572 research outputs found

    Variable-Speed Simulation of a Dual-Clutch Gearbox Tiltrotor Driveline

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    This investigation explores the variable-speed operation and shift response of a prototypical two-speed dual-clutch transmission tiltrotor driveline in forward flight. Here, a Comprehensive Variable-Speed Rotorcraft Propulsion System Modeling (CVSRPM) tool developed under a NASA funded NRA program is utilized to simulate the drive system dynamics. In this study, a sequential shifting control strategy is analyzed under a steady forward cruise condition. This investigation attempts to build upon previous variable-speed rotorcraft propulsion studies by 1) including a fully nonlinear transient gas-turbine engine model, 2) including clutch stick-slip friction effects, 3) including shaft flexibility, 4) incorporating a basic flight dynamics model to account for interactions with the flight control system. Through exploring the interactions between the various subsystems, this analysis provides important insights into the continuing development of variable-speed rotorcraft propulsion systems

    Red Ribbon Living Well: Free Travelling Blankets Film Project Workshop 2

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    A post-production collaging and recording workshop following a day of filming ( 9 June 2023) with Red Ribbon Living Well and the Free Travelling Blankets (created during 2021 workshops at Goldsmiths). This led to the production of 7 short films telling the Red Ribbon story and to be released in 2024 as part of a Goldsmiths/Deptford People's Heritage Museum project funded by the Major of London (Untold Stories)

    Red Ribbon Living Well: Free Travelling Blankets Film Project Workshop 1

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    A post-production collaging and recording workshop following a day of filming ( 9 June 2023) with Red Ribbon Living Well and the Free Travelling Blankets (created during 2021 workshops at Goldsmiths). This led to the production of 7 short films telling the Red Ribbon story and to be released in 2024 as part of a Goldsmiths/Deptford People's Heritage Museum project funded by the Major of London (Untold Stories)

    An illness-focused interactive booklet to optimise management and medication for childhood fever and infections in out-of-hours primary care: Study protocol for a cluster randomised trial

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    Background: Fever is the most common reason for a child to be taken to a general practitioner (GP), especially during out-of-hours care. It is mostly caused by self-limiting infections. However, antibiotic prescription rates remain high, especially during out-of-hours care. Anxiety and lack of knowledge among parents, and perceived pressure to prescribe antibiotics amongst GPs, are important determinants of excessive antibiotic prescriptions. An illness-focused interactive booklet has the potential to improve this by providing parents with information about fever self-management strategies. The aim of this study is to develop and determine the effectiveness of an interactive booklet on management of children presenting with fever at Dutch GP out-of-hours cooperatives. Methods/design: We are conducting a cluster randomised controlled trial (RCT) with 20 GP out-of-hours cooperatives randomised to 1 of 2 arms: GP access to the illness-focused interactive booklet or care as usual. GPs working at intervention sites will have access to the booklet, which was developed in a multistage process. It consists of a traffic light system for parents on how to respond to fever-related symptoms, as well as information on natural course of infections, benefits and harms of (antibiotic) medications, self-management strategies and 'safety net' instructions. Children < 12 years of age with parent-reported or physician-measured fever are eligible for inclusion. The primary outcome is antibiotic prescribing during the initial consultation. Secondary outcomes are (intention to) (re)consult, antibiotic prescriptions during re-consultations, referrals, parental satisfaction and reassurance. In 6 months, 20,000 children will be recruited to find a difference in antibiotic prescribing rates of 25% in the control group and 19% in the intervention group. Statistical analysis will be performed using descriptive statistics and by fitting two-level (GP out-of-hours cooperative and patient) random intercept logistic regression models. Discussion: This will be the first and largest cluster RCT evaluating the effectiveness of an illness-focused interactive booklet during GP out-of-hours consultations with febrile children receiving antibiotic prescriptions. It is hypothesised that use of the booklet will result in a reduced number of antibiotic prescriptions, improved parental satisfaction and reduced intention to re-consult. Trial registration: ClinicalTrials.gov identifier: NCT02594553. Registered on 26 Oct 2015, last updated 15 Sept 2016

    An illness-focused interactive booklet to optimise management and medication for childhood fever and infections in out-of-hours primary care: study protocol for a cluster randomised trial

