358 research outputs found

    Principles of thermoacoustic energy harvesting

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    Thermoacoustics exploit a temperature gradient to produce powerful acoustic pressure waves. The technology has a key role to play in energy harvesting systems. A time-line in the development of thermoacoustics is presented from its earliest recorded example in glass blowing through to the development of the Sondhauss and Rijke tubes to Stirling engines and pulse-tube cryo-cooling. The review sets the current literature in context, identifies key publications and promising areas of research. The fundamental principles of thermoacoustic phenomena are explained; design challenges and factors influencing efficiency are explored. Thermoacoustic processes involve complex multi-physical coupling and transient, highly non-linear relationships which are computationally expensive to model; appropriate numerical modelling techniques and options for analyses are presented. Potential methods of harvesting the energy in the acoustic waves are also examined

    Implementation of a novel antimicrobial stewardship strategy for rural facilities utilising telehealth

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    A significant portion of healthcare takes place in small hospitals, and many are located in rural and regional areas. Facilities in these regions frequently do not have adequate resources to implement an onsite antimicrobial stewardship programme and there are limited data relating to their implementation and effectiveness. We present an innovative model of providing a specialist telehealth antimicrobial stewardship service utilising a centralised service (Queensland Statewide Antimicrobial Stewardship Program) to a rural Hospital and Health Service. Results of a 2-year post-implementation follow-up showed an improvement in adherence to guidelines [33.7% (95% CI 27.0–40.4%) vs. 54.1% (95% CI 48.7–59.5%)] and appropriateness of antimicrobial prescribing [49.0% (95% CI 42.2–55.9%) vs. 67.5% (95% CI 62.7–72.4%) (P < 0.001). This finding was sustained after adjustment for hospitals, with improvement occurring sequentially across the years for adherence to guidelines [adjusted odds ratio (aOR) = 2.44, 95% CI 1.70–3.51] and appropriateness of prescribing (aOR = 2.48, 95% CI 1.70–3.61). There was a decrease in mean total antibiotic use (DDDs/1000 patient-days) between the years 2016 (52.82, 95% CI 44.09–61.54) and 2018 (39.74, 95% CI 32.76–46.73), however this did not reach statistical significance. Additionally, there was a decrease in mean hospital length of stay (days) from 2016 (3.74, 95% CI 3.08–4.41) to 2018 (2.55, 95% CI 1.98–3.12), although this was not statistically significant. New telehealth-based models of antimicrobial stewardship can be effective in improving prescribing in rural areas. Programmes similar to ours should be considered for rural facilities

    N,N′-Dineopentyl­naphthalene-1,8-diamine

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    In the title compound, C20H30N2, all bond distances and angles fall within the usual ranges but the C(ipso)—N distances [1.391 (5) and 1.398 (4) Å] are slightly shorter than the corresponding typical average distance of 1.42 (3) Å. The N atoms may be described as pyramidal sp 3-hybridized with an N—H⋯H—N separation of 2.07 (2) Å. This is necessitated because the two C(bridgehead)—C(ipso)—N—C torsion angles [170.6 (4) and 172.6 (3)°] would require the amine H atoms to be in prohibitively close proximity if the N atoms were assumed to be sp 2-hybridized

    Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution

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    The structures of the molecules (XMe2Si)2C(SiMe3)2, where X = H, Cl, Br, have been determined by gas electron diffraction (GED) using the SARACEN method of restraints, with all analogues existing in the gas phase as mixtures of C1- and C2-symmetric conformers. Variable temperature 1H and 29Si solution-phase NMR studies, as well as 13C NMR and 1H/29Si NMR shift correlation and 1H NMR saturation transfer experiments for the chlorine and bromine analogues, are reported. At low temperatures in solution there appear to be two C1 conformers and two C2 conformers, agreeing with the isolated-molecule calculations used to guide the electron diffraction refinements. For (HMe2Si)2C(SiMe3)2 the calculations indicated six conformers close in energy, and these were modeled in the GED refinement

    Enduring Legacy? Charles Tilly and Durable Inequality

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    This article assesses Charles Tilly’s Durable Inequality and traces its influence. In writing Durable Inequality, Tilly sought to shift the research agenda of stratification scholars. But the book’s initial impact was disappointing. In recent years, however, its influence has grown, suggesting a more enduring legacy

    Hydrogen Bonding in Ionic Liquids Probed by Linear and Nonlinear Vibrational Spectroscopy

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    Three imidazolium-based ionic liquids of the type [Cnmim][NTf2] with varying alkyl chain lengths (n = 1, 2 and 8) at the 1 position of the imidazolium ring were studied applying IR, linear Raman, and multiplex CARS spectroscopy. The focus has been on the CH-stretching region of the imidazolium ring, which is supposed to carry information about a possible hydrogen bonding network in the ionic liquid. The measurements are compared to calculations of the corresponding anharmonic vibrational spectra for a cluster of [C2mim][NTf2] consisting of four ion pairs. The results support the hypothesis of weak hydrogen bonding involving the C(4)-H and C(5)-H groups and somewhat stronger hydrogen bonds of the C(2)-H groups.Comment: revised manuscript, accepted for publication in New J. Phy

    Intensive community care services for children and young people in psychiatric crisis: an expert opinion.

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    BACKGROUND: Children and young people's (CYP) mental health is worsening, and an increasing number are seeking psychiatric and mental health care. Whilst many CYPs with low-to-medium levels of psychiatric distress can be treated in outpatient services, CYPs in crisis often require inpatient hospital treatment. Although necessary in many cases, inpatient care can be distressing for CYPs and their families. Amongst other things, inpatient stays often isolate CYPs from their support networks and disrupt their education. In response to such limitations, and in order to effectively support CYPs with complex mental health needs, intensive community-based treatment models, which are known in this paper as intensive community care services (ICCS), have been developed. Although ICCS have been developed in a number of settings, there is, at present, little to no consensus of what ICCS entails. METHODS: A group of child and adolescent mental health clinicians, researchers and academics convened in London in January 2023. They met to discuss and agree upon the minimum requirements of ICCS. The discussion was semi-structured and used the Dartmouth Assertive Community Treatment Fidelity Scale as a framework. Following the meeting, the agreed features of ICCS, as described in this paper, were written up. RESULTS: ICCS was defined as a service which provides treatment primarily outside of hospital in community settings such as the school or home. Alongside this, ICCS should provide at least some out-of-hours support, and a minimum of 90% of CYPs should be supported at least twice per week. The maximum caseload should be approximately 5 clients per full time equivalent (FTE), and the minimum number of staff for an ICCS team should be 4 FTE. The group also confirmed the importance of supporting CYPs engagement with their communities and the need to remain flexible in treatment provision. Finally, the importance of robust evaluation utilising tools including the Children's Global Assessment Scale were agreed. CONCLUSIONS: This paper presents the agreed minimum requirements of intensive community-based psychiatric care. Using the parameters laid out herein, clinicians, academics, and related colleagues working in ICCS should seek to further develop the evidence base for this treatment model
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