3 research outputs found

    Prediction of Peak Temperatures of Nigeria Research Reactor Core Components under Several Reactivity Accident Tests

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    The Nigeria Research Reactor-1 (NIRR-1) consists of small water cooled square cylindrical core of 23cm in diameter and 23cm high. The small dimension of the core of this reactor facilitated our choice of PARET to perform reactivity accident analysis for NIRR-1 system. Our goal in this work is to predict the peak temperature of some important Nigeria Research Reactor (NIRR-1) core components under several reactivity accident tests. At power levels below 80kW, there were no significant differences between the peak fuel centerline temperatures, the peak fuel surface temperature and the peak clad surface temperature in the hot channel as well as in the average channel. The result from the reactivity accident test shows that power can never rise to an uncontrollable level in the core of NIRR-1 under ramp or step insertion of up to 4mk of reactivity. The calculated temperature of the important core components (e.g. fuel and clad) in the two channels (during this reactivity accident test) were far below their melting point temperatures. Boiling of any kind was not observed during this reactivity accident test. Therefore, NIRR-1 can be operated safely even if there is an inadvertent addition of up to 4mk of positive reactivit

    Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

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    BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways
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