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Large And Medium-Scale Dynamics In The Mesosphere And Lower Thermosphere Measured By Mf And Meteor Vhf Radars, Thayananthan Thayaparan
Large And Medium-Scale Dynamics In The Mesosphere And Lower Thermosphere Measured By Mf And Meteor Vhf Radars, Thayananthan Thayaparan
Digitized Theses
This thesis focuses on the experimental investigation of large- and medium-scale dynamics in the 70-100 km height range measured with MF (2.219 MHz) and meteor VHF (40.68 MHz) radar systems located at London (43{dollar}\sp\circ{dollar} N, 81{dollar}\sp\circ{dollar} W) Ontario, Canada. The MF radar uses the spaced antenna method by means of partial reflections to determine the horizontal winds. The VHF radar determines the horizontal wind velocity by means of radio reflections from meteor trails.;The major studies in this thesis include the following: (1) development of a numerical model to simulate the spaced antenna method, (2) validation of both radars, (3) studies …
Convective Properties Of Farley-Buneman Waves At High Latitude E-Region, Donglei Chen
Convective Properties Of Farley-Buneman Waves At High Latitude E-Region, Donglei Chen
Digitized Theses
The convective properties of the propagation of electrostatic Farley-Buneman waves in the high-latitude E-region have been studied using fluid theory based on their non-local character. This case is particularly useful for HF radar echoes. A principal objective of this thesis is to develop a new approach to solving the non-local problem of the Farley-Buneman waves in the high latitude E-region, and to explore the convective properties of wave propagation.;We first discussed the traditional treatment of the non-local problem and related approaches to solving such a non-local problem. Based on these, a new formulation of the non-local problem for the Farley-Buneman …
Compositional Analysis Of Gate Dielectric Films, Hongtao Tang
Compositional Analysis Of Gate Dielectric Films, Hongtao Tang
Digitized Theses
Oxynitride has recently drawn attention as a candidate gate dielectric material for deep sub-micron devices, e.g. MOSFET's. Since the oxide growth rates in pure oxygen are high, efforts to scale down device dimensions with high quality ultrathin ({dollar}<{dollar}100A) SiO{dollar}\sb2{dollar} films are encountering some difficulties. Recently, it has been found that oxynitride films fabricated directly by a N{dollar}\sb2{dollar}O-rapid thermal processing method exhibit improved electrical properties compared to SiO{dollar}\sb2{dollar} films. Structural analysis for such oxynitride films is necessary in order to understand the physical reasons behind the observed improvements.;Nuclear reaction analysis combined with a chemical step-etching method was performed to depth profile nitrogen quantitatively in N{dollar}\sb2{dollar}O-RTP grown oxynitride films. The oxynitride dielectric composition dependence on growth conditions in a rapid thermal processing system was also investigated by nuclear reaction analysis. It is found that most N in the oxynitride films accumulates in a region close to the interface (less than 25 A from the interface in the oxynitride). Both N concentration and film thickness increase with temperature. Furthermore, a UHV initial growth study of oxynitride films on a Si(100) substrate was carried out by nuclear reaction analysis and Auger electron spectroscopy. The results clearly confirm that the nitrogen involvement occurs primarily before an oxynitride film thickness of {dollar}\sim{dollar}25 A is developed, and the subsequent film growth is dominated by oxidation. For the first time, it is found that there is a special growth period at the very beginning during which nitridation (with no simultaneous oxidation) dominates the growth process. It is speculated that the phenomenon results from a competition between reactions of Si with O and N. The dependence of film growth on temperature is such that below 950{dollar}\sp\circ{dollar}C, there is little nitrogen incorporated in the oxide film.
A Quasiclassical Trajectory Study Of Impulsive Collisions Between Hydroxyl (Nu = 1--9, K = 1,2,5,10) And Molecular Oxygen In The Upper Mesophere, Kathleen L. Gilbert
A Quasiclassical Trajectory Study Of Impulsive Collisions Between Hydroxyl (Nu = 1--9, K = 1,2,5,10) And Molecular Oxygen In The Upper Mesophere, Kathleen L. Gilbert
Digitized Theses
Observations of the hydroxyl airglow are widely used as a remote sensing tool in the study of middle atmosphere dynamics. To assess the validity of this technique, a comprehensive understanding of the excitation and emission processes is required. The effect of collisional quenching of vibrationally excited OH by {dollar}\rm O\sb2{dollar} remains an outstanding problem in interpreting OH airglow intensity variations. Impulsive collisions between {dollar}\rm OH\sp\*(\nu{dollar} = 1-9, K = 1,2,5,10) and {dollar}\rm O\sb2{dollar} are modelled using quasiclassical trajectories to investigate the distribution of product {dollar}\rm OH\sp\*{dollar} states. The mode of vibrational deactivation depends on whether the O or H atom …
Surface And Interfacial Alloys Of Palladium With Copper(100): Structure, Chemistry, And Kinematics, Timothy Daniel Pope
Surface And Interfacial Alloys Of Palladium With Copper(100): Structure, Chemistry, And Kinematics, Timothy Daniel Pope
Digitized Theses
The interaction between Pd and the Cu(100) surface has been studied by surface science techniques. When Pd is evaporated onto Cu(100) at 110 K, small Pd islands form on the surface. At substrate temperatures above approximately 180 K, mixed Pd-Cu interfacial layers form. For Pd deposition at 300 K, c(2x2) and p4g surface alloy structures form near 0.5 and 1.0 monolayer (ML) Pd coverage respectively. Above one ML, disordered Pd overlayers form. The surface alloy structures are metastable only, since heating irreversibly segregates Cu to the surface.;The chemistry of the Pd and Cu atoms in the interfacial layers is changed …
The Reduction Of Concentration Values In A Contaminant Cloud In Environmental Flows, William Kenneth Heagy
The Reduction Of Concentration Values In A Contaminant Cloud In Environmental Flows, William Kenneth Heagy
Digitized Theses
This thesis considers the spread of contaminant after the release of a cloud of toxic gas into the atmosphere. A new measure, the Expected Mass Fraction (EMF), presents an improvement over the mean dosage as an indicator of the risk associated with the cloud release. The study shows that the variability of estimates of the EMF should be comparable to that of the dosage, so that reliable evaluation should be possible in many situations. The theory is based on the Chatwin-Sullivan {dollar}\alpha{dollar}-{dollar}\beta{dