149 research outputs found

    Gas-flow animation by unsteady heating in a microchannel

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    We study the flow-field generated in a one-dimensional wall-bounded gas layer due to an arbitrary small-amplitude time variation in the temperature of its boundaries. Using the Fourier transform technique, analytical results are obtained for the slip-flow/Navier–Stokes limit. These results are complemented by low-variance simulations of the Boltzmann equation, which are useful for establishing the limits of the slip-flow description, as well as for bridging the gap between the slip-flow analysis and previously developed free-molecular analytical predictions. Results are presented for both periodic (sinusoidal) and nonperiodic (step-jump) heating profiles. Our slip-flow solution is used to elucidate a singular limit reported in the literature for oscillatory heating of a dynamically incompressible fluid

    Point vortex model for prediction of sound generated by a wing with flap interacting with a passing vortex

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    Free-molecular and near-free-molecular gas flows over backward facing steps

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    START (STrAtegies for RelaTives) coping strategy for family carers of adults with dementia: qualitative study of participants' views about the intervention.

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    To analyse the experience of individual family carers of people with dementia who received a manual-based coping strategy programme (STrAtegies for RelaTives, START), demonstrated in a randomised-controlled trial to reduce affective symptoms

    Development, feasibility, and acceptability of an intervention to improve care for agitation in people living in nursing homes with dementia nearing the end-of-life

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    OBJECTIVES: To develop a staff training intervention for agitation in people with severe dementia, reaching end-of-life, residing in nursing homes (NHs), test feasibility, acceptability, and whether a trial is warranted. DESIGN: Feasibility study with pre- and post-intervention data collection, qualitative interviews, and focus groups. SETTING: Three NHs in South East England with dementia units, diverse in terms of size, ownership status, and location. PARTICIPANTS: Residents with a dementia diagnosis or scoring ≥2 on the Noticeable Problems Checklist, rated as "severe" on Clinical Dementia Rating Scale, family carers, and staff (healthcare assistants and nurses). INTERVENTION: Manualized training, delivered by nonclinical psychology graduates focusing on agitation in severe dementia, underpinned by a palliative care framework. MEASUREMENTS: Main outcomes were feasibility of recruitment, data collection, follow-up, and intervention acceptability. We collected resident, family carer, and staff demographics. Staff provided data on resident's agitation, pain, quality of life, and service receipt. Staff reported their sense of competence in dementia care. Family carers reported on satisfaction with end-of-life care. In qualitative interviews, we explored staff and family carers' views on the intervention. RESULTS: The target three NHs participated: 28 (49%) residents, 53 (74%) staff, and 11 (85%) family carers who were eligible to participate consented. Eight-four percent of staff attended ≥3 sessions, and we achieved 93% follow-up. We were able to complete quantitative interviews. Staff and family carers reported the intervention and delivery were acceptable and helpful. CONCLUSIONS: The intervention was feasible and acceptable indicating a larger trial for effectiveness may be warranted

    Robust optical delay lines via topological protection

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    Phenomena associated with topological properties of physical systems are naturally robust against perturbations. This robustness is exemplified by quantized conductance and edge state transport in the quantum Hall and quantum spin Hall effects. Here we show how exploiting topological properties of optical systems can be used to implement robust photonic devices. We demonstrate how quantum spin Hall Hamiltonians can be created with linear optical elements using a network of coupled resonator optical waveguides (CROW) in two dimensions. We find that key features of quantum Hall systems, including the characteristic Hofstadter butterfly and robust edge state transport, can be obtained in such systems. As a specific application, we show that the topological protection can be used to dramatically improve the performance of optical delay lines and to overcome limitations related to disorder in photonic technologies.Comment: 9 pages, 5 figures + 12 pages of supplementary informatio

    Carer coping and resident agitation as predictors of quality of life in care home residents living with dementia: Managing Agitation and Raising Quality of Life (MARQUE) English national care home prospective cohort study

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    OBJECTIVES: The objectives of the study are (1) to test our primary hypothesis that carers using more dysfunctional coping strategies predict lower quality of life in care home residents living with dementia, and this is moderated by levels of resident agitation, and (2) to explore relationships between carer dysfunctional coping strategy use, agitation, quality of life, and resident survival. METHODS: In the largest prospective cohort to date, we interviewed carers from 97 care home units (baseline, 4, 8, 12, 16 months) about quality of life (DEMQOL-Proxy) and agitation (Cohen-Mansfield Agitation Inventory) of 1483 residents living with dementia. At baseline, we interviewed 1566 carers about coping strategies (Brief COPE), averaging scores across care home units. RESULTS: Carer dysfunctional coping strategies did not predict resident quality of life over 16 months (0.03, 95% CI -0.40 to 0.46). Lower resident quality of life was longitudinally associated with worse Cohen-Mansfield Agitation Inventory score (-0.25, 95% CI -0.26 to -0.23). Survival was not associated with carer dysfunctional coping, resident quality of life, or agitation scores. CONCLUSIONS: Carer dysfunctional coping did not predict resident quality of life. Levels of resident agitation were consistently high and related to lower quality of life, over 16 months. Lack of association between carer dysfunctional coping and resident quality of life may reflect the influence of the care home or an insensitivity of aggregated coping strategy scores. The lack of relationship with survival indicates that agitation is not explained mainly by illness. Scalable interventions to reduce agitation in care home residents living with dementia are urgently needed
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