Tribological Behavior of Very Thin Confined Films

The tribological properties of two smooth surfaces in the presence of a thin confined film are investigated with a generic model for the interaction between two surfaces and with computer simulations. It is shown that at large normal contact pressures, an ultra thin film automatically leads to static friction between two flat surfaces - even if the surfaces are incommensurate. Commensurability is nevertheless the key quantity to understand the tribological behavior of the contact. Qualitative differences between commensurate and incommensurate contacts remain even in the presence of a thin film. The differences mainly concern the thermal diffusion of the contact and the transition between smooth sliding and stick-slip.Comment: 7 pages, 6 figure

The case for a london-wide authority and agency responsible for burial and cremation

Each year around 55,000 Londoners are buried or cremated within one of 122 municipal cemeteries and 17 crematoria. The 32 London boroughs, the Corporation of London and 7 borough joint committees and boards run these separately. This report was completed to determine whether there is a case for these 40 separate municipal agencies, and the one cemetery run by the Government's Royal Parks Agency, being put under a single London Burial and Cremation Authority. The way in which municipal cemeteries and crematoria are run reveal myriad of problems that the current providers have not been able to address as individual burial and cremation authorities. The main problems faced may be summarized as follows: London is running out of burial space: by 2010 most of central London will have run out of space for new graves; the absence of any coherent policy and resources to deal with the hundreds of thousands of old gravestones that are dilapidated and unstable, making cemeteries unsafe places to visit; the deterioration of historic cemetery landscapes and a continual decline in the fabric and infrastructure of London's cemeteries, most of which date back to the nineteenth century; annual deficit of £5M per annum on London's municipal cemeteries and crematoria; inequality in burial and cremation fees and charges for Londoners. No pan-London strategic approach to the control of pollution from cemeteries and crematoria; and no career structure to facilitate professional development or to attract high calibre people. These problems are inter-related and feed-off each other and have led to the idea of a single authority. They are also dated and no sustained attempt has been made to address them in a sensible and realistic manner. The absence of any Government response is put down to the fact that the disposal of the dead is a taboo subject with no political kudos. Cemeteries and crematoria became the remit of the London boroughs by political default and a political unwillingness to address strategically a highly sensitive public concern. This also occurred due to the relatively small nature of these services (in terms of physical size, financial implications and the number of people dependent upon the service at any one time) which are 'lost' in the massive scale of metropolitan local government. However, when considered on a pan-London basis, the important and significant role that municipal cemeteries and crematoria play, in the lives of Londoners and London per se, is evident. Their impact upon the urban landscape is formidable. Unfortunately, they are not seen or treated as such at the borough level. A third of Londoners come into contact with a cemetery or crematorium each year and ultimately everyone is dependent upon these services: they deserve more than they are getting and this is only likely to be achieved by the boroughs acting on a collective basis. Ideally, the provision of cemeteries and crematoria should come under the new Greater London Authority, which provides the right and natural platform for a pan-London approach. However, such a proposal has been rejected by the Minister for London and the Government Office for London, and would also be strongly opposed by the Association of London Government and the London Boroughs generally. Political reality dictates that any attempt to pursue such a proposal would be unlikely to gain the support and co-operation of the boroughs, which would be necessary for the initiative to work. For these reasons and on the basis that the proposal is unrealistic, the possibility of the GLA taking a major role in the provision of municipal cemeteries and crematoria has been discounted

Response bias in job satisfaction surveys: English general practitioners

Job satisfaction may affect the propensity to respond to job satisfaction surveys, so that estimates of average satisfaction and the effects of determinants of satisfaction may be biased. We examine response bias using data from a postal job satisfaction survey of family doctors. We link all the sampled doctors to an administrative database and so have information on the characteristics of responders and non-responders. Allowing for selection increases the estimate of mean job satisfaction in 2005 and the estimated change in mean job satisfaction between 2004 and 2005. Estimates of the determinants of job satisfaction are generally insensitive to response bias.Job satisfaction. Response bias. Sample selection. Family practitioners.