Did the Celtic Tiger Decrease Socio-Economic Differentials in Perinatal Mortality in Ireland?

Irish perinatal mortality rates have been falling steadily for a number of decades but evidence from the 1980s showed pronounced differentials in mortality rates across socio-economic groups. Between 1995 and 2006 Irish gross national product increased from 60 per cent of the EU average to 110 per cent. Real incomes increased across the income distribution during this period but income inequality between the top and bottom income deciles increased marginally. This paper examines whether socio-economic differentials in Irish perinatal mortality rates changed between the 1980s and 2000s. This task is complicated by demographic change in Ireland since the 1980s and its interaction with the birth registration process. Overall perinatal mortality rates have fallen from 14 per 1,000 in 1984 to 7 per 1,000 in 2006. Without adjusting for demographic change, differentials between professional and unskilled/unemployed groups have decreased from 1.99 to 1.79. Adjusted estimates suggest the real differential has decreased to 1.88.

Modelling of gas permeation through ceramic coatings produced by thermal spraying

An analytical model has been developed for simulation of gas permeation through thermal spray coatings, and for prediction of the permeability. The model is based on a geometrical representation of the coating microstructure. This involves thin splats, with limited inter-splat bridging, and microcracks within the splats. Important variables include the thickness (smallest dimension) of the inter-splat pores and intra-splat microcracks. Uniform values of these parameters are used in the model. Predicted permeabilities are compared with experimental data obtained using plasma-sprayed zirconia coatings, both in the as-sprayed state and after heat treatments sufficient to generate significant microstructural changes via sintering effects. In general, good agreement is obtained and it is concluded that the model constitutes a useful tool for exploration of gas permeation characteristics in coatings or layers produced by thermal sprayin

The Effect of a High Thermal Gradient on Sintering and Stiffening in the Top Coat of a Thermal Barrier Coating (TBC) System

Superalloy substrates coated with plasma sprayed CoNiCrAlY bond coats and yttria-stabilized zirconia top coats have been subjected to a high heat flux in a controlled atmosphere chamber. The sintering exhibited by the top coat under these conditions has been studied and compared with the behavior observed during isothermal heating, both when attached to the substrate and when detached. Sintering has been characterized by (a) microstructural examinations, (b) dilatometry, in both in-plane and through-thickness directions, and (c) stiffness measurements, using both cantilever bending and nanoindentation. A numerical heat flow model has been used to explore the stress state under isothermal and thermal gradient conditions. Sintering proceeds faster at higher temperature, but is retarded by the presence of tensile stresses (from differential thermal expansion between coating and substrate) within the top coat. Sintering occurs preferentially near the free surface of the top coat under gradient conditions, not only because of the higher temperature, but also because the in-plane stress is more compressive in that region

Rate constants for the reaction of Cl atoms with O3 at temperatures from 298 to 184 K

Using the standard, low pressure, discharge-flow technique, with resonance fluorescence in the vacuum ultraviolet to observe Cl atoms, rate constants have been determined for the reaction of Cl atoms with O$_3$ at temperatures down to 184 K. The measured rate constants for 298-184 K fit the Arrhenius expression: k(T) = (3.6 $\pm$ 0.7) $\times$ 10$^{-11}$ exp(( - 310 $\pm$ 50 K) / T) cm$^3$ molecule$^{-1}$ s$^{-1}$. The results extend the data on this key atmospheric reaction to slightly lower temperatures. The data are in fairly good agreement with those currently in the literature but suggest that the rate constant approximately 15% lower than that given by currently recommended rate expressions at the lowest temperatures found in the stratosphere

Numerically determined transport laws for fingering ("thermohaline") convection in astrophysics

We present the first three-dimensional simulations of fingering convection performed in a parameter regime close to the one relevant for astrophysics, and reveal the existence of simple asymptotic scaling laws for turbulent heat and compositional transport. These laws can straightforwardly be extrapolated to the true astrophysical regime. Our investigation also indicates that thermocompositional "staircases," a key consequence of fingering convection in the ocean, cannot form spontaneously in the fingering regime in stellar interiors. Our proposed empirically-determined transport laws thus provide simple prescriptions for mixing by fingering convection in a variety of astrophysical situations, and should, from here on, be used preferentially over older and less accurate parameterizations. They also establish that fingering convection does not provide sufficient extra mixing to explain observed chemical abundances in RGB stars.Comment: Submitted to ApJ Letters on October 29th. 15 pages, 4 figures. See Garaud 2010 for companion pape

Fragile Interlude

Fiction by Margaret Clyn

Deep Blue Fantasy

Fiction by Margaret Clyn

Earthquakes, Glaciers, and Sediments, Oh My! Subjects: Earth Science, Environmental Science, Life Science/Biology Grades: 9-12

This lesson plan is developed for 9th grade earth science classrooms, but can be scaled up or down. Students will explore how marine sediments serve as a history book for geologic activity. They will collect mock cores and developing conclusions about earth history