Accurate, spatially resolved wind measurements in the lower atmosphere are critical to improving current weather forecasting models. Wind shear detection for midsized airports, not covered under the Federal Aviation Administration's (FAA's) Terminal Doppler Weather Radars, would significantly reduce personal aircraft accidents. Atmospheric dynamics studies would also benefit from high accuracy, spatially resolved wind profiles within the planetary boundary layer.This dissertation discusses a thorough investigation of a novel alternating frequency incoherent Doppler lidar method named, the Alternating Edge Technique. After discussing the necessary background, a theoretical development of how the Alternating Edge Technique can be used to estimate the molecular to aerosol backscatter ratio is presented. The ability to estimate the molecular component vastly improves the accuracy of wind measurements, and adds additional information about the atmosphere being probed. A detailed modeling program was developed to evaluate the expected performance of this instrument, and to allow comparisons to be made of various components and operating conditions. Several of the key components are then evaluated experimentally, and these results are used to perform realistic Monte Carlo simulations in order to evaluate the ability of the Alternating edge technique, using available components, to estimate the molecular component of the backscattered light, and to accurately estimate average wind speed.

Magister Scientiae Dentium - MSc(Dent) / The Tip-Edge and edgewise techniques are the main techniques that are mostly used in orthodontics, and are applicable to the treatment of any type of malocclusion from the most simple to the most complex. The edgewise bracket wire combination produces bodily tooth movement simultaneously or separately in all three planes of space and hence permits correction of the most extreme tooth malpositions. On the other hand Tip-Edge offers a differential tooth movement (just like the previously used Begg technique) within an edgewise based bracket system (Parkhouse 2003). When treating patients using the Tip-Edge technique, it is recommended that a specialized archwire i.e. Australian stainless steel wire be used. This wire can be described as a round austenitic stainless steel wire that is heat-treated and cold-drawn to its proper diameter. This was done in order to produce its special and needed properties such as toughness, resiliency and tensile strength (Kesling, 1985). It is used in conjunction with light (2oz) class II elastics. The aim of this study was to compare cephalometric changes in skeletal and dento-alveolar parameters in cases treated by these two different orthodontic techniques. This was to be established by calculating and comparing the pre- and post-treatment cephalometric variables of cases treated with these techniques by looking at the skeletal and dento-alveolar measurements. Thirty Tip-Edge and thirty edgewise treated cases that had class II malocclusion, had extraction of four premolars and were treated with Class II elastics were selected. The gender distribution between the Tip-Edge and the edgewise techniques were 47% and 60% respectively for females. For males it was 53% in Tip-Edge and 40% in the edgewise techniques.