93,639 research outputs found

    Wavy-ply sandwich with composite skins and crushable core for ductility and energy absorption

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    Conventional composite materials offer high specific stiffness and strength, but suffer from low failure strains and failure without warning. This work proposes a new design for sandwich structures with symmetrically-wavy composite skins and a crushable foam core, aiming to achieve large strains (due to unfolding of the skins) and energy absorption (due to crushing of the foam core) under tensile loading. The structure is designed by a combination of analytical modelling and finite element simulations, and the concept is demonstrated experimentally. When loaded under quasi-static tension, wavy-ply sandwich specimens with carbon–epoxy skins and optimised geometry exhibited an average failure strain of 8.6%, a specific energy dissipated of 9.4 kJ/kg, and ultimate strength of 1570 MPa. The scope for further developing the wavy-ply sandwich concept and potential applications requiring large deformations and energy absorption are discussed

    Towards an understanding of corporate web identity

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    'Working our way to health': Final Evaluation Report

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    This summary presents the findings of an independent evaluation of the ‘Working our Way to Health’ programme. This programme was delivered by Sefton PCT, funded through the Neighbourhood Renewal Fund, and was aimed at improving the health of men in three of the most deprived wards in its locality. It aimed to encourage men to be health aware and increase access to health and leisure services in order to improve key lifestyle behaviours and advance gender equity. The programme included: ‱ Community agency and health staff training ‱ Peer mentoring programme ‱ Healthy lifestyle programme It aimed to promote community partnerships to assist the expansion of health advice and services into a new community arena and engage a previously unattainable section of the male population in healthier lifestyle interventions

    A SAM Based Global CGE Model using GTAP Data January 2005

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    This paper provides a technical description of a global computable general equilibrium (CGE) model that is calibrated from a Social Accounting Matrix (SAM) representation of the Global Trade Analysis Project (GTAP) database. A distinctive feature of the model is the treatment of nominal and real exchange rates and hence the specification of multiple numéraire

    A new algorithm for microwave delay estimation from water vapor radiometer data

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    A new algorithm has been developed for the estimation of tropospheric microwave path delays from water vapor radiometer (WVR) data, which does not require site and weather dependent empirical parameters to produce high accuracy. Instead of taking the conventional linear approach, the new algorithm first uses the observables with an emission model to determine an approximate form of the vertical water vapor distribution which is then explicitly integrated to estimate wet path delays, in a second step. The intrinsic accuracy of this algorithm has been examined for two channel WVR data using path delays and stimulated observables computed from archived radiosonde data. It is found that annual RMS errors for a wide range of sites are in the range from 1.3 mm to 2.3 mm, in the absence of clouds. This is comparable to the best overall accuracy obtainable from conventional linear algorithms, which must be tailored to site and weather conditions using large radiosonde data bases. The new algorithm's accuracy and flexibility are indications that it may be a good candidate for almost all WVR data interpretation

    Intrinsic Variability and Field Statistics for the Vela Pulsar: 2. Systematics and Single-Component Fits

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    Individual pulses from pulsars have intensity-phase profiles that differ widely from pulse to pulse, from the average profile, and from phase to phase within a pulse. Widely accepted explanations do not exist for this variability or for the mechanism producing the radiation. The variability corresponds to the field statistics, particularly the distribution of wave field amplitudes, which are predicted by theories for wave growth in inhomogeneous media. This paper shows that the field statistics of the Vela pulsar (PSR B0833-45) are well-defined and vary as a function of pulse phase, evolving from Gaussian intensity statistics off-pulse to approximately power-law and then lognormal distributions near the pulse peak to approximately power-law and eventually Gaussian statistics off-pulse again. Detailed single-component fits confirm that the variability corresponds to lognormal statistics near the peak of the pulse profile and Gaussian intensity statistics off-pulse. The lognormal field statistics observed are consistent with the prediction of stochastic growth theory (SGT) for a purely linear system close to marginal stability. The simplest interpretations are that the pulsar's variability is a direct manifestation of an SGT state and the emission mechanism is linear (either direct or indirect), with no evidence for nonlinear mechanisms like modulational instability and wave collapse which produce power-law field statistics. Stringent constraints are placed on nonlinear mechanisms: they must produce lognormal statistics when suitably ensemble-averaged. Field statistics are thus a powerful, potentially widely applicable tool for understanding variability and constraining mechanisms and source characteristics of coherent astrophysical and space emissions.Comment: 11 pages, 12 figures. Accepted by Monthly Notices of the Royal Astronmical Society in April 200

