Experimental Potentials for the XΣ+2 and AΠ2 States of NaHe

Experimental potentials for the XΣ+2 and AΠ2 states of the NaHe molecule are presented. The potentials are generated from the temperature dependence of the red wing of the Na resonance line perturbed by He. For the AΠ2 state an unexpectedly large value is obtained for De=480(50) cm−1at Re=4.4(2)a0. The physical basis for this result, which indicates an important role for the internal structure of the rare gas in determining the repulsive part of the alkali-rare-gas interaction, is discussed

Model-based development of MAV altitude control via ground-based equipment

This paper presents the development and demonstration of an automated altitude controller for a very low weight Micro Air Vehicle (MAV) (i.e. less than 15g), via low-cost ground-based equipment, and without the provision of active telemetry data from the airframe: this approach contrasts with current technologies that generally seek to place greater functionality within the airframe itself. It is shown that development of a suitable control algorithm is most efficiently achieved by simultaneous creation of an adequate airframe dynamic model, allowing stable control laws to be developed away from the unpredictable flight-test environment and adequate model development to be closely verified against flight-test data. The methodology is practically demonstrated with a simple commercial-off-the-shelf (COTS) MAV whose internal stabilization controller is not available for modification and has no facility for transmission of airframe parameters to the controlling ground-station

Analysis of a multiple-porosity model for single-phase flow through naturally fractured porous media

A derivation of a multiple-porosity model for the flow of a single phase, slightly compressible fluid in a multiscale, naturally fractured reservoir is presented by means of recursive use of homagnetization theory. We obtain a model which generalizes the double-porosity model of Arbogast et al. (1990) to a flow system with an arbitrary finite number of scales