Iron oxidation at low temperature (260–500 C) in air and the effect of water vapor

The oxidation of iron has been studied at low temperatures (between 260 and 500 C) in dry air or air with 2 vol% H2O, in the framework of research on dry corrosion of nuclear waste containers during long-term interim storage. Pure iron is regarded as a model material for low-alloyed steel. Oxidation tests were performed in a thermobalance (up to 250 h) or in a laboratory furnace (up to 1000 h). The oxide scales formed were characterized using SEM-EDX, TEM, XRD, SIMS and EBSD techniques. The parabolic rate constants deduced from microbalance experiments were found to be in good agreement with the few existing values of the literature. The presence of water vapor in air was found to strongly influence the transitory stages of the kinetics. The entire structure of the oxide scale was composed of an internal duplex magnetite scale made of columnar grains and an external hematite scale made of equiaxed grains. 18O tracer experiments performed at 400 C allowed to propose a growth mechanism of the scale

The examination of archaeometallurgical remains; some recent examples and conclusions

This paper starts with a description of the investigational techniques now being used and goes on to discuss some of the problems and results. Examples have been taken from such finds as mattes and slags, litharge and speiss, native copper and crucible melting, edge tools, copper and bronze ingots, and oxidation enrichment in wrought iron

Technology, ritual and Anglo-Saxon agrarian production: the biography of a seventh-century century plough coulter from Lyminge, Kent

The discovery of an unusual early medieval plough coulter in a well-dated Anglo-Saxon settlement context in Kent suggests that continentally derived technology was in use in this powerful kingdom centuries before heavy ploughs were first depicted in Late Saxon manuscripts. The substantial investment required to manufacture the coulter, the significant damage and wear that it sustained during use and the circumstances of its ultimate ritual deposition are explored. Investigative conservation, high-resolution recording and metallographic analysis illuminate the form, function and use-life of the coulter. An examination of the deposition contexts of plough-irons in early medieval northern Europe sheds important new light on the ritual actions of plough symbolism in an age of religious hybridity and transformation

Why do mainland Chinese firms succeed in some sectors and fail in others? A critical view of the Chinese system of innovation

Domestically owned firms in mainland China have shown disappointing technological performance in higher-technology sectors. We argue that deficiencies in the systems of finance and corporate governance are largely to blame. Private firms have been starved of financial resources. The key weakness of Chinese State-Owned Enterprises (SOEs), lies in their corporate governance: the officials monitoring them have been 'disengaged', with the consequence that the investment of money and effort, which was low in visibility ('opaque') and/or slow in pay-off, has been discouraged. 'Disengagement' also discourages the development of close interfirm relationships and employee 'inclusion'. We examine a small number of sectors, notably telecoms and motor vehicles, in which Chinese firms appear to be doing well, showing that 'untypical' corporate governance produces untypically good results. We conclude by warning against relying on financial accounting measures in monitoring large SOEs, pointing to the UK example. China should find Chinese ways to achieve engagement and inclusion

State ownership and innovation : the relative merits of local and central state judged by innovation performance

Peer reviewedPostprin

‘Fire Burn and Cauldron Bubble’: Iron Age and Early Roman Cauldrons of Britain and Ireland

‘A man can live to 50 but a cauldron will live to 100’ – Old Kazakh sayingThis paper presents a re-examination of Iron Age and early Roman cauldrons, a little studied but important artefact class that have not been considered as a group since the unpublished study of Loughran of 1989. Cauldrons are categorised into two broad types (projecting-bellied and globular) and four groups. New dating evidence is presented, pushing the dating of these cauldrons back to the 4th centurybc. A long held belief that cauldrons are largely absent from Britain and Ireland between 600 and 200bcis also challenged through this re-dating and the identification of cauldrons dating from 600–400bc. Detailed examination of the technology of manufacture and physical evidence of use and repair indicates that cauldrons are technically accomplished objects requiring great skill to make. Many have been extensively repaired, showing they were in use for some time. It is argued that owing to their large capacity cauldrons were not used every day but were instead used at large social gatherings, specifically at feasts. The social role of feasting is explored and it is argued that cauldrons derive much of their significance from their use at feasts, making them socially powerful objects, likely to be selected for special deposition.This is the author's accepted manuscript. The final version is published by CUP in Proceedings of the Prehistoric Society: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9392057&fileId=S0079497X14000073