Observations of the 57Fe+23 hyperfine transition in clusters of galaxies

We present a search for the hyperfine transition of the 57Fe+23 ion at 3.071 mm in clusters of galaxies with the ATNF Mopra telescope. The results are compared with a realistic estimate of the peak brightness temperature of the line in a cooling flow cluster A85, using the available X-ray data

Characterisation of the Mopra Radio Telescope at 16--50 GHz

We present the results of a programme of scanning and mapping observations of astronomical masers and Jupiter designed to characterise the performance of the Mopra Radio Telescope at frequencies between 16-50 GHz using the 12-mm and 7-mm receivers. We use these observations to determine the telescope beam size, beam shape and overall telescope beam efficiency as a function of frequency. We find that the beam size is well fit by $\lambda$/$D$ over the frequency range with a correlation coefficient of ~90%. We determine the telescope main beam efficiencies are between ~48-64% for the 12-mm receiver and reasonably flat at ~50% for the 7-mm receiver. Beam maps of strong H$_2$O (22 GHz) and SiO masers (43 GHz) provide a means to examine the radial beam pattern of the telescope. At both frequencies the radial beam pattern reveals the presence of three components, a central `core', which is well fit by a Gaussian and constitutes the telescopes main beam, and inner and outer error beams. At both frequencies the inner and outer error beams extend out to approximately 2 and 3.4 times the full-width half maximum of the main beam respectively. Sources with angular sizes a factor of two or more larger than the telescope main beam will couple to the main and error beams, and therefore the power contributed by the error beams needs to be considered. From measurements of the radial beam power pattern we estimate the amount of power contained in the inner and outer error beams is of order one-fifth at 22 GHz rising slightly to one-third at 43 GHz.Comment: Accepted for publication in PAS

Everyday reveries: recorded music, memory & emotion

This thesis investigates recorded music in everyday life and its relationship to memory. It does this by establishing the social and historical context in which sound recording was invented and developed, and by formulating a theory of how recorded music signifies. It argues that musical recordings do not simply facilitate remembering but are equally bound up with processes of forgetting. Each chapter of the thesis examines a different aspect of the relationship between recorded music and memory. Chapter one analyses the origins of sound recording and charts its subsequent development in terms of a continuum between social and solitary listening. Chapter two interrogates common assumptions about what is meant by the ‘everyday’, and argues that music in everyday life tends to be consumed and remembered in fragmentary form. Chapter three investigates the significance of, and reasons for, involuntary musical memories. Chapter four analyses the relationship between recorded music and nostalgia. Chapter five examines recorded music’s role in pleasurable forms of forgetting or self-oblivion. Chapter six is a summation of the whole thesis, arguing that recorded music in everyday life contains utopian traces which, when reflected upon, yield insights into the nature of social reality. The thesis also contains two ‘interludes’ that deal with pertinent theoretical issues in the field of cultural studies. The first of these interludes argues that Peircean semiotics is better suited to the task of analysing music than Saussurean semiology and that, furthermore, it is able to contribute to the emerging field of affect theory. The second interlude continues this analysis by arguing that mimesis or creative imitation should become a key concept in cultural studies

A study on the wireless power transfer efficiency of electrically small, perfectly conducting electric and magnetic dipoles

This paper presents a general theoretical analysis of the Wireless Power Transfer (WPT) efficiency that exists between electrically short, Perfect Electric Conductor (PEC) electric and magnetic dipoles, with particular relevance to near-field applications. The figure of merit for the dipoles is derived in closed-form, and used to study the WPT efficiency as the criteria of interest. The analysis reveals novel results regarding the WPT efficiency for both sets of dipoles, and describes how electrically short perfectly conducting dipoles can achieve efficient WPT over distances that are considerably greater than their size

Corporate tax competition between firms

Firms' tax planning decisions, similar to their other operational decisions, are made in a competitive environment. Various stakeholders observe the tax payments and evaluate these against the relevant peer group, which creates interdependencies in the tax planning activities of firms. Introducing the concept of reputational loss we show the positive interdependence in a theoretical model and test it in a spatial econometric model. Empirical evidence suggests that benchmarking takes place both within countries and within industries, however for the latter it is important to include firms in large non-EU OECD countries. Further, the analysis shows that spatial interdependence is stronger for the largest firms and if they have an average effective tax rate above the statutory tax rate

Investigation of High-Efficiency Wireless Power Transfer Criteria of Resonantly-Coupled Loops and Dipoles through Analysis of the Figure of Merit

The efficiency of a Wireless Power Transfer (WPT) system is greatly dependent on both the geometry and operating frequency of the transmitting and receiving structures. By using Coupled Mode Theory (CMT), the figure of merit is calculated for resonantly-coupled loop and dipole systems. An in-depth analysis of the figure of merit is performed with respect to the key geometric parameters of the loops and dipoles, along with the resonant frequency, in order to identify the key relationships leading to high-efficiency WPT. For systems consisting of two identical single-turn loops, it is shown that the choice of both the loop radius and resonant frequency are essential in achieving high-efficiency WPT. For the dipole geometries studied, it is shown that the choice of length is largely irrelevant and that as a result of their capacitive nature, low-MHz frequency dipoles are able to produce significantly higher figures of merit than those of the loops considered. The results of the figure of merit analysis are used to propose and subsequently compare two mid-range loop and dipole WPT systems of equal size and operating frequency, where it is shown that the dipole system is able to achieve higher efficiencies than the loop system of the distance range examine