Charge structure in volcanic plumes: a comparison of plume properties predicted by an integral plume model to observations of volcanic lightning during the 2010 eruption of Eyjafjallajökull, Iceland

Observations of volcanic lightning made using a lightning mapping array during the 2010 eruption of Eyjafjallajökull allow the trajectory and growth of the volcanic plume to be determined. The lightning observations are compared with predictions of an integral model of volcanic plumes that includes descriptions of the interaction with wind and the effects of moisture. We show that the trajectory predicted by the integral model closely matches the observational data and the model well describes the growth of the plume downwind of the vent. Analysis of the lightning signals reveals information on the dominant charge structure within the volcanic plume. During the Eyjafjallajökull eruption both monopole and dipole charge structures were observed in the plume. By using the integral plume model, we propose the varying charge structure is connected to the availability of condensed water and low temperatures at high altitudes in the plume, suggesting ice formation may have contributed to the generation of a dipole charge structure via thunderstorm-style ice-based charging mechanisms, though overall this charging mechanism is believed to have had only a weak influence on the production of lightning

The Relationship of Food and Academic Performance: A Preliminary Examination of the Factors of Nutritional Neuroscience, Malnutrition, and Diet Adequacy

This article examines the extent of food’s impact on children’s academic achievement. The purpose of this study is to summarize existing research concerning the food-learning correlation and to synthesize studies regarding nutritional needs of the brain, malnutrition during development, and overall diet quality as related to academic achievement. Data finds a fundamental link between nutrition and cognition. Results suggest to the extent the brains of many United States schoolchildren do not receive the nutrients needed for optimal cognition, that academic performance may be consequentially reduced. Finally, a discussion of related learning theory and current debate, and practical implications for educational settings is offered

BRST Extension of Geometric Quantization

Consider a physical system for which a mathematically rigorous geometric quantization procedure exists. Now subject the system to a finite set of irreducible first class (bosonic) constraints. It is shown that there is a mathematically rigorous BRST quantization of the constrained system whose cohomology at ghost number zero recovers the constrained quantum states. Moreover this space of constrained states has a well-defined Hilbert space structure inherited from that of the original system. Treatments of these ideas in the Physics literature are more general but suffer from having states with infinite or zero "norms" and thus are not admissible as states. Also the BRST operator for many systems require regularization to be well-defined. In our more restricted context we show that our treatment does not suffer from any of these difficulties. This work was submitted for publication March 21,2006

Sighted: an overview

This article is an examination of audience responses to Sighted, two solo dance performances presented individually and simultaneously. The work was presented at venues related to different disciplines. Audience members, who numbered up to 20 and who were free to choose where to stand or move around the space and how to behave, were invited immediately following the performance to write down their responses. This was in order to elicit direct and undigested thoughts before conversation or dialogue has started. These, together with interviews with the dancers, form the basis for this research, which looks at the nature of venues and audiences and to what extent privately felt and communally understood audience commentary can correlate

Time and Geometric Quantization

In this paper we briefly review the functional version of the Koopman-von Neumann operatorial approach to classical mechanics. We then show that its quantization can be achieved by freezing to zero two Grassmannian partners of time. This method of quantization presents many similarities with the one known as Geometric Quantization.Comment: Talk given by EG at "Spacetime and Fundamental Interactions: Quantum Aspects. A conference to honour A.P.Balachandran's 65th birthday

Hype or Hope: Can the Scholarship of Teaching and Learning Fulfill Its Promise?

Proponents of the scholarship of teaching and learning claim that it holds huge potential to improve teaching in higher education. The viability of this claim is assessed by examining epistemic and educational challenges to the assumptions that underlie prevailing models of SoTL. The assessment indicates that the assumptions are flawed and identifies significant questions about what has been achieved and how to move forward. An alternative model for the scholarship of teaching is proposed

Tree-ring analysis of winter climate variability and ENSO in Mediterranean California

The feasibility of using tree-ring data as a proxy for regional precipitation and ENSO events in the Mediterranean region of California is explored. A transect of moisture-sensitive tree-ring sites, extending from southwestern to northcentral California, documents regional patterns of winter precipitation and replicates the regional response to ENSO events in the 20th century. Proxy records of ENSO were used with the tree-ring data to examine precipitation/ENSO patterns in the 18 and 19th centuries. Results suggest some temporal and spatial variability in the regional precipitation response to ENSO over the last three centuries

Identifying short-term variation of dynamic friction by means of its frequency response function

A challenging case study of dynamic friction was presented in a previous study (A. Cabboi, J. Woodhouse, Validation of a constitutive law for friction-induced vibration under different wear conditions, Wear 396–397 (2018) 107–125), concerning tests performed with a Polycarbonate pin sliding on a steel disc. Identifying and modelling the frictional frequency response for this system turned out to be rarely possible, since the measurements were affected by significant wear and by intermittent squeal occurrence. To shed light on the observed “capricious” behaviour, an “instantaneous” estimation of the frequency response of dynamic friction was developed, allowing the dynamic friction behaviour to be captured and tracked before, and for few cases during, squeal events. Each “instantaneous” frequency response of dynamic friction was fitted by a rate-and-state model, and variations of the model parameters for different sliding speeds, changing normal forces and at different wear stages were tracked. With direct relevance to squeal predictions, the model parameters identified through the proposed processing and fitting methodology could detect rapid transitions between velocity-strengthening and weakening behaviour. These transitions may occur at different sliding speeds, but they also occur during measurements carried out at a constant sliding speed. Based on the identified model parameters, a first qualitative attempt to predict squeal events by means of rate-and-state models is presented, and shown to give promising correlation with experimental results

Religious Relationships with the Environment in a Tibetan Rural Community : Interactions and Contrasts with Popular Notions of Indigenous Environmentalism

Acknowledgments: We thank Beijing Forestry University, our field assistants Tashi Rabden, Pema Dechin, Tsewang Chomtso and Gele Chopel for their invaluable help, the Forest Bureau of Daocheng county for permission and support, and the people of Samdo for their hospitality and participation. The research was funded by the ESRC and the World Pheasant Association. This paper is a contribution to Imperial College’s Grand Challenges in Ecosystems and the Environment initiative. Two anonymous reviewers gave valuable comments on the manuscript.Peer reviewedPublisher PD

Symplectic Cuts and Projection Quantization

The recently proposed projection quantization, which is a method to quantize particular subspaces of systems with known quantum theory, is shown to yield a genuine quantization in several cases. This may be inferred from exact results established within symplectic cutting.Comment: 12 pages, v2: additional examples and a new reference to related wor