Uncertainty in incident rates for trucks carrying dangerous goods

This paper addresses the uncertainty associated with release and fire incident rates for trucks in transit carrying dangerous goods. The research extends the treatment of uncertainty beyond sensitivity analysis, low–best–high estimates and confidence intervals, and represents the uncertainty through probability density functions. The analysis uses Monte Carlo simulations to propagate the uncertainty in the input variables through to the resulting release and fire incident rates. The paper illustrates how we can combine information on accident and non-accident releases and fires to generate probability density functions for the total expected releases and fires per billion vehicle kilometres for trucks carrying dangerous goods.     

Melt processing of superconducting YBa2Cu3O7−∂ thick films on AgPd substrates via atmosphere control

Superconducting YBa₂Cu₃O_7– (123) c-axis textured thick films have been prepared on AgPd substrates by a modified screen printing and melt processing method. Heating the samples in an inert gas (N₂) has enabled melt processing to take place at lower temperatures than conventional YBCO thick film processing in O₂. The atmosphere is switched to p(O₂) = 100% at peak temperature in order to initiate the crystallisation of the 123 phase. Variation in properties of the films with changes in the peak processing temperature has been investigated. Samples processed at peak temperatures of 980°C show better microstructures and superconducting properties than those processed at lower temperatures. Quenching experiments have also been performed in order to investigate further the phase relationships and crystallisation mechanism of the 123 phase.