45 research outputs found
Relational physics with real rods and clocks and the measurement problem of quantum mechanics
The use of real clocks and measuring rods in quantum mechanics implies a
natural loss of unitarity in the description of the theory. We briefly review
this point and then discuss the implications it has for the measurement problem
in quantum mechanics. The intrinsic loss of coherence allows to circumvent some
of the usual objections to the measurement process as due to environmental
decoherence.Comment: 19 pages, RevTex, no figure
Use of acoustic emission to determine the lubrication conditions in simulated gear contacts
This research investigates the use of Acoustic Emission (AE) measurement to monitor the lubrication conditions in simulated gear tooth contacts. It is experimentally shown that a strong correlation between lambda value (an indicator of the lubrication regime) and the AE exists, and that for a constant speed a simple empirical relationship exists between them. This benefits those seeking to use AE for condition monitoring of gears
A systematic review of phenotypic responses to between-population outbreeding
This work was supported by the UK Population Biology Network, through funding from the Natural Environment Research Council and Natural England. We thank Jack Brodie, Helen Hipperson, Marie Chadburn and Sophie Allen for assistance with literature searching, article assessment and data extraction. We also thank our review group for constructive criticism on the scope, development and structure of this review, and two peer reviewers for useful feedback on the review protocol. Finally we thank three peer reviewers who each provided constructive comments on this systematic review report.Peer reviewedPublisher PD
On the use of Acoustic Emission as an aid to understanding of lubricated contacts in tribological systems
Acoustic Emission (AE) has been long established as a sensitive tool for detecting damage and failure in engi-neering structures, where sensors are used to detect the elastic stress waves originating from crack growth, impact damage, plastic deformation and other failure mechanisms. It is a useful tool capable of detecting failure at an earlier stage than more conventional moni-toring techniques, and offers much potential insight into conditions in tribological contacts. This paper examines the sensitivity of AE to mixed lubrication conditions, with a view to evaluating the suitability of the technique for monitoring heavily load-ed concentrated contacts in power transmission gear systems where roughness scale fatigue phenomena such as micropitting are a problem. It then discusses the results of using AE to monitor bearings, highlighting some of the challenges which must be overcome to enable its adoption as a condition monitoring tool
Quantifying the Detrimental Impacts of Land-Use and Management Change on European Forest Bird Populations
The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health
Leadership in Compassionate Care: Final Report 2012
This report reflects the initiation, planning, running and the important outcomes emerging from the Leadership in Compassionate Care Programme. The team worked in close partnership across the School of Nursing, Midwifery and Social Care, Edinburgh Napier University and NHS Lothian. This report also shares the highlights, challenges and solutions to embed compassionate care education and nursing practice.Additional co-authors: Fiona Smith, Stephen DM Smith, Ria Tocher, and Anne Waug
Quasi-Normal Modes of Stars and Black Holes
Perturbations of stars and black holes have been one of the main topics of
relativistic astrophysics for the last few decades. They are of particular
importance today, because of their relevance to gravitational wave astronomy.
In this review we present the theory of quasi-normal modes of compact objects
from both the mathematical and astrophysical points of view. The discussion
includes perturbations of black holes (Schwarzschild, Reissner-Nordstr\"om,
Kerr and Kerr-Newman) and relativistic stars (non-rotating and
slowly-rotating). The properties of the various families of quasi-normal modes
are described, and numerical techniques for calculating quasi-normal modes
reviewed. The successes, as well as the limits, of perturbation theory are
presented, and its role in the emerging era of numerical relativity and
supercomputers is discussed.Comment: 74 pages, 7 figures, Review article for "Living Reviews in
Relativity
Recommended from our members
A Niche-Based Framework to Assess Current Monitoring of European Forest Birds and Guide Indicator Species' Selection
Concern that European forest biodiversity is depleted and declining has provoked widespread efforts to improve management practices. To gauge the success of these actions, appropriate monitoring of forest ecosystems is paramount. Multi-species indicators are frequently used to assess the state of biodiversity and its response to implemented management, but generally applicable and objective methodologies for species' selection are lacking. Here we use a niche-based approach, underpinned by coarse quantification of species' resource use, to objectively select species for inclusion in a pan-European forest bird indicator. We identify both the minimum number of species required to deliver full resource coverage and the most sensitive species' combination, and explore the trade-off between two key characteristics, sensitivity and redundancy, associated with indicators comprising different numbers of species. We compare our indicator to an existing forest bird indicator selected on the basis of expert opinion and show it is more representative of the wider community. We also present alternative indicators for regional and forest type specific monitoring and show that species' choice can have a significant impact on the indicator and consequent projections about the state of the biodiversity it represents. Furthermore, by comparing indicator sets drawn from currently monitored species and the full forest bird community, we identify gaps in the coverage of the current monitoring scheme. We believe that adopting this niche-based framework for species' selection supports the objective development of multi-species indicators and that it has good potential to be extended to a range of habitats and taxa