Numerical analysis of a high velocity oxygen fuel (HVOF) process

The HVOF process is used for coating protective layers on surfaces exposed to corrosion and wear. This process involves a supersonic two-phase flow of gas-solid particles. The main objective of this thesis is to explore certain key factors that influence the process efficiency such as gas-particle interactions, particle in-flight conditions, and particle loading. To study the effect of gas-particles interactions, a Lagrangian approach which tracks individual particles in the continuous gas, is used. The supersonic gas flow leaving an HVOF nozzle is over-expanded and its adjustment to the atmospheric pressure results in shock diamonds formation, while flow impingement on a substrate results in bow-shock development. Both the shocks are responsible for affecting the particle conditions. The strength and location of bow shock vary for different substrate geometries and stand-off distances. In this work, various particle sizes impinging on different substrate configurations are simulated and the particle interactions with both the shocks are presented in detail. To find the effect of particle loading on the gas phase, a dense particulate phase scenario is assumed. A fully Eulerian approach, which treats the particles as a fluid, is used to simulate the HVOF process and the two-phase flow characteristics were investigated for various particle loadings. The particulate phase was found to be dense near the nozzle centerline and dilute near the wall. In the particle-dense region, the gas phase characteristics were found to be severely affected, which significantly affects the particle velocit

Addressing Planetary Health through the Blockchain—Hype or Hope? A Scoping Review

Planetary health is an emergent transdisciplinary field, focused on understanding and addressing the interactions of climate change and human health, which offers interventional challenges given its complexity. While various articles have assessed the use of blockchain (web3) technologies in health, little consideration has been given to the potential use of web3 for addressing planetary health. A scoping review to explore the intersection of web3 and planetary health was conducted. Seven databases (Ovid Medline, Global Health, Web of Science, Scopus, Geobase, ACM Digital Library, and IEEE Xplore) were searched for peer-reviewed literature using key terms relating to planetary health and blockchain. Findings were reported narratively. A total of 3245 articles were identified and screened, with 23 articles included in the final review. The health focus of the articles included pandemics and disease outbreaks, the health of vulnerable groups, population health, health financing, research and medicines use, environmental health, and the negative impacts of blockchain mining on human health. All articles included the use of blockchain technology, with others additionally incorporating smart contracts, the Internet of Things, artificial intelligence and machine learning. The application of web3 to planetary health can be broadly categorised across data, financing, identity, medicines and devices, and research. Shared values that emerged include equity, decentralisation, transparency and trust, and managing complexity. Web3 has the potential to facilitate approaches towards planetary health, with the use of tools and applications that are underpinned by shared values. Further research, particularly primary research into blockchain for public goods and planetary health, will allow this hypothesis to be better tested

Planet.Health: An Ecosystem Approach to Imagine and Coordinate for Planetary Health Futures

Planet.Health addresses imagination and coordination challenges for planetary health through innovative approaches to social organising. This report presents the findings from the inaugural Planet.Health event in 2022, including the Planet.Health unconference. An unconference is a participant-driven event format that provides flexibility for emergent ideas and connections. In this (un)conference report, we share the challenges, achievements, and lessons learned during the initial year of activities in the leadup to and following the Planet.Health unconference event. We also discuss how the intersection of web3 and planetary health—a major focus of the first year—provides an alternative lens for envisioning, innovating, and coordinating beyond conventional social and institutional frameworks. We explore the potential impact of web3 technologies and decentralised social, economic, and financial networks and highlight the implications of these approaches for addressing planetary crises and supporting a flourishing human–environment relationship. As a new contribution to the planetary health field, this work emphasises the importance of building decentralised systems to foster creative actions and inspire global engagement for planetary wellbeing. The report concludes with some practical insights on how we begin to build and sustain decentralised social networks, including a discussion of the benefits and limitations of these approaches

Planet.Health : an ecosystem approach to imagine and coordinate for planetary health futures

Planet.Health addresses imagination and coordination challenges for planetary health through innovative approaches to social organising. This report presents the findings from the inaugural Planet.Health event in 2022, including the Planet.Health unconference. An unconference is a participant-driven event format that provides flexibility for emergent ideas and connections. In this (un)conference report, we share the challenges, achievements, and lessons learned during the initial year of activities in the leadup to and following the Planet.Health unconference event. We also discuss how the intersection of web3 and planetary health—a major focus of the first year—provides an alternative lens for envisioning, innovating, and coordinating beyond conventional social and institutional frameworks. We explore the potential impact of web3 technologies and decentralised social, economic, and financial networks and highlight the implications of these approaches for addressing planetary crises and supporting a flourishing human–environment relationship. As a new contribution to the planetary health field, this work emphasises the importance of building decentralised systems to foster creative actions and inspire global engagement for planetary wellbeing. The report concludes with some practical insights on how we begin to build and sustain decentralised social networks, including a discussion of the benefits and limitations of these approaches