Nonlinear wavepackets in pair-ion and electron-positron-ion plasmas

The occurrence of amplitude-modulated electrostatic and electromagnetic
wavepackets in pair plasmas is investigated. A static additional charged background species is considered, accounting for dust defects or for heavy ion
presence in the background. Relying on a two-fluid description, a nonlinear
Schrodinger type evolution equation is obtained and analyzed, in terms of the
slow dynamics of the wave amplitude. Exact envelope excitations are obtained,
modelling envelope pulses or holes, and their characteristics are discussed.

'Easter Rising', 1914-1918-online. International Encyclopedia of the First World War

Although a military failure, the 1916 rebellion transformed Ireland by destroying the possibility of a political settlement between Irish nationalists and the British state and by popularising a republican movement prepared to use violence to achieve independence. This essay surveys the political background to the Easter Rising, its planning, the motivations and ideology of the rebels and the battle for Dublin. It concludes by assessing the Rising’s political impact and briefly summarising historiographical interpretations and commemorative trends. It argues that the origins, conduct, impact and aftermath of the insurrection are best understood within the wider context of the First World War.

Autonomous COLREGs Compliant Ship Navigation, Using BridgeSimulators and an Unmanned Vessel

This paper presents an approach to COLREGs compliant ship navigation. A system architecture is proposed, which will be implemented and tested on two platforms: networked bridge simulators and at sea trials using an autonomous unmanned surface vessel. Attention is paid to collision avoidance software and its risk mitigation.