    Intrinsic Variability and Field Statistics for the Vela Pulsar: 3. Two-Component Fits and Detailed Assessment of Stochastic Growth Theory

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    The variability of the Vela pulsar (PSR B0833-45) corresponds to well-defined field statistics that vary with pulsar phase, ranging from Gaussian intensity statistics off-pulse to approximately power-law statistics in a transition region and then lognormal statistics on-pulse, excluding giant micropulses. These data are analyzed here in terms of two superposed wave populations, using a new calculation for the amplitude statistics of two vectorially-combined transverse fields. Detailed analyses show that the approximately power-law and lognormal distributions observed are fitted well at essentially all on-pulse phases by Gaussian-lognormal and double-lognormal combinations, respectively. These good fits, plus the smooth but significant variations in fit parameters across the source, provide strong evidence that the approximately power-law statistics observed in the transition region are not intrinsic. Instead, the data are consistent with normal pulsar emission having lognormal statistics at all phases. This is consistent with generation in an inhomogeneous source obeying stochastic growth theory (SGT) and with the emission mechanism being purely linear (either direct or indirect). A nonlinear mechanism is viable only if it produces lognormal statistics when suitably ensemble-averaged. Variations in the SGT fit parameters with phase imply that the radiation is relatively more variable near the pulse edges than near the center, as found in earlier work. In contrast, Vela's giant micropulses come from a very restricted phase range and have power-law statistics with indices (6.7±0.66.7 \pm 0.6) not inconsistent with nonlinear wave collapse. These results imply that normal pulses have a different source and generation mechanism than giant micropulses, as suggested previously on other grounds.Comment: 10 pages and 14 figures. Accepted by Monthly Notices of the Royal Astronomical Society in April 200

    "Talk" about male suicide? Learning from community programmes

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    Purpose – The purpose of this paper is to examine the contribution of public awareness campaigning in developing community capacity toward preventing male suicide and explores emerging considerations for suicide prevention programme development. Design/methodology/approach – The paper draws on campaign evaluation data, specifically qualitative discussion groups with the general public, to report results concerning campaign processes, and “interim” effectiveness in changing public awareness and attitudes, and then discusses how progress is to be lasting and transformational. Findings – The campaign raised the awareness of a substantial proportion of those targeted, and affected attitudes and behaviour of those who were highly aware. The community settings approach was effective in reaching younger men, but there were challenges targeting the public more selectively, and engaging communities in a sustained way. Practical implications – The paper discusses emerging considerations for suicide prevention, focusing on gender and approaches and materials for engaging with the public as “influencers”. There are challenges to target audiences more specifically, provide a clear call to action, and engage the public in a sustained way. Social implications – The paper discusses emerging considerations for suicide prevention, focusing on gender and approaches and materials for engaging with the public as “influencers”. There are challenges to target audiences more specifically, provide a clear call to action, and engage the public in a sustained way. Originality/value – The paper adds fresh evidence of gendered communication processes, including their effects on public awareness, attitudes and engagement. Application of a theory of change model leads to systems level findings for sustaining programme gains

    Philosophy into Practice? Community Policing Units and Domestic Violence Victim Participation

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    Much research has focused on the police response to domestic violence; however, relatively little research has considered performance differences of various types of police officers. Although there has been widespread adoption of community policing by police departments across the country, it is not conclusive as to whether units with a specific community policing philosophy perform better than traditional units when handling domestic violence calls. The current study addresses this issue by analyzing the factors associated with victim participation; specifically, do officers and detectives operating under a specific community policing mandate produce higher rates of victim participation? Bivariate and multivariate analyses indicate that victim participation rates did not differ by a community policing orientation; rather, situational factors exert the strongest effect on victim participation
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