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It has been known for some time that warped extra dimensions offer a potential explanation of the large hierarchy that exists between the electroweak scale and the Planck scale. The majority of this work has focused on a five dimensional slice of AdS space. This thesis attempts to address the question, what possible spaces offer phenomenologically viable resolutions to this gauge hierarchy problem. In order for a space to offer a potential resolution to the hierarchy problem two conditions must be met: Firstly one should be able to demonstrate that the space can be stabilised such that a small effective electroweak scale (or large effective Planck scale) can be obtained. Secondly one must demonstrate that the space allows for a Kaluza Klein (KK) scale that is small enough such that one does not reintroduce a hierarchy in the effective theory. Here we focus on the second condition and examine the constraints, on the KK scale, coming from corrections to electroweak observables and flavour physics which arise when gauge fields propagate in an additional dimension. We study a large class of possible spaces of different geometries and dimensionalities. In five dimensions it is found that such constraints are generically large. In more than five dimensions it is found that a significant proportion of such spaces suffer from either a high density of KK modes or alternatively strongly coupled KK fields. The latter would not offer viable resolutions to the hierarchy problem. Models in which the Higgs propagates in the bulk are also studied, in the context of models with a ‘soft wall' and it is found these have significantly reduced constraints from flavour physics as well as a notion of a minimum fermion mass.

The research undertaken unites two distinct areas of quantum information processing: single ions stored in radio-frequency traps and single photons in optical fibres. Strings of ions are presently the most successful implementation of quantum computing, with elementary quantum algorithm and quantum simulations realised. The principal challenge in the field is to enhance the quantum processing power by scaling up current devices to larger systems. We pursue one of the most promising strategies: distributed quantum computation in which multiple small-scale ion processors are interlinked by exchanging photonic quantum bits via optical fibres. This requires a coherent quantum interface between ions and photons, mapping ionic to photonic quantum states and vice versa. To maximise fidelity and the success rate of the scheme, the interaction of ions and photons must take place in a microscopic optical cavity with high finesse. To this end, single 40Ca+ were trapped in a radio-frequency ion trap whose trapping electrodes are hollow cylinders. Optical fibres with mirrors machined on the facets are inserted into the electrodes to form a Fabry-Pérot cavity. Because the fibres are shielded by the electrodes the detrimental distortion of the trapping field due to their presence is suppressed and ions can be trapped for several hours. 40Ca+ has a -type energy level scheme wherein the ion is cooled on the 42P1/2 ⇔ 42S1/2 transition and the cavity is tuned to the 42P1/2 ⇔ 32D3/2 transition. This thesis reports the successful coupling of single ions to a high finesse optical fibre based cavity, with coupling strength g = 2π · 4:6 MHz. The cavity has length 367 μm, finesse of 40,000 and linewidth 2k = 2π · 9:4 MHz. In this coupling regime, the enhancement of the ion's emission rate through the Purcell effect was observed. Further, anti-correlation was observed in the emission rates between the P1/2 ⇔ D3/2 and P1/2 ⇔ S1/2 transitions with an effective emission rate suppression of up to 60% in the latter transition. The built system offers greater promises. Once the position in the cavity mode has been optimised we expect to reach the long-sought after strong coupling regime with (g, k, y) = 2π · (12:2; 4:7; 11:2) MHz.

abstract: Rapid development of new technology has significantly disrupted the way radiotherapy is planned and delivered. These processes involve delivering high radiation doses to the target tumor while minimizing dose to the surrounding healthy tissue. However, with rapid implementation of these new technologies, there is a need for the detection of prescribed ionizing radiation for radioprotection of the patient and quality assurance of the technique employed. Most available clinical sensors are subjected to various limitations including requirement of extensive training, loss of readout with sequential measurements, sensitivity to light and post-irradiation wait time prior to analysis. Considering these disadvantages, there is still a need for a sensor that can be fabricated with ease and still operate effectively in predicting the delivered radiation dose. The dissertation discusses the development of a sensor that changes color upon exposure to therapeutic levels of ionizing radiation used during routine radiotherapy. The underlying principle behind the sensor is based on the formation of gold nanoparticles from its colorless precursor salt solution upon exposure to ionizing radiation. Exposure to ionizing radiation generates free radicals which reduce ionic gold to its zerovalent gold form which further nucleate and mature into nanoparticles. The generation of these nanoparticles render a change in color from colorless to a maroon/pink depending on the intensity of incident ionizing radiation. The shade and the intensity of the color developed is used to quantitatively and qualitatively predict the prescribed radiation dose. The dissertation further describes the applicability of sensor to detect a wide range of ionizing radiation including high energy photons, protons, electrons and emissions from radioactive isotopes while remaining insensitive to non-ionizing radiation. The sensor was further augmented with a capability to differentiate regions that are irradiated and non-irradiated in two dimensions. The dissertation further describes the ability of the sensor to predict dose deposition in all three dimensions. The efficacy of the sensor to predict the prescribed dose delivered to canine patients undergoing radiotherapy was also demonstrated. All these taken together demonstrate the potential of this technology to be translatable to the clinic to ensure patient safety during routine radiotherapy. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2019

