Cooperative Interactions in Lattices of Atomic Dipoles

Coherent radiation by an ensemble of scatterers can dramatically modify the ensemble's optical response. This can include, for example, enhanced and suppressed decay rates (superradiance and subradiance respectively), energy level shifts, and highly directional scattering. This behaviour is referred to as cooperative, since the scatterers in the ensemble behave as a collective rather than independently. In this Thesis, we investigate the cooperative behaviour of one- and two-dimensional arrays of interacting atoms. We calculate the extinction cross-section of these arrays, analysing how the cooperative eigenmodes of the ensemble contribute to the overall extinction. Typically, the dominant eigenmode if the atoms are driven by a uniform or Gaussian light beam is the mode in which the atomic dipoles oscillate in phase together and with the same polarisation as the driving field. The eigenvalues of this mode become strongly resonant as the atom number is increased. For a one-dimensional array, the location of these resonances occurs when the atomic spacing is an integer or half integer multiple of the wavelength, thus behaving analogously to a single atom in a cavity. The interference between this mode and additional eigenmodes can result in Fano-like asymmetric lineshapes in the extinction. We find that the kagome lattice in particular exhibits an exceptionally strong interference lineshape, like a cooperative analog of electromagnetically induced transparency. Triangular, square and hexagonal lattices however are typically dominated by one single mode which, for lattice spacings of the order of a wavelength, can be highly subradiant. This can result in near-perfect extinction of a resonant driving field, signifying a significant increase in the atom-light coupling efficiency. We show that this extinction is robust to possible experimental imperfections

Satire and the Necessity of Locale: Genealogical Readings in Max Beerbohm and Karl Kraus

This thesis focuses on the satirical works of Max Beerbohm’s Zuleika Dobson and Karl Kraus’ The Last Days of Mankind. The thesis, examining the locality of satire and the particularities of each individual text, asks whether satire ever transcends time and geographical barriers, or whether it necessarily remains local and confined within a particular time period. Beerbohm wrote in Oxford in 1911 and Kraus in Vienna in 1918, and the thesis contends that satire must be grounded in the period the satirist is writing in. It then questions whether or not there can be specific elements of the texts that can be deemed universal. Such social parameters as power structures, acquiescence, and complicity provide the ground to probe methodologically at the works of Foucault, Russell, Bakhtin, and Hutcheon

Interspecific hybridization between sympatric coastal cutthroat and coastal rainbow/steelhead trout on Vancouver Island, British Columbia: A conservation and evolutionary examination.

Sympatric coastal cutthroat trout (Oncorhynchus clarki clarki ) and coastal rainbow/steelhead trout (O. mykiss irideus ) are thought to be reproductively isolated primarily by spatial and temporal separation. However, interspecific hybridization has been documented, thus raising the questions of how widespread hybridization is within their native range, and what are the nature and status of reproductive isolating mechanisms (i.e. prezygotic or postzygotic) in the hybridizing sympatric populations? In a broad survey of 37 populations on Vancouver Island, hybridization between these trout species was found to be widespread (Chapter 2). The frequency of hybridization varied among locations (HI = 3%--88%; II = 2%--54%), with some populations displaying hybrid levels indicative of hybrid swarms and may be undergoing \u27hybrid meltdown\u27. Several environmental factors appear to influence hybridization (e.g. forest harvesting, stocking, habitat availability, watershed size), however, no single factor appears to have a dominant effect. There is no consistent evidence for selection acting against first-generation (F1) hybrids, and in backcross hybrids inconsistent results implicate environment-dependent (i.e. extrinsic) selection (Chapter 3). Hybridization is reciprocal, but nuclear marker patterns show that the direction of hybridization is unidirectional in some populations (n = 5 out of 13 populations). Based on cytonuclear disequilibrium levels, a remarkable reproductive bias appears to exist (i.e. frequency of backcross hybrids with matched nuclear-mitochondrial marker composition exceeded mismatched genotypes). Selection against mismatch genotypes may be occurring, although a behavioural mating bias is more likely.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .B44. Source: Masters Abstracts International, Volume: 43-01, page: 0157. Adviser: Daniel Heath. Thesis (M.Sc.)--University of Windsor (Canada), 2004

P3_7 A Solar Powered Leicester

In this paper the feasibility of meeting the power consumption demands of Leicester using only solar panels fitted to the rooftops of houses was studied. It was found that every household in the city would need at least 47 of the highest efficiency solar panels commercially available today affixed to the rooftops, which would not be practical

The role of inhibitory control in defining typologies of internet sex offenders

Developing a greater understanding of the characteristics of Internet sex offenders is an important area of research for reducing recidivism and working towards prevention strategies for the future, particularly given the risk of individuals committing both online and offline offences. One characteristic that is lacking comprehensive examination for Internet sex offenders is deficient inhibitory control, which has previously been evidenced in offline sexual offenders (e.g., Smith & Waterman, 2004). This may enhance our understanding of risk factors for online offending and the presence of distinct Internet sex offender typologies. This thesis explores the characteristics and typologies of Internet sex offenders with a specific focus on inhibitory control. An introduction is provided for this area of research, followed by a systematic review of the literature. Impulsiveness is then explored through a critique of a psychometric tool which is further utilised in a novel research project. Finally, a comprehensive discussion is provided on the content of this thesis, including implications for research and clinical practice. The thesis appears to highlight a link between self-regulation deficits and sexual offending against children commissioned online. However, this characteristic does not appear to differentiate Internet sex offenders, suggesting important implications for assessing, managing and treating future risk in online-only offenders

P3_4 Keeping your head in the clouds

 An investigation into whether the ship "Cloudbase" from the Captain Scarlet TV series could actually maintain stationary altitude. The weight of the Cloudbase structure was calculated to be 3.22x1010N assuming it is mostly comprised of carbon fibre, it would need a power of 1.61x1013W to run the engines alone equivalent to roughly 644 thousand nuclear power plants. This idea was determined infeasible

P3_3 Radiation Study around nuclear plant in Fukushima

 This paper investigates possible health effects of the recent Fukushima nuclear emergency. We look at the dose rates at Onami, 62km away from the facility, and the adverse effects it could potentially have upon its residents over the following year. From an absorbed dose of 9.1μSv hr-1 it was calculated that 79.7mSv yr-1 would be the effective dose with a 0.3985% chance of getting cancer from the incident, with a low chance of permanent effects

P3_5 All These Worlds Are Yours

 This paper investigates a plot point of the novel 2010: Odyssey Two by Arthur C. Clarke in which self replicating monoliths engulf Jupiter, increasing its density to the point when nuclear fusion can take place, giving birth to a new star. It was found that 1.629x1020 monoliths would be needed to trigger nuclear fusion in Jupiter's core, taking 136 hours to do so

P3_1 Shocking Revelations

The feasibility of using lightning as a renewable source of energy is studied. It was found that, while a good idea in practice, efficiently converting electricity into a useful product presents a problem as well as the rarity of lightning strikes themselves. It was calculated that even in a location that experiences lots of lightning, it would only get struck on average once per year. Due to this, it is unlikely that the power obtained from lightning itself would outweigh the expense of building a facility to efficiently harvest it