1,607 research outputs found
Performing the archive: following in the footsteps
No full textUsing documentation of Mike Pearson's performance 'Bubbling Tom', Deirdre Heddon attempts to step into his shoes and re-perform it
"Test me and treat me" - attitudes to vitamin D deficiency and supplementation: a qualitative study
No full text© 2015 BMJ Open, "Test me and treat me"-attitudes to vitamin D deficiency and supplementation: a qualitative study. This manuscript version is made available under the Creative Commons Attribution Licens
Shortening uncrewed aircraft development cycles via automated flight testing
No full textAircraft flight testing is generally a long, laborious task and understanding parameters of an aircraft, such as its drag coefficients, is an important outcome and a key aspect for performance modelling and mission planning. The present project developed an automated flight-testing capability that is suitable for fixed wing Uncrewed Aerial Vehicles (UAVs) and is capable of guiding an iterative UAV design process.To maximise the quality of the data generated from flight testing and minimise the human effort involved, it is necessary to set up an automated flight test framework. PSI D, a tool developed by the author, enables the performance of fully automated flight tests. Automated unpowered glide slope and slow down manoeuvres are implemented to collect the required data for lift and drag curve generation.Vast amounts of data are generated in a typical flight testing campaign. Therefore, a process to evaluate the data in a time efficient manner with minimal manual input is required. In order to tackle this, the author developed an open source flight visualisation and report generation software (Automated Flight Log python – AutoFLpy). The tool is capable of providing rapid visualisation of the test flight to evaluate the success of the manoeuvres whilst still at the airfield.The author also identified several potential pitfalls encountered in flight testing for the purposes of UAV lift and drag determination using wind tunnel data. These errors are taken into account in PSI D whilst extracting coefficients from the flight data.Furthermore, in order to maximise the effectiveness of the proposed iterative design process, the author outlines a process for developing robust optimal manoeuvre strategies based on real flight data. The strategies maximise the quality of the flight data collected whilst minimising the flight time required. It is found that the strategies vary depending on the atmospheric conditions.The framework presented here lays the foundation of the rapid flight test based prototyping process, demonstrating the capabilities of automated flight testing and data processing and optimising the flight testing strategies for minimising the error in the coefficients and the flight testing time
Mapping interventional cardiology in Europe: the European Association of Percutaneous Cardiovascular Interventions (EAPCI) Atlas Project
No full textThis is a pre-copyedited, author-produced version of an article accepted for publication in European Heart Journal, following peer review. The version of record: Emanuele Barbato, Marko Noc, Andreas Baumbach, Dariusz Dudek, Matjaz Bunc, Emmanouil Skalidis, Adrian Banning, Jacek Legutko, Nils Witt, Manuel Pan, Hans-Henrik Tilsted, Holger Nef, Giuseppe Tarantini, Dzianis Kazakiewicz, Radu Huculeci, Stephane Cook, Ahmed Magdy, Walter Desmet, Guillaume Cayla, Dragos Vinereanu, Michiel Voskuil, Omer Goktekin, Panos Vardas, Adam Timmis, Michael Haude, Mapping interventional cardiology in Europe: the European Association of Percutaneous Cardiovascular Interventions (EAPCI) Atlas Project, European Heart Journal, Volume 41, Issue 27, 14 July 2020, Pages 2579–2588, https://doi.org/10.1093/eurheartj/ehaa475
is available online at: https://doi.org/10.1093/eurheartj/ehaa47
Sensitivity analysis for buckling characterisation using the vibration correlation technique
No full textThe Vibration Correlation Technique (VCT) is a non-destructive method to predict buckling loads for imperfection-sensitive structures. While successfully used to validate numerical models and predict experimental buckling loads, recommendations for defining the VCT experiment are scarce. Here, its sensitivity towards the number of load steps and the maximum load level measured is studied, and an uncertainty quantification of the measured frequency affecting the VCT prediction is performed First, a series of finite element (FE) models representing nominally identical cylinders, and validated by buckling experiments, are used to perform a sensitivity study. When no frequency deviations are introduced in the FE results, a positive correlation between the VCT predictions and the maximum load used for measurements is found, the number of load steps used being only relevant in reducing the errors. Introducing frequency deviations deterred the predictions correlation with the maximum load, while using more load steps reduced this influence. Second, a sensitivity study based on experimental data confirmed most of the trends previously observed using the FE results, the exception being a poor prediction sensitivity as a function of the maximum load, owing to several cylinders for which the VCT method gave predictions that progressively decreased with increasing the load.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Aerospace Structures & Computational Mechanic
