Antipathogenic applications of copper nanoparticles in air filtration systems

The COVID-19 pandemic has underscored the critical need for effective air filtration systems in healthcare environments to mitigate the spread of viral and bacterial pathogens. This study explores the utilization of copper nanoparticle-coated materials for air filtration, offering both antiviral and antimicrobial properties. Highly uniform spherical copper oxide nanoparticles (~10 nm) were synthesized via a spinning disc reactor and subsequently functionalized with carboxylated ligands to ensure colloidal stability in aqueous solutions. The functionalized copper oxide nanoparticles were applied as antipathogenic coatings on extruded polyethylene and melt-blown polypropylene fibers to assess their efficacy in air filtration applications. Notably, Type IIR medical facemasks incorporating the copper nanoparticle-coated polyethylene fibers demonstrated a >90% reduction in influenza virus and SARS-CoV-2 within 2 h of exposure. Similarly, heating, ventilation, and air conditioning (HVAC) filtration pre-(polyester) and post (polypropylene)-filtration media were functionalised with the copper nanoparticles and exhibited a 99% reduction in various viral and bacterial strains, including SARS-CoV-2, Pseudomonas aeruginosa, Acinetobacter baumannii, Salmonella enterica, and Escherichia coli. In both cases, this mitigates not only the immediate threat from these pathogens but also the risk of biofouling and secondary risk factors. The assessment of leaching properties confirmed that the copper nanoparticle coatings remained intact on the polymeric fiber surfaces without releasing nanoparticles into the solution or airflow. These findings highlight the potential of nanoparticle-coated materials in developing biocompatible and environmentally friendly air filtration systems for healthcare settings, crucial in combating current and future pandemic threats

The effect of social support and resource support on emotional exhaustion, insomnia, and suicidal ideation among allied health trainees and post-graduate year doctors in Taiwan

Background: COVID-19-related stigmatization refers to COVID-19-related judgements by others that devalue the individual. Such stigmatization towards healthcare workers may cause psychological burden and negative consequences. Such stigmatization may have particularly overwhelmed allied health trainees (AHTs) and post-graduate year doctors (PGYDs) because they just started their medical career. Social support and resource support have been reported to benefit psychological health and reduce stigmatization. Therefore, the present study used a cross-sectional study design to investigate the association between perceived stigma, self-stigma, psychological distress, and negative outcomes (including emotional exhaustion, insomnia and suicidal ideation) among AHTs and PGYDs in Taiwan. Methods: An online survey distributed between July and December, 2022 received 522 responses. Variables were assessed using the 21-item Depression, Anxiety and Stress Scale, Insomnia Severity Index and a series of self-designed questions to assess social support, resource support, perceived stigma, self-stigma, emotional exhaustion, and suicidal ideation. Results: Structural equation modeling showed that perceived stigma was associated with self-stigma (standardized coefficient [β] = 0.428, p < 0.001), and self-stigma was associated with psychological distress (β = 0.197, p < 0.001), as well as being associated with emotional exhaustion, insomnia, and suicidal ideation (β = 0.349, 0.556 and 0.212, all p-values < 0.001). While social support and resource support were negatively associated with perceived stigma (β= − 0.175 and − 0.152, p < 0.01), additional associations were found between social support and emotional exhaustion (β= − 0.093, p < 0.001), as well as between resource support and insomnia (β= − 0.120, p < 0.001). Conclusions: The results showed that COVID-19 related stigmatization was correlated to the detrimental consequences of emotional exhaustion, insomnia and suicidal ideation. Clear paths regarding the associations of social support and resource support with the three negative associations were found as the possible solutions. Strategies to reduce the stigmatization and these negative outcomes, or improve the psychological health will benefit AHTs and PGYDs in maintaining a healthy mental status

A multi-fidelity approach for aerodynamics and aeroacoustics of vertical axis wind turbines

