Euan Bennet

Controlled microdroplet transport in an atmospheric pressure microplasma

We report the controlled injection of near-isolated micron-sized liquid droplets into a low temperature He-Ne steady-state rf plasma at atmospheric pressure. The H2O droplet stream is constrained within a 2 mm diameter quartz tube. Imaging at the tube exit indicates a log-normal droplet size distribution with an initial count mean diameter of 15 μm falling to 13 μm with plasma exposure. The radial velocity profile is approximately parabolic indicating near laminar flow conditions with the majority of droplets travelling at >75% of the local gas speed and having a plasma transit time of <100 μs. The maximum gas temperature, determined from nitrogen spectral lines, was below 400 K and the observed droplet size reduction implies additional factors beyond standard evaporation, including charge and surface chemistry effects. The demonstration of controlled microdroplet streams opens up possibilities for gas-phase microreactors and remote delivery of active species for plasma medicine.

Fédération Equestre Internationale endurance events: Risk factors for failure to qualify outcomes at the level of the horse, ride and rider (2010–2015)

An epidemiological study of elite endurance riding was conducted using data from every Fédération Equestre Internationale (FEI) endurance event from 2010 to 2015, comprising 82,917 starts. The aim of the study was to identify risk factors associated with failure to qualify outcomes for horses during FEI endurance rides. The FEI endurance rules state that, during a ride, horses must be assessed by veterinarians several times, giving veterinarians the opportunity to prevent those horses exhibiting signs of lameness or metabolic problems from continuing further. Multivariable logistic regression models were constructed to identify horse, ride and rider level risk factors associated with failure to qualify. Risk factors particularly associated with increased likelihood of failure to qualify due to lameness included age of horse≥9 years, male horse, male rider, field size≥61 horses and if the ride was held in region group II (Northern and Eastern Europe). Factors associated with increased likelihood of failure to qualify due to metabolic problems included whether the ride was held in region group VII (North Africa and the Middle East), ride distance≥100km and male rider. Some risk factors, such as field size, may be modifiable at the ride level. Other risk factors such as horse age or sex are unmodifiable, but awareness of the risk contributed by these factors can provide veterinarians with additional information while treating horses during endurance rides.