Top-down ventilation: improving indoor air quality whilst providing low-energy conditioning of more infection resilient indoor environments

Theme: Indoor air quality

The importance of indoor exposures has been brought to the forefront of attention over recent years, and improving building ventilation is key to managing these exposures. This PhD will explore ‘top-down ventilation’ in which the air flow is brought into rooms at high-level and drawn out near the floor – this can more efficiently remove aerosols. Combining of simple theoretical modelling and laboratory simulations will establish the potential for top-down ventilation to improve indoor air quality whilst providing low-energy conditioning of more infection resilient indoor environments. These potential benefits include enhanced aerosol settling whilst warming the lower part of the room. 

Lead supervisor: Dr Henry Burridge

Evaluating the role of sulphur in aircraft engine particle emissions and contrail formation

Theme: Aerosol Technology / Atmospheric Aerosol Studies

Half of aviation’s climate impact is attributed to the radiative forcing of contrails and contrail cirrus. Contrails are formed when ice particles are formed in the exhaust plume of aircraft engines, and we see them as line-shaped clouds trailing behind aircraft. There is recent evidence that changing engine particle emissions, due to engine technology or fuels can reduce contrails. However, there is limited experimental evidence as to the mechanisms by which semi-volatile particles, including sulphur and lubrication oils, could play a role in contrail formation. Further work is needed to understand the precise role that sulphur has in low-soot conditions and this project will build on previous work using controlled laboratory studies.

This project is anticipated to be sponsored in partnership with GE Research

Lead supervisor: Prof. Marc Stettler

Exploring the size-resolved toxicological properties of aerosols

Theme: Aerosols and Health

Air pollution has been declared a public health emergency by the World Health Organisation, yet significant gaps remain in understanding the most harmful characteristics of the different pollutants. This project aims to investigate the impact of aerosol particle size and shape on health, focusing on their toxic and inflammatory effects on human lung cells. Candidates will collaborate with leading experts in aerosol science, toxicology, and immunology to develop innovative solutions with substantial industry applications. By utilizing state-of-the-science facilities and technology, this research provides a unique multidisciplinary approach to addressing air pollution, contributing to essential public health advancements and product development.

This project is anticipated to be sponsored in partnership with Cambustion.

Lead supervisor: Dr Aristeidis Voliotis

Ultrafine particles abatement from green infrastructure

Theme: Aerosols and Health

Green Infrastructure (GI) serves as a passive method to mitigate exposure to roadside vehicular emissions, including airborne ultrafine particles (≤100nm; UFPs) that have significant health implications despite being unregulated.

This project aims to investigate the interactions between UFPs and urban GI in roadside environments, with a specific focus on UFP number and surface area.

The objectives will be achieved through a combination of novel field studies to understand the competing influences of particle transformation processes, laboratory investigations for physico-chemical characterisation of UFPs, and utilising the acquired knowledge to propose best practice recommendations for holistic urban GI planning.

Lead supervisor: Prof. Prashant Kumar

The potential for air conditioning systems to recirculate pathogens

Theme: Aerosol Technology / Atmospheric Aerosol Studies / Aerosols and Health

In this project, we will clarify whether pathogens circulated through HVAC systems can increase infection transmission for different building system configurations. It is expected that indoor transmission through HVAC systems operations can be affected by many parameters, including proximity of the particle emission source (infected human) to return air, amount of fresh air added to the system, filters used in air handling units, frequency of cleaning/changing filters, variation in the number of occupants, and changes to airflow pathways due to changes in furniture/equipment location. The outcomes of this study are crucial to inform decisions on future HVAC and building philosophies. If COVID-19 and other respiratory diseases can spread through ventilation systems, strategies such as increasing fresh air supply and technologies such as ultraviolet (UV) germicidal irradiation could become critical and their effectiveness as part of the building system needs to be understood.

Lead supervisor: Prof. Lidia Morawska

Mechanistic study of how viruses such as SARS-CoV-2 and flu do or do not survive long enough in aerosols to be transmitted across the air

Theme: Aerosols and Health

Pandemics are caused by respiratory viruses (COVID-19, flu) that spread in aerosols. These pandemics hit us at a rate of about one pandemic per century, and cause about 10 million deaths/pandemic. Despite this, we know surprisingly little about how viruses spread in aerosols. The PhD will use state-of-the-art experimental aerosol science and molecular biology to investigate the mechanism by which viruses are destroyed by the sudden drying in an aerosol. For example, is it the virus’s spike protein that is destroyed by drying? The project is interdisciplinary in nature. It will involve producing proteins and viruses, and quantifying their survival after aerosol drying.

Lead supervisor: Dr Richard Sear

AI models for airborne particulate matter forecasting in urban areas

Theme: Atmospheric Aerosol Studies

People are often exposed to hazardous levels of particulate matter (PM) concentrations while performing daily activities, inadvertently putting their health and wellbeing at risk. Artificial intelligence (AI) has been a game-changer in several areas of knowledge, including atmospheric sciences. Thus, this project aims to develop novel data-driven and physics-informed AI models based on state-of-the-art deep learning techniques to predict the concentrations of PM at urban scale under desired intervention scenarios, with improved performance and less computational requirements, using Guildford Living Lab as a case study to validate the solution against conventional models such as the ADMS-Urban.

Lead supervisor: Dr Erick G. Sperandio Nascimento