Browsing by Subject "Electrolytes"

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    Degradation of the beta-alumina electrolyte in a zebra cell
    (1988) Van Heerden, D P; Hutchings, Ron; Ball, Anthony
    Beta-alumina solid electrolytes studied were subjected to charge and discharge cycles in a secondary, high energy density Na/beta-alumina/NaAlCl₄/FeCl₂ cell (known as the Zebra cell) at 250⁰ C. These electrolytes were studied by means of optical microscopy, as well as SEM and EDS analyses to est ablish possible failure modes. After cycling little discolouration, or impurity pickup was found to have occurred in the electrolyte. The forms of degradation of the beta-alumina electrolyte identified appeared to be a result of inherent flaws in the beta-alumina electrolyte tube, problems due to protracted storage of the tubes, or an apparent interfacial film on the cathode/electrolyte interface. A lead wetting agent was used in the cells to enhance the wetting of the beta-alumina electrolyte by the liquid Na. A study of the coating after cycling of the cell showed that the coating was adherent irrespective of the number of cycles completed. The coating did not appear to influence cracking of the electrolyte during cycling. Cracking of the beta-alumina electrolyte was found to have initiated from the Na/electrolyte interface. No evidence of crack initiation nor internal damage was found on the cathode/electrolyte interface. The cracks through the beta-alumina electrolyte wall were found to have sealed by the formation of a plug consisting largely of Na and Cl. On the basis of EDS analyses of the fracture surface of the sealed crack possible sealing mechanisms are proposed.
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    The individualised versus the public health approach to treating Ebola
    (Public Library of Science, 2015) Boyles, Tom H
    The mortality rate for patients with Ebola virus disease (EVD) in West Africa is approximately 65% [1]. There are no published figures for high-resource settings, but media sources and individual case reports suggest it is much lower and approaches 0% for those who receive this level of care from the beginning of their illness. In their article "Ebola Viral Disease: Experience and Decision Making for the First Cases outside of Africa," David Stephens and colleagues give insight into the care that can be provided when available resources are not the limiting factor [2]. They describe the decision to open the Serious Communicable Diseases Unit (SCDU) of Emory University Hospital (EUH) when two United States patients contracted EVD while working in West Africa. Using a large specialist team, they provided high-quality care in a safe working environment and disseminated their knowledge and experience widely. In particular, they were able to respond to the huge increase in requests from health care facilities in the US for help in excluding the diagnosis of EVD. Caring for patients using an individualised approach under ideal circumstances contrasts with, but can also inform, the public health approach to care under resource-limited conditions in West Africa. The models of care employed in each environment show some similarities and also have a number of key differences.