220 research outputs found
An industry-inspired civil engineering curriculum
This article describes the design of an undergraduate civil engineering curriculum that uses industry approaches to personal professional development and problem-based learning to educate the graduates that industry needs. The new curriculum is structured at a programme level, so that assessment and skills are matched and evaluation of professional skills from an early point in the degree is enabled. In contrast to traditional module-based assessment, programme-level assessment design also benefits coherence across the curriculum with reduced assessment loads of improved quality. This has allowed us to focus on educating students in their broad understanding and skills, which we believe will benefit their long-term employability and adaptability
Ice as a granular material
Ice is a unique material, fundamental to vital processes on earth, in the atmosphere [1] and as planets and comets form [2]. In this work, we introduce two experiments investigating ice as a granular material, to provide snippets of insight into those processes. Initial investigations of ice particles in a granular flow show that the energy spent in collisions can generate localised surface wetting, even below the melting point [3]. This wetting reduces friction between granules, leading to acceleration of the bulk flow and in turn more wetting. The experiments described here are designed to show how even wetting invisible to an observer, can fundamentally alter the flow. The experiments also use the diamagnetic properties of ice to investigate how the outcome of high speed binary collisions, energetic enough to generate some melting, depends on this wetting
Grain Reynolds number scale effects in dry granular slides
©2020. The Authors. Scale effects are differences in physical behavior that manifest between a large event and a geometrically scaled laboratory model and may cause misleading predictions. This study focuses on scale effects in granular slides, important in the environment and to industry. A versatile 6 m long laboratory setup has been built following Froude similarity to investigate dry granular slides at scales varied by a factor of 4, with grain Reynolds numbers Rein the range of 102 to 103. To provide further comparison, discrete element method simulations have also been conducted. Significant scale effects were identified; the nondimensional surface velocity increased by up to 35%, while the deposit runout distance increased by up to 26% from the smallest to the largest model. These scale effects are strongly correlated with Re, suggesting that interactions between grains and air are primarily responsible for the observed scale effects. This is supported by the discrete element method data, which did not show these scale effects in the absence of air. Furthermore, the particle drag force accounted for a significant part of the observed scale effects. Cauchy number scale effects caused by unscaled particle stiffness resulting in varying dust formation with scale are found to be of secondary importance. Comparisons of the laboratory data to that of other studies and of natural events show that data normalization with Re is an effective method of quantitatively comparing laboratory results to natural events. This upscaling technique can improve hazard assessment in nature and is potentially useful for modeling industrial flows
Europe’s Covid-19 recovery package has failed to increase public support for the EU
Did the announcement of the Covid-19 recovery package (Next Generation EU) in 2020 have a positive impact on people’s support for the EU? Barbara Krumpholz, Daniel Devine and Stuart J. Turnbull Dugarte present survey evidence that the €750bn package passed by the European council on 21 July 2020 had no effect on attitudes towards the EU, regardless of how severely member states were affected by the crisis
Identification of particle-laden flow features from wavelet decomposition
A wavelet decomposition based technique is applied to air pressure data obtained from laboratory-scale powder snow avalanches. This technique is shown to be a powerful tool for identifying both repeatable and chaotic features at any frequency within the signal. Additionally, this technique is demonstrated to be a robust method for the removal of noise from the signal as well as being capable of removing other contaminants from the signal. Whilst powder snow avalanches are the focus of the experiments analysed here, the features identified can provide insight to other particle-laden gravity currents and the technique described is applicable to a wide variety of experimental signals
Ice as a granular material
Ice is a unique material, fundamental to vital processes on earth, in the atmosphere [1] and as planets and comets form [2]. In this work, we introduce two experiments investigating ice as a granular material, to provide snippets of insight into those processes. Initial investigations of ice particles in a granular flow show that the energy spent in collisions can generate localised surface wetting, even below the melting point [3]. This wetting reduces friction between granules, leading to acceleration of the bulk flow and in turn more wetting. The experiments described here are designed to show how even wetting invisible to an observer, can fundamentally alter the flow. The experiments also use the diamagnetic properties of ice to investigate how the outcome of high speed binary collisions, energetic enough to generate some melting, depends on this wetting
