in the last decade, decrease of the wear rate, increase in the axel load, and the velocity of the trains have changed the main damage mechanism of railway wheels from wear to rolling contact fatigue (rcf). rcf may lead to surface and subsurface cracks. the interaction between wear and rcf, removes the surface cracks, but the subsurface crack propagate gradually, and may lead to deeper and more ...

Over the last few years a theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology is described as it applies to total lifetimes, and the underlying theoretical issues are discussed. Theoretical expectations are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly ...

A two stage health promotion programme is in progress in the Vale of Leven in Dunbartonshire. The first stage has been completed within a local factory (Polaroid UK Limited), the largest private employer in the district. A total of 1205 employees, representing 87% of the workforce, took part in the programme and were initially screened for coronary artery risk factors. Blood pressure, serum cho...

This research proposes a model that calculates the customer lifetime value and simultaneously considers network effects. An oligopoly market is also considered in which companies compete with each other. Each company has number of buyers sellers offers its services to free while receiving sellers' membership fees return. Interestingly, customers interact other change companies' clients. interac...

Editorial – Cohabitation, marriage and separation: contrasts in Europe • Premarital cohabitation: more common in the north than in the south p. 2 • Cohabitation leads less often to marriage p. 2 • Fewer men and women are marryingp. 2 • Unions are more short-lived p. 3 • Several unions in a lifetime: a general trend? p. 4 • Box: Study population p. 4 C O N TE N TS are not marrying at all. Unions...

In today's fiercely competitive products market, product warranty has started playing an important role. The warranty period offered by the manufacturer/dealer has been progressively increasing since the beginning of the 20th Century. Currently, a large number of products are being sold with long-term warranty policies in the form of extended warranty, warranty for used products, service contra...

The SPIN extension presented in this article is meant as a way to facilitate the modeling and verification of object-oriented programs. It provides means for the formal representation of some run-time mechanisms intensively used in OO software, such as dynamic object creation and deletion, virtual function calls, etc. This article presents a number of language extensions along with their implem...