An approach to metal fatigue

Cumulative fatigue damage based on investigation of fatigue limit associated with crack, crack propagation rate, and stress interaction cycle in metal

Hands On Biofilm! A multidisciplinary public engagement event using kombucha tea pellicle as an accessible example of biofilm

Public engagement with science has become increasingly important for the scientific community. There are many documented public engagement events that focus on aspects of microbiology, but relatively few utilise biofilms as a topic, despite their importance. Kombucha tea pellicles are easy to grow biofilms, facilitating their use within the public domain as examples of these complex communities. The aim of this work was to deliver a public engagement event that introduced visitors to general concepts about biofilm, and applications around sustainability, using kombucha. The event encouraged visitors to: build a biofilm using model clay; inoculate kombucha tea cultures using different incubation conditions, as part of a citizen science experiment to assess impact on pellicle biofilm yield; create garments and drapes on mini-mannequins using dried kombucha pellicle fabric, and demonstrate the range and importance of fermented foods (including kombucha tea), and ‘good bacteria’. Quantitative and qualitative indicators of engagement were built into the activities. More than 1200 visitors, mainly in family groups, visited the event over a 4-h period. Knowledge of biofilms was low at the beginning of the event. Participation in all activities was high. Indicators of quantitative engagement were impressive, but it was difficult to obtain qualitative evidence other than observations from the delivery team (nineteen members) because of the intensity of the event and volume of visitors. The event was clearly successful in terms of fulfilment of aims, audience engagement and enthusiasm: the embedded evaluations helped to evidence the impact and reach of the event, enabling confidence in dissemination of good practice in the enhancement of public understanding of the importance of biofilm in general, and kombucha in particular

Optimal Allocation and Scheduling of Irrigation Water for Cotton and Soybeans

This study evaluated alternative irrigation scheduling strategies for cotton and soybean production on Sharkey clay soils in southeast Arkansas. Strategies were ranked on the basis of two basic criteria: expected net revenue and risk efficiency. Risk efficiency was defined for different risk preferences using stochastic dominance techniques. Preferred strategies for cotton employed tensiometer thresholds between -.45 atm and -.75 atm. Risk efficient soybean irrigation strategies varied with the degree of risk aversion--more risk averse decision makers prefer strategies with lower thresholds

Refreshing the public appetite for ‘good bacteria’: menus made by microbes

© 2018 Royal Society of Biology. A series of events was developed to engage audiences in discussion around the importance of microorganisms in the production of fermented foods, particularly through tasting. The events were designed to attract different audiences: families attending a science museum; families in their community space; and adults in different informal eating environments. Information was provided, alongside interactive activities where possible. Feedback was positive in that the audiences enjoyed the format, the food and the events themselves, although science itself was not always specifically mentioned. The dining experience format provided a versatile and informal opportunity for engagement between experts and non-experts, and is suggested as a valuable template for similar activities, assuming appropriate budgeting and advertising issues are addressed, alongside appropriate objective setting and effective evaluation

Unpulsed UBV Optical Emission from the Crab Pulsar

Based on observations of the Crab pulsar using the TRIFFID high speed imaging photometer in the UBV bands using the Special Astrophysical Observatory's 6m telescope in the Russian Caucasus, we report the detection of pronounced emission during the so-called `off' phase of emission. Following de-extinction, this unpulsed component of emission is shown to be consistent with a power law with an exponent of alpha = -0.60 +/- 0.37, the uncertainty being dominated by the error associated with the independent CCD photometry used to reference the TRIFFID data. This suggests a steeper power law form than that reported elsewhere in the literature for the total integrated spectrum, which is essentially flat with alpha ~ 0.1, although the difference in this case is only significant at the ~ 2 sigma level. Deeper reference integrated and TRIFFID phase-resolved photometry in these bands in conjunction with further observations in the UV and R region would constrain this fit further.Comment: 26 pages, 2 figures, uses aasms4.sty, accepted for publication in the Astrophysical Journa

