Flexible conformable hydrophobized surfaces for turbulent flow drag reduction

In recent years extensive work has been focused onto using superhydrophobic surfaces for drag reduction applications. Superhydrophobic surfaces retain a gas layer, called a plastron, when submerged underwater in the Cassie-Baxter state with water in contact with the tops of surface roughness features. In this state the plastron allows slip to occur across the surface which results in a drag reduction. In this work we report flexible and relatively large area superhydrophobic surfaces produced using two different methods: Large roughness features were created by electrodeposition on copper meshes; Small roughness features were created by embedding carbon nanoparticles (soot) into Polydimethylsiloxane (PDMS). Both samples were made into cylinders with a diameter under 12 mm. To characterize the samples, scanning electron microscope (SEM) images and confocal microscope images were taken. The confocal microscope images were taken with each sample submerged in water to show the extent of the plastron. The hydrophobized electrodeposited copper mesh cylinders showed drag reductions of up to 32% when comparing the superhydrophobic state with a wetted out state. The soot covered cylinders achieved a 30% drag reduction when comparing the superhydrophobic state to a plain cylinder. These results were obtained for turbulent flows with Reynolds numbers 10,000 to 32,500

Robust spatially resolved pressure measurements using MRI with novel buoyant advection-free preparations of stable microbubbles in polysaccharide gels

MRI of fluids containing lipid coated microbubbles has been shown to be an effective tool for measuring the local fluid pressure. However, the intrinsically buoyant nature of these microbubbles precludes lengthy measurements due to their vertical migration under gravity and pressure-induced coalescence. A novel preparation is presented which is shown to minimize both these effects for at least 25 min. By using a 2% polysaccharide gel base with a small concentration of glycerol and 1,2-distearoyl-sn-glycero-3-phosphocholine coated gas microbubbles, MR measurements are made for pressures between 0.95 and 1.44 bar. The signal drifts due to migration and amalgamation are shown to be minimized for such an experiment whilst yielding very high NMR sensitivities up to 38% signal change per bar

As light as your footsteps: altering walking sounds to change perceived body weight, emotional state and gait

An ever more sedentary lifestyle is a serious problem in our society. Enhancing people’s exercise adherence through technology remains an important research challenge. We propose a novel approach for a system supporting walking that draws from basic findings in neuroscience research. Our shoe-based prototype senses a person’s footsteps and alters in real-time the frequency spectra of the sound they produce while walking. The resulting sounds are consistent with those produced by either a lighter or heavier body. Our user study showed that modified walking sounds change one’s own perceived body weight and lead to a related gait pattern. In particular, augmenting the high frequencies of the sound leads to the perception of having a thinner body and enhances the motivation for physical activity inducing a more dynamic swing and a shorter heel strike. We here discuss the opportunities and the questions our findings open

Recommendations for optimising pilot and feasibility work in surgery

BackgroundSurgical trials are recognised as inherently challenging. Pilot and feasibility studies (PAFS) are increasingly acknowledged as a key method to optimise the design and conduct of randomised trials but remain limited in surgery. We used a mixed methods approach to develop recommendations for how surgical PAFS could be optimised. MethodsThe findings from a quantitative analysis of funded surgical PAFS over a 10-year period and in-depth qualitative interviews with surgeons, methodologists and funders were triangulated and synthesised with available methodological guidance on PAFS.ResultsThe synthesis informed development of an explanatory model describing root causes and compounding challenges that contribute to how and why surgical PAFS are not currently optimised. The four root causes identified include issues relating to i) understanding the full scope of PAFS; ii) design and conduct of PAFS; iii) reporting of PAFS; and iv) lack of appreciation of the value of PAFS by all stakeholder groups. Compounding challenges relate to both cultural issues and access to and interpretation of available methodological PAFS guidance. The study findings and explanatory model were used to inform development of a practical guidance tool for surgeons and study teams to improve research practice.ConclusionsOptimisation of PAFS in surgery requires a cultural shift in research practice amongst funders, academic institutions, regulatory bodies and journal editors, as well as amongst surgeons. Our ‘Top Tips’ guidance tool offers an accessible framework for surgeons designing PAFS. Adoption and utilisation of these recommendations will optimise surgical PAFS, facilitating successful and efficient future surgical trials.<br/

Author Correction: Contingent sounds change the mental representation of one’s finger length

Correction to: Scientific Reports https://doi.org/10.1038/s41598-017-05870-4, published online 18 July 201