Fines-controlled drainage in just-saturated, inertial column collapses
The wide particle size distributions, over several orders of magnitude, observed in debris flows leads to a diverse range of rheological behaviours controlling flow outcomes. This study explores the influence of different scale grains by conducting subaerial, fully saturated granular column collapse experiments with extreme, bimodal particle size distributions. The primary particles were of a size where their behaviour was controlled by their inertia while a suspension of kaolin clay particles within the fluid phase acts at spatial scales smaller than the pore space between the primary particles. The use of a geotechnical centrifuge allowed for the systematic variation of gravitational acceleration, inertial particle size and the degree of kaolin fines. Characteristic velocity- and time-scales of the acceleration phase of the collapse were quantified using high-speed cameras. Comparing tests containing fines to equivalent collapses with a glycerol solution mimicking the enhanced viscosity but not the particle behaviour of the fines, it was found that all characteristic dynamic quantities were dependent on the degree of fines, the system size, the grain fluid-density ratio and the column– and grain-scale Bond and Capillary numbers. We introduce a fine-scale Capillary number showing that, although surface tension effects at the column scale are negligible, fines do control the movement of fluid through the pore spaces
Performance and durability tests of smart icephobic coatings to reduce ice adhesion
The accretion of ice can damage applications ranging from power lines and shipping decks; to wind turbines and rail infrastructure. In particular on aircraft, it can change aerodynamic characteristics, greatly affecting the flight safety. Commercial aircraft are therefore required to be equipped with de-icing devices, such as heating mats over the wings. The application of icephobic coatings near the leading edge of a wing can in theory reduce the high power requirements of heating mats, which melt ice that forms there. Such coatings are effective in preventing the accretion of runback ice, formed from airborne supercooled droplets, or the water that the heating mats generate as it is sheared back over the wing’s upper surface. However, the durability and the practicality of applying them over a large wing surface have been prohibitive factors in deploying this technology so far
Barriers and facilitators to use of digital health tools by healthcare practitioners and their patients, before and during the COVID-19 pandemic: a multimethods study
Objectives To explore how healthcare practitioners (HCPs) made decisions about the implementation of digital health technologies (DHTs) in their clinical practice before and during the COVID-19 pandemic.
Design A multimethods study, comprising semistructured interviews conducted prior to the COVID-19 pandemic, supplemented with an online survey that was conducted during the pandemic with a different sample, to ensure the qualitative findings remained relevant within the rapidly changing healthcare context. Participants were recruited through HCP networks, snowballing and social media. Data were analysed thematically.
Setting Phone interviews and online survey.
Participants HCPs represented a range of professions from primary and secondary care across England, with varied socioeconomic deprivation.
Results 24 HCPs were interviewed, and 16 HCPs responded to the survey. In the interviews, HCPs described three levels where decisions were made, which determined who would have access to what DHTs: health organisation, HCP and patient levels. These decisions resulted in the unequal implementation of DHTs across health services, created barriers for HCPs using DHTs in their practice and influenced HCPs’ decisions on which patients to supply DHTs with. In the survey, HCPs described being provided support to overcome some of the barriers at the organisation and HCP level during the pandemic. However, they cited similar concerns to pre-pandemic about barriers patients faced using DHTs (eg, digital literacy). In the absence of centralised guidance on how to manage these barriers, health services made their own decisions about how to adapt their services for those who struggled with DHTs.
Conclusions Decision-making at the health organisation, HCP and patient levels influences inequalities in access to DHTs for HCPs and patients. The mobilisation of centralised information and resources during the pandemic can be viewed as good practice for reducing barriers to use of DHTs for HCPs. However, attention must also be paid to reducing barriers to accessing DHTs for patients
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