Steady-state negative Wigner functions of nonlinear nanomechanical oscillators

We propose a scheme to prepare nanomechanical oscillators in nonclassical steady states, characterized by a pronounced negative Wigner function. In our optomechanical approach, the mechanical oscillator couples to multiple laser driven resonances of an optical cavity. By lowering the resonance frequency of the oscillator via an inhomogeneous electrostatic field, we significantly enhance its intrinsic geometric nonlinearity per phonon. This causes the motional sidebands to split into separate spectral lines for each phonon number and transitions between individual phonon Fock states can be selectively addressed. We show that this enables the preparation of the nanomechanical oscillator in a single phonon Fock state. Our scheme can for example be implemented with a carbon nanotube dispersively coupled to the evanescent field of a state of the art whispering gallery mode microcavity

Agulhas retroflection rings in the South Atlantic Ocean

The western boundary current rings shed from the Agulhas retroflection may be responsible for a considerable transfer of heat, salt and energy from the South Indian into the South Atlantic Ocean. Few hydrographic measurements have been collected from Agulhas rings in the South Atlantic Ocean and their characteristics and influence on the waters of the Cape Basin through which they pass are thus little known. The temperature, salinity, and nutrient data presented in the thesis were collected from three Agulhas rings on a number of recent hydrographic cruises in the South Atlantic Ocean. Temperature profiles, conductivity-temperature-depth measurements, nutrient data, GEOSAT altimeter data, and NOAA-11 satellite imagery were used to investigate one of the rings in May 1989. It had previously been postulated that the rings could have an important effect on the Benguela upwelling system and this thesis demonstrates the interaction of the ring with a filament from the upwelling system. An adverse influence of this interaction on the anchovy larval population is postulated, and cited as a possible cause of the very poor anchovy yearclass of 1989. The other two rings were encountered during winter (August 1990 and June 1992), closer to the retroflection, and only hydrographic observations were possible. One of the rings showed a very deep isothermal surface layer and evidence of a deep pycnostad at its centre. The deep stad is shown to be likely due to vortex stretching and possible sources for the water in the stad are suggested. Comparative hydrographic characteristics, water mass structure, velocity fields, and the potential for contribution to interbasin transfer of the three rings are presented and discussed in the thesis

A broader flight season for Norway’s Odonata across a century and a half

publishedVersio

Philosophy at Cambridge

Newsletter of the Faculty of Philosophy. Articles: Rae Langton, 'From the Chair'; Michael Potter, 'The Birth of a Book'; Huw Price, 'Two Projects from 2012--a progress report; Rae Langton 'The Enlightening of Maria von Herbert, Klagenfert, 1770-1803; Philosophy and the LMU Partnership; Jessie Munton, 'Perceptual Confidence Workshop'

Auditing the Election Ecosystem

Election administration is a highly complex process that involves multiple actors all working to achieve the goal of running an effective election. One critical technique for gathering the performance data needed to improve election management is through comprehensive evaluations, which we refer to as election ecosystem audits (EEA). These audits are evaluations of an election from start to finish. Accomplishing this goal requires election officials coordinating the efforts of contractors—from ballot printers to voting machine companies—third parties, like the US Postal Service who transport absentee ballots and the entities who agree to house polling places, and the poll workers who actually implement the election at the polls. Managing this vast enterprise requires election officials to evaluate their election activities so that they can improve the implementation of the process over time

Sustainability Reporting in the Mining Industry

The purpose of this thesis was to examine the sustainability reporting of global mining companies. A review of prior literature indicated that sustainability has grown as a concept of interest in recent decades. Early studies concentrated on the characteristics of organisations producing sustainability reports and proffered different theories explaining why these reports are produced. While more recent research has focused on sustainability in the mining sector, no prior study had looked at the content of the sustainability reports of multiple mining organisations. This study, therefore, provides greater understanding of the concepts and themes used within mining companies’ sustainability reports. The study data drew on 104 electronically available sustainability reports collected from 32 mining companies covering the period 2010 to 2013. The mining companies were further classified according to their International Council on Mining and Minerals (ICMM) membership status. A content and thematic analysis was conducted using Leximancer software, a computer textual analysis program. The software analysed the data and produced concept findings, key themes, and concept maps from it. The findings showed that the most frequently used concepts across all the sustainability reports were community, employees, local, production, and safety. At 27,727 interactions, the concept of community had the greatest number of interactions with other concepts. When the number of interactions was divided by the concept count, education was seen to have the highest number of interactions per concept appearance, followed by power, consumption, coal, and employment. The theme findings identified five theme groups: Community, Safety, Production, Water, and Employees. The summarised findings for the individual companies revealed variation across the different companies. The count percentage of the second most frequent concept, compared to the most frequent, ranged from 99% to 49%. The third most frequent concept’s average relevance score ranged from 97% 38%. When limiting the individual companies to their 5 most frequent concepts, 29 concepts were found to be in use across the 32 different companies. The most common concepts to rank in the top 5 overall were operations, ‘company name’, management, development, and mine. The findings revealed 65 concepts across the 4 investigated years; 22 of these concepts were found to be common concepts. The study identified 17 top 10 ranked concepts for the 4-year period; however, 4 of these ranked consistently in the top 10. These were community, production, report, and local. The findings for the three different ICMM member categories revealed 19 concepts that ranked in the top 40 across all categories. The concepts of community, employees, report, production, and local all had an average rank inside the top 10, regardless of ICMM membership. This study provided greater insight into the sustainability reporting practices of leading global mining companies. The findings revealed the concepts and themes that appeared within the sustainability reports. More research is needed to understand the different concepts and the reasons for the variability in reporting and reporting trends over time. This study has provided a preliminary review which can be used to better understand how mining companies are using sustainability reporting in light of the inherent paradox between sustainability and mining.