The measurement of stress and phase fraction distributions in pre and post-transition Zircaloy oxides using nano-beam synchrotron X-ray diffraction

Zircaloy-4 oxide stress profiles and tetragonal:monoclinic oxide phase fraction distributions were studied using nano-beam transmission X-ray diffraction. Continuous stress relief and phase transformation during the first cycle of oxide growth was observed. The in-plane monoclinic stress was shown to relax strongly up to each transition, whereas in-plane tetragonal stress-relief (near the metal-oxide interface) was only observed post transition. The research demonstrates that plasticity in the metal and the development of a band of in-plane cracking both relax the monoclinic in-plane stress.The observations are consistent with a model of transition in which in-plane cracking becomes interlinked prior to transition. These cracks, combined with the development of cracks with a through-thickness component (driven primarily by plasticity in the metal) and/or a porous network of fine cracks (associated with phase transformation), form a percolation path through the oxide layer. The oxidising species can then percolate from the oxide surface to the metal/oxide interface, at which stage transition then ensues

Ta(l)king sides: ethical and methodological challenges in comparative fieldwork on avid football rivalries

Previous research on football (soccer) fan cultures has documented the lived experiences of devoted football supporters. Few studies, however, have used participant observation and intensive interviewing to examine the deep-rooted inter-group oppositions that characterize avid football rivalries. Even fewer have done this involving both sides of a rivalry and in countries and cultures unknown or unfamiliar to the researcher. This essay examines the process of doing qualitative research in such settings. Fieldwork experiences in Italy, Spain, England and the Netherlands are used to report and reflect on the ethical and methodological challenges associated with comparative research into inter-group conflicts in the football context. There are specific dilemmas that relate directly to the task of studying multiple sides of a football rivalry. Accusations of partiality and ethical criticisms of the researcher’s betrayal of one side against the other are rife, particularly in situations where intra-group cleavages and a strong distrust of the police exist