinum) meals were determined for juvenile Nile tilapia (Oreochromis niloticus). The highest ADC was obtained with processed (fermented, hardened and dehulled) chickpea meals compared with non-processed. Results indicated that fermentation increased the protein content by 13.1%, decreased the content of ash and phytic acid (47.5 and 45%, respectively), and increased the ingredient apparent digestibility of dry matter (ADM) by 23.2%, and the ingredient apparent digestibility of protein (ADP) by 41.9%. Dehulling meal increased the protein (5.7%) and lipid (6.4%) content of chickpea grains; decreased fiber, ash and tannin content (75.3%, 19.1%, and 84.5%, respectively); and increased ADM by 12.8%, and ADP by 10.4%. We conclude that fermented, hardened and dehulled chickpea meals represent a potential alternative in diets for juvenile O. niloticus

A structure-preserving upwind DG scheme for a degenerate phase-field tumor model

In this work, we present a modification of the phase-field tumor growth model given in [26] that leads to bounded, more physically meaningful, volume fraction variables. In addition, we develop an upwind discontinuous Galerkin (DG) scheme preserving the mass conservation, pointwise bounds and energy stability of the continuous model. Finally, some computational tests in accordance with the theoretical results are introduced. In the first test, we compare our DG scheme with the finite element (FE) scheme related to the same time approximation. The DG scheme shows a well-behavior even for strong cross-diffusion effects in contrast with FE where numerical spurious oscillations appear. Moreover, the second test exhibits the behavior of the tumor-growth model under different choices of parameters and also of mobility and proliferation functions.Comment: 32 pages, 15 figure

An unconditionally energy stable and positive upwind DG scheme for the Keller-Segel model

The well-suited discretization of the Keller-Segel equations for chemotaxis has become a very challenging problem due to the convective nature inherent to them. This paper aims to introduce a new upwind, mass-conservative, positive and energy-dissipative discontinuous Galerkin scheme for the Keller-Segel model. This approach is based on the gradient-flow structure of the equations. In addition, we show some numerical experiments in accordance with the aforementioned properties of the discretization. The numerical results obtained emphasize the really good behaviour of the approximation in the case of chemotactic collapse, where very steep gradients appear.Comment: 24 pages, 17 figures, 4 table

Concrete Swelling in Two Spanish Dams

Several chemical reactions are able to produce swelling of concrete for decades after its initial curing, a problem that affects a considerable number of concrete dams around the world. Principia has had several contracts to study this problem in recent years, which have required reviewing the state-ofthe-art, adopting appropriate mathematical descriptions, programming them into user routines in Abaqus, determining model parameters on the basis of some parts of the dams’ monitored histories, ensuring reliability using some other parts, and finally predicting the future evolution of the dams and their safety margins. The paper describes some of the above experience, including the programming of sophisticated nonisotropic swelling models, that must be compatible with cracking and other nonlinearities involved in concrete behaviour. The applications concentrate on two specific cases, an arch-gravity dam and a double-curvature arch dam, both with a long history of concrete swelling and which, interestingly, entailed different degrees of success in the modelling effort