682 research outputs found
Multiple-orifice throttle valve
Multiple-orifice throttle valve is not subject to cold welding in a vacuum environment and is compatible with strong oxidizing fluid. The valve is of all metal construction using simple components that do not slide or rotate and excludes static or dynamic seals
Multiple orifice throttle valve Patent
Throttle valve for regulating fluid flow volum
Adoption of sustainable retrofit in UK social housing 2010 – 2015
Purpose
The Retrofit State of the Nation Survey has tracked the perceptions of social housing sector professionals’ views of retrofit since 2010. It has taken the form of 3 surveys conducted in 2010, 2013 and 2015. Here we bring together the three surveys to specifically address the adoption and perceived effectiveness of retrofit technology in social housing projects. This identifies the changing perceptions of social housing professionals over a period of significant policy change within in the sector.
Design/methodology/approach
The research takes the form of a cross-sectional attitudinal, self-completion survey, covering sections considering the adoption levels and perceived effectiveness of different retrofit technologies. The target sample was medium to larger scale registered social housing providers. The surveys were conducted in 2010, 2013, and 2015.
Findings
In terms of effectiveness, the reliance on tried and tested technologies is apparent. Emerging or more complex technologies have declined in perceived effectiveness over the period. It is clear that social housing has adopted a wide range of technologies, and the larger providers, with whom this survey is undertaken, potentially represent a significant pool of UK retrofit experience.
Originality/value
The survey provides a record of the changing attitudes of social housing providers to specific technologies over the period 2010-2015, which has seen significant changes in energy and social housing policy. The findings show the link between policy instruments and adoption, with policy instruments mapping to adoption in the sector. Perceived effectiveness reflects a preference for more established technologies, an issue that is highlighted in the recent Bonfield Review
The role of lithosphere thickness in the formation of ocean islands and seamounts: contrasts between the Louisville and Emperor-Hawaiian hotspot trails
The Hawaii-Emperor and Louisville seamounts form the two most prominent time-progressive hotspot trails on Earth. Both formed over a similar time interval on lithosphere with a similar range of ages and thickness. The Hawaii-Emperor seamounts are large and magma productivity appears to be increasing at present. The Louisville seamounts, by contrast, are smaller and the trail appears to be waning. We present new major-and trace element data from five of the older (74-50 Ma) Louisville seamounts drilled during International Ocean Drilling Program (IODP) Expedition 330 and compare these to published data from the Emperor seamounts of the same age. Despite drilling deep into the shield-forming volcanic rocks at three of the Louisville seamounts, our data confirm the results of earlier studies based on dredge samples that the Louisville seamounts are composed of remarkably uniform alkali basalt. The basalt composition can be modelled by ~1.5–3% partial melting of a dominantly garnet lherzolite mantle with a composition similar to that of the Ontong Java Plateau mantle source. Rock samples recovered by dredging and drilling on the Emperor Seamounts range in composition from tholeiitic to alkali basalt and require larger degrees of melting (2–10%) and spinel-to garnet lherzolite mantle sources. We use a simple decompression melting model to show that melting of mantle with a potential temperature of 1500ºC under lithosphere of varying thickness can account for the composition of the shield-forming tholeiitic basalts from the Emperor seamounts, while post-shield alkali basalt requires a lower temperature (1300–1400ºC). This is consistent with the derivation of Hawaii-Emperor shield-forming magmas from the hotter axis of a mantle plume and the post-shield magmas from the cooler plume sheath as the seamount drifts away from the plume axis. The composition of basalt from the Louisville seamounts shows no significant variation with lithosphere thickness at the time of seamount formation, contrary to the predictions of our decompression melting model. This lack of influence of lithospheric thickness ischaracteristic of basalt from most ocean islands. Theproblem can be resolved if the Louisville seamounts were formed by dehydration melting of mantle containinga small amount of water in a cooler plume. Hydrous melting in a relatively cool mantle plume (Tp=1350–1400°C) could produce a small amount of melt and then be inhibited by increasing viscosity from reaching the dry mantle solidus and melting further. The failure of the plume to reach the dry mantle solidus or the base of the lithosphere means that the resulting magmas would have the same composition irrespective of lithosphere thickness. A hotter mantle plume (Tp≈1500°C) beneath the Emperor seamounts and the Hawaiian Islands would have lower viscosity before the onset of melting, melt to a larger extent, and decompress to the base of the lithosphere. Thus our decompression melting model could potentially explain the composition of both the Emperor and Louisville seamounts. The absence of a significant lithospheric control on the composition of basalt from nearly all ocean islands suggests that dehydration melting is the rule and the Hawaiian islands the exception. Alternatively, many ocean islands may not be the product of mantle plumes but instead be formed by decompression melting of heterogeneous mantle sources composed of peridotite containing discrete bodies of carbonated and silica-oversaturated eclogite within the general upper mantle convective flow
The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent
Peer reviewedPublisher PD
'Staying safe' – A narrative review of falls prevention in people with Parkinson’s -'PDSAFE'
This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.Background:
Parkinson's disease demonstrates a spectrum of motor and non-motor symptoms. Falling is
common and disabling. Current medical management shows minimal impact to reduce falls, or
fall related risk factors such as deficits in gait, strength and postural instability. Despite evidence
supporting rehabilitation in reducing fall risk factors, the most appropriate intervention to reduce
overall fall rate remains inconclusive.
