Bristol Industrial and Research Associates (United Kingdom)

<p>Volcanoes are increasingly better monitored around the world. Nonetheless, the detection and monitoring of volcanic ash plumes remains difficult, especially in remote areas. Intense electrical activity and lightning in volcanic plumes suggests that electrical monitoring of active volcanoes can aid the detection of ash emissions in near real-time. Current very low frequency and wide-band thunderstorm networks have proven to be able to detect plumes of large magnitude. However, the time delay and the relatively high number of non-detected explosive episodes show that the applicability of these systems to the detection of smaller (and often more frequent) ash-rich explosive events is limited. Here we use a different type of thunderstorm detector to observe electrical discharges generated by the persistent Vulcanian activity of Minamidake crater at Sakurajima volcano in Japan. The sensors consist of two antennas that measure the induced current due to the change in electric field with time. In contrast to the current thunderstorm networks, these sensors measure within the extremely low frequency range (1-45 Hz) and can detect lightning up to 35 kilometres distance.</p><p>Two detectors were installed at a distance of 3 and 4 kilometres from Minamidake crater and recorded almost continuously since July 2018. Within this period, the ash plumes reached a maximum height of 5.5 kilometres above the crater rim. Using a volcanic lightning detection algorithm and the catalogue of volcanic explosions compiled by the Japan Meteorological Agency (JMA), the number of electrical discharges was determined for each individual explosive event. In addition, the start of electrical discharges was compared to the eruption onset estimated by the JMA.</p><p>Preliminary results show that the detector closest to the crater had the highest detection efficiency. It detected electrical discharges during 60% of the eruptions listed by the JMA. This is significantly higher than for the World Wide Lightning Location Network, which detected electrical discharges (in the very low frequency range) within 20 kilometres of Sakurajima for less than 0.005% of the eruptions. Furthermore, the results show that for 40% of the detected eruptions, electrical discharges were detected before the estimated JMA timing. Hence, electrical discharges can mark the inception of the explosion with a higher precision and are an indication of ash emission. This demonstrates the value of the cost-effective sensors used here as a monitoring tool at active volcanoes.</p>

A plume of Saharan dust and Iberian smoke was carried across the southern UK on 16th October 2017, entrained into an Atlantic cyclone which had originated as Hurricane Ophelia. The dust plume aloft was widely noticed as it was sufficiently dense to redden the visual appearance of the sun. Time series of backscatter from ceilometers at Reading and Chilbolton show two plumes: one carried upwards to 2.5 km, and another below 800 m into the boundary layer, with a clear slot between. Steady descent of particles at about 50 cm s−1 continued throughout the morning, and coarse mode particles reached the surface. Plumes containing dust are frequently observed to be strongly charged, often through frictional effects. This plume passed over atmospheric electric field sensors at Bristol, Chilbolton and Reading. Consistent measurements at these three sites indicated negative plume charge. The lower edge plume charge density was (−8.0 ± 3.3) nC m−2, which is several times greater than that typical for stratiform water clouds, implying an active in situ charge generation mechanism such as turbulent triboelectrification. A meteorological radiosonde measuring temperature and humidity was launched into the plume at 1412 UTC, specially instrumented with charge and turbulence sensors. This detected charge in the boundary layer and in the upper plume region, and strong turbulent mixing was observed throughout the atmosphere’s lowest 4 km. The clear slot region, through which particles sedimented, was anomalously dry compared with modelled values, with water clouds forming intermittently in the air beneath. Electrical aspects of dust should be included in numerical models, particularly the charge-related effects on cloud microphysical properties, to accurately represent particle behaviour and transport.

The spectral response of atmospheric electric potential gradient gives important information about phenomena affecting this gradient at characteristic time scales ranging from years (e.g., solar modulation) to fractions of a second (e.g., turbulence). While long-term time scales have been exhaustively explored, short-term scales have received less attention. At such frequencies, space-charge transport inside the planetary boundary layer becomes a sizeable contribution to the potential gradient variability. For the first time, co-located (Evora, Portugal) measurements of boundary-layer backscatter profiles and the 100-Hz potential gradient are reported. Five campaign days are analyzed, providing evidence for a relation between high-frequency response of the potential gradient and strong dry convection.

Purpose – The purpose of this paper is to review the literature on the role that mindfulness meditation can play in supporting people with dementia to live well. Design/methodology/approach – This paper reviews the literature in a structured way, focussing first on the general effectiveness on mindfulness and then going on to assess its role in attention, emotion regulation, cognitive decline, physical changes in the brain, prevention, and quality of life. Findings – Spirituality has been defined as a process of personal transformation which in many cases can involve a blend of humanistic psychology and esoteric traditions. Meditation, even if practised in a secular fashion can be said to fit within this definition of spirituality. The paper reviews the evidence for the relevance of mindfulness meditation in supporting people to live well with dementia. Research limitations/implications – The evidence is not yet conclusive; however, there is nevertheless a growing body of evidence which suggests that this is a fruitful area for further research. Practical implications – There are numerous implications for practice: if sufficient self-reported benefit from the application of mindfulness to people with dementia to warrant this being offered more generally. If further research substantiates the quality of life benefits then this could be an important development to accompany early diagnosis of dementia. If mindfulness were found to have a preventative effect then that would be of huge practical importance. Social implications – Mindfulness gives people more control of their emotional and thought processes and therefore this could be a significant development for empowering people with dementia and their carers. Originality/value – This is one of the first times that the literature regarding mindfulness and dementia has been reviewed in a systematic way.

The following paper describes the core technology of a real time optical biological agent detection system which has been developed from Biral's existing and proven ASAS TM family of biological agent triggers and sensors. The sensor for the system has additional capabilities based on the introduction of a fluorescence sensor providing greater discrimination than previously available. The new sensor will be incorporated in the Integrated Sensor Management System (ISMS) which utilises complex real-time data tracking algorithms that simultaneously monitor the different aerosol characteristics. The system is capable of tracking and adjusting the sensor alert levels to take into account the constantly changing aerosol environment and thus significantly reduces the risk of false alarms. The use of two measurement systems, ASAS TM and fluorescence in one sensor is a unique combination and a major advancement in the field of airborne biological agent detection and warning.