Elementos para entender el comportamiento de las cajas de ahorros andaluzas entre 1990 y 2000

En este trabajo analizamos el proceso de fusiones llevados a cabo en Andalucía entre sus cajas de ahorros que no han obedecido a modelos asépticos, sino que por el contrario han sido inducidos desde el gobierno autonómico. Al final el modelo resultante ha padecido esa intervención y se han producido cambios en las estrategias. La consecuencia ha sido que aquellas entidades con una mayor presión política están siendo las más débiles. También los mejores resultados lo han conseguido aquellas cajas que han mantenido a sus equipos directivos. Al mismo tiempo la especialización geográfica también ha sido y está siendo determinante en la solvencia, rentabilidad y expansión-consolidación. No ha habido un modelo de fusión y la cooperación, como alternativa, ha fracasado

Laser surface texturing of a WC-CoNi cemented carbide grade: surface topography design for honing application

Abrasive effectiveness of composite-like honing stones is related to the intrinsic surface topography resulting from the cubic boron nitride (CBN) grains protruding out of the metallic matrix. Within this framework, Laser Surface Texturing (LST) is implemented for replicating topographic features of a honing stone in a WC-base cemented carbide grade, commonly employed for making tools. In doing so, regular arrays of hexagonal pyramids (similar to CBN grains) are sculpted by a laser micromachining system. Micrometric precision is attained and surface integrity does not get affected by such surface modification. Finally, potential of laser-patterned cemented carbide tools, as alternative to conventional honing stones, is supported by successful material removal and enhanced surface smoothness of a steel workpiece in the abrasive testing.Peer ReviewedPostprint (author's final draft

Influence of the microstructure on the thermal shock behavior of cemented carbides

The influence of single and repetitive sudden changes of temperature on the mechanical integrity of cemented carbides was investigated as a function of their microstructure. Thermal shock resistance was assessed by testing the residual flexural strength of hardmetal beams after being subjected to thermal shock by water quenching. Results indicate that hard cemented carbides tend to exhibit a superior resistance to the nucleation of thermal shock damage but a lower resistance to the propagation of this damage mechanism than tough grades, and vice versa. These trends are in agreement with those expected from the evaluation of the thermal shock Hasselman’s parameters. The evidenced strength loss after thermal shock may be related to the subcritical growth of intrinsic flaws driven by localized microcracking surrounding them. Results also point out on Ni-base hardmetals to exhibit a slightly higher resistance to abrupt changes of temperature than Co-base ones.Peer ReviewedPostprint (author's final draft

Collider production of Electroweak resonances from photon-photon states

We estimate production cross sections for 2-body resonances of the Electroweak Symmetry Breaking sector (in $W_LW_L$ and $Z_LZ_L$ rescattering) from $\gamma\gamma$ scattering. We employ unitarized Higgs Effective Field Theory amplitudes previously computed coupling the two photon channel to the EWSBS. We work in the Effective Photon Approximation and examine both $e^-e^+$ collisions at energies of order 1-2 TeV (as relevant for future lepton machines) and $pp$ collisions at LHC energies. Dynamically generating a spin-0 resonance around 1.5 TeV (by appropriately choosing the parameters of the effective theory) we find that the differential cross section per unit $s$, $p_t^2$ is of order 0.01 fbarn/TeV$^4$ at the LHC. Injecting a spin-2 resonance around 2 TeV we find an additional factor 100 suppression for $p_t$ up to 200 GeV. The very small cross sections put these $\gamma\gamma$ processes, though very clean, out of reach of immediate future searches.Comment: 36 pages, 20 plot

Corrosion effects on hertzian contact fatigue behavior of a WC-Co cemented carbide

