Utilising DualEELS to probe the nanoscale mechanisms of the corrosion of Zircaloy-4 in 350 °C pressurised water

Characterisation of materials utilised for fuel cladding in nuclear reactors prior to service is integral in order to understand corrosion mechanisms which would take place in reactor. Zircaloy-4 is one such material of choice for nuclear fuel containment in Pressurised Water Reactors (PWRs). In particular, the metal-oxide interface has been a predominant focus of previous research, however, due to the complex oxidation process of zirconium cladding, there is still no clear understanding of what is present at the interface. Using Scanning Transmission Electron Microscopy (STEM) and Dual Electron Energy Loss Spectroscopy (DualEELS), we have studied the corrosion of this material under conditions similar to those that could be encountered in service. It is shown that under all conditions, whether during faster oxidation in the early stages, slow growth just prior to the transition to a new growth regime, or in the faster growth that happens after this transition, the surface of the metal below the scale is loaded with oxygen up to around 33 at%. Approaching transition, in conditions of slow growth and slow oxygen supply, an additional metastable suboxide is apparent with a thickness of tens of nm. By studying changes in both chemical composition and dielectric function of the material at the oxide scale – metal interface with nanometre resolution, quantitative mapping could be achieved, clearly showing that this is a suboxide composition of ZrO and a Zr oxidation state close to +2

Intimate partner violence, health behaviours, and chronic physical illness among South African women

The original publication is available at http://www.samj.org.zaObjectives: An association between intimate partner violence and adverse physical health outcomes and health-risk behaviours among women has been established, most scientific research having been conducted in the USA and other developed countries. There have been few studies in developing countries, including South Africa, which has one of the highest rates of intimate partner violence in the world. We therefore sought to study the association between physical intimate partner violence and physical health outcomes and behaviours among South African women. Methods: Using data from the cross-sectional, nationally representative South African Stress and Health Study, we assessed exposure to intimate partner violence, health-risk behaviours, health-seeking behaviours and chronic physical illness among a sample of 1 229 married and cohabiting women. Results: The prevalence of reported violence was 31%. This correlated with several health-risk behaviours (smoking, alcohol consumption, and use of non-medical sedatives, analgesics and cannabis) and health-seeking behaviours (recent visits to a medical doctor or healer). Intimate partner violence was not significantly associated with chronic physical illness, although rates of headache, heart attack and high blood pressure reached near-significance. Conclusions: Partner violence against women is a significant public health problem in South Africa, associated with healthrisk behaviours and increased use of medical services. Public health programmes should incorporate interventions to mitigate the impact of violence on victims and reduce the risk of negative behavioural outcomes. Further investigation of the pathways between violence exposure and health behaviours is needed to inform the design of such programming.Publishers' versio

Compositional analysis of InAs-GaAs-GaSb heterostructures by low-loss electron energy loss spectroscopy

As an alternative to Core-Loss Electron Energy Loss Spectroscopy, Low-Loss EELS is suitable for compositional analysis of complex heterostructures, such as the InAs-GaAs-GaSb system, since in this energy range the edges corresponding to these elements are better defined than in Core-Loss. Furthermore, the analysis of the bulk plasmon peak, which is present in this energy range, also provides information about the composition. In this work, compositional information in an InAs-GaAs-GaSb heterostructure has been obtained from Low-Loss EEL spectra

Atmospheric water vapor absorption at 12 CO2 laser frequencies

Measurements of the absorption of CO2 laser radiation in the 9.4 micron band by pressure broadened water vapor samples are summarized. The water vapor temperatures used were 25, 30, and 35 C

Pairwise comparison matrices and the error-free property of the decision maker

Pairwise comparison is a popular assessment method either for deriving criteria-weights or for evaluating alternatives according to a given criterion. In real-world applications consistency of the comparisons rarely happens: intransitivity can occur. The aim of the paper is to discuss the relationship between the consistency of the decision maker—described with the error-free property—and the consistency of the pairwise comparison matrix (PCM). The concept of error-free matrix is used to demonstrate that consistency of the PCM is not a sufficient condition of the error-free property of the decision maker. Informed and uninformed decision makers are defined. In the first stage of an assessment method a consistent or near-consistent matrix should be achieved: detecting, measuring and improving consistency are part of any procedure with both types of decision makers. In the second stage additional information are needed to reveal the decision maker’s real preferences. Interactive questioning procedures are recommended to reach that goal