Nuevas metodologías docentes para la enseñanza de estructuras aeronáuticas.

La asignatura “Estructuras Aeronáuticas” está orientada a completar los conocimientos del análisis de estructuras del futuro ingeniero aeronáutico. La organización y programación de la asignatura está pensada para transmitir los conocimientos necesarios para el cálculo de estructuras laminares mediante métodos clásicos y modernos, como el basado en el Análisis con Elementos Finitos (AEF), de manera que el alumno posea una perspectiva amplia de la problemática asociada al diseño de estructuras laminares como las que integran una aeronave. Ello se lleva a cabo mediante clases teóricas, clases de problemas, clases prácticas de estructuras por ordenador y trabajos prácticos. En este trabajo se presentan nuevas metodologías docentes implementadas e introducidas en el esquema docente de dicha asignatura con objeto de satisfacer las líneas prioritarias del Plan Propio de la Universidad de Sevilla sobre metodologías docentes. De esta forma se llevan a cabo diferentes frentes de actuación: estudio y experimentación de nuevas metodologías didácticas como la enseñanza virtual, usando plataformas virtuales tipo WebCT, la elaboración de clases por transparencias PowerPoint y animaciones a partir de material específico, y la promoción del trabajo en equipo mediante la realización de un proyecto en grupo de AEF de un ala de una aeronave de recreo. El modelado mediante elementos finitos se realizará empleando el software comercial NASTRAN ® y PATRAN ® , de extensa aplicación en el sector aeronáutico

Optimal growth under endogenous depreciation, capital utilization and maintenance costs

This paper analyzes the equilibrium dynamics of an optimal growth model that incorporates endogenous depreciation, variable capital utilization, and expenditures on the maintenance of physical capital. Maintenance acts as a substitute for investment, since it reduces the depreciation of capital. Investment is subject to adjustment costs, and capital is not fully utilized, the degree of capital utilization affecting the activity of maintaining. We establish a set of sufficient conditions for the existence and uniqueness of a steady state equilibrium. Also, we define a “delta golden rule” consistent with the proposed economic environment and we analyze the dynamic efficiency of this economy. Finally, the steady state is found locally saddle-path stable. These results provide a framework for the analysis of comparative dynamics in general equilibrium with these features

Comment on "Steady-state planar ablative flow"

In a recent paper Manheimer et al.1 attempted to proceed beyond older analyses2 on the ablative corona ejected by planar láser targets. Here we comment on some aspects of the analysis of Ref. 1, common to most previous papers on the subject

Microdroplet fabrication of silver–agarose nanocomposite beads for SERS optical accumulation

Microdroplets have been used as reactors for the fabrication of agarose beads with high uniformity in shape and size, and densely loaded with silver ions, which were subsequently reduced into nanoparticles using hydrazine. The resulting nanocomposite beads not only display a high plasmonic activity, but can also trap/concentrate analytes, which can be identified by means of surface-enhanced Raman scattering (SERS) spectroscopy. The size of the beads is such that it allows the detection of a single bead under a conventional optical microscope, which is very useful to reduce the amount of material required for SERS detectio

Development of a critical structure state alarm system based on the instrumentation of the Botafoc breakwater nº 8 caisson

Balearic Port Authority has developed an instrumentation system for the #8 caisson of the Botafoc breakwater that integrates 12 pressure sensors located at three surfaces, two in contact with the sea water and another with the bottom. This design was completed with an inertial system that measures the angular velocities and the accelerations over the three Cartesian axes. Consequently, the system measures actions (pressures) and reactions (movements and accelerations) experimented by the caisson, due to sea waves and/or other service loads. R+D department of the Port Authority and Polytechnic University of Madrid are working on two directions, the development of new theories on vertical breakwater design that go beyond Goda and Sainflou, and on the creation of a real-time critical structure alarm system, based on the instrumentation installed. This alarm system has two main parts: the instrumentation itself that collects data and processes it on real-time (the data processing compares the pressure law suffered by the caisson in every step process with the design critical state of the caisson, in this case the Goda pressure law for a 6.5 m wave), giving a security coefficient that points out the risk level on real-time; and the alarm system consisting of a monitoring panel located in the Port Control Center that shows the risk level and advises in case of an incidental evacuation of this critical portuary installation

