Quantity Precommitment with Price Competition versus Quantity Precommitment with Market Clearing Prices in the Laboratory

The paper reports the results of 39 laboratory duopoly markets for which pricing institution and participant experience are treatments. Cournot (C) duopolies (quantity precommitment and a price determined to clear the market) are contrasted with Kreps-Scheinkman (KS) duopolies (quantity precommitment and posted prices). Inexperienced participants in KS markets have much more difficulty selecting capacities consistent with the theoretical predictions than do those in C markets. With experience, the differences disappear.Duopoly; Laboratory experiment; Quantity precommitment; Posted prices; Price competition; Market-clearing prices; Experience

Advance Production Duopolies and Posted Prices or Market-Clearing Prices

The paper reports the results of 39 laboratory duopoly markets for which pricing institution and participant experience are treatments. Duopolies in which producers with complete information about market demand make advance-production output decisions and sell their output at a clearing price (Cournot markets) are contrasted with comparable duopolies who post prices for sale through an efficient rationing mechanism (Kreps-Scheinkman or KS markets). Inexperienced participants in KS markets have much more difficulty selecting capacities consistent with the theoretical predictions than do those in Cournot markets. With experience, the differences disappear. If trading sessions last sufficiently long, it is likely that differences will disappear with inexperienced participants.

Aggregates in Clay Bodies - A Research Project

An article outlining the origins of my current research. Featured in international ceramics magazine: Ceramics Technical. Originally published in 200

The thermal history of the Western Irish onshore

We present here a low-temperature thermochronological study that combines the apatite fission-track and (U + Th)/He dating methods with a pseudo-vertical sampling approach to generate continuous and well-constrained temperature–time histories from the onshore Irish Atlantic margin. The apatite fission-track and (U + Th)/He ages range from the Late Jurassic to Early Cretaceous and the mean track lengths are relatively short. Thermal histories derived from inverse modelling show that following post-orogenic exhumation the sample profiles cooled to c. 75 °C. A rapid cooling event to surface temperatures occurred during the Late Jurassic to Early Cretaceous and was diachronous from north to south. It was most probably caused by c. 2.5 km of rift-shoulder related exhumation and can be temporally linked to the main stage of Mesozoic rifting in the offshore basins. A slow phase of reheating during the Late Cretaceous and Early Cenozoic is attributed to the deposition of a thick sedimentary sequence that resulted in c. 1.5 km of burial. Our data imply a final pulse of exhumation in Neogene times, probably related to compression of the margin. However, it is possible that an Early Cenozoic cooling event, compatible with our data but not seen in our inverse models, accounts for part of the Cenozoic exhumation

Fatigue life prediction of z-fibre pinned composite laminate under mode I loading

A hybrid method is presented combining linear elastic fracture mechanics with nonlinear damage mechanics that can predict the fatigue crack growth rate in z-fibre pinned composites under mode I loading. The strain energy release rate is evaluated using the virtual crack closure technique via finite element analysis. Cohesive elements are used in the pinned region to represent the crack bridging force generated by the pins. The reduction of the pins' bridging force under the fatigue loading is accommodated by applying a degradation law, based on damage mechanics with empirical fitting parameters. A modified degradation law is proposed which is capable of accumulating fatigue damage under varying crack opening displacement ranges experienced by the pins during fatigue loading. Fatigue testing was performed with a z-pinned double cantilever beam at two different values of applied displacement amplitude. The predictions show reasonably good agreement with the test results in terms of the fatigue crack propagation rate and fatigue life