The Interaction between Otto Fuel II and Aqueous Hydroxylammonium Perchlorate (HAP), Part III: Depletion of Components within the Reacting Liquids

Gas chromatography (GC) with a Flame Ionisation Detector (FID) has been used to determine changes in the concentrations of the components of Otto Fuel II (OF) in contact with an 82% aqueous solution of hydroxylammonium perchlorate (HAP) in sealed vials at 31.7 °C during the period leading up to auto‐ignition of the two liquids. The concentration of hydroxylamine in HAP was monitored over the same period using a titration method. It was found that 2‐nitrodiphenylamine (2NDPA), the stabiliser in the OF, is completely consumed after about 65–70 h and that the concentration of hydroxylamine begins to fall at this point. 1,2‐Propanediol dinitrate (propylene glycol dinitrate, PGDN), the energetic component in the OF, is not depleted significantly until after about 90 h. The evolution of nitrous oxide (N₂O) between 65 and 90 h is attributed to the reaction of the hydroxylammonium ion with nitrous acids produced by PGDN decomposition at the liquid‐liquid interface. Carbon dioxide (CO₂) is evolved after ~ 90 h and is attributed to PGDN decomposition. HAP and PGDN are each thought to contribute to N₂O evolution after ~ 90 h.     

A new approach to characterize scratch and mar resistance of automotive coatings

Mar damage is a major customer concern of the automotive coatings industry. Our study of mar performance can be separated into two distinct areas, a detailed understanding of the damage formation mechanism, and an investigation of the relationship between the damage morphology and appearance. We have developed a nanoscratch technique that can measure important physical quantities, such as penetration depth, normal force and tangential force during the formation of the scratch. Mar resistance of three coatings was evaluated and compared based on the damage mechanisms: plastic flow and fracture. The different deformation mechanisms result in different damage morphologies and a corresponding change in visual impact of the scratch. Statistical surveys of appearance of well-defined scratches indicate that in very short observation times, scratches where fracture has occurred are much more visible than those made by plastic deformation alone. However, with sufficient time and strong illumination a significant percentage of observers could see plastic deformation as well.     

Colouring the Claddagh: A Distorted View?

This article examines the dress worn in a selection of Marguerite Mespoulet’s autochromes taken of the inhabitants of the Claddagh and in the vicinity of Galway City, western Ireland in 1913. They belong to the Archives de la Planète, an ambitious project launched by French financier Albert Kahn in 1908 to record the culture of ordinary people in fifty countries in order to promote peace through mutual understanding. The Lumière brothers’ autochrome was the first viable photographic process to reproduce authentic colours, unmitigated by intervention or manipulation, and was used for commercial and private purposes between 1907 and the early 1930s. Mespoulet’s images are thought to be the first colour photographs ever taken in Ireland, and so are invaluable records of the folk dress of a region where the last vestiges of Gaelic culture survived into the twentieth century. Along with her diary notes, they provide a platform from which to explore the slippery nexus between myth and reality, and to question the veracity of some commonly held assumptions about Irish folk dress.