Colleen Coleman in a Sophomore Recital

This is the program for the sophomore voice recital of Colleen Coleman, accompanied by Pam Dennis. The recital was held on February 18, 1994, in Mabee Fine Arts Center\u27s Recital Hall

Jahn-Teller Solitons, Structural Phase Transitions and Phase Separation

It is demonstrated that under common conditions a molecular solid subject to Jahn-Teller interactions supports stable Q-ball-like non-topological solitons. Such solitons represent a localized lump of excess electric charge in periodic motion accompanied by a time-dependent shape distortion of a set of adjacent molecules. The motion of the distortion can correspond to a true rotation or to a pseudo-rotation about the symmetric shape configuration. These solitons are stable for Jahn-Teller coupling strengths below a critical value; however, as the Jahn-Teller coupling approaches this critical value, the size of the soliton diverges signaling an incipient structural phase transition. The soliton phase mimics features commonly attributed to phase separation in complex solids.Comment: 8 pages, 3 figure

Enhancing new venture creation success in South Africa: a project management perspective

Published ArticleSouth Africa’s new venture creation rate is disturbingly low. Ineffective management during start-up can lead to a low venture creation rate. Amidst the growing importance of project management in effective business management, utilizing project management in the entrepreneurial process has become very appealing. The purpose of this paper is to provide a project management model for starting a new venture. Desk research is undertaken through which relevant literature on the key components of the study is reviewed and synthesized. The authors find that through action research, project management aspects can be integrated into the entrepreneurial process to improve the new venture success rate. Based on this framework, the authors conclude that it is possible to improve Total Entrepreneurial Activity (TEA) in South Africa and elsewhere. This theoretical framework is yet to be tested. However, even in its present untested form, the paper is important because it theoretically enriches the entrepreneurship literature whilst also offering a possible practical solution to the vexing problem of high new venture creation failure rate in South Africa and elsewhere through a structured framework

Polarons and Solitons in Jahn-Teller Systems

Using a semiclassical continuum model of an electron in a deformable molecular crystal, some properties of multicomponent generalizations of the polaron--``vector polarons''-- are elucidated. Analytical solutions for the case of two electronic bands coupled to two vibrational modes are given in detail. Within the model considered, the vector polaron can be classified by its wavefunction into several types and can have features that include: (1) a spatial variation in the electronic and vibrational character, and (2) low-energy internal degrees of freedom. For the case of electronic and vibrational degeneracy, local Jahn-Teller interactions can also lead to a novel spatiotemporal soliton, a long-lived excited state of the many-electron system stabilized by the conservation law resulting from degeneracy.Comment: 10 pages, 0 figures. International Symposium on Jahn-Teller Effects, ICTP, Trieste, Ital

Novel functionalised phosphines relevant to the methoxycarbonylation of ethylene

Several novel o-xylene bridged diphosphine ligands have been synthesised, and their activity tested in the palladium catalysed methoxycarbonylation of ethylene. Particular interest has been paid to the synthesis of phosphine ligands with tertiary-alkyl groups pendant to the phosphorus atoms. Results obtained from catalysis compare favourably with ligand systems described in the chemical literature, with l,2-Z>/s(di-l-adamantylphosphinomethyl)benzene and l,2-Z>/5(di-l-methylcyclopentylphosphinomethyl)benzene providing highly active catalyst systems, with selectivity towards methylpropionate. Alternative synthetic strategies are described, which have provided novel routes to the phosphines of interest. These methodologies having increased the scope of phosphine ligand synthesis with di-terr/ary-alkyl substituted species. Several complexes of the new ligands have been prepared and characterised, giving insight into the properties of the novel ligands

A Deeper Look at Leo IV: Star Formation History and Extended Structure

We present MMT/Megacam imaging of the Leo~IV dwarf galaxy in order to investigate its structure and star formation history, and to search for signs of association with the recently discovered Leo~V satellite. Based on parameterized fits, we find that Leo~IV is round, with $\epsilon < 0.23$ (at the 68\% confidence limit) and a half-light radius of $r_{h} \simeq 130$ pc. Additionally, we perform a thorough search for extended structures in the plane of the sky and along the line of sight. We derive our surface brightness detection limit by implanting fake structures into our catalog with stellar populations identical to that of Leo~IV. We show that we are sensitive to stream-like structures with surface brightness $\mu_{r}\lesssim29.6$ mag arcsec$^{-2}$, and at this limit, we find no stellar bridge between Leo IV (out to a radius of $\sim$0.5 kpc) and the recently discovered, nearby satellite Leo V. Using the color magnitude fitting package StarFISH, we determine that Leo~IV is consistent with a single age ($\sim$14 Gyr), single metallicity ($[Fe/H]\sim-2.3$) stellar population, although we can not rule out a significant spread in these value. We derive a luminosity of $M_{V}=-5.5\pm0.3$. Studying both the spatial distribution and frequency of Leo~IV's 'blue plume' stars reveals evidence for a young ($\sim$2 Gyr) stellar population which makes up $\sim$2\% of its stellar mass. This sprinkling of star formation, only detectable in this deep study, highlights the need for further imaging of the new Milky Way satellites along with theoretical work on the expected, detailed properties of these possible 'reionization fossils'.Comment: 26 pages, 14 figures, emulateapj format, ApJ accepted versio

Recent Developments and Future Trends in Volunteered Geographic Information Research: The Case of OpenStreetMap

User-generated content (UGC) platforms on the Internet have experienced a steep increase in data contributions in recent years. The ubiquitous usage of location-enabled devices, such as smartphones, allows contributors to share their geographic information on a number of selected online portals. The collected information is oftentimes referred to as volunteered geographic information (VGI). One of the most utilized, analyzed and cited VGI-platforms, with an increasing popularity over the past few years, is OpenStreetMap (OSM), whose main goal it is to create a freely available geographic database of the world. This paper presents a comprehensive overview of the latest developments in VGI research, focusing on its collaboratively collected geodata and corresponding contributor patterns. Additionally, trends in the realm of OSM research are discussed, highlighting which aspects need to be investigated more closely in the near future

Enhancing new venture creation success in South Africa: a project management perspective

Published ArticleSouth Africa’s new venture creation rate is disturbingly low. Ineffective management during start-up can lead to a low venture creation rate. Amidst the growing importance of project management in effective business management, utilizing project management in the entrepreneurial process has become very appealing. The purpose of this paper is to provide a project management model for starting a new venture. Desk research is undertaken through which relevant literature on the key components of the study is reviewed and synthesized. The authors find that through action research, project management aspects can be integrated into the entrepreneurial process to improve the new venture success rate. Based on this framework, the authors conclude that it is possible to improve Total Entrepreneurial Activity (TEA) in South Africa and elsewhere. This theoretical framework is yet to be tested. However, even in its present untested form, the paper is important because it theoretically enriches the entrepreneurship literature whilst also offering a possible practical solution to the vexing problem of high new venture creation failure rate in South Africa and elsewhere through a structured framework