This thesis performs an in-depth exploration of Vertical Axis Wind Turbines (VAWTs), motivated by the urgent need to address global climate change through sustainable energy solutions. The research predominantly focuses on the aerodynamics and aeroacoustics of VAWTs using computational simulations. This thesis aims to contribute to the body of knowledge and state-of-the-art surrounding VAWTs, a less explored yet promising design of wind turbines, especially suitable for urban and floating offshore applications. This thesis employs a multi-fidelity computational approach, leveraging both mid-fidelity and high-fidelity methods. The mid-fidelity Lifting Line Free Vortex Wake (LLFVW) method offers a balance between computational cost and accuracy. The high-fidelity Lattice Boltzmann/Very Large Eddy Simulation (LB-VLES) method provides detailed insights into the complex aerodynamics and aeroacoustics of VAWTs. These methodologies are implemented using the open-source software QBlade and the commercial software Dassault Systèmes SIMULIA PowerFLOW, respectively. The thesis examines VAWTs over a range of both design and operational parameters, including different number of blades, supporting structures (struts and central towers), tip speed ratio, and non-uniform inflow such as skewed inflow and VAWT clusters in parallel and tandem configurations. The study highlights how the above-mentioned operational and design parameters significantly influence the force-field and flow-field of VAWTs and how the force-field mutually affects the flow-field. Additionally, the focus is on understanding how the VAWT force-field affects the pressure perturbations in the far-field and therefore, the noise generated. The study shows the potential of VAWT designs which can exhibit high power performance and low aerodynamic noise. Notably, the research underscores the increased power density achievable in VAWT clusters compared to standalone VAWTs. A comparative analysis between mid-fidelity and high-fidelity methods demonstrates that while mid-fidelity methods accurately predict general performance trends, high-fidelity methods are essential for capturing the complex fluid dynamic interactions in the VAWT force-field and flow-field. This is found to be true when any combination of the design or operational parameters is used. The thesis concludes that VAWTs hold significant potential for urban and offshore applications, debunking common misconceptions about their inefficiency. The thesis outlines numerous areas for future research, including exploring different VAWT blade shapes, assessing the impact of flow control devices, and understanding the influence of variable pitch on performance and aeroacoustics. Further investigations into the clustering of VAWTs and the use of different vortex methods for performance prediction are also recommended

Hot dogs – advancing the epidemiology and clinical definition of heat-related illness in UK dogs

Heat-related illness (HRI) is a progressive, potentially fatal disorder that occurs when body temperature overwhelms thermoregulation leading to biochemical derangements, organ damage and ultimately irreversible damage to the neurological system. Traditionally termed heatstroke, the British public have typically associated severe HRI with dogs dying in hot cars. However, dogs can develop HRI following exposure to heat in any environment not just in hot cars - and following exercise. As global warming increases the severity and frequency of extreme heat events, understanding the triggers of canine HRI and which dogs are most at risk is vital to protect canine welfare. This thesis aimed to explore the epidemiology of HRI in dogs in the UK and review the clinical presentation and diagnosis of canine HRI to identify future strategies to protect the health and welfare of dogs amidst rising global temperatures. This thesis included investigating tympanic membrane temperature as a method for monitoring body temperature in exercising dogs. Male dogs, increasing ambient temperature, and high speed were factors associated with exercise induced hyperthermia. VetCompass, a database of primary-care veterinary practice patient records, was used to identify dogs presented for treatment of HRI. Analysis of these HRI events identified canine risk factors for HRI including breed, skull shape, age, bodyweight and being overweight, and identified that exercise was the predominant trigger of HRI in UK dogs. Relative risk analysis of clinical signs reported for dogs with HRI was used to develop the novel VetCompass Clinical Grading Tool to support the diagnosis and management of HRI in dogs. These results triggered a national educational campaign “Dogs Die on Hot Walks” aiming to improve public awareness of the leading cause of canine HRI and suggest improving veterinary and public recognition of mild HRI is a key strategy to reduce canine mortality from HRI

Artistic practice-based/autoethnographic exploration into the issues of belongings, identity, loss, and trauma through photography: the Yugoslav case

This PhD thesis addresses the issues surrounding the Yugoslav Civil war by offering my personal narrative in relation to loss and disappearance resulting from the exposure to war and sanctions in the nineties and the "Merciful Angel" bombing operation of Serbia by NATO in 1999. It thus focuses on the female interpretation of people, ways of life, buildings and human artefacts belonging to the historical period of communist Yugoslavia which once were, yet no longer remain. The research tackles different issues concerning life during Yugoslavia and the subsequent reestablishment of patriarchal values which occurred at the start of Yugoslav Civil war and conflicts that marked it. Photographic practice-based research allows an insight into individual stories which form a deeper understanding of the pre- and post- war Yugoslav society and the political circumstances surrounding it. The usage of photography as a vehicle for meaning making, allows an insight into the lives of people during communism through the lens of my closest family members. The work with archives, especially the photographs which originate from my personal family possession, brings closer these ghosts of the past times to the present moment. Microscope photography, as an element of practice-based research, offers a unique contribution by conveying my emotional response to what Yugoslavia represents in my experience. Furthermore, photography as a visual narrative is a means to investigate the society during and after the period of Yugoslavia. Autoethnography and site writing, as research methods combined with personal narrative, are also employed to allow a deeper understanding of culture and values of Yugoslav society and their subsequent clash. In addition, this research celebrates the importance of female voice and activism in the constant battle against patriarchy by acknowledging responsibility and patriarchal nature of war