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    Background Fever is the most common reason for a child to be taken to a general practitioner (GP), especially during out-of-hours care. It is mostly caused by self-limiting infections. However, antibiotic prescription rates remain high, especially during out-of-hours care. Anxiety and lack of knowledge among parents, and perceived pressure to prescribe antibiotics amongst GPs, are important determinants of excessive antibiotic prescriptions. An illness-focused interactive booklet has the potential to improve this by providing parents with information about fever self-management strategies. The aim of this study is to develop and determine the effectiveness of an interactive booklet on management of children presenting with fever at Dutch GP out-of-hours cooperatives. Methods/design We are conducting a cluster randomised controlled trial (RCT) with 20 GP out-of-hours cooperatives randomised to 1 of 2 arms: GP access to the illness-focused interactive booklet or care as usual. GPs working at intervention sites will have access to the booklet, which was developed in a multistage process. It consists of a traffic light system for parents on how to respond to fever-related symptoms, as well as information on natural course of infections, benefits and harms of (antibiotic) medications, self-management strategies and ‘safety net’ instructions. Children < 12 years of age with parent-reported or physician-measured fever are eligible for inclusion. The primary outcome is antibiotic prescribing during the initial consultation. Secondary outcomes are (intention to) (re)consult, antibiotic prescriptions during re-consultations, referrals, parental satisfaction and reassurance. In 6 months, 20,000 children will be recruited to find a difference in antibiotic prescribing rates of 25% in the control group and 19% in the intervention group. Statistical analysis will be performed using descriptive statistics and by fitting two-level (GP out-of-hours cooperative and patient) random intercept logistic regression models. Discussion This will be the first and largest cluster RCT evaluating the effectiveness of an illness-focused interactive booklet during GP out-of-hours consultations with febrile children receiving antibiotic prescriptions. It is hypothesised that use of the booklet will result in a reduced number of antibiotic prescriptions, improved parental satisfaction and reduced intention to re-consult

    Sound-propagation gap in fluid mixtures

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    We discuss the behavior of the extended sound modes of a dense binary hard-sphere mixture. In a dense simple hard-sphere fluid the Enskog theory predicts a gap in the sound propagation at large wave vectors. In a binary mixture the gap is only present for low concentrations of one of the two species. At intermediate concentrations sound modes are always propagating. This behavior is not affected by the mass difference of the two species, but it only depends on the packing fractions. The gap is absent when the packing fractions are comparable and the mixture structurally resembles a metallic glass.Comment: Published; withdrawn since ordering in archive gives misleading impression of new publicatio

    Pervasive refusal syndrome as part of the refusal–withdrawal–regression spectrum: critical review of the literature illustrated by a case report

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    Pervasive refusal syndrome (PRS) is a rare child psychiatric disorder characterized by pervasive refusal, active/angry resistance to help and social withdrawal leading to an endangered state. Little has been written about PRS. A literature search yielded only 15 relevant articles, all published between 1991 and 2006. This article presents a critical review of the published literature, illustrated by a case report of an 11-year-old girl. PRS most often affects girls (75%). The mean age of the known population is 10.5 years. A premorbid high-achieving, perfectionist, conscientious personality seems to play an important role in the aetiology of PRS, as can a psychiatric history of parents or child and environmental stressors. PRS shows a symptom overlap with many other psychiatric disorders. However, none of the current DSM diagnoses can account for the full range of symptoms seen in PRS, and the active/angry resistance can be considered as the main distinguishing feature. Treatment should be multidisciplinary and characterized by patience, gentle encouragement and tender loving care. Hospitalization, ideally in a child and adolescent psychiatric unit, is almost always required. Although the recovery process is painfully slow (average duration of therapy 12.8 months), most children recover fully (complete recovery in 67% of known cases). In our opinion, it is important to increase knowledge of PRS, not only because of its disabling, potential life-threatening character, but also because there is hope for recovery through suitable treatment. We therefore propose an incorporation of PRS into the DSM and ICD classifications. However, an adaptation of the current diagnostic criteria is needed. We also consider PRS closely related to regression, which is why we introduce a new concept: “the refusal–withdrawal–regression spectrum”

    Charged Particles in a 2+1 Curved Background

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    The coupling to a 2+1 background geometry of a quantized charged test particle in a strong magnetic field is analyzed. Canonical operators adapting to the fast and slow freedoms produce a natural expansion in the inverse square root of the magnetic field strength. The fast freedom is solved to the second order. At any given time, space is parameterized by a couple of conjugate operators and effectively behaves as the `phase space' of the slow freedom. The slow Hamiltonian depends on the magnetic field norm, its covariant derivatives, the scalar curvature and presents a peculiar coupling with the spin-connection.Comment: 22 page

    Modelling of an imaging beamline at the ISIS pulsed neutron source

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    A combined neutron imaging and neutron diffraction facility, IMAT, is currently being built at the pulsed neutron spallation source ISIS in the U.K. A supermirror neutron guide is required to combine imaging and diffraction modes at the sample position in order to obtain suitable time of flight resolutions for energy selective imaging and diffraction experiments. IMAT will make use of a straight neutron guide and we consider here the optimization of the supermirror guide dimensions and characterisation of the resulting beam characteristics, including the homogeneity of the flux distribution in space and energy and the average and peak neutron fluxes. These investigations take into account some main design criteria: to maximise the neutron flux, to minimise geometrical artefacts in the open beam image at the sample position and to obtain a good energy resolution whilst retaining a large neutron bandwidth. All of these are desirable beam characteristics for the proposed imaging and diffraction analysis modes of IMAT
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