Investigating the effect of energy dissipation on flotation kinetics in an oscillating grid flotation cell

This thesis investigates the effect of energy dissipation on the flotation kinetics of quartz in an oscillating grid flotation cell. Oscillating grids exhibit relatively isotropic and homogeneous turbulence, which cannot be achieved in standard impeller agitated flotation cells. Due to this they provide a potentially ideal environment in which to investigate the effects of energy dissipation on flotation kinetics. Previous work in an oscillating grid flotation cell was limited to energy dissipations of up to 0.6 kW/m³, which is low when compared to 0.6 - 3 kW/m³ commonly used in both flotation literature and industry. The current work uses a new oscillating grid cell which can operate at energy dissipations of up to 5 kW/m³. Quartz (sub 100 μm) has been floated in the new cell at energy dissipations ranging from 0.5 - 5 kW/m³ and using three discrete bubble sizes (0.13 mm, 0.24 mm and 0.82 mm). Characterisation experiments show that the new cell operates in a similar manner to the oscillating grid cell used by Changunda et al. (2008), and produces repeatable results. The effect of changing bubble and particle size on flotation kinetics is in agreement with literature findings, indicating that as a flotation device the oscillating grid cell is operating as expected

Music Technology, Gender, and Sexuality: Case Studies of Women and Queer Electroacoustic Music Composers

This document aims to contribute to the established scholarship that highlights the role gender and sexuality has with one’s fundamental relationship to composition and music technology. The profession of electronic music composition and music production are strongly associated with notions of power and control, as much of this technology was built during the World Wars and Cold War. These aggressive views have created gendered language and metaphors in the field. Metaphors are the primary way in which we accommodate and assimilate information and experience to our conceptual organization of the world. It is at the source of our capacity to learn and at the center of our creative thought. I hope to continue the discussion of language, metaphors, and various approaches to composing and working with music technology through a historical overview of women’s achievements and difficulties in the electroacoustic community. Elainie Lillios, Jess Rowland, and Carolyn Borcherding were selected to be interviewed for this document. Each interview allows them the opportunity to discuss their music, their approach to composition and their use of technology as part of their artistic process, and to discuss their roles of educators and their approach to pedagogy to further contribute to the scholarship and history of electroacoustic composers

Find Unique Usages: Helping Developers Understand Common Usages

When working in large and complex codebases, developers face challenges using \textit{Find Usages} to understand how to reuse classes and methods. To better understand these challenges, we conducted a small exploratory study with 4 participants. We found that developers often wasted time reading long lists of similar usages or prematurely focused on a single usage. Based on these findings, we hypothesized that clustering usages by the similarity of their surrounding context might enable developers to more rapidly understand how to use a function. To explore this idea, we designed and implemented \textit{Find Unique Usages}, which extracts usages, computes a diff between pairs of usages, generates similarity scores, and uses these scores to form usage clusters. To evaluate this approach, we conducted a controlled experiment with 12 participants. We found that developers with Find Unique Usages were significantly faster, completing their task in 35% less time

The Changing Nature of Regional Poverty

We’re witnessing a dramatic change in the social geography of greater Richmond. It’s becoming more like that of the global south, where wealth is centered in the cities and poverty rings the outskirts of the city