Monopoles from Rational Maps

The moduli space of charge k SU(2) BPS monopoles is diffeomorphic to the moduli space of degree k rational maps between Riemann spheres. In this note we describe a numerical algorithm to compute the monopole fields and energy density from the rational map. The results for some symmetric examples are presented.Comment: 8 pages, 2 figures. To appear in Phys. Lett.

Perceptual and electrophysiological masking of the auditory brainstem response : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

Effective masking levels of the auditory brainstem response (ABR) to tonepips were established on 10 normal-hearing subjects at 500, 1000, 2000 and 4000 Hz, using white noise. Effective masking levels of perceptual responses to the same stimuli were also established, for both presentation of single (1/second) and repeated (41.7/second) tonepips. Perceptual masking levels for repeated tonepips were significantly higher than levels for single tonepips, indicating temporal summation effects. Levels which effectively masked the ABR did not differ significantly from perceptual masking levels at either presentation rate. A signal-to-noise ratio of -5 to -10 dB was found to provide effective masking for all conditions. For the stimulus and recording parameters in the present study, a behavioural method of determining effective masking levels is considered appropriate. Behavioural thresholds determined for single tonepips were higher than thresholds for repeated tonepips, demonstrating dependence of nHL behavioural references for ABR thresholds on stimulus repetition rate. Effective masking levels determined in the present study may be applied to the use of tonepip ABRs to provide an objective frequency-specific measure of hearing in infants

Measurements of spectral attenuation coefficients in the lower Chesapeake Bay

The spectral transmission was measured for water samples taken in the lower Chesapeake Bay to allow characterization of several optical properties. The coefficients of total attenuation, particle attenuation, and absorption by dissolved organic matter were determined over a wavelength range from 3500 A to 8000 A. The data were taken over a 3 year period and at a number of sites so that an indication of spatial and temporal variations could be obtained. The attenuations determined in this work are, on the average, 10 times greater than those obtained by Hulburt in 1944, which are commonly accepted in the literature for Chesapeake Bay attenuation

Uplift Quadratic Program in Irish Electricity Price Setting

Bord Gis required a deeper insight into the dynamics of Uplift prices. The aim of the group was to apply a variety of analytical tools to the problem in order to satisfy Bord Gis requirements. The group conducted a KKT Optimality Analysis of the quadratic program used to determine the Uplift prices, performed statistical analysis to identify the binding constraints and their sensitives to the Uplift prices, simulated a synthetic stochastic process that is consistent with the Uplift pricing series and investigated alternative objective functions for the quadratic program

Effect of carbon dioxide and water vapor on the induction period of the hydrogen-oxygen reaction

Carbon dioxide and water vapor effects on induction period kinetics of hydrogen-oxygen reactio

Analysis of the Caddisflies (Trichoptera) of the Manistee River Watershed, Michigan

We document 134 caddisfly species and their seasonal and habitat affinities based on 93 samples collected from 26 sites throughout the Manistee River watershed in the lower peninsula of Michigan from May through September, 2010. Eleven of these species: Banksiola dossuaria (Say), Cheumatopsyche aphanta Ross, Cheumatopsyche pasella Ross, Hydroptila xera Ross, Ironoquia lyrata (Ross), Lepidostoma vernale (Banks), Neotrichia vibrans Ross, Nyctiophylax affinis (Banks), Oxyethira aeola Ross, Oxyethira rivicola Blickle and Morse, and Polycentropus timesis (Denning) are reported from Michigan for the first time. More than 85% of species reached peak adult abundance during June or July, although a few species reached peak abundance or emerged exclusively during the other months. Overall species richness reached its peak during early July, with a smaller peak of unique species in September. Caddisfly faunas in lakes, small streams, medium rivers, and large rivers were all distinct from each other, suggesting that the overall watershed is following patterns predicted by the River Continuum Concept. It is likely that the Michigan caddisfly fauna contains considerably more species than what is currently known

On the constraints defining BPS monopoles

We discuss the explicit formulation of the transcendental constraints defining spectral curves of SU(2) BPS monopoles in the twistor approach of Hitchin, following Ercolani and Sinha. We obtain an improved version of the Ercolani-Sinha constraints, and show that the Corrigan-Goddard conditions for constructing monopoles of arbitrary charge can be regarded as a special case of these. As an application, we study the spectral curve of the tetrahedrally symmetric 3-monopole, an example where the Corrigan-Goddard conditions need to be modified. A particular 1-cycle on the spectral curve plays an important role in our analysis.Comment: 29 pages, 7 eps figure

Electrical charging of ash in Icelandic volcanic plumes

The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcanic plumes. Here we present laboratory measurements of particle size distributions, triboelectrification and radioactivity in ash samples from the Gr\'{i}msv\"{o}tn and Eyjafjallaj\"{o}kull volcanic eruptions in 2011 and 2010 respectively, and discuss the implications of our findings.Comment: XV Conference on Atmospheric Electricity, 15-20 June 2014, Norman, Oklahoma, US

The Market for Lawyers in Montana

The Market for Lawyers in Montan