The Federal Reserve's Primary Dealer Credit Facility
No full textAs liquidity conditions in the "repo market"--the market where broker-dealers obtain financing for their securities--deteriorated following the near-bankruptcy of Bear Stearns in March 2008, the Federal Reserve took the step of creating a special facility to provide overnight loans to dealers that have a trading relationship with the Federal Reserve Bank of New York. Six months later, in the wake of new strains in the repo market, the Fed expanded the facility by broadening the types of collateral accepted for loans. Both initiatives were designed to help restore the orderly functioning of the market and to prevent the spillover of distress to other financial firms.Federal Reserve Bank of New York ; Loans ; Financial crises ; Brokers
Reign of the Beast: The Atheist World of W. D. Saull and his Museum of Evolution (PDF)
No full textIn the 1830s, decades before Darwin published the Origin of Species, a museum of evolution flourished in London. Reign of the Beast pieces together the extraordinary story of this lost working-man's institution and its enigmatic owner, the wine merchant W. D. Saull. A financial backer of the anti-clerical Richard Carlile, the ‘Devil's Chaplain’ Robert Taylor, and socialist Robert Owen, Saull outraged polite society by putting humanity’s ape ancestry on display. He weaponized his museum fossils and empowered artisans with a knowledge of deep geological time that undermined the Creationist base of the Anglican state. His geology museum, called the biggest in Britain, housed over 20,000 fossils, including famous dinosaurs. Saull was indicted for blasphemy and reviled during his lifetime. After his death in 1855, his museum was demolished and he was expunged from the collective memory. Now multi-award-winning author Adrian Desmond undertakes a thorough reading of Home Office spy reports and subversive street prints to re-establish Saull's pivotal place at the intersection of the history of geology, atheism, socialism, and working-class radicalism
Vortex organization in a turbulent boundary layer overlying sparse roughness elements
No full textVortex organization in the outer layer of a turbulent boundary layer overlying sparse, hemispherical roughness elements is explored with two-component particle-image velocimetry (PIV) in multiple streamwise-wall-normal measurement planes downstream and between elements. The presence of sparse roughness elements causes a shortening of the streamwise length scale in the near-wall region. These measurements confirm that vortex packets exist in the outer layer of flow over rough walls, but that their organization is altered, and this is interpreted as the underlying cause of the length-scale reduction. In particular, the elements shed vortices which appear to align in the near-wall region, but are distinct from the packets. Further, it is observed that ejection events triggered in the element wakes are more intense compared to the ejection events in smooth wall. We speculate that this may initiate a self-sustaining mechanism leading to the formation of hairpin packets as a much more effective instability compared to those typical of smooth-wall turbulence.This is an Author's Accepted Manuscript of an article published as Michele Guala , Christopher D. Tomkins , Kenneth T. Christensen , Ronald J. Adrian. (2012) Vortex organization in a turbulent boundary layer overlying sparse roughness elements, Journal of Hydraulic Research, 50(5), 465-481 http://dx.doi.org/10.1080/00221686.2012.729229
Copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/00221686.2012.72922
Vitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials
No full textIn recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L
Reign of the Beast
No full textIn the 1830s, decades before Darwin published the Origin of Species, a museum of evolution flourished in London. Reign of the Beast pieces together the extraordinary story of this lost working-man's institution and its enigmatic owner, the wine merchant W. D. Saull. A financial backer of the anti-clerical Richard Carlile, the ‘Devil's Chaplain’ Robert Taylor, and socialist Robert Owen, Saull outraged polite society by putting humanity’s ape ancestry on display. He weaponized his museum fossils and empowered artisans with a knowledge of deep geological time that undermined the Creationist base of the Anglican state. His geology museum, called the biggest in Britain, housed over 20,000 fossils, including famous dinosaurs. Saull was indicted for blasphemy and reviled during his lifetime. After his death in 1855, his museum was demolished and he was expunged from the collective memory. Now multi-award-winning author Adrian Desmond undertakes a thorough reading of Home Office spy reports and subversive street prints to re-establish Saull's pivotal place at the intersection of the history of geology, atheism, socialism, and working-class radicalism
- …
