Integración del alumnado con discapacidad en la formación on-line: una propuesta de accesibilidad universal

El proyecto trata de dar solución de accesibilidad a un curso previamente diseñado de formación oficial on-line. El proyecto pretende dotar de altas condiciones de accesibilidad para todas las personas. En concreto se implantará sobre una plataforma moodle ya establecida al objeto de dotarla del mayor grado de accesibilidad técnica y conceptual en atención al alumnado con discapacidades físicas, psíquicas y sensoriales.

Properties of polycrystalline gas sensors based on d.c. and a.c. electrical measurements

Electrical properties of polycrystalline gas sensors are analyzed by d.c. and a.c. measurements. d.c. electrical conductivity values compared with those obtained by admittance spectroscopy methods help to obtain a detailed 'on line' analysis of conductivity-modulated gas sensors. The electrical behaviour of grain boundaries is obtained and a new design of sensors can be achieved by enhancing the activity of surface states in the detecting operation. A Schottky barrier model is used to explain the grain boundary action under the presence of surrounding gases. The height of this barrier is a function of gas concentration due to the trapping of excess charge generated by gas adsorption at the interface. A comparison between this dependence, and a plot of the real and imaginary components of the admittance versus frequency at different gas concentrations, provides information on the different parameters that play a role in the conduction mechanisms. These methods have been applied to the design of a CO sensor based on tin oxide films for domestic purposes, the characteristics of which are presented.