The SARS-CoV-2 virus is primarily transmitted through virus-laden fluid particles ejected from the mouth of infected people. Face covers can mitigate the risk of virus transmission but their outward effectiveness is not fully ascertained. Objective: by using a background oriented schlieren technique, we aim to investigate the air flow ejected by a person while quietly and heavily breathing, while coughing, and with different face covers. Results: we found that all face covers without an outlet valve reduce the front flow through by at least 63% and perhaps as high as 86% if the unfiltered cough jet distance was resolved to the anticipated maximum distance of 2-3 m. However, surgical and handmade masks, and face shields, generate significant leakage jets that may present major hazards. Conclusions: the effectiveness of the masks should mostly be considered based on the generation of secondary jets rather than on the ability to mitigate the front throughflow. INDEX TERMS COVID-19 pandemic, face coverings, face masks, aerosol dispersal, aerosol generating procedures. IMPACT STATEMENT These results show the effectiveness of face coverings in mitigating aerosol dispersion and can aid policy makers to make informed decisions and PPE developers to improve their product effectiveness.

Silica derived from variety of sources and its functionalized form has been studied as an antiblock additive in polypropylene (PP). Commonly inorganic antiblock additives are added to PP films to reduce the blocking and facilitate separation of polymeric films. However, such types of additives can cause a reduction of clarity in transparent films. In the present work, comparative analysis of silica obtained from various sources specifically from rice husk ash and its further functionalization/modifications using n-octyltriethoxysilane has been performed. Since silica synthesized via rice husk ash was obtained from waste (rice husk ash), this further solves the problem of ash disposal. The functionalized silica has been characterized using Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The morphological analysis and particle shape and size has been characterized by scanning electron microscopy (SEM). The melt flow index (MFI), yellowness index and other mechanical characterizations including tensile and impact strength was performed for 30–40 µm thick tubular quenched polypropylene (TQPP) films. These films were evaluated to have high transmittance (above 93%), high clarity (above 98%) and very low haze (less than 2%) indicating the high transparency and improved optical properties. The blocking force and optical properties are quite similar for TQPP film containing silica synthesized from rice husk ash and commercial grade silica and hence, proving silica synthesized from rice husk ash to be an effective substitute for commercial silica in TQPP films.

The large-scale relocation of a paediatric hospital is a significant undertaking. New environments change the system, and ways of working must adapt to maintain quality healthcare. There are risks to patients and staff well-being, with high anxiety around change. There is evidence for the efficacy of simulation as a tool for safe training and rehearsal of staff and teams [1] but less so on such a large scale. Simulation for many is still perceived as a test of performance and a threat. We connected with the international simulation community to design a hospital-wide programme of Patient Environment Simulations for Systems Integration (PESSI). This paper outlines challenges in establishing buy-in from stakeholders and departments, developing a framework for implementation and our reflections on delivery of large-scale simulation activities to assist a hospital move.How can simulation-based methodology be used to support clinical departments on a large scale to adapt/integrate/prepare in moving to a brand-new hospital?Collaboration with authors of PEARLS for system integration use [1], using it as the main framework for delivery and structure of PESSI. Stages of delivery were: pre-phase work, system testing day, debrief/reflection and evaluation. Immediate feedback of enjoyment and learning was collated from all participants. Three-month post-move feedback is planned to review ongoing impact/behaviour change plus analysis of safety incidents.Pre-phase work involved meeting stakeholders and establishing aims of testing. Ward managers were key departmental links, meeting with members of PESSI to plan scenarios. System testing days involved familiarizing themselves with the environment, followed by ‘day in the life’ simulations with a representation of the whole team. All participants were called ‘co-faculty’ and knew exactly what would happen. Debrief involved facilitated conversations with the whole team describing reactions, and deeper analysis of the key events, with concerted efforts by facilitators to give a balanced approach of positives and challenges. A short report was given back to the department detailing the findings teams would need solutions to. Solutions from simulation were implemented prior to the move, increasing staff confidence, with many feeling PESSI played a major role in feeling prepared for the new site. The PESSI framework is being utilized in adult services and we hope to publish our methodology to share with the wider simulation community.

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