Special Issue : Highlights from the ITS European Congress in Glasgow (2016)

Peer reviewedPostprin

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

Quadratic Residues and Non-Residues: Selected Topics

Number theory as a coherent mathematical subject started with the work of Fermat in the decade from 1630 to 1640, but modern number theory, that is, the systematic and mathematically rigorous development of the subject from fundamental properties of the integers, began in 1801 with the appearance of the landmark text of Gauss, Disquisitiones Arithmeticae. A major part of the Disquisitiones deals with quadratic residues and nonresidues. Beginning with these fundamental contributions of Gauss, the study of quadratic residues and nonresidues has subsequently led directly to many of the key ideas and techniques that are used everywhere in number theory today, and the primary goal of these lectures is to use this study as a window through which to view the development of some of those ideas and techniques. In pursuit of that goal, we will employ methods from elementary, analytic, and combinatorial number theory, as well as methods from the theory of algebraic numbers.Comment: xi+265 pp., 4 tables, 20 figures in Lecture Notes in Mathematics no. 2171, Springer, New York, 201

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

The nature of ‘document work’, and its implications for radical community archives and their holdings

Around fifty years ago, much of the world experienced a new cycle of mass social unrest. In their wake, the movements of that time have left a mass of records and other documents (typically leaflets, journals, newspapers, posters and bulletins). Today, many of these materials are curated by community-based archives that continue to identify in some manner both with those movements and their successors. But what might these materials be able to tell us about the ‘document work’ (to use Ciaran Trace’s useful concept) that originally led to their creation and use – and, in a broader sense, the experiences of the movement participants who utilised them as integral components of their political engagement? This paper will explore the meaning of document work within the practices of members of Potere Operaio [Potop], one of the most influential of the revolutionary groups formed in Italy during the late 1960s, before concluding with some brief reflections as to the implications of this for the present day work of radical community archive