This thesis has undertaken extensive field investigation into the response of helical culverts during incremental backfilling and under legal live loads on sinusoidal profile and ribbed profile helical culverts. Deformation, earth pressure and steel strains were measured. The strains were decomposed into hoop force and bending moment. Force-deflection tests were undertaken to determine the effective section properties that took into account the cold-formed section properties and irregularities from rolling during manufacture. High lateral earth pressures were measured during backfilling. A model was developed to demonstrate the formation of those pressures that approach the passive state. This has important implications for the design of buried structures and retaining walls. The response of helical culverts to legal live loads was examined. The effect of vehicle offset and time-dependent effects were considered. Dynamic load allowance was determined. The thesis also examined collapse mechanisms of helical culverts. It is essential that installers fully understand the response during backfilling A simplified design method has been developed which incorporates the maximum crown moment during backfilling. This is the critical load case. The results of the field measurements and numerical modelling have been compared with published literature.

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This project stems from the dualities joining two worlds: couture, the art of fashion and architecture, the art of building. They both involve the intelligible and the sensible, the skill of the artist and the engineer. Architecture tends towards the rational whereas fashion depends on the emotional. Architecture constructs rational things discovered through conventional methods. Fashion brings the emotional and the sheer immediacy and drama of momentary seasonal trends. This study is made up of two sections, the first, a collection of screen prints and images the second, a collection of conventional methods and projections. The gossamer like screen prints serve as cameras into the world within the Maison de Couture. They capture the essence of the creative process, always-in-motion spirit of a fashion house. The architectural projections describe the architectural skeleton of the Maison. The house is a place for expression; design, fabrication, and demonstration of the spectacle of couture. The heart of this building lies on the central longitudinal axis, where a double helix stair case rotates down to the basement level and spirals up to the rooftop level. Couture pieces are styled and modeled on a series of catwalks that are cartesian extensions of the stair landings. Invited guests can view the spectacle of the fashion show. The stair is a place to see and be seen. The stair becomes the spirit of the Maison de Couture. The works of art worn by the models trickle down the stair, one by one, allowing a select few to view these unique pieces for the first time. / Master of Architecture / This project explores the intersections and concepts that underlie the two disciplines: Architecture and Fashion. Both worlds revolve around the human body, ideas of space, texture, and movement. Each fulfills the need for shelter and protection; acting as a barrier between us and the surrounding environment. Both work to produce three-dimensional volumes from flat, modular materials. Perhaps the most exciting similarity, Fashion and Architecture are expressive art forms; they offer their creators a platform to communicate and project personal, political, and cultural identities into the world. Through the ages buildings and clothes have echoed one another in terms of concept and form; each look to the other for new technology of material, construction, and fabrication. While fashions are "of the moment," architecture has a more solidified presence, permanence. Time, timely, and timelessness are at the essence of both.

This dissertation details the development of a novel reduced size axial mode helical antenna called the Stub Loaded Helix (SLH). The SLH achieves a significant reduction in helix size, both diameter and length, compared to the conventional axial mode helix antenna with only small compromises in performance. The SLH achieves this entirely through the use of a unique geometry. The performance characteristics of the SLH are explored through the use of computer simulations using NEC (Numerical Electromagnetics Code) to study the effects of design parameter variations. Based on those simulations, design guides are developed. The numerical simulations are verified though measurements of experimental prototypes. The program of experimental prototypes included the development of an appropriate impedance matching network for the SLH, which is also detailed. / Ph. D.

Antennas are designed to radiate or receive electromagnetic waves in the part of transmitting or receiving system. They are transducers which transform electric energy into waves so as to radiate radio waves, that¡¦s the primary purpose of antennae. Utilizing the characteristics of helical antennae operating in the axial mode including high directivity, broad bandwidth and circular polarization in satellite communication (ex. GPS) is detailed described in this thesis. The microwave dielectric ceramic material becomes very popular in satellite and wireless communication in recent years because of its high-K, high-Q,and stable-temperature-coefficient characteristics.Our study also utilizes its feature of high dielectric coefficient to shrink the size of the antenna significantly. In this study, we fabricate and analyze the antenna combining the advantages of the helical antenna and the microwave dielectric ceramic material.

It has been realized that a p-wave order parameter can emerge in a synthetic superconductor constructed from a semiconductor and an s-wave superconductor, provided that fermion doubling is removed. In one dimension, the required electron spectrum consists of two counter-propagating modes with opposite spin orientations, so-called helical channels. Helical channels can be realized in nanowires with spin-orbit interactions in the presence of magnetic field, topological insulators, at the edges of the quantum spin Hall system, or in the integer and fractional quantum Hall effect regimes. This thesis will discuss the formation and control of helical states in different systems.

