Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs

A novel method of applying a two-dimensional Fourier transform (2D-FFT) to SEM was developed to map the CNT orientation in pre-formed arrays. Local 2D-FFTs were integrated azimuthally to determine an orientation distribution function and the associated Herman parameter. This approach provides data rapidly and over a wide range of lengthscales. Although likely to be applicable to a wide range of anisotropic nanoscale structures, the method was specifically developed to study CNT veils, a system in which orientation critically controls mechanical properties. Using this system as a model, key parameters for the 2D-FFT analysis were optimised, including magnification and domain size; a model set of CNT veils were pre-strained to 5%, 10% and 15%, to vary the alignment degree. The algorithm confirmed a narrower orientation distribution function and increasing Herman parameter, with increasing pre-strain. To validate the algorithm, the local orientation was compared to that derived from a common polarised Raman spectroscopy. Orientation maps of the Herman parameter, derived by both methods, showed good agreement. Quantitatively, the mean Herman parameter calculated using the polarised Raman spectroscopy was 0.42 ± 0.004 compared to 0.32 ± 0.002 for the 2D-FFT method, with a correlation coefficient of 0.73. Possible reasons for the modest and systematic discrepancy were discussed

Literature review of Devonian source rocks and Devonian-sourced hydrocarbons in the Orcadian Basin

This report summarises existing work on the Devonian source rocks and migrated oils in the Orcadian Basin. It aims to clarify the current literature with regards to the contribution of Devonian source rocks to proven hydrocarbon accumulations within the basin by providing a comprehensive summary of; the quality and maturity of the lacustrine source rocks; the evidence for Devonian oils in hydrocarbon fields, discoveries, shows and stains; perceived risks for Devonian-sourced plays. Good quality oil-prone lacustrine source rocks are present in the Devonian both on- and offshore, and are believed to have co-sourced the three Inner Moray Firth oil fields – Beatrice, Lybster and Jacky. Thus an understanding of the distribution and burial history of the Devonian source rocks could be important in the search for new hydrocarbon discoveries in the region. The complex pre-, syn- and post-rift tectonic history has given rise to significant local variability in both the thickness of the Devonian section and the present-day thermal maturity. Offshore, determination of the extent of the Middle Devonian Orcadian Lake, the main source rock interval, is constrained by only a limited number of well penetrations of the Devonian interval centred on Quadrants 12 & 13, although an oil-correlation study by Robertson Research International (2001) suggested that Devonian source rocks may be developed as far east as Quadrant 15 and may therefore be more widespread than previously thought. Studies have shown that Devonian-sourced oils have some key characteristics meaning they can confidently be differentiated from Jurassic-sourced oils. In particular, the presence of carotane and gammacerane (which can both be indicative of hyper-saline depositional environments), the absence of C28-bisnorhopane (commonly found within Jurassic sourced oils), the relatively light carbon isotope ratios and depletion of C27 steranes are distinguishing features when contrasted to Upper Jurassic to Middle Jurassic sourced hydrocarbons. Basin modelling studies suggest that onshore, the Devonian source rock experienced early hydrocarbon generation, reaching mid-late oil window thermal maturity by the Late Palaeozoic. Offshore, the preferred model is for Mesozoic generation with the onset of oil generation from the Devonian lacustrine source rocks in the Beatrice Field kitchen area in the Early Cretaceous, negating the need to invoke long-range migration from mature Jurassic mudstones to charge the Beatrice structure. This report was completed before the Palaeozoic Project organic geochemistry work on the Orcadian area (Vane et al., 2016), to inform the scope of work on that study. As such, it does not integrate the results of the Palaeozoic organic geochemistry study. This report contains citations of donated proprietary and commercial reports

Adoption and non-adoption of a shared electronic summary record in England: a mixed-method case study

Publisher version: http://www.bmj.com/content/340/bmj.c3111.full?sid=fcb22308-64fe-4070-9067-15a172b3aea

Summary care record early adopter programme: an independent evaluation by University College London.

