Lightweight aerial vehicles for monitoring, assessment and mapping of radiation anomalies.

The Fukushima Daiichi nuclear power plant (FDNPP) incident released a significant mass of radioactive material into the atmosphere. An estimated 22% of this material fell out over land following the incident. Immediately following the disaster, there was a severe lack of information not only pertaining to the identity of the radioactive material released, but also its distribution as fallout in the surrounding regions. Indeed, emergency aid groups including the UN did not have sufficient location specific radiation data to accurately assign exclusion and evacuation zones surrounding the plant in the days and weeks following the incident. A newly developed instrument to provide rapid and high spatial resolution assessment of radionuclide contamination in the environment is presented. The device consists of a low cost, lightweight, unmanned aerial platform with a microcontroller and integrated gamma spectrometer, GPS and LIDAR. We demonstrate that with this instrument it is possible to rapidly and remotely detect ground-based radiation anomalies with a high spatial resolution (<1 m). Critically, as the device is remotely operated, the user is removed from any unnecessary or unforeseen exposure to elevated levels of radiation.

Reduction of carbon dioxide on jet spray formed titanium dioxide surfaces.

The photocatalytic reduction of carbon dioxide (CO(2)) on jet spray formed titanium dioxide (TiO(2)) was studied using light-emitting diode (LED) illumination centred at a wavelength of 388 nm. In addition, the photocatalytic reduction of CO(2) under soft X-ray irradiation was also studied. Specifically, the experiments examined the reduction of CO(2) in a gaseous and liquid-gas system using residual gas analysis mass spectrometry. A photochemical reduction of CO(2) was observed over a course of 250 min, with transformation to a major product, C(2)H(3)O(-) (ethenolate), until equilibrium was reached. The product was observed to be surface stabilised, with it reverting back to CO(2) over the course of 100 min without illumination. A proposed free radical mechanism is presented for the formation of this product. A similar effect to that of UV illumination is also observed to occur under the influence of soft X-rays, which presents a potentially significant alternative method for the activation of TiO(2).