In this work a Finite Difference Time Domain (FDTD) simulation is employed to explore local field enhancement, plasmonic coupling, and charge distribution patterns. This 3D simulation calculates the magnetic and electric field components in a large matrix of Yee cells using Maxwell’s equations. An absorbing boundary condition is included to eliminate reflection back into the simulation chamber, and a sample system of cells is checked for convergence. In the specific simulations considered here, a laser pulse of single wavelength is incident on a silicon substrate, travels through an embedded ZnO nanowire (NW) waveguide only (due to an Ag filter), then incites plasmonic coupling at the gap between an Au nanoparticle tip and an Au substrate, an Au nanoparticle (NP), or a trio of Au nanoparticles incident on an angled Si substrate. The angle between the axis of the NW and the normal of the substrate is varied from 0-60°. The NP perpendicular deflection with respect to the NW axis is also varied from -115 - 75 nm. The enhancement patterns reveal superior signal to noise ratio compared to Near Field Scanning Optical Microscopy (NSOM), three times smaller than the NP diameter 100 nm, as well as resolution and spot size of less than 50 nm. This method of Apertureless NSOM (ANSOM) using a NW waveguide grown on a transparent microcantilever therefore shows promise for imaging of single molecules incident on a substrate and NP-labeled cell membrane. / text

This thesis discusses the design and construction of a Near-field Scanning Optical Microscope (NSOM). Basic principles of operation, the characteristics of the hardware components, and the control software are discussed. A unique method of controlling the position of the probe is developed, and scans of a diffraction grating are presented. We show the influence that the surface topology and reflectivity and the interference of direct and reflected light have on the images. A second design of the instrument, for use in a vacuum chamber and with a flexure stage for lateral motion, is accomplished. / text

Near shore hydrodynamics has been an important research area dealing with coastal processes. The nearshore coastal region is the region between the shoreline and a fictive offshore limit which usually is defined as the limit where the depth becomes so large that it no longer influences the waves. This spatially limited but highly energetic zone is where water waves shoal, break and transmit energy to the shoreline and are governed by highly dispersive and non-linear effects. An accurate understanding of this phenomena is extremely useful, especially in emergency situations during hurricanes and storms. While the shallow water assumption is valid in regions where the characteristic wavelength exceeds a typical depth by orders of magnitude, Boussinesq-type equations have been used to model near-shore wave motion. Unfortunately these equations are complex system of coupled non-linear and dispersive differential equations that have made the developement of numerical approximations extremely challenging. In this dissertation, a local discontinuous Galerkin method for Boussinesq-Green Naghdi Equations is presented and validated against experimental results. Currently Green-Naghdi equations have many variants. We develop a numerical method in one horizontal dimension for the Green-Naghdi equations based on rotational characteristics in the velocity field. Stability criterion is also established for the linearized Green-Naghdi equations and a careful proof of linear stability of the numerical method is carried out. Verification is done against a linearized standing wave problem in flat bathymetry and h,p (denoted by K in this thesis) error rates are plotted. The numerical method is validated with experimental data from dispersive and non-linear test cases. / text

Negatively buoyant jets are turbulent flows that are frequently employed by the desalination industry to disperse reject brines into oceanic environments. Although such brines are characterised by elevated concentrations of the same elemental components as the discharge environment contains, there is significant potential for marine ecosystem damage if this waste is not diluted properly. Numerous workers have analysed the dilution and spatial characteristics of negatively buoyant jets, but published data demonstrates notable inconsistencies. An important reason for these discrepancies is the variety of bottom-boundary conditions employed. This complicates comparison with predictions by integral models typically employed for discharge design, as these generally have not been developed with consideration to boundary interaction. In the present study, negatively buoyant jet experimental data is collected where bottom boundary distances are sufficiently large to avoid boundary influence at the point where the discharge returns to its source height (the return point). Near-field centreline dilution data is measured under still ambient conditions, for the source inclinations of 15–75°. Considerable attention is paid to experimental data quality, and all relevant issues are mitigated where possible. In order to ensure the boundary has no influence, source heights in this study range between 2.33 d F0 and 8.07 d F0. A variety of time-averaged and temporal statistics are calculated, and these statistics are compared with published experimental data and predictions by integral models. Normalised trajectory and dilution data from the source through to the return point collapses well at each inclination. The attention to signal quality and the self-consistency of derived experimental results in this study suggest a high level of accuracy, and large distances to the bottom boundary ensure that results are not confused by boundary interaction. Data for dilution rate at the return point supports the use of higher source inclinations (60° and 75°) to maximise dilution capability. A new ‘forced jet’ model is developed that incorporates the concept of a reducing buoyancy flux as the flow rises to maximum height. While this model is not applicable above source inclinations of 60°, predictions at other inclinations are reasonable. Dilution predictions are notably improved when compared to those from existing integral models. Finally, CFD simulations of negatively buoyant jets are conducted using the k-ε turbulence model. Despite the sophistication of this model, the quality of spatial and dilution bulk flow predictions at the centreline maximum height are no better than those obtained from the forced jet model or analytical solutions of Kikkert et al. (2007).

