Old Time Music--New World Business: Bristol 1927 and the Exploitation and Appropriation of Depression Era Southern Folk Music

This article discusses the origins of the commercialization of rural Southern music into the country music genre. It also discusses the way that the music was changed from an oral tradition to something to passively listen to

Magnetic-moment measurements by the transient-field and recoil-in-vacuum techniques in fpg-shell nuclei

Picosecond-lifetime nuclear-state g factors are challenging to measure, with the transient-field (TF) and recoil-in-vacuum (RIV) techniques best able to probe them. The TF is experienced by a swift ion traversing a polarised ferromagnetic material, while RIV relies on hyperfine interactions between the nucleus and its electrons that occur in isolated ions. Both techniques often require independent calibration, a key limitation in their use. The objective of this thesis is to improve the precision of g-factor measurements with these techniques. This was achieved by developing procedures that minimise systematic uncertainty in TF measurements to obtain reliable relative g factors, and then scaling them by developing atomic-structure calculations that enabled absolute g factors to be determined from RIV measurements focused on Na-like ions. Relative TF measurements were used to determine the first-excited-state g-factor ratio between Mg-24 and Mg-26, which was then scaled using a literature value of g(Mg-24), obtained using RIV, to determine g(Mg-26). TF measurements were also performed to obtain first-excited-state g-factor ratios between the stable even-A isotopes of Ge and Se, with the first-ever simultaneous measurement performed on isobaric nuclides (Ge-74, Se-74) in a cocktail beam. An ab initio approach to modelling Fe-56 first-excited-state time-differential RIV data focused on Na-like ions was developed. Time-differential Ge-76 and time-integral Fe-54,56 first-excited-state data were also analysed. The analysis utilised a Monte-Carlo simulation of atomic decays to model the hyperfine interaction through time. The combined use of relative TF and calibration-independent RIV measurements allowed the determination of precise absolute g-factor values. These were used to interrogate TF-strength calibrations, and shell-model predictions. Together, TF and RIV procedures presented in this work were effective in determining accurate g-factor values with improved precision in picosecond-lifetime nuclear states

Pushing the limits of excited-state g-factor measurements

Current developments in excited-state g-factor measurements are discussed with an emphasis on cases where the experimental methodology is being extended into new regimes. The transient-field technique, the recoil in vacuum method, and moment measurements with LaBr3 detectors are discussed.This research was supported in part by the Australian Research Council grant numbers DP140102986, DP140103317 and DP70101673. B.P.M. T.J.G. and B.J.C. acknowledge the support of the Australian Government Research Training Program. Support for the Heavy Ion Accelerator Facility operations through the Australian National Collaborative Research Infrastructure Strategy (NCRIS) program is acknowledged

Observing eruptions of gas-rich compressible magmas from space

Observations of volcanoes from space are a critical component of volcano monitoring, but we lack quantitative integrated models to interpret them. The atmospheric sulfur yields of eruptions are variable and not well correlated with eruption magnitude and for many eruptions the volume of erupted material is much greater than the subsurface volume change inferred from ground displacements. Up to now, these observations have been treated independently, but they are fundamentally linked. If magmas are vapour-saturated before eruption, bubbles cause the magma to become more compressible, resulting in muted ground displacements. The bubbles contain the sulfur-bearing vapour injected into the atmosphere during eruptions. Here we present a model that allows the inferred volume change of the reservoir and the sulfur mass loading to be predicted as a function of reservoir depth and the magma’s oxidation state and volatile content, which is consistent with the array of natural data

Persistent growth of a young andesite lava cone: Bagana volcano, Papua New Guinea

Bagana, an andesite lava cone on Bougainville Island, Papua New Guinea, is thought to be a very young central volcano. We have tested this idea by estimating the volumes of lava extruded over different time intervals (1-, 2-, 3-, 9-, 15-, 70- years) using digital elevation models (DEMs), mainly created from satellite data. Our results show that the long-term extrusion rate at Bagana, measured over years to decades, has remained at about 1.0 m3s-1. We present models of the total edifice volume, and show that, if our measured extrusion rates are representative, the volcano could have been built in only ~300 years. It could also possibly have been built at a slower rate during a longer, earlier period of growth. Six kilometres NNW of Bagana, an andesite-dacite volcano, Billy Mitchell, had a large, caldera-forming plinian eruption 437 years ago. We consider the possibility that, as a result of this eruption, the magma supply was diverted from Billy Mitchell to Bagana. It seems that Bagana is a rare example of a very youthful, polygenetic, andesite volcano. The characteristics of such a volcano, based on the example of Bagana, are: a preponderance of lava products over pyroclastic products, a high rate of lava extrusion maintained for decades, a very high rate of SO2 emission, evidence of magma batch fractionation and location in a trans-tensional setting at the end of an arc segment above a very steeply dipping and rapidly converging subduction zone