The coordination and distribution of B in foraminiferal calcite

The isotopic ratio and concentration of B in foraminiferal calcite appear to reflect the pH and bicarbonate concentration of seawater. The use of B as a chemical proxy tracer has the potential to transform our understanding of the global carbon cycle, and ocean acidification processes. However, discrepancies between the theory underpinning the B proxies, and mineralogical observations of B coordination in biomineral carbonates call the basis of these proxies into question. Here, we use synchrotron X-ray spectromicroscopy to show that B is hosted solely as trigonal BO3 in the calcite test of Amphistegina lessonii, and that B concentration exhibits banding at the micron length scale. In contrast to previous results, our observation of trigonal B agrees with the predictions of the theoretical mechanism behind B palaeoproxies. These data strengthen the use of B for producing palaeo-pH records. The observation of systematic B heterogeneity, however, highlights the complexity of foraminiferal biomineralisation, implying that B incorporation is modulated by biological or crystal growth processes.We would like to acknowledge David Nicol, Iris Buisman and Martin Walker for invaluable technical assistance, and James Bryson for his help with synchrotron data collection. Wewould like to thank Jean DeMouthe (California Academy of Sciences) and Mike Rumsey (Natural History Museum, London) for provision of B-containing minerals for use as reference materials. This work was funded by ERC (grant 2010-ADG-267931 to HE), NERC, Jesus College (Cambridge)and the US Department of Energy (via ALS).This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0012821X15000849

Structure and elastic properties of Mg(OH)2_2 from density functional theory

The structure, lattice dynamics and mechanical properties of the magnesium hydroxide have been investigated with static density functional theory calculations as well as \it {ab initio} molecular dynamics. The hypothesis of a superstructure existing in the lattice formed by the hydrogen atoms has been tested. The elastic constants of the material have been calculated with static deformations approach and are in fair agreement with the experimental data. The hydrogen subsystem structure exhibits signs of disordered behaviour while maintaining correlations between angular positions of neighbouring atoms. We establish that the essential angular correlations between hydrogen positions are maintained to the temperature of at least 150 K and show that they are well described by a physically motivated probabilistic model. The rotational degree of freedom appears to be decoupled from the lattice directions above 30K

First-principles study of orthorhombic CdTiO3 perovskite

In this work we perform an ab-initio study of CdTiO3 perovskite in its orthorhombic phase using FLAPW method. Our calculations help to decide between the different cristallographic structures proposed for this perovskite from X-Ray measurements. We compute the electric field gradient tensor (EFG) at Cd site and obtain excellent agreement with available experimental information from a perturbed angular correlation (PAC) experiment. We study EFG under an isotropic change of volume and show that in this case the widely used "point charge model approximation" to determine EFG works quite well.Comment: 4 pages, 1 figure. Accepted in Physical Review

Implementing Kanyini GAP, a pragmatic randomised controlled trial in Australia: Findings from a qualitative study

© 2015 Liu et al. Background: Pragmatic randomised controlled trials (PRCTs) aim to assess intervention effectiveness by accounting for 'real life' implementation challenges in routine practice. The methodological challenges of PRCT implementation, particularly in primary care, are not well understood. The Kanyini Guidelines Adherence to Polypill study (Kanyini GAP) was a recent primary care PRCT involving multiple private general practices, Indigenous community controlled health services and private community pharmacies. Through the experiences of Kanyini GAP participants, and using data from study materials, this paper identifies the critical enablers and barriers to implementing a PRCT across diverse practice settings and makes recommendations for future PRCT implementation. Methods: Qualitative data from 94 semi-structured interviews (47 healthcare providers (pharmacists, general practitioners, Aboriginal health workers; 47 patients) conducted for the process evaluation of Kanyini GAP was used. Data coded to 'trial impact', 'research motivation' and 'real world' were explored and triangulated with data extracted from study materials (e.g. Emails, memoranda of understanding and financial statements). Results: PRCT implementation was facilitated by an extensive process of relationship building at the trial outset including building on existing relationships between core investigators and service providers. Health providers' and participants' altruism, increased professional satisfaction, collaboration, research capacity and opportunities for improved patient care enabled implementation. Inadequate research infrastructure, excessive administrative demands, insufficient numbers of adequately trained staff and the potential financial impact on private practice were considered implementation barriers. These were largely related to this being the first experience of trial involvement for many sites. The significant costs of addressing these barriers drew study resources from the task of achieving recruitment targets. Conclusions: Conducting PRCTs is crucial to generating credible evidence of intervention effectiveness in routine practice. PRCT implementation needs to account for the particular challenges of implementing collaborative research across diverse stakeholder organisations. Reliance on goodwill to participate is crucial at the outset. However, participation costs, particularly for organisations with little or no research experience, can be substantial and should be factored into PRCT funding models. Investment in a pool to fund infrastructure in the form of primary health research networks will offset some of these costs, enabling future studies to be implemented more cost-effectively. Trial registration:ACTRN12608000583334