8,763 research outputs found

    Hot-flow tests of a series of 10-percent-scale turbofan forced mixing nozzles

    Get PDF
    An approximately 1/10-scale model of a mixed-flow exhaust system was tested in a static facility with fully simulated hot-flow cruise and takeoff conditions. Nine mixer geometries with 12 to 24 lobes were tested. The areas of the core and fan stream were held constant to maintain a bypass ratio of approximately 5. The research results presented in this report were obtained as part of a program directed toward developing an improved mixer design methodology by using a combined analytical and experimental approach. The effects of lobe spacing, lobe penetration, lobe-to-centerbody gap, lobe contour, and scalloping of the radial side walls were investigated. Test measurements included total pressure and temperature surveys, flow angularity surveys, and wall and centerbody surface static pressure measurements. Contour plots at various stations in the mixing region are presented to show the mixing effectiveness for the various lobe geometries

    Do depressive symptoms predict cancer incidence?: 17-year follow-up of the Whitehall II study

    Get PDF
    Objective: To explore the association between depressive symptom history and cancer incidence. Methods: Affective/emotional depressive symptoms were assessed using the General Health Questionnaire (GHQ-30) depression sub-scale across phase 1 (1985-1988), phase 2 (1989-1990), and phase 3 (1991-1994) of the Whitehall II prospective cohort study; ‘chronic’= depressive episode at phase 1, 2 and 3; ‘new’= depressive episode at phase 3 only. Cancer Incidence was obtained from the National Health Service Central Register with an average follow-up of 15.6 years (range 0.08–17.4). The study sample consisted of 6983 participants, aged 35–55 years at baseline. Results were adjusted for age, sex, socio-economic position, health behaviours, health status/conditions, medication, and social support. Results: Over a 17.4 year follow-up, chronic depressive symptoms did not increase the risk of cancer incidence compared to those who never experienced symptoms (hazard ratio (HR)=1.03, 95% confidence interval (CI): 0.71-1.49). Participants who experienced new depressive symptoms had an increased risk of cancer incidence in the first 9 years of follow-up (HR=1.89, 95% CI: 1.23-2.90) but no increased risk in later years (HR=0.84, 95% CI: 0.52-1.35). Conclusion: Chronic depressive symptoms were not associated with cancer incidence. In contrast, new-onset symptoms were associated with a substantially increased risk, possibly due to reverse causality

    Court Interpreter Training in the Language Laboratory

    Get PDF
    Demographic studies and statistics from state and federal courts indicate agrowing need for Spanish-English court interpreters with special training in consecutiveand simultaneous court interpretation. The authors conducted a survey of 466 ofCalifornia's Spanish-English court interpreters to determine what the Spanish-Englishcourt interpreter's strongest skills needs are. Survey results are reported in this article,and the five strongest skills training needs are identified. The authors indicate how thelanguage laboratory may efficiently be used to develop and enhance these five skillsand how it may best serve a court interpreter training program. Emphasis is onapplying the work of G.A. Miller and the training techniques of Robert Ingram toSpanish-English court interpreter training

    Universal persistence exponents in an extremally driven system

    Full text link
    The local persistence R(t), defined as the proportion of the system still in its initial state at time t, is measured for the Bak--Sneppen model. For 1 and 2 dimensions, it is found that the decay of R(t) depends on one of two classes of initial configuration. For a subcritical initial state, R(t)\sim t^{-\theta}, where the persistence exponent \theta can be expressed in terms of a known universal exponent. Hence \theta is universal. Conversely, starting from a supercritical state, R(t) decays by the anomalous form 1-R(t)\sim t^{\tau_{\rm ALL}} until a finite time t_{0}, where \tau_{\rm ALL} is also a known exponent. Finally, for the high dimensional model R(t) decays exponentially with a non--universal decay constant.Comment: 4 pages, 6 figures. To appear in Phys. Rev.

    Triumph of hope over experience: learning from interventions to reduce avoidable hospital admissions identified through an Academic Health and Social Care Network.

    Get PDF
    BACKGROUND: Internationally health services are facing increasing demands due to new and more expensive health technologies and treatments, coupled with the needs of an ageing population. Reducing avoidable use of expensive secondary care services, especially high cost admissions where no procedure is carried out, has become a focus for the commissioners of healthcare. METHOD: We set out to identify, evaluate and share learning about interventions to reduce avoidable hospital admission across a regional Academic Health and Social Care Network (AHSN). We conducted a service evaluation identifying initiatives that had taken place across the AHSN. This comprised a literature review, case studies, and two workshops. RESULTS: We identified three types of intervention: pre-hospital; within the emergency department (ED); and post-admission evaluation of appropriateness. Pre-hospital interventions included the use of predictive modelling tools (PARR - Patients at risk of readmission and ACG - Adjusted Clinical Groups) sometimes supported by community matrons or virtual wards. GP-advisers and outreach nurses were employed within the ED. The principal post-hoc interventions were the audit of records in primary care or the application of the Appropriateness Evaluation Protocol (AEP) within the admission ward. Overall there was a shortage of independent evaluation and limited evidence that each intervention had an impact on rates of admission. CONCLUSIONS: Despite the frequency and cost of emergency admission there has been little independent evaluation of interventions to reduce avoidable admission. Commissioners of healthcare should consider interventions at all stages of the admission pathway, including regular audit, to ensure admission thresholds don't change