Self-authorship to Create and Shape the Identity of Women in STEM

Problem: The very low and declining percentage of females undertaking advanced science and mathematics subjects in Year 12 has been noted by the Office of the Chief Scientist (2014) and the Australian Mathematical Sciences Institute (Roberts, 2014). In 2011, only 28% of STEM-employed Australians were female, and this figure dropped to 14% for engineering students (Professionals Australia, 2014). Similar figures are evident in the US where Nobel Laureate Carol Grinder notes not only a deficit of women entering STEM-related fields, but also that many women experience many practical, psychological, and social barriers to continuing and advancing in their STEM careers 1. Given the low level of females employed in STEM-related careers and the high proportion of female primary preservice teachers, the focus on supporting and developing female STEM teachers is crucial. This study asserts that the communication and collaboration between female STEM teachers and females employed in STEM-related industries is key to raising the profile of females in this space, creating communities, and sharing expertise. Plan: To support the development of empowered and resilient women in STEM, the project employed a process of self-authorship (Kegan, 1994) to support and capture the emergent STEM identity of preservice teachers and engineering students. Self-authorship is “the ability to collect, interpret, and analyse information and reflect on one’s own beliefs in order to form judgements” (Baxter Magolda, 1998, p. 143). Self-authorship is “about the cognitive process people use to make meaning” (Creamer & Laughlin, 2005, p. 14). Action: Whilst working as members of a STEM Community of Practice comprising pre-service teachers and engineering students at Curtin University, members (students and academics) participated in guided reflective writing. Guiding questions asked about participants’ interest in STEM, influential others, their self-view as Steminists, how their self-view developed over the period of the project, and how they envisaged their future STEM selves. The Community of Practice was formed during an internally funded Makerspace in STEM project in 2016 that engaged higher education students on campus in a designated physical Makerspace in the Engineering Pavilion, virtually (via a closed Facebook site), and at an Independent Catholic girls’ school in Perth. Reflection: This presentation reports on the initial questions of influence and impact of the project, in particular the Community of Practice as an incubator to nurture professional identity. The narratives authored by the students and the research team (female academics) indicate diverse reasons for participating in the community and the reflections on personal and professional growth were insightful and support the physical and virtual modes of the community

Seasonal rainfall at long-term migratory staging sites is associated with altered carry-over effects in a Palearctic-African migratory bird.

BACKGROUND: An understanding of year-round habitat use is essential for determining how carry-over effects shape population dynamics in long-distance migratory songbirds. The recent discovery of long-term migratory staging sites in many species, prior to arrival at final wintering sites, adds complexity to efforts to decipher non-breeding habitat use and connections between sites. We investigated whether habitat conditions during migratory staging carry over to influence great reed warbler (Acrocephalus arundinaceus) body condition at final wintering sites in Zambia. We asked whether the presence/absence and strength of such carry-over effects were modified by contrasting rainfall conditions during 2 years. RESULTS: First, we found that individuals staging in a dry year had higher corticosterone (CORTf) and stable nitrogen isotope values (suggesting higher aridity) than birds staging in a wet year, indicating that regional weather affected staging conditions. Second, we found that carry-over effects from staging habitat conditions (measured via carbon and nitrogen isotopes) to final winter site body condition (measured via scaled mass index and β-hydroxybutyrate) were only present in a dry year, suggesting that environmental factors have consequences for the strength of carry-over effects. Our results also suggest that wet conditions at final winter sites may buffer the effects of poor staging conditions, at least in the short term, since individuals that staged in a dry year had higher scaled mass indices in Zambia than individuals that staged in a wet year. CONCLUSIONS: This study provides a first insight into the connections between long-term migratory staging sites and final wintering sites, and suggests that local environmental factors can modify the strength of carry-over effects for long-distance migratory birds.Gates Cambridge Trust, Natural Sciences and Engineering Research Council of Canada, Royal Society (Dorothy Hodgkin Fellowship), Biotechnology and Biological Sciences Research Council (David Phillips Fellowship, Grant ID: BB/J014109/1), DST-NRF Centre of Excellence at the FitzPatrick Institute, NERC (LSMSF Grant ID: EK206-16/12)This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1186/s12898-016-0096-

Electromagnetic follow-up of gravitational wave transient signal candidates

Pioneering efforts aiming at the development of multi-messenger gravitational wave and electromagnetic astronomy have been made. An electromagnetic observation follow-up program of candidate gravitational wave events has been performed (Dec 17 2009 to Jan 8 2010 and Sep 4 to Oct 20 2010) during the recent runs of the LIGO and Virgo gravitational wave detectors. It involved ground-based and space electromagnetic facilities observing the sky at optical, X-ray and radio wavelengths. The joint gravitational wave and electromagnetic observation study requires the development of specific image analysis procedures able to discriminate the possible electromagnetic counterpart of gravitational wave triggers from contaminant/background events. The paper presents an overview of the electromagnetic follow-up program and the image analysis procedures.Comment: Proceedings of the 12th International Conference on "Topics in Astroparticle and Underground Physics" (TAUP 2011), Munich, September 2011 (to appear in IoP Journal of Physics: Conference Series