Investigation of the relationship between classical and nonclassical ultrasound nonlinearity parameters and microstructural mechanisms in metals.

This research studies two nonlinear ultrasound techniques: second harmonic generation and nonlinear resonant ultrasound spectroscopy, and the relationship to microstructural mechanisms in metals. The results show that there is a large change in both the classical, ß, and nonclassical, α, ultrasound nonlinearity parameters in response to three specific microstructural mechanisms: precipitate growth in and along the grain boundaries, dislocations, and precipitate pinned dislocations. For example, both ß and α increase with the growth of the precipitate radii (precipitate-pinned-dislocations). Additionally, both ß and α increase when there is a growth of precipitates in and along the grain boundaries. As expected, ß and α decrease when there is a removal of dislocations in the material. The relationship between ß and α, and the microstructural mechanisms studied provide a quantitative understanding of the relationship between measured nonlinearity parameters and microstructural changes in metals, helping to demonstrate the possibility of using these two independent, but complementary, nonlinear ultrasound procedures to monitor microstructural damage.

[Pregnancy and parenthood in the context of addiction]. / Grossesse et accession à la parentalité en contexte d'addiction.

Addictive behaviour in the perinatal period gives rise to significant health risks for the infant and the mother. When the experience of new parenthood coincides with the problem of addiction the parents' psychological problems can be intensified. These specific issues, sometimes difficult for the teams to have to deal with, require the creation of a complex and coordinated care programme.

[Building a care relationship in the home of drug-addicted parents]. / Construire une relation de soins au domicile des parents addictés.

Professionals' visits to the home of drug-addicted parents are a way of constructing a flexible and original framework.Whether the objective is simply to create the opportunity for the parties to meet with each other or to carry out intensive and complex treatment, it involves establishing the conditions for a trust relationship between the parents, children and partners.