Optimal Growth under Endogeneous Depreciation, Capital Utilization and Maintenance Costs

Se analiza la dinámica de un modelo de crecimiento que incorpora depreciación endógena, utilización variable del capital y gastos de mantenimiento. La actividad de mantenimiento actúa en cierta medida como sustituto de la inversión puesto que reduce la depreciación de capital.Capital y gastos de mantenimiento, Depreciación endógena

Innovación y mejora docente en el ámbito de la enseñanza de estructuras metálicas.

La asignatura “Estructuras Metálicas” está orientada a completar los conocimientos del análisis de estructuras del futuro ingeniero industrial con su aplicación práctica al diseño de estructuras metálicas. La organización y programación de la asignatura está pensada para transmitir los conocimientos necesarios para el cálculo de elementos estructurales simples, de manera que el alumno posea una perspectiva amplia de la problemática asociada al diseño de estructuras metálicas complejas. Ello se lleva a cabo mediante clases teóricas, clases de problemas, clases prácticas de estructuras por ordenador, prácticas de laboratorio, y trabajos prácticos. Este trabajo presenta nuevas metodologías docentes, de acuerdo con las líneas prioritarias del Plan Propio de la Universidad de Sevilla, para mejorar los diferentes frentes de docencia que la asignatura posee. Para ello se profundiza en el estudio y experimentación de nuevas metodologías didácticas como la enseñanza virtual, usando plataformas virtuales tipo WebCT, la elaboración de clases por transparencias PowerPoint y animaciones numéricas realizadas mediante elementos finitos, todo ello basadas en la normativa vigente actual y bibliografía referente actualizada. Además se fomenta el trabajo en equipo mediante la realización de prácticas de campo y un proyecto en grupo, y se desarrollan nuevas prácticas de laboratorio y actividades de manera que el alumno contemple la visión práctica de los conocimientos adquiridos

Fast response and temporal coherent oscillations in small-world networks

We have investigated the role that different connectivity regimes play in the dynamics of a network of Hodgkin-Huxley neurons by computer simulations. The different connectivity topologies exhibit the following features: random topologies give rise to fast system response yet are unable to produce coherent oscillations in the average activity of the network; on the other hand, regular topologies give rise to coherent oscillations, but in a temporal scale that is not in accordance with fast signal processing. Finally, small-world topologies, which fall between random and regular ones, take advantage of the best features of both, giving rise to fast system response with coherent oscillations.We acknowledge G. Laurent, A. Bäcker, M. Bazhenov, M. Rabinovich, and H. Abarbanel for insightful discussions. We thank the Dirección General de Enseñanza Superior e Investigación Científica for financial support (PB97-1448), the CAM for financial support to L. F. L., and the CCCFC (UAM) for the use of computation resources

On the transparency of nanostructured alumina: Rayleigh-Gans model for anisotropic spheres

14 páginas, 6 figuras, 2 tablas.A light scattering model under the Rayleigh-Gans-Debye approximation has been developed for polycristalline alumina. The model states that transmittance of dense alumina ceramics basically depends not only on the maximum grain size but also on the preferential orientation of their c-axis, or texture. The effect of texture in transparency has been experimentally measured on several dense alumina samples with different grain size and compared to that obtained from x-ray Rietveld refinements with a very good agreement. The Rayleigh-Gans-Debye approximation also allows to represent optical data in a very simple way (logarithm of transmittance vs. the inverse of the wavelength square). Using these variables, a straight line is obtained for the Rayleigh-Gans-Debye approximation, its slope being proportional to the maximum grain size and textural parameter. Deviation from this law implies the presence of pores or grain of extremely large size.Peer reviewe