Combined EISCAT radar and optical multispectral and tomographic observations of black aurora

Black auroras are recognized as spatially well-defined regions within a uniform diffuse auroral background where the optical emission is significantly reduced. Black auroras typically appear post-magnetic midnight and during the substorm recovery phase, but not exclusively so. We report on the first combined multimonochromatic optical imaging, bistatic white-light TV recordings and incoherent scatter radar observations of black aurora by EISCAT of the phenomenon. From the relatively larger reduction in luminosity at 4278 Å than at 8446 Å we show that nonsheared black auroras are most probably not caused by downward directed electrical fields at low altitude. From the observations, we determine this by relating the height and intensity of the black aurora to precipitating particle energy within the surrounding background diffuse aurora. The observations are more consistent with an energy selective loss cone. Hence the mechanism causing black aurora is most probably active in the magnetosphere rather than close to Earth

Stimuli Responsive Ionogels for Sensing Applications - An Overview.

This overview aims to summarise the exiting potential of “Ionogels” as a platform to develop stimuli responsive materials. Ionogels are a class of materials that contain an Ionic Liquid (IL) confined within a polymer matrix. Recently defined as “a solid interconnected network spreading throughout a liquid phase”, the ionogel therefore combines the properties of both its solid and liquid components. ILs are low melting salts that exist as liquids composed entirely of cations and anions at or around 100 0C. Important physical properties of these liquids such as viscosity, density, melting point and conductivity can be altered to suit a purpose by choice of the cation / anion. Here we provide an overview to highlight the literature thus far detailing the encapsulation of IL and responsive materials within these polymeric structures. Exciting applications in the areas of optical and electrochemical sensing, solid state electrolytes and actuating materials shall be discussed. Keywords: Stimuli Responsive Polymers; Ionogels; Ionic Liquids; Hybrid Materials; Molecular Photoswitches; Solid State Electrolytes

Physical and mechanical properties of phosphonium based poly(ionic liquids)

Currently for applications in materials science, there is a growing interest in Ionogels i.e. polymers with ionic liquids (ILs) integrated such that they retain their specific properties within the polymer/gel environment. However one disadvantage of ionogels is the leaching of the IL in the liquid phase1. To overcome this, ‘poly (ionic liquids) PILs, are gaining momentum in the literature. Interesting applications for the incorporation of PILs into polymers have been published such as ultrasensitive and selective chemiresistive CO2 sensors2, and potential applications in fuel cell technology as some reported PIL films, display very high ionic conductivities (exceeding 90 mS cm-1 at 100 oC and 75% relative humidity)3. However the range of possible monomeric IL structures is far greater than has so far been explored4 In recent years functional materials have been developed to respond to a wide variety of stimuli, but their use in practical macro-scale devices has been hindered by slow response times arising mainly due to the diffusion processes that typically govern polymer swelling/contraction. The scaling-down to microfluidic devices should improve response times, due to the improved surface-to-volume ratios of these actuators. At these dimensions, stimuli-responsive PIL materials could dramatically enhance the capabilities of micro-fluidic systems by allowing self-regulated flow control. In this study we synthesis, characterise and photopattern a family of PILs, Tributyl 4-Vinylbenzylphosphonium ([P4,4,4,4VB]+ ), Trihexyl 4-Vinylbenzylphosphonium ([P6,6,6,4VB]+) and Trihexyl-allyl phosphonium [P6,6,6,allyl]+ cations coupled with commonly found anions in the ionic liquid literature (chloride, dicyanamide and bis(trifluoromethylsulfonyl)imide). As one might expect varying the anion of the PIL gave varying behaviour (thermal stability and electrochemically). The resulting polymer gels from the PILs also gave drastic mechanical stability differences. Finally the synthesised polymer gels have been photo-structured to submicron resolution as both planar and 3D patterns employing both single and multi- photon polymerisation (MPP) techniques. These materials will form a platform for the next generation of sensors & actuators currently being developed

The capabilities and human rights of high performance athletes

High performance athletes participate and function in sports systems where exploitative behaviours may become manifest. These behaviours potentially violate an individual athlete’s human rights. Using the Capability Approach first outlined by Amartya Sen the paper details how a more precise analysis of human rights, in the context of high performance sport, may be arrived at. Using in-depth narrative accounts from high performance athletes, data illustrate how athlete maltreatment is related to individual capabilities and functionings. The loss of individual freedoms infringes accepted notions of human rights. The implications for practice concern how human rights may be protected within and for systems of high performance production

Temperature & pH triggered release characteristics of water/fluorescein from 1-ethyl-3-methylimidazolium ethylsulfate based ionogels.