The effect of corrosion on the damage induced under cyclic contact loading for a medium-grained WC-6%wtCo hardmetal grade is investigated. Contact fatigue tests are conducted by means of Hertzian indentation techniques. Corrosion damage is introduced in a controlled way by previous immersion of specimens in a stirred acidic medium. Results reveal that corrosion significantly influences the contact fatigue behavior of the material under consideration, in terms of the emergence and evolution of specific failure events: partial/full ring, radial cracks, and grain pull-out, among others. As cycle number increases, damage in the uncorroded condition evolves from partial to full ring cracks. Meanwhile, in the corroded condition, damage evolution is dominated by the appearance of grain pull-out when the number of cycles reaches a certain value. These findings are rationalized on the basis of phase assemblage changes linked to corrosion which are then enhanced by the cyclic nature of the applied loads.Postprint (published version

Fatigue testing and properties of hardmetals in the gigacycle range

Hardmetal products are frequently fatigue loaded in service, such as e.g. cutting tools for milling or percussion drills. In the present work, the fatigue behaviour of hardmetals was investigated into the gigacycle range using ultrasonic resonance fatigue testing at 20 kHz in push-pull mode at R = - 1. Liquid cooling was afforded using water with addition of a corrosion inhibitor. Hourglass shaped specimens were prepared, the surface being ground and polished with subsequent stress-relieving anneal to remove the high compressive residual stresses introduced during grinding. S-N curves with fairly low scatter were obtained, which indicates microstructure-controlled and not defect-controlled failure. Low binder content as well as fine WC grains were found to improve the fatigue endurance strength. In no case, however, a horizontal branch of the S-N curve was observed, i.e. there is no fatigue “limit” at least up to 1010 cycles. The initiation sites were in part difficult to identify; in such cases when the site was clearly visible, decohesion of the binder from large WC grains seems to have caused crack initiation. This further corroborates that microstructural features and not singular defects as e.g. inclusions are the initiation sites, which underlines the high purity of the hardmetal grades used. Based on fracture mechanical consideration a damage diagram was determined allowing to deduce critical defect sizes.Peer ReviewedPostprint (author's final draft

EL DELITO DE INICIADOS: CONSEJOS DE ADMINISTRACIÓN Y CONTABILIDAD

With this paper, we intend to approach the crime of insider trading, or crime of initiated, and to determine its structure and origin. We will not only stop with the insider, but we will also cover the figure of the outsider.  Besides we will show its legal aspects as well as the theory and the practice in the operation of the board of directors. On this point we highlight the need to have independent, professional and a dedicated Boards We are also interested in covering those factors that cause the genesis and development of this illegal conduct. Besides we will dedicate space to Accounting. We consider that Accounting can report and even prevent  practices of insider trading. Accounting should be understood as information for the public, information to decide, information to control, plus information that cannot be restricted to preparing a standard statement that does not comply with their informative mission. As such, we study Enron’s way to operate, gathering all the variety of corporate actions and possible accounting manipulations in a business. Finally we will cover the relation of insider trading with financial markets.  We will discuss aspects as ethics and breaking the limits of the law.Con la presente comunicación pretendemos aproximarnos al insider trading, o delito de iniciados, y determinar su estructura y origen. No nos detendremos sólo en el insider, sino que abordaremos la figura del outsider. Además mostraremos sus aspectos jurídicos así como la teoría y la práctica en el funcionamiento de los consejos de administración. En este punto resaltamos la necesidad de unos consejos realmente independientes, profesionales, con dedicación. También nos interesa abordar aquellos factores que favorecen la génesis y desarrollo de estas conductas ilegales. Además dedicaremos espacio a la contabilidad. Consideramos que la Contabilidad puede informar e incluso prevenir sobre prácticas de insider trading. La Contabilidad debe entenderse como información para el público, información para decidir, información para controlar, y que además su papel no se debe ni se puede reducir a cumplimentar unos estados normalizados que no informan. Para ello recogemos la forma de operar de Enron que aglutina toda la variedad de actuaciones societarias y manipulaciones contables posibles en una empresa. Por último abordaremos la relación del insider trading con los mercados financieros. Planteamos aspectos como la ética e ir más allá de la ley

Sistema basado en FPGA para la reproducción de tráfico en redes 10 Gigabit Ethernet