Pushing the limits of excited-state gg-factor measurements

Current developments in excited-state $g$-factor measurements are discussed with an emphasis on cases where the experimental methodology is being extended into new regimes. The transient-field technique, the recoil in vacuum method, and moment measurements with LaBr$_3$ detectors are discussed.Comment: 5 pages, 6 figure

First synoptic analysis of volcanic degassing in Papua New Guinea

We report the first satellite-based survey of volcanic sulphur dioxide (SO2) degassing in Papua New Guinea, using Ozone Monitoring Instrument (OMI) data. OMI is sensitive to low-level passive degassing. These observations are useful for volcano monitoring, hazard assessment (particularly aviation hazard) and assessment of arc geochemical budgets and are of immense value in remote regions with little ground-based instrumentation, such as Papua New Guinea. We identify Bagana, Manam, Rabaul, Ulawun and Langila as the active sources of volcanic SO2 in Papua New Guinea, with Bagana being the largest source. We present an OMI SO2 time series for 2005–2008 and a total detected regional output of ∼1.8 × 109 kg SO2. About 40% of emissions were released by major eruption events at Manam (January 2005), Bagana (June 2006) and Rabaul (October 2006). Over the past century however, we estimate that major explosive eruptions contribute <5% of the arc-scale SO2 emission budget. Ground-based DOAS measurements of SO2 degassing at five of Papua New Guinea's volcanoes are compared with our OMI observations. The total OMI SO2 output is only ∼20% of the total extrapolated from DOAS, a discrepancy which we demonstrate is consistent with other volcanic arcs. Therefore, the true total regional SO2 output may be considerably higher than that detected by OMI. Uncertainties in the OMI SO2 data include the effects of in-plume chemical processing and dilution of SO2 prior to the satellite overpass, OMI's reduced sensitivity to low levels of SO2 in the planetary boundary layer and interference by meteorological clouds

Assessing Quality and Equity in High-Impact Practices: Comprehensive Report

The Assessing Quality and Equity in High-Impact Practices: Comprehensive Report is the inial report on findings from the Lumina Foundation supported examination of High-Impact Practice (HIP) quality and equity. This report summarizes the project purpose, research design and questions, development and testing HIP quality instrument, and early findings about assessment feasibility, evidence of elements of HIP quality, measuring high-quality HIPs, and evidence of equity. The report also explores measures of students' satisfaction with their HIP experience, differences by racial identity, and evidence of high quality and equity by HIP.Lumina Foundatio

A comparison of satellite- and ground-based measurements of SO2emissions from Tungurahua volcano, Ecuador

Satellite-measured SO2 mass loadings and ground-based measurements of SO2 emission rate are not directly comparable, with ∼40% differences between mean emissions reported by each technique from Tungurahua volcano, Ecuador, during late 2007. Numerical simulations of postemission processing and dispersal of Tungurahua's SO2 emissions enable more effective comparison of ground- and satellite-based SO2 data sets, reducing the difference between them and constraining the impact of plume processing on satellite SO2 observations. Ground-based measurements of SO2 emission rate are used as the model input, and simulated SO2 mass loadings are compared to those measured by the Ozone Monitoring Instrument (OMI). The changing extent of SO2 processing has a significant impact on daily variation in SO2 mass loading for a fixed volcanic emission rate. However, variations in emission rate at Tungurahua are large, suggesting that overall volcanic source strength and not subsequent processing is more likely to be the dominant control on atmospheric mass loading. SO2 emission rate estimates are derived directly from the OMI observations using modeled SO2 lifetime. Good agreement is achieved between both observed and simulated mass loadings (∼21%) and satellite-derived and ground-measured SO2 emission rates (∼18%), with a factor of 2 improvement over the differences found by simple direct comparison. While the balance of emission source strength and postemission processing will differ between volcanoes and regions, under good observation conditions and where SO2 lifetime is ∼24 hours, satellite-based sensors like OMI may provide daily observations of SO2 mass loading which are a good proxy for volcanic source strength