The distribution of particles in the Eastern Pacific Ocean was investigated from 2 January to 14 February, l969, on the YALOC-69 cruise of Oregon State University. The size distributions were well fitted by the two-parameter Weibull distribution function, with a predominant number of them nearly exponential in distributional shape. Although particles smaller in diameter than 1i could not be measured, extrapolation of the Weibull distribution into the small particle range indicated the median particle diameter was smaller than 1μ. Measurements of light scattering were taken simultaneously with the particle size determinations. A linear relationship between the total particulate surface area and the volume scattering function, β(45°) was indicated, as well as between β(45°)/β(135°) and the mean particle diameter of distributions sharing a common shape parameter. Five different characteristic distributional shapes were found which typified all but a few of the distributions. No direct relationship was found between the distributional shapes and the water types encountered on the cruise. The first-order exponential shapes of the size distributions suggest that a detrital decay mechanism of the larger particles (i. e. phytoplankton) could be a dominant factor in determining the small particle end of oceanic particle distributions. / Graduation date: 1970

Thesis (M.Sc.)--York University, 2004. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 117-120). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL:http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss&rft%5Fval%5Ffmt=info:ofi/fmt:kev:mtx:dissertation&rft%5Fdat=xri:pqdiss:MQ99407

Thesis (M.C.E.)--University of Delaware, 2006. / Principal faculty advisor: Jack Puleo, Dept. of Civil & Environmental Engineer. Includes bibliographical references.

Most current models for the deposition of aerosol particles in the human lung are based on a Lagrangian reference frame, which is ill-suited for modeling transient eects. Deposition models based on an Eulerian reference frame are much better at capturing instantaneous time-dependent eects, though they are dicult to create. In the interest of developing such models, mathematical techniques were used to describe the velocity elds of simple particle ows. Analytic expressions describing the time-dependent ow of particles through a curved pipe were created and implemented numerically. The numerical simulations were used to determine which ow regimes required the use of Eulerian modelling for deposition prediction.

Supersymmetric extensions to the Standard Model (SM) have many interesting experimental consequences which can provide important hints to the physics beyond the SM. In this thesis, we first study the anomalous magnetic moment of the muon and show that a significant constraint on the parameter space can be obtained from its current experimental value. In the next topic, we study the CP violations in B -> phi K decays and show that the SM and the minimal supergravity model (mSUGRA) cannot account for the current experimental observation. We then show that all the data can be accommodated for a wide range of parameters in models with non-universal soft breaking left-right A terms. In our last topic, which is based on a Horava-Witten inspired model proposed by R. Arnowitt and B. Dutta, we extend their analysis to the full fermion sector of the SM and propose a new mechanism different from the usual see saw mechanism to generate small neutrino masses which are in good agreement with the current neutrino oscillation data.

The annihilation of weakly interacting massive particles (WIMPs), accumulated in gravitational potentials (e.g., the core of the Earth, the Sun or the Galactic halo) would lead to neutrino production. This thesis investigates the possibility of searching for WIMPs in the form of the lightest supersymmetric particle (neutralino) trapped in the Sun using the AMANDA-II neutrino telescope. AMANDA-II is a large Cherenkov detector located deep in the ice at the geographical South Pole. The presented work is based on data taken during the year 2001. An analysis optimized to search for the neutralino-induced flux from the Sun has been developed. The observation of no excess with respect to the expected atmospheric neutrino background has been interpreted as an upper limit on the neutralino annihilation rate in the Sun and on the neutralino-induced muon flux in the vicinity of the detector.