El aumento de la penetración del uso de Internet, del uso de las redes sociales y el streaming de video y audio, ha hecho necesario aumentar el ancho de banda del que disponen los usuarios finales, provocando un incremento considerable del tráfico tcp/ip que tienen que soportar los primeros niveles de agregación. A la par que se aumenta el ancho de banda de las redes, es necesario desarrollar e investigar nuevos sistemas de procesamiento de paquetes que sean capaces de trabajar a estas tasas de línea. Generar tráfico que refleje adecuadamente diferentes condiciones y topologías de red, es crítico para realizar experimentos válidos sobre testbeds de red, por lo que la generación de tráfico real es necesaria para poder comprobar el funcionamiento real de cualquier sistema de procesamiento de paquetes como por ejemplo routers, rewalls, sistemas IDS, etc. La manera más fiable de generar tráfico real es mediante la reproducción de tráfico previamente capturado. El objetivo de este proyecto es el diseño, desarrollo e implementación de una arquitectura de reproducción de tráfico. Esta arquitectura permitirá retransmitir tráfico previamente capturado y almacenado en un fichero PCAP. Posibilitará reproducir dicha captura de tráfico con exactamente el mismo tiempo entre paquetes con el que fue capturado, así como aplicar distribuciones de tiempos entre paquetes según el caso o escenario que se quiera probar. Para su diseño, se ha planteado una solución híbrida basada en la plataforma NetCOPE. Se va a implementar un software de control y un rmware que se cargará en la FPGA Virtex-5 que proporciona la tarjeta COMBO v2. El software de control proporcionará al usuario una serie de opciones que le permitirán cargar un fichero de trazas, cargar unos tiempos entre paquetes y modfi car de manera interactiva los tiempos entre paquetes cargados.The increasing use of the Internet, social networking and new video and audio streaming applications, has led to an increment in the end users bandwidth demand. This has meant a considerable increment in the TCP/IP tra c that the distribution network has to handle. Due to this increasing bandwidth demand, it is necessary to develop new packet processing systems that are capable of working at higher bit rates. It is critical to perform valid experiments on network testbeds, the use of a tra c generation tool that adequately re ects di erent network topologies and conditions. In order to test how the packet processing systems (routers, rewalls, IDS systems, etc) would operate in a real environment, it is required to generate tra c as similar as possible to the tra c generated on a real environment. The easiest way to achieve this is by replicating previously captured real tra c. The aim of this project is to design, develop and implement a tra c replication architecture. This architecture will be able to replicate previously captured tra c stored in a PCAP le. It will allow the replication of the network trace exactly with the same interpacket times as when it was captured, as well as other interpacket time distributions depending on the scenario under evaluation. In this project we propose a hybrid solution based on the NetCOPE platform. It consist on an administration software and a rmware that will be loaded into a Virtex-5 FPGA provided by the COMBOv2 network card. The administration software will provide di erent options to the user. Using these options, the end user will be able to: load a previously captured pcap le, load the original interpacket time model and interactively modify the loaded interpackets

Wear characterization of cemented carbides (WC-CoNi) processed by laser surface texturing under abrasive machining conditions

Cemented carbides are outstanding engineering materials widely used in quite demanding material removal applications. In this study, laser surface texturing is implemented for enhancing, at the surface level, the intrinsic bulk-like tribological performance of these materials. In this regard, hexagonal pyramids patterned on the cutting surface of a tungsten cemented carbide grade (WC-CoNi) have been successfully introduced by means of laser surface texturing. It simulates the surface topography of conventional honing stones for abrasive application. The laser-produced structure has been tested under abrasive machining conditions with full lubrication. Wear of the structure has been characterized and compared, before and after the abrasive machining test, in terms of changes in geometry aspect and surface integrity. It is found that surface roughness of the machined workpiece was improved by the laser-produced structure. Wear characterization shows that laser treatment did not induce any significant damage to the cemented carbide. During the abrasive machining test, the structure exhibited a high wear resistance. Damage features were only discerned at the contacting surface, whereas geometrical shape of pyramids remained unchanged.Peer ReviewedPostprint (author's final draft