Benefits The main potential benefit of the SCR is considered to be in emergency and unscheduled care settings, especially for people who are unconscious, confused, unsure of their medical details, or unable to communicate effectively in English. Other benefits may include improved efficiency of care and avoidance of hospital admission, but it is too early for potential benefits to be verified or quantified. Progress As of end April 2008, the SCR of 153,188 patients in the first two Early Adopter sites (Bolton and Bury) had been created. A total of 614,052 patients in four Early Adopter sites had been sent a letter informing them of the programme and their choices for opting out of having a SCR. Staff attitudes and usage The evaluation found that many NHS staff in Early Adopter sites (which had been selected partly for their keenness to innovate in ICT) were enthusiastic about the SCR and keen to see it up and running, but a significant minority of GPs had chosen not to participate in the programme and others had deferred participation until data quality improvement work was completed. Whilst 80 per cent of patients interviewed were either positive about the idea of having a SCR or ?did not mind?, others were strongly opposed ?on principle?. Staff who had attempted to use the SCR when caring for patients felt that the current version was technically immature (describing it as ?clunky? and ?complicated?), and were looking forward to a more definitive version of the technology. A comparable technology (the Emergency Care Summary) introduced in Scotland two years ago is now working well, and over a million records have been accessed in emergency and out-of-hours care. Patient attitudes and awareness Having a SCR is optional (people may opt out if they wish, though fewer than one per cent of people in Early Adopter sites have done so) and technical security is said to be high via a system of password protection and strict access controls. Nevertheless, the evaluation showed that recent stories about data loss by government and NHS organisations had raised concerns amongst both staff and patients that human fallibility could potentially jeopardise the operational security of the system. Despite an extensive information programme to inform the public in Early Adopter sites about the SCR, many patients interviewed by the UCL team were not aware of the programme at all. This raises important questions about the ethics of an ?implied consent? model for creating the SCR. The evaluation recommended that the developers of the SCR should consider a model in which the patient is asked for ?consent to view? whenever a member of staff wishes to access their record. Not a single patient interviewed in the evaluation was confident that the SCR would be 100 per cent secure, but they were philosophical about the risks of security breaches. Typically, people said that the potential benefit of a doctor having access to key medical details in an emergency outweighed the small but real risk of data loss due to human or technical error. Even patients whose medical record contained potentially sensitive data such as mental health problems, HIV or drug use were often (though not always) keen to have a SCR and generally trusted NHS staff to treat sensitive data appropriately. However, they and many other NHS patients wanted to be able to control which staff members were allowed to access their record at the point of care. Some doctors, nurses and receptionists, it seems, are trusted to view a person?s SCR, whereas others are not, and this is a decision which patients would like to make in real time

On the dynamic tensile behaviour of thermoplastic composite carbon/polyamide 6.6 using split Hopkinson pressure bar

A dynamic tensile experiment was performed on a rectangular specimen of a non-crimp fabric (NCF) thermoplastic composite T700 carbon/polyamide 6.6 specimens using a split Hopkinson pressure (Kolsky) bar (SHPB). The experiment successfully provided useful information on the strain-rate sensitivity of the NCF carbon/thermoplastic material system. The average tensile strength at three varying strain rates: 700, 1400, and 2100/s was calculated and compared to the tensile strength measured from a standardized (quasi-static) procedure. The increase in tensile strength was found to be 3.5, 24.2, and 45.1% at 700, 1400, and 2100/s strain rate, respectively. The experimental findings were used as input parameters for the numerical model developed using a commercial finite element (FE) explicit solver LS-DYNA®. The dynamic FE model was validated against experimental gathering and used to predict the composite system’s behavior in various engineering applications under high strain-rate loading conditions. The SHPB tension test detailed in this study provided the enhanced understanding of the T700/polyamide 6.6 composite material’s behavior under different strain rates and allowed for the prediction of the material’s behavior under real-world, dynamic loading conditions, such as low-velocity and high-velocity impact

A novel bio-inspired microstructure for progressive compressive failure in multidirectional composite laminates

n this study we take inspiration from biological materials to design a modified microstructure for laminated multidirectional (MD) carbon fiber reinforced polymers (CFRP), with the objective of mitigating their compressive failure behavior. We introduce soft inclusions in the form of thin longitudinal strips of foam in 0° load bearing layers, aiming at arresting kinkband propagation. We conceived a bespoke stacking sequence and developed a tailored procedure for manufacturing the microstructure. We then performed in-situ tests on small scale notched specimens from a baseline laminate and a modified one. Results are presented and discussed

On the translaminar fracture toughness of vectran/epoxy composite material

The mode I fracture toughness associated with fibre tensile failure was investigated for a Vectran/MTM57 composite system. A modified compact tension specimen was designed and manufactured to mitigate compressive and buckling failure due to the low compressive properties which are an inherent characteristic of Vectran fibres. On average, the mode I translaminar fracture toughness for Vectran/MTM57 was found to be approximately 130–145 kJ/m2 for initiation and 250–260 kJ/m2 for propagation. In contrast with other composite systems such as carbon and glass fibre, the fracture toughness of Vectran/MTM57 was found to be relatively higher, with up to 48.26% and 95.27% for initiation and propagation, respectively for some carbon fibre composite system; 9.93% and 68.6% for initiation and propagation, respectively for S2-Glass/epoxy system