Characterisation and categorisation of the diversity in viscoelastic vibrational properties between 98 wood types

International audienceContext Increased knowledge on diversity in wood properties would have implications both for fundamental research and for promoting a diversification of uses as material. *Aims The objective is to contribute to overcoming the critical lack of data on the diversity of wood dynamic mechanical/viscoelastic vibrational properties, by testing lesser-known species and categorizing sources of variability. *Methods Air-dry axial specific dynamic modulus of elasticity (E'/γ) and damping coefficient (tanδ) were measured on a wide sampling (1792 specimens) of 98 wood types from 79 species. An experimental device and protocol was designed for conducting systematic (i.e. rapid and reproducible) characterizations. *Results Diversity at the specimens' level corroborates the "standard" relationship between tanδ and E'/γ, which is discussed in terms of orientation of wood elements and of chemical composition. Diversity at the species level is expressed on the basis of results for normal heartwood, with specific gravity (γ) ranging from 0.2 to 1.3. Axial E'/γ ranges from 9 to 32 GPa and tanδ from 4×10-3 to 19×10-3. Properties distribution follows a continuum, but with group characteristics. The lowest values of tanδ are only found in certain tropical hardwoods. Results can also suggest alternative species for musical instruments making

Estimating the extra cost of living for people with disabilities

Addressing the extra economic costs of disability is a logical step towards alleviating elements of social exclusion for people with disabilities. This study estimates the long-run economic cost of disability in Ireland in terms of the additional spending needs that arise due to disability. It defines and estimates models of the private costs borne by families with individuals who have a disability in Ireland when compared with the wider population, both in general and by severity of disability. Our modelling framework is based on the standard of living approach to estimating the cost of disability. We extend on previous research by applying panel ordered probit models to living in Ireland survey data 1995–2001 in order to control for the effects of previous disability and income and correlated unobserved heterogeneity. The approach allows us to quantify, for the first time, the additional long‐run economic costs of living associated with disability. Our findings suggest that the extra economic cost of disability in Ireland is large and varies by severity of disability, with important implications for measures of poverty. Copyright (C) 2010 John Wiley & Sons, Ltd.disability , long‐run cost of disability , standard of living , panel ordered probit ,