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 influence of online posting dates on the bibliometric indicators of scientific articles

This article analyses the difference in timing between the online availability of articles and their corresponding print publication and how it affects two bibliometric indicators: Journal Impact Factor (JIF) and Immediacy Index. This research examined 18,526 articles, the complete collection of articles and reviews published by a set of 61 journals on Urology and Nephrology in 2013 and 2014. The findings suggest that Advance Online Publication (AOP) accelerates the citation of articles and affects the JIF and Immediacy Index values. Regarding the JIF values, the comparison between journals with or without AOP showed statistically significant differences (P=0.001, Mann-Whitney U test). The Spearman's correlation between the JIF and the median online-to-print publication delay was not statistically significant. As to the Immediacy Index, a significant Spearman's correlation (rs=0.280, P=0.029) was found regarding the median online-to-print publication delays for journals published in 2014, although no statistically significant correlation was found for those published in 2013. Most journals examined (n=52 out of 61) published their articles in AOP. The analysis also showed different publisher practices: eight journals did not include the online posting dates in the full-text and nine journals published articles showing two different online posting dates--the date provided on the journal website and another provided by Elsevier's Science Direct. These practices suggest the need for transparency and standardization of the AOP dates of scientific articles for calculating bibliometric indicators for journals

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