Boutique neutrons advance Ar/Ar geochronology.

We designed and tested a compact deuteron-deuteron fusion neutron generator for application to Ar/Ar geochronology. The nearly monoenergetic neutrons produced for sample irradiation are anticipated to provide several advantages compared with conventional fission spectrum neutrons: Reduction of collateral nuclear reactions increases age accuracy and precision. Irradiation parameters within the neutron generator are more controllable compared with fission reactors.

Pressure transmission across dentine in response to an external pressure: a laboratory study.

Purpose: To determine whether transducers could provide a convenient method of measuring dentine permeability and to investigate the effects of removal of pulp tissue and perfusion time on the pressure increase across human dentine after low-pressure perfusion.

Method: Human premolar teeth that had been stored for 1-2 months were prepared for full crown preparations. The pulp tissue was removed from half the samples and all the coronal segments perfused with saline at 1.