A crosslinked Poly(N-isopropylacrylamide) ionogel encapsulating an ionic liquid exhibits improved transmittance properties, enhanced water uptake/release, greater thermal actuation behaviour and distinct solvatomorphology over its hydrogel equivalent. It was also found that the rate of release of fluorescein pre-loaded into membranes was considerably enhanced for ionogels compared to equivalent hydrogels, and could be triggered through changes in pH and temperature

Radiation belt slot-region filling events: sustained energetic precipitation into the mesosphere

Precipitation of energetic electrons to the atmosphere is both a loss mechanism for radiation belt particles and a means by which the geospace environment influences the Earth's atmosphere; thus it is important to fully understand the extent of this precipitation. A set of polar orbiting satellites have been used to identify periods when energetic charged particles fill the slot region between the inner and outer radiation belts. These suggest that electrons with energies >30 keV penetrate this region, even under levels of modest geomagnetic activity. Those events with sufficient fluxes of particles produce enough ionization to be detected by a ground‐based radar in Antarctica; this precipitation lasts for ~10 days on average. Analysis of these data reveal that the average precipitation penetrates to the stratopause (~55 km altitude). For some (if not all) of these events, the likely cause of the most energetic precipitation is an interaction between (relativistic) electrons and plasmaspheric hiss leading to little, if no, local time variation in precipitation. This does not preclude a longitudinal effect given that all radar measurements are fixed in longitude. During winter months the radar is under the stable southern polar atmospheric vortex. This transports atmospheric species to lower altitudes including the ozone destroying chemicals that are produced by energetic precipitation. Thus the precipitation from the slot region in the southern hemisphere will likely contribute to the destruction of ozone and changes to atmospheric heat balance and chemistry; more work is required to determine the true impact of these events

Two techniques for determining F-region ion velocities at meso-scales: Differences and impacts on Joule heating

We have investigated the difference between two standard techniques for deriving the ionospheric ion velocity using data taken with the EISCAT incoherent scatter radar between 1987 and 2007. For large-scale convection flows, there is little difference between the tristatic and monostatic techniques, though the biggest relative difference occurs during periods when the interplanetary magnetic field (IMF) is strongly northward. At small scales the difference between the two techniques is correlated with a measure of the variability of the tristatic measurement. This suggests that small-scale flow bursts, such as those associated with enhanced auroral arcs, could explain the local time variation in the velocity difference distributions. The difference in velocities obtained from the monostatic and tristatic techniques can make a significant difference in the estimate of the magnitude of Joule heating in the thermosphere. Considering only the electric field dominated component of Joule heating, Q, the difference in the two techniques can be as much as 52% of the tristatic measurement (Qm = 0.48Qt) in the morning sector (0 – 6 MLT), during a moderate to large geomagnetic storm. This reduces to a difference of 36% at non-storm times in the same MLT period. Careful averaging of the velocity field with the future EISCAT_3D radar system will allow us to establish the impact of both spatial and temporal scales on the magnitude of the observations

Multidimensional Perfectionism and Cortisol Stress Response in Non-Clinical Populations: A Systematic Review and Evaluation

The purpose of the study was to conduct a systematic review and evaluation of research examining multidimensional perfectionism and cortisol in non-clinical populations. A literature search yielded 6 studies examining cortisol reactivity (CR) and 2 studies examining cortisol awakening response (CAR). Each study was rated in terms of the methodological quality and evidence for the relationship between dimensions of perfectionism (perfectionistic strivings, PS, and perfectionistic concerns, PC) and cortisol was recorded. For CR, 1 study was rated as low methodological quality, 1 study was rated as medium methodological quality, and 4 studies were rated as high methodological quality. Of the high-quality studies, one study provided supportive evidence of a positive relationship between PC and CR, and a further 3 provided inconclusive/null evidence. The only high-quality study to examine the relationship between PS and CR provided inconclusive/null evidence. For CAR, 1 study was rated as low methodological quality and the other as medium methodological quality. Based on these findings, no firm conclusions can be drawn regarding the relationship between perfectionism and cortisol. Moreover, if research continues in the same vein, future research is unlikely to examine the relationship appropriately. We therefore recommend future research follows expert guidelines regarding assessing cortisol responses