Investigations on entropy layer along hypersonic hyperboloids using a defect boundary layer

A defect approach coupled with matched asymptotic expansions is used to derive a new set of boundary layer equations. This method ensures a smooth matching of the boundary layer with the inviscid solution. These equations are solved to calculate boundary layers over hypersonic blunt bodies involving the entropy gradient effect. Systematic comparisons are made for both axisymmetric and plane flows in several cases with different Mach and Reynolds numbers. After a brief survey of the entropy layer characteristics, the defect boundary layer results are compared with standard boundary layer and full Navier-Stokes solutions. The entropy gradient effects are found to be more important in the axisymmetric case than in the plane one. The wall temperature has a great influence on the results through the displacement effect. Good predictions can be obtained with the defect approach over a cold wall in the nose region, with a first order solution. However, the defect approach gives less accurate results far from the nose on axisymmetric bodies because of the thinning of the entropy layer

Case-mix methodology for the NHS outcomes framework GP Patient Survey Questionnaire Data

The objective of the research described in the current report was to explore alternative methodologies which could be used to determine whether the health status of people living with long- term conditions in England is changing over time, all other factors being equal. Data from the Health Survey for England (HSE) were used in the analyses and EQ-5D was used to represent health related quality of life (HRQoL). The proposed case mix ratio approach which utilised ordinary least square regressions (with the EQ-5D preference - based score as the dependent variable) was replicated and alternatives using logistic regressions and two part models (both using the responses to the EQ-5D health dimensions as the dependent variables) were explored. An alternative method using the HSE year as a performance indicator (PI) was explored and results presented for the four most prevalent health conditions. Results were compared in terms of errors in predicted scores and the ability to capture changes in the distributions of the preference-based scores. Both expected and simulated values were compared

Solution phase, solid state, and theoretical investigations on the MacMillan imidazolidinone

A combination of soln. phase NMR, X-ray crystallog. studies, and DFT calcns. provide a consistent structural conformation for iminium ions derived from the MacMillan imidazolidinone

Predicting preference-based utility values using partial proportional odds models.

BACKGROUND: The majority of analyses on utility data have used ordinary least square (OLS) regressions to explore potential relationships. The aim of this paper is to explore the benefits of response mapping onto health dimension profiles to generate preference-based utility scores using partial proportional odds models (PPOM). METHODS: Models are estimated using EQ-5D data collected in the Health Survey for England and the predicted utility scores are compared with those obtained using OLS regressions. Explanatory variables include age, acute illness, educational level, general health, deprivation and survey year. The expected EQ-5D scores for the PPOMs are obtained by weighting the predicted probabilities of scoring one, two or three for the five health dimensions by the corresponding preference-weights. RESULTS: The EQ-5D scores obtained using the probabilities from the PPOMs characterise the actual distribution of EQ-5D preference-based utility scores more accurately than those obtained from the linear model. The mean absolute and mean squared errors in the individual predicted values are also reduced for the PPOM models. CONCLUSIONS: The PPOM models characterise the underlying distributions of the EQ-5D data better than models obtained using OLS regressions. Additional research exploring the effect of modelling conditional responses and two part models could potentially improve the results further