Gerald Near's Chantworks has pedagogical value for the intermediate-level organ student seeking to attain advanced-level skills. Chantworks, composed for organ solo, is a collection of twenty-three pieces of short to moderate duration, based upon Gregorian chants. Gerald Near is an established composer who has won awards, completed numerous commissions, and published a multitude of organ and choral works. The Chantworks pieces are analyzed for their usefulness in the development of the following skills: (1) the advanced use of the expression pedal; (2) advanced manual changes and registration changes; (3) voice-crossing; and (4) the ability to play Gregorian chants with rhythmic sensitivity and appropriate phrase shaping. The study highlights the particular usefulness of Near's collection by comparing its technical demands to selected organ instructional books and musical collections that have been identified as having pedagogical value. This study provides a definition of an "intermediate organist," listing techniques acquired from the successful completion of any of the selected organ pedagogy publications. An examination of selected organ pedagogy publications addresses several techniques characteristic of pipe organ performance mastery that are not emphasized in the method books, but that would be necessary for an organist to acquire in order to tackle the more difficult works of the organ literature. Musical examples and explanations will illustrate how these other techniques can be learned and practiced in a structured manner through the study of pieces from Gerald Near's Chantworks collection. Several pieces within Chantworks contain passages that have pedagogical bearing on aspects of general musicianship, such as irregular meters and cross rhythms. Appendix A includes a compilation of information about each piece within the Chantworks collection, with emphasis on each piece's compositional style, pedagogical merits, and other details worthy of analysis.

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Introduction: Currently, there are no objective techniques to assess burn depth. An early assessment of burn depth would enable accurate management decisions, which would improve patient outcomes. Near infrared (NIR) technology has shown promise as a non-invasive monitor of oxygenation and perfusion, and its potential to assess the depth of burn injuries has been investigated clinically over the past five years. The purpose of the thesis was to determine the capacity of NIR technology to differentiate acute thermal injuries. Methods: Burn sites (n=5) and control sites (n=5) were created on the dorsum of sixteen animals with brass rods held at constant pressure and heated to 100°C and 37.5°C respectively. NIR data was collected from the burns and control sites pre-burn, immediately post-burn, and 1, 12, 24, 36, 48 and 96 hours after the burn injury. Biopsies of the burn and control sites were acquired at each time point and used to confirm the depth of injury. NIR data was processed for the content of water, oxy-, deoxy- and methemoglobin. Results: Oxyhemoglobin and total hemoglobin decreased as burn depth increased. The proportion of oxy- and deoxyhemoglobin to total hemoglobin showed that the ratio of oxy- to deoxyhemoglobin decreased as burn injury increased. Methemoglobin levels as a ratio of total hemoglobin also showed that as the severity of injury increased the proportion of methemoglobin also increased. Finally, superficial partial thickness injuries (3 s and 12 s) showed early peak levels of water, which rapidly declined towards baseline. The deep partial thickness injuries (20 s and 30 s) do not experience peak levels and retain water over the course of the experiment. The full thickness injuries water levels remain close or below baseline levels throughout the experiment. Conclusion: NIR spectroscopy could distinguish burn depth using water, oxy-, met- and total hemoglobin as separate entities. The presence of methemoglobin in the burn wounds is a novel finding that has not been described previously in burn literature.

