65 resultados para Boundaries.


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Flutter prediction as currently practiced is usually deterministic, with a single structural model used to represent an aircraft. By using interval analysis to take into account structural variability, recent work has demonstrated that small changes in the structure can lead to very large changes in the altitude at which
utter occurs (Marques, Badcock, et al., J. Aircraft, 2010). In this follow-up work we examine the same phenomenon using probabilistic collocation (PC), an uncertainty quantification technique which can eficiently propagate multivariate stochastic input through a simulation code,
in this case an eigenvalue-based fluid-structure stability code. The resulting analysis predicts the consequences of an uncertain structure on incidence of
utter in probabilistic terms { information that could be useful in planning
flight-tests and assessing the risk of structural failure. The uncertainty in
utter altitude is confirmed to be substantial. Assuming that the structural uncertainty represents a epistemic uncertainty regarding the
structure, it may be reduced with the availability of additional information { for example aeroelastic response data from a flight-test. Such data is used to update the structural uncertainty using Bayes' theorem. The consequent
utter uncertainty is significantly reduced across the entire Mach number range.

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1. The population characteristics and distribution of wood mice Apodemus sylvaticus (L.) were investigated along field margins of farmland dominated by grass production. 2. Turnover, sex ratio, breeding season, spatial density dependence and density dependence in reproductive activity indicated that the population ecology of A. sylvaticus is consistent in different habitats in the same geographical region. 3. Spatial variation in the abundance of A.sylvaticus was related negatively to percentage of land under pasture and distance from woodland and positively related to variables associated with food supply and cover. 4. Variation in numbers of overwintered mice at the start of the breeding season was related more closely to breeding opportunity than to environmental factors. This was particularly so in males. 5. The association of overwintered male and female A. sylvaticus remained evident in the later half of the breeding season. Young males and females of the year, however, were distributed more with respect to physical and biological features than towards adults or reproductive opportunity. 6. A. sylvaticus is an important species of field margins, even where these are poorly developed and agriculture is pastoral rather than arable. Further studies of this species in a wider range of agricultural systems are desirable.

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This paper reports the findings of an evaluation of the ‘Housing Support, Outreach and Referral’ service developed to support people living with HIV who were homeless or at risk of homelessness. The service was set up as part of the Supporting People Health Pilot programme established to demonstrate the policy links between housing support services and health and social care services by encouraging the development of integrated services. The paper considers the role of housing support in improving people's health, and considers the challenges of working across housing, health and social care boundaries. The evaluation of the health pilot employed two main sources of data collection: quarterly project evaluation reports, which collected process data as well as reporting progress against aims and objectives, and semi-structured interviews with professionals from all key stakeholder groups and agencies, and with people who used services. Over the course of 15 months, 56 referrals were received of which 27 were accepted. Fifteen people received tenancy support of whom 12 were helped to access temporary accommodation. At the end of the 15 months, all of the tenancies had been maintained. In addition, 18 people registered with a general practitioner and 13 registered with an HIV clinic. Interviews with professionals emphasised the importance of the local joint working context, the involvement of the voluntary sector and the role of the support workers as factors that accounted for these outcomes. Those using services placed most emphasis on the flexibility of the support worker role. Importantly, interviews with professionals and those using services suggest that the role of support worker incorporates two dimensions – those of networker/navigator as well as advocate – and that both dimensions are important in determining the effectiveness of the service.

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Naturally occurring boundaries between bundles of 90° stripe domains, which form in BaTiO3 lamellae on cooling through the Curie Temperature, have been characterized using both piezoresponse force microscopy (PFM) and scanning transmission electron microscopy (STEM). Detailed interpretation of the dipole configurations present at these boundaries (using data taken from PFM) shows that in the vast majority of cases they are composed of simple zigzag 180° domain walls. Topological information from STEM shows that occasionally domain bundle boundaries can support chains of dipole flux closure and quadrupole nanostructures, but these kinds of boundaries are comparatively rare; when such chains do exist, it is notable that singularities at the cores of the dipole
structures are avoided. The symmetry of the boundary shows that diads and centers of inversion exist at positions where core singularities should have been expected.

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The review essay opens with positive attributes of Ireland but then considers that the island has been subject to centuries of bitter dispute and unrest. The historical background to this is outlined, particularly the interactions between Ireland and its neighbouring island, Great Britain, which dominated Irish affairs. One policy adopted by the British was to encourage migration of Protestants into the largely Catholic island in the vain hope that this would reduce unrest. The
two islands were then united from 1801 as the United Kingdom of Great Britain and Ireland but demands from indigenous Irish Catholics for independence continued, resisted by the Protestant minority who wished to remain inside the UK. After the Great War a solution was imposed that granted most of Ireland independence but left the largely Protestant northeast corner within the UK as Northern Ireland. Reaction to and life with the Irish border are considered and the paper concludes with musings about its future.