A novel antenna made of a spiral wire wrapped into a larger helical shape is introduced. The geometry of this antenna, which is a doubly helical structure, is fully described by five independent parameters, including two radial dimensions, two pitch angles, and the number of turns. Radiation properties of this antenna are examined both theoretically and experimentally. The Numerical Electromagnetic Code (NEC-2) is used to obtain simulation results. A large number of cases with different radii, pitch angles, and number of turns are investigated. Results for far-field patterns, gain, axial ratio, and bandwidth are presented. The influence of parameters on radiation properties are examined. Several prototypes of the antenna were constructed and tested using an outdoor antenna range. Measured far-field patterns are presented over a wide range of frequencies. The measured and computed radiation patterns are in good agreement. The results of this study indicate that the proposed antenna provides circular polarization and high gain over a wide frequency range. For example, when the number of turns is 10, a gain of 11-14 dB, a boresight axial ratio of less than 3 dB, and a half-power beamwidth of about 40 degrees are achieved over a 30% bandwidth. The side-lobe level for most cases examined is better than 10 dB below the main beam. A unique advantage of this antenna is its much smaller size compared with a conventional helical antenna made of straight wire shaped into a helix. Having about the same radiation characteristics, including gain, circular polarization, bandwidth, and side-lobe level, this new antenna occupies a volume more than 2.5 to 3 times smaller than the conventional helix. This reduction in size, which in turn may imply smaller weight and lower packaging and manufacturing costs, makes the proposed antenna very appealing to many communications and aerospace applications. / Master of Science

This thesis presents the results of investigations in two areasA) Laminar helical flow of Herschel Bulkley fluids in annular space; and B) Cuttings transport in deviated wellbores. Description of area A: This is a theoretical study that consists of the modelling of non-Newtonian fluid flowing through annular space. The rheology of the fluid is represented by a three-parameter fluid model to account for a non-linear behaviour of the rheologic curve followed by the presence of a yield stress. Two distinct methodologies were used to study the effects of inner pipe rotation and inner pipe eccentricity on the velocity profiles of the annular flow. I. Laminar Helical Flow of a Herschel-Bulkley Fluid in a Concentric Annulus and its Extension to a Narrow Eccentric Annulus: The method consists of the use of the boundary conditions to enable the numerical integration of the motion equation. The subsequent extension to eccentric annuli is based on division of the annulus into sectors, where each sector is treated as an equivalent sector of a concentric annulus. Profiles of velocity presented in 2-D and 3-D contour plots explain the effects of eccentricity, inner pipe rotation and yield stress in many different situations. This analysis is useful to simulate the flow field in a borehole during directional drilling and primary cementing particularly for narrow eccentric annuli. II. Laminar Helical Flow of a Herschel-Bulkley Fluid in an Eccentric Annulus and The Special Case of a Pure Axial Flow: A new methodology to obtain the governing equations is proposed here as a first step to the solution of this complicated problem. It consists of eliminating the unknown radial and tangential pressure gradients from the equation of motion by defining vorticity between these two components of the velocity vector. The vorticity equation and the remaining axial component of the motion equation, written in bipolar co-ordinates, are then made discrete using two different finite difference approaches. Firstly, the inertial terms of both equations are made discrete using a modified upwind scheme proposed by O. Axelsson and I. Gustafsson, while the viscous terms are made discrete using central difference approximation. Secondly, the moving boundary conditions are set by enforcing continuity of pressure on the inner annular wall. The future solution of these equations will provide a very accurate model, unavailable until now, that accounts for both effects, the eccentricity and rotation of the drill string, to simulate the flow field of drilling mud in directional and horizontal wells. Description of area B: The fluid models developed are incorporated in the development of two semi-empirical correlations to predict the critical conditions of cuttings transport in deviated weI/bore. The numerical fluid models are modified to predict the velocity of the fluid at the vicinity of the cutting that is at the point of being transported. An extensive bank of data of the critical conditions of transport, emulating many different field conditions, was used in this analysis. The experimental data was provided by an industry sponsored project which did four years of experimental work in a simulated testing column to generate the data. The two semi-empirical correlations developed in this research are based on: • a dimensional analysis of the variables involved in two distinct mechanisms of transport experimentally observed: 1. Rolling or Sliding and 2. Suspension; • a force balance applied to a cutting resting on the low-side wall of an inclined annulus, under fluid dynamic conditions. The semi-empirical correlations can be used as general criteria for evaluating and correlating the effects of various parameters on cuttings transport, and as a guideline for cuttings transport programme design during directional drilling.