Predicting temporary wetland plant community responses to changes in the hydroperiod

The expected changes on rainfall in the next decades may cause significant changes of the hydroperiod of temporary wetlands and, consequently, shifts on plant community distributions. Predicting plant community responses to changes in the hydroperiod is a key issue for conservation and management of temporary wetlands. We present a predictive distribution model for Arthrocnemum macrostachyum communities in the Doñana wetland (Southern Spain). Logistic regression was used to fit the model using the number of days of inundation and the mean water height as predictors. The internal validation of the model yielded good performance measures. The model was applied to a set of expected scenarios of changes in the hydroperiod to anticipate the most likely shifts in the distribution of Arthrocnemum macrostachyum communities.

Security devices based on liquid crystals doped with a colour dye

Liquid crystal properties make them useful for the development of security devices in applications of authentication and detection of fakes. Induced orientation of liquid crystal molecules and birefringence are the two main properties used in security devices. Employing liquid crystal and dichroic colorants, we have developed devices that show, with the aid of a polarizer, multiple images on each side of the device. Rubbed polyimide is used as alignment layer on each substrate of the LC cell. By rubbing the polyimide in different directions in each substrate it is possible to create any kind of symbols, drawings or motifs with a greyscale; the more complex the created device is, the more difficult is to fake it. To identify the motifs it is necessary to use polarized light. Depending on whether the polarizer is located in front of the LC cell or behind it, different motifs from one or the other substrate are shown. The effect arises from the dopant colour dye added to the liquid crystal, the induced orientation and the twist structure. In practice, a grazing reflection on a dielectric surface is polarized enough to see the effect. Any LC flat panel display can obviously be used as backlight as well.

Comportamiento bajo cargas estáticas de sistemas provisionales de protección de borde realizados con elementos de acero = Behavior under static loads of temporary edge protection systems built with steel elements

La norma UNE-EN 13374 “Sistemas provisionales de protección de borde. Especificaciones del producto, métodos de ensayo” (1) clasifica los sistemas provisionales de protección de borde (SPPB) en tres clases (A, B y C), en función del ángulo de la superficie de trabajo y de la altura de caída de la persona a proteger. Los sistemas clase A son los indicados cuando la inclinación de la superficie de trabajo es menor de 10º. La norma establece los requisitos de flecha y de resistencia de los SPPB. Los requisitos se pueden comprobar tanto analítica como experimentalmente. El objetivo del trabajo ha sido la evaluación del comportamiento de los SPPB utilizados habitualmente en las obras y establecer los cambios necesarios para que cumplan con la norma UNE-EN 13374. Para ello se han evaluado analítica y experimentalmente tres SPPB clase A, fabricados con acero S235. Los resultados obtenidos muestran que, el sistema empleado de forma habitual en obras no supera los requisitos de la norma ni analítica ni experimentalmente. El tercer sistema supera los requisitos con las dos metodologías de análisis. El segundo sistema supera los requisitos cuando la evaluación se realiza analíticamente pero no cuando la vía utilizada es la experimental.

Inner-Hair Cells Parameterized-Hardware Implementation for Personalized Auditory Nerve Stimulation

In this paper the hardware implementation of an inner hair cell model is presented. Main features of the design are the use of Meddis’ transduction structure and the methodology for Design with Reusability. Which allows future migration to new hardware and design refinements for speech processing and custom-made hearing aids