We study the interaction of highly nonlinear solitary waves propagating in granular crystals with an adjacent linear elastic medium. We investigate the effects of interface dynamics on the reflection of incident waves and on the formation of primary and secondary reflected waves. Experimental tests are performed to correlate the linear medium geometry, materials, and mass with the formation and propagation of reflected waves. We compare the experimental results with theoretical analysis based on the long-wavelength approximation and with numerical predictions obtained from discrete particle models. Experimental results are found to be in agreement with theoretical analysis and numerical simulations. This preliminary study establishes the foundation for utilizing reflected solitary waves as novel information carriers in nondestructive evaluation of elastic material systems.

An evaluation of nurse rostering practices in the National Health Service The scheduling of nursing time on hospital wards is critical to the delivery of patient care, resource utilization and employee satisfaction. Over the past decade many hospital wards in the United Kingdom (UK) have moved away from the traditional planning of rosters by a single manager, towards more participative processes known as self-rostering and team rostering. This paper tests the hypothesis, developed from the literature, that the three types of rostering approach may be positioned along a continuum. Self-rostering at one extreme, is conducive to staff empowerment, motivation and roster effectiveness, whilst departmental rostering, at the other, leads to perceived autocracy, reduced empowerment, lower levels of staff motivation and roster effectiveness. Team rostering is positioned mid-way on this continuum. This paper reports the findings of an empirical study of nurse rostering practices in the UK National Health Service (NHS), with a view to developing an understanding of the implications of implementing these three rostering approaches and testing the above hypothesis. The survey of rostering practices in 50 NHS wards, and in-depth case studies of seven wards, revealed that each of the three rostering approaches has benefits and limitations and a picture emerges quite different from that implied by the research hypothesis. Whilst the literature suggests that the choice of rostering approach determines the level of perceived autocracy, staff motivation and roster effectiveness, it is proposed in this paper that selection of rostering approach should be contingent upon operational context. The paper concludes with a framework which stipulates that the choice of rostering approach for a ward should be determined on the basis of four contingent variables, namely, ward size, demand variability, demand predictability, and complexity of skill mix. It is recommended that departmental rostering be applied in large wards with complex rostering problems, whilst team rostering is more appropriate for medium sized wards, and self-rostering appropriate for small wards.

Despite the criticality of nurse rostering practices, there is a surprising lack of attention paid to this managerial activity both in practice and in the health-service management literature. This paper reports the results of an inductive, empirical study of rostering practices in the UK National Health Service with a view to developing a shared understanding of roster planning processes and of what constitutes rostering effectiveness. A survey of rostering practices in 50 wards, followed by five in-depth, longitudinal case studies, revealed the complexity of rostering activities, and identified the main design parameters, which were used to specify rostering systems and to prepare periodic rosters. Rostering activities were perceived to directly impact upon service delivery, resource utilization and nurse retention. A number of poor rostering practices were identified, which could lead to dysfunctional behaviour. This analysis points to a clear managerial imperative to improve local competencies in roster planning and control, recognizing their strategic significance in contributing to hospital effectiveness. A 'Strategic Roster Planning and Control (SRPC)' model is proposed, which may provide a framework for evaluating rostering effectiveness, and a platform for the sharing of best practice, in order to stimulate organizational learning and achieve nationwide improvements in hospital performance.