    Memory in aged granular media

    Full text link
    Stimulated by recent experimental results, we simulate ``temperature''-cycling experiments in a model for the compaction of granular media. We report on the existence of two types of memory effects: short-term dependence on the history of the sample, and long-term memory for highly compact (aged) systems. A natural interpretation of these results is provided by the analysis of the density heterogeneities.Comment: 5 eps figures, uses euromacr.tex and europhys.sty (included

    Studies in early American History: The Legends of Jekyll Island

    Get PDF
    BE9FFD03-DA60-4C4E-8F48-69B4CE8337A9 Head, Franklin H. (1832-1914), Studies in early American History: The Legends of Jekyll Island. Chicago: Priv. print, 1902.The Legends of Jekyll Island By Franklin H. Head. This work was originally read before the Chicago Historical Society in (k2 and was then printed in New England Magazine without comment. DeRenne, having acquired a copy of the magazine, revealed that the whole thing was hoax, made up by Head and illustrated with black and white photos of his friends and acquaintances rather than real pictures of Oglethorpe and Sii Francis Drake. This booklet came out around the same time as the magazine article and differs slightly from the article according to DeRenne. NUC lists ten copies virtually all in northern libraries. It is a rarely seen Georgia oddity - and quite funny. #8561 $125.00 1893? U-GAPaper"These 'homegrown legends,' ... soon took on a life of their own and had by 1894 already begun to be taken seriously by occasional authors in earnest publications such as the Christian Advocate. The last version was privately published in 1902 as a little booklet that Head distributed among club members and friends. To the later version he added a few additional historical 'facts' and photographs of 'General Oglethorpe' and other distinguished figures- in reality, photographs of Chicago men who were members of both the Jekyll Island Club and the Chicago Literary Club"--cf. Page ix, McCash, June Hall. Jekyll Island's early years (Athens : University of Georgia Press, 2005)

    A mean field description of jamming in non-cohesive frictionless particulate systems

    Full text link
    A theory for kinetic arrest in isotropic systems of repulsive, radially-interacting particles is presented that predicts exponents for the scaling of various macroscopic quantities near the rigidity transition that are in agreement with simulations, including the non-trivial shear exponent. Both statics and dynamics are treated in a simplified, one-particle level description, and coupled via the assumption that kinetic arrest occurs on the boundary between mechanically stable and unstable regions of the static parameter diagram. This suggests the arrested states observed in simulations are at (or near) an elastic buckling transition. Some additional numerical evidence to confirm the scaling of microscopic quantities is also provided.Comment: 9 pages, 3 figs; additional clarification of different elastic moduli exponents, plus typo fix. To appear in PR

    Late Life Employment Histories and Their Association With Work and Family Formation During Adulthood: A Sequence Analysis Based on ELSA

    Get PDF
    Objectives: To extend research on workforce participation beyond age 50 by describing entire employment histories in later life and testing their links to prior life course conditions. Methods: We use data from the English Longitudinal Study of Ageing, with retrospective information on employment histories between age 50 and 70 for 1,103 men and 1,195 women (n = 2,298). We apply sequence analysis and group respondents into eight clusters with similar histories. Using multinomial regressions, we then test their links to labor market participation, partnership, and parenthood histories during early (age 20–34) and mid-adulthood (age 35–49). Results: Three clusters include histories dominated by full-time employees but with varying age of retirement (before, at, and after age 60). One cluster is dominated by self-employment with comparatively later retirement. Remaining clusters include part-time work (retirement around age 60 or no retirement), continuous domestic work (mostly women), or other forms of nonemployment. Those who had strong attachments to the labor market during adulthood are more likely to have histories of full-time work up until and beyond age 60, especially men. Parenthood in early adulthood is related to later retirement (for men only). Continued domestic work was not linked to parenthood. Partnered women tend to work part-time or do domestic work. The findings remain consistent after adjusting for birth cohort, childhood adversity, life course health, and occupational position. Discussion: Policies aimed at increasing the proportion of older workers not only need to address later stages of the life course but also early and mid-adulthood
    • 

    corecore