Surface-mounted finite-height circular cylinders and square prisms can be found in many industrial and engineering applications. The local flow fields around these bluff bodies are not yet well understood due to lack of experimental and numerical data close to the cylinder and prism. The aim of this thesis was therefore to gain an improved physical description of the flow field above the free end surface and around the cylinders and prisms. In the present experimental study, the particle image velocimetry (PIV) technique was used to measure the flow field very close to these bluff bodies in the test section of a low-speed wind tunnel. Four finite circular cylinders and square prisms of aspect ratios AR = 9, 7, 5 and 3 were tested at a Reynolds number of ReD = 4.2×104. At the location of the cylinder or prism, the boundary layer thickness relative to the cylinder diameter or prism width (D) was δ/D = 1.6. PIV velocity field measurements in the near-wake region were made in a vertical plane parallel to the mean flow direction on the flow centreline (the symmetry plane), within 2D upstream and 5D downstream of the cylinder or prism. Additional PIV measurements were carried out in three orthogonal x-z, x-y, and y-z planes above the free end surface of the models. In the near-wake region of the finite circular cylinders, the large recirculation zone contained a vortex immediately behind and below the free end; this vortex was found for all four aspect ratios. A second vortex was found behind the cylinder near the cylinder-wall junction; this vortex was not observed for the cylinder of AR = 3, indicating a distinct wake structure for this cylinder. Similar to the circular cylinder case, in the near-wake region of the square prisms, a vortex was observed immediately behind and below the free end in the recirculation zone. The size and strength of this vortex increased as the aspect ratio of the prism decreased. Also, a second vortex was found near the prism-wall junction downstream of the prisms of AR = 9 and 7, while this vortex was not observed for the prisms of AR = 5 and 3. The PIV results in the near-wake regions of the circular cylinders and square prisms show that the effect of the bluff body shape (circular or square cross-section) is evident in the maximum length of the mean recirculation zone. A considerable difference was seen between the maximum length of the mean recirculation zones of the circular cylinder and square prism of AR = 9, while the shape of the bluff body does not considerably affect the length of the recirculation zones for the bodies of AR = 7, 5, and 3. The present PIV results also provided insight into the separated flow above the free ends, including the effects of AR and body shape. Above the free end of the cylinders, flow separation from the leading edge led to the formation of a mean recirculation zone on the free-end surface. The point of reattachment of the flow onto the free-end surface moved towards the trailing edge as the cylinder aspect ratio was decreased. Large regions of elevated turbulence intensity and Reynolds shear stress were found above the free end. For the finite circular cylinders, the flow pattern above the free end was similar in all three x-z planes for all aspect ratios, consisting of a cross-stream vortex at approximately x/D = 0. According to the PIV results in the x-y planes, one of the main characteristics of the flow over the free end surface of the circular cylinders was a pair of focal points at x/D ≈ 0 and near the edge of the free end. As the cylinder aspect ratio increased, the size and strength of these vortices decreased. Also, the centers of the vortices moved downstream as the aspect ratio increased. For the finite square prism, the large, separated, recirculating flow region extended into the near wake. For the square prism of AR = 3, considerable difference was seen in the free-end flow pattern compared to the more slender prisms of AR = 9, 7 and 5. In particular, a cross-stream vortex formed due to interaction between the separated flow from the leading edge of the prism and the reverse flow over the trailing edge of the free end. This vortex was seen in all three planes at different cross-stream locations for AR = 3 but only in the symmetry plane for AR = 9. Hence, the present PIV results in the x-z planes revealed the effect of the near-wake flow on the flow above the prism free end. The results also showed a considerable effect of the aspect ratio on the mean velocity field as well as the Reynolds stress fields. The results in the x-y planes showed different flow patterns for the prism of AR = 3 including wall-normal vortices close to the free end at the sides of the prism as well as two saddle points close to the corners of the trailing edge and one node downstream of the trailing edge, while for AR = 9, no vortices and node were observed. Two streamwise vortices with opposite sign of rotation were seen in the y-z plane at x/D = 0.2 for all aspect ratios. The present results illustrate in-plane vorticities originating from the vertices of the leading edge of the prism for all aspect ratios.

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