Lead induced intergranular fracture in aluminum alloy AA6262

The influence of lead on the fracture behavior of aluminum alloy AA6262 is investigated. Under certain conditions, the mode of fracture changes from transgranular microvoid coalescence to an intergranular mechanism. Three different intergranular fracture mechanisms are observed: liquid metal embrittlement, dynamic embrittlement at temperatures below the melting temperature of lead, and intergranular microvoid coalescence. An attempt is made to examine the dependence of these three mechanisms on temperature, strain rate, and stress state using in situ scanning electron microscopy (SEM). Liquid metal embrittlement occurs when the alloy is fractured at temperatures above the melting temperature of lead and at low strain rates. At lower temperatures, the occurrence of dynamic embrittlement depends largely on strain rate, stress state, and temperature. Intergranular microvoid coalescence is not often observed.

Serious Games and the Pleasure of Learning: The Whys and How of a Serious Game about Poverty and Social Exclusion

This paper describes and explains the decisions that have been made in the conceptualization and development of the serious game Poverty Is Not a Game (PING). PING is 3D adventure game in which the player takes the identity of one of two youngsters, Sophia or Jim, who find themselves in a difficult situation. Sophia comes from a poor family and now that her grandma has moved to a home, she has to start taking care of herself. Jim fell out with his parents and decided to sell his motorbike and move out to the big city. The game involves finding your way around in PING city, find a place to live, work, education and perhaps even the partner of your dreams. The game can be played online in browser or standalone. The target audience is teenagers. The target context is school, as an introduction to a lesson about poverty

Excitations and superfluidity in non-equilibrium Bose-Einstein condensates of exciton-polaritons

We present a generic model for the description of non-equilibrium Bose-Einstein condensates, suited for the modelling of non-resonantly pumped polariton condensates in a semiconductor microcavity. The excitation spectrum and scattering of the non-equilibrium condensate with a defect are discussed.Comment: 4 pages, 2 figure

Dynamics and monetary policy in a fair wage model of the business cycle

We first build a fair wage model in which effort varies over the business cycle. This mechanism decreases the need for other sources of sluggishness to explain the observed high inflation persistence. Second, we confront empirically our fair wage model with a New Keynesian model based on the standard assumption of monopolistic competition in the labor market. We show that, in terms of overall fit, the fair wage model outperforms the New Keynesian one. The extension of the fair wage model with lagged wage is judged insignificant by the data, but the extension based on a rent sharing argument including firm’s productivity gains in the fair wage is not. Looking at the implications for monetary policy, we conclude that the additional trade-off problem created by the inefficient real wage behavior significantly affects nominal interest rates and inflation outcomesEfficiency wage, effort, inflation persistence, monetary policy

Dynamics and monetary policy in a fair wage model of the business cycle

We first build a fair wage model in which effort varies over the business cycle. This mechanism decreases the need for other sources of sluggishness to explain the observed high inflation persistence. Second, we confront empirically our fair wage model with a New Keynesian model based on the standard assumption of monopolistic competition in the labor market. We show that, in terms of overall fit, the fair wage model outperforms the New Keynesian one. The extension of the fair wage model with lagged wage is judged insignificant by the data, but the extension based on a rent sharing argument including firm’s productivity gains in the fair wage is not. Looking at the implications for monetary policy, we conclude that the additional trade-off problem created by the inefficient real wage behavior significantly affect nominal interest rates and inflation outcomes. JEL Classification: E4, E5efficiency wage, effort, Inflation persistence, monetary policy

Firm-specific production factors in a DSGE model with Taylor price setting

This paper compares the Calvo model with a Taylor contracting model in the context of the Smets-Wouters (2003) Dynamic Stochastic General Equilibrium (DSGE) model. In the Taylor price setting model, we introduce firm-specific production factors and discuss how this assumption can help to reduce the estimated nominal price stickiness. Furthermore, we show that a Taylor contracting model with firm-specific capital and sticky wage and with a relatively short price contract length of four quarters is able to outperform, in terms of empirical fit, the standard Calvo model with homogeneous production factors and high nominal price stickiness. In order to obtain this result, we need very large real rigidities either in the form of a huge (constant) elasticity of substitution between goods or in the form of an elasticity of substitution that is endogenous and very sensitive to the relative price. JEL Classification: E1, E3DSGE Models, Inflation persistence

Is the pull-out force of the Meniscus Arrow in bone affected by the inward curling of the barbs during biodegradation? An in vitro study

Background: Inward curling of the barbs of Meniscus Arrows during degradation was observed in a previous study, in which swelling, distention, and water uptake by Meniscus Arrows was evaluated. This change of configuration could have consequences with respect to anchorage capacity in bone. Material/Methods: Eight non-degraded Meniscus Arrows in the original configuration were pulled out of thawed, fresh-frozen human femoral condyle, and pull-out force was measured and compared with that of 6 Meniscus Arrows after 31 days of degradation under controlled conditions. Results: No significant difference was found between the 2 groups with respect to the required pull-out force (t test), the distribution of the data, or the interaction between degradation and location, as evaluated by mann-Whitney test, and no significant difference was found between the 2 groups with respect to the degradation state or position in the coudyles, as evaluated by 2-way analysis of variance. Conclusions: Our results indicate that the decrease in barb-barb diameter during the first month of degradation of the Meniscus Arrows has no significant effect on the tensile pull-out force required for removal from human femur condyle. Further research should be undertaken to examine whether the same is true for other biodegradable devices with barbs