30,410 research outputs found

    12CaO.7Al2O3 ceramic: A review of the electronic and optoelectronic applications in display devices

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    The alumina-based compound, 12CaO.7Al2O3, is a ceramic material with a unique cage-like lattice. Such a structure has enabled scientists to extract various new characteristics from this compound, most of which were unknown until quite recently. This compound has the ability to incorporate different anionic species and even electrons to the empty space inside its cages, thereby changing from an insulator into a conductive oxide. The cage walls can also incorporate different rare earth phosphor elements producing an oxide-based phosphor. All these characteristics are obtained without a significant change in the structure of the lattice. It is, therefore, reasonable to expect that this compound will receive attention as a potential material for display applications. This review article presents recent investigations into the application of 12CaO.7Al2O3 ceramic in various display devices, the challenges, opportunities and possible areas of future investigation into the development of this naturally abundant and environmental friendly material in the field of display.LP Displays Ltd, Blackburn, UK for partial funding of the studentship at Queen Mary, University of London. Dr Lesley Hanna of Wolfson Centre for Materials Processing, Brunel University Londo

    THE FAIR ACT: WHAT DOES IT ALL MEAN?

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    Agricultural and Food Policy,

    Brain damage following whooping cough vaccination : is it time to lay the myth to rest?

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    Whooping cough causes significant morbidity and mortality, especially in early infancy. Although an effective vaccine exists, vaccine uptake in Malta was previously disappointing due to the general public’s and the medical community’s doubts regarding vaccine efficacy and safety. The aim of this study was to review population-based studies which have analysed the potential short and long term neurological sequelae following pertussis and pertussis vaccination, to describe vaccine uptake globally and in Malta over the past 15 years, and to analyse the effect of vaccine uptake on pertussis epidemics in Malta. This study found that pertussis vaccine uptake has only become satisfactory in recent years, with a resulting attenuation in the most recent pertussis outbreak. Uptake has increased progressively all over the world, and no study has ever incriminated pertussis vaccination as a cause of permanent neurological disability, both locally and abroad. This should encourage the present continuing trend of pertussis uptake.peer-reviewe

    Relationship between tonic and phasic craving for alcohol.

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    BackgroundMultiple measures are utilized to assess alcohol craving, often interchangeably. Little is known about the relationship between tonic and phasic craving. This study fills this gap in the literature by examining the association between tonic levels of alcohol craving and phasic craving for alcohol that is provoked by alcohol administration.MethodsForty-three non-treatment seeking problem drinkers underwent an initial interview and two laboratory testing sessions, where either alcohol or a saline placebo was administered intravenously. Tonic craving was assessed via the Penn Alcohol Craving Scale (PACS) and Obsessive Compulsive Drinking Scale (OCDS) at the initial interview. Phasic craving was assessed during the laboratory sessions (i.e., alcohol and saline administrations, single blinded) at baseline and at 3 subsequent breath alcohol concentrations (0.02, 0.04, and 0.06 g/dl).ResultsThere was a main effect of PACS in predicting phasic craving across both saline and alcohol administration conditions (p < 0.05). The OCDS was predictive of phasic craving when alcohol, but not saline, was administered (p = 0.058); the obsessive subscale (p = 0.01), but not the compulsive subscale (p > 0.10), predicted phasic craving during alcohol, as compared to saline administration.ConclusionIn sum, tonic craving captured by the OCDS was predictive of phasic craving during alcohol administration whereas the PACS more generally captured the increase in phasic craving. Therefore, these measures of tonic craving may function differently in capturing the experience of phasic craving. Implications for the utilization of the PACS and OCDS as well as assessments of craving in alcoholism research are discussed

    Vibrational spectroscopic studies on crystallisation of sol-gel derived thin films of calcia-alumina binary compound

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    An optimized sol-gel process has been developed to produce homogeneous thin films of calcium aluminate binary (12CaO·7Al2O3) compound, on magnesium oxide substrates via spin coating. Fourier transform infrared and Raman spectroscopies have been employed to investigate the effect of annealing temperature and duration on the phase transformations in the films. Heat treatment at 1,300 °C under air atmosphere for 2 h produced single-phase 12CaO·7Al2O3 films. However, annealing at a lower temperature of 1,100 °C in air for a period of 4 h in total resulted in the crystallization of 5CaO·3Al2O3 rather than 12CaO·7Al2O3. The X-ray photoelectron spectrum of the thin film annealed at 1,300 °C corresponds to the binding energies of C12A7 compound. The annealing temperature of 1,300 °C for 2 h is found to be sufficient for formulating single phase calcia-alumina binary films in correct stoichiometric ratio of 12:7. © 2014 Springer Science+Business Media New York
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