LOTUS: A low cost, ultraviolet spectrograph

We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5x95 arcsec) and wide (5x25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Angstroms with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R=225-430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is less than 2 Angstroms rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

Towards automated Android app collusion detection

Android OS supports multiple communication methods between apps. This opens the possibility to carry out threats in a collaborative fashion, c.f. the Soundcomber example from 2011. In this paper we provide a concise definition of collusion and report on a number of automated detection approaches, developed in co-operation with Intel Security.

Divided Conquerors: the Rump Parliament, Cromwell's Army and Ireland

This article reassesses the relationship that existed in the period 1649–53 between war in Ireland and politics in England. Drawing upon a largely overlooked Irish army petition, it seeks to remedy an evident disconnect between the respective historiographies of the Cromwellian conquest of Ireland on the one hand and the Rump Parliament on the other. The article reconstructs some of the various disputes over religion, authority and violence that undermined the unity of the English wartime regime in Ireland. It then charts the eventual spilling over of these disputes into Westminster politics, arguing that their impact on deteriorating army-parliament relations in the year prior to Oliver Cromwell’s expulsion of the Rump in April 1653 has not been fully appreciated. The key driver of these developments was John Weaver, a republican MP and commissioner for the civil government of Ireland. The article explains how his efforts both to place restraints on the excessive violence of the conquest and to exert civilian control over the military evolved, by 1652, into a determined campaign at Westminster to strengthen the powers of Ireland’s civil government and to limit the army’s share in the prospective Irish land settlement. Weaver’s campaign forced the army officers in Ireland to intervene at Westminster, thus placing increased pressure on the Rump Parliament. This reassessment also enables the early 1650s to be viewed more clearly as a key phase in the operation of the longer-term relationships of mutual influence that existed between Dublin and London in the seventeenth century.

Efficient and Selectable Production of Reactive Species Using a Nanosecond Pulsed Discharge in Gas Bubbles in Liquid

A plasma gas bubble-in-liquid method for high production of selectable reactive species using a nanosecond pulse generator has been developed. The gas of choice is fed through a hollow needle in a point-to-plate bubble discharge, enabling improved selection of reactive species. The increased interface reactions, between the gas-plasma and water through bubbles, give higher productivity. H₂O₂ was the predominant species produced using Ar plasma, while predominantly  and NO₂ were generated using air plasma, in good agreement with the observed emission spectra. This method has nearly 100% selectivity for H₂O₂, with seven times higher production, and 92% selectivity for , with nearly twice the production, compared with a plasma above the water.