This paper aims to 1) synthesise current evidence and conceptual models of falls rehabilitation in
Parkinson's in a narrative review; and based on this evidence 2) introduce the treatment protocol
used in the falls prevention, multi-centre clinical trial 'PDSAFE'.
Method: Search of four bibliographic databases using the terms ‘Parkinson*’ and ‘Fall*’ combined
with each of the following; ‘Rehab*, Balanc*, Strength*, Strateg*and Exercis*' and a framework for
narrative review was followed.
3557 papers were identified, 416 were selected for review. The majority report the impact of
rehabilitation on isolated fall risk factors. Twelve directly measure the impact on overall fall rate.
Discussion: Results were used to construct a narrative review with conceptual discussion based
on the 'International Classification of Functioning’, leading to presentation of the 'PDSAFE'
intervention protocol.
Conclusion: Evidence suggests training single, fall risk factors may not affect overall fall rate.
Combining with behavioural and strategy training in a functional, personalised multi-dimensional
model, addressing all components of the ‘International Classification of Functioning’ is likely to
provide a greater influence on falls reduction.
'PDSAFE' is a multi-dimensional, physiotherapist delivered, individually tailored, progressive,
home-based programme. It is designed with a strong evidence based approach and illustrates a
model for the clinical delivery of the conceptual theory discussed.This project was funded by the National Institute for Health Research Health Technologies Assessment
programme (project number 10/57/21). VG is supported by the National Institute of Health Research
Collaboration for Applied Health Research and Care South West Peninsula.
The Development of a Measure of Orthographic Processing in the Arabic Language: A Psychometric Evaluation
Although Arabic is an official language in 27 countries, standardized measures to assess Arabic literacy are scarce. The purpose of this research was to examine the item functioning of an assessment of Arabic orthographic knowledge. Sixty novel items were piloted with 201 third grade Arabic-speaking students. Participants were asked to identify the correctly spelled word from a pair of two words. Although the assessment was designed to be unidimensional, competing models were tested to determine whether item performance was attributable to multidimensionality. No multidimensional structure fit the data significantly better than the unidimensional model. The 60 original items were evaluated through item fit statistics and comparing performance against theoretical expectations. Twenty-eight items were identified as functioning poorly and were iteratively removed from the scale, resulting in a 32-item set. A value of 0.987 was obtained for McDonald’s coefficient ω from this final scale. Participants’ scores on the measure correlated with an external word reading accuracy measure at 0.79 (p \u3c .001), suggesting that the tool may measure skills important to word reading in Arabic. The task is simple to score and can discriminate among children with below-average orthographic knowledge. This work provides a foundation to develop Arabic literacy assessment
“Children are precious cargo; we don’t let them take any risks!”: Hearing from adults on safety and risk in children’s active play in schools: a systematic review
BACKGROUND: Understanding determinants of children’s outdoor play is important for improving low physical activity levels, and schools are a key setting for both. Safety concerns shape children’s opportunity to play actively outdoors, therefore, this qualitative evidence synthesis aimed to i) examine adult (e.g., parent, teacher, yard supervisor, principal) perspectives on safety and risk in children’s active play during recess in elementary and/or middle schools, and ii) identify how safety and risk influence playground supervision and decision making in this setting. METHODS: Six electronic databases were systematically searched in March 2021, with an updated search in June 2022. Records were screened against eligibility criteria using Covidence software, and data extraction and synthesis were performed using predesigned coding forms in Microsoft Excel and NVivo. Framework synthesis methodology was employed, guided by a conceptual framework structured on the socio-ecological model (SEM) and affordance theory. RESULTS: From 10,370 records, 25 studies were included that represented 608 adults across 89 schools from nine countries. The synthesis identified 10 constraining and four affording factors that influenced whether school staff were risk-averse or risk tolerant during recess, and, in turn, the degree to which children’s play was managed. Constraining factors stemmed from fears for children’s physical safety, and fear of blame and liability in the event of playground injury, which shaped parent, school staff and institutional responses to risk. Interrelated factors across SEM levels combined to drive risk-averse decision making and constraining supervision. Emerging evidence suggests children’s active play in schools can be promoted by fostering a risk tolerant and play friendly culture in schools through play facilitation training (e.g., risk-reframing, conflict resolution) and engaging stakeholders in the development of school policies and rules that balance benefits of play against potential risks. CONCLUSIONS: Findings show several socio-cultural factors limited the ability of school staff to genuinely promote active play. Future work should seek to foster risk tolerance in schools, challenge the cultural norms that shape parent attitudes and institutional responses to risk in children’s play, and explore novel methods for overcoming policy barriers and fear of liability in schools. TRIAL REGISTRATION: PROSPERO registration: CRD42021238719. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12966-022-01344-7
Sr-Nd-Pb-Hf isotope results from ODP Leg 187: Evidence for mantle dynamics of the Australian-Antarctic Discordance and origin of the Indian MORB source
New high precision PIMMS Hf and Pb isotope data for 14–28 Ma basalts recovered during ODP Leg 187 are compared with zero-age dredge samples from the Australian-Antarctic Discordance (AAD). These new data show that combined Nd-Hf isotope systematics can be used as an effective discriminant between Indian and Pacific MORB source mantle domains. In particular, Indian mantle is displaced to lower εNd and higher εHf ratios compared to Pacific mantle. As with Pb isotope plots, there is almost no overlap between the two mantle types in Nd-Hf isotope space. On the basis of our new Nd-Hf isotope data, we demonstrate that Pacific MORB-source mantle was present near the eastern margin of the AAD from as early as 28 Ma, its boundary with Indian MORB-source mantle coinciding with the eastern edge of a basin-wide arcuate depth anomaly that is centered on the AAD. This observation rules out models requiring rapid migration of Pacific MORB mantle into the Indian Ocean basin since separation of Australia from Antarctica. Although temporal variations in isotopic composition can be discerned relative to the fracture zone boundary of the modern AAD at 127°E, the distribution of different compositional groups appears to have remained much the same relative to the position of the residual depth anomaly for the past 30 m.y. Thus significant lateral flow of mantle along the ridge axis toward the interface appears unlikely. Instead, the dynamics that maintain both the residual depth anomaly and the isotopic boundary between Indian and Pacific mantle are due to eastward migration of the Australian and Antarctic plates over a stagnated, but slowly upwelling, slab oriented roughly orthogonal to the ridge axis. Temporal and spatial variations in the compositions of Indian MORB basalts within the AAD can be explained by progressive displacement of shallower Indian MORB-source mantle by deeper mantle having a higher εHf composition ascending ahead of the upwelling slab. Models for the origin of the distinctive composition of the Indian MORB-source based on recycling of a heterogeneous enriched component that consist of ancient altered ocean crust plus<10% pelagic sediment are inconsistent with Nd-Hf isotope systematics. Instead, the data can be explained by a model in which Indian mantle includes a significant proportion of material that was processed in the mantle wedge above a subduction zone and was subsequently mixed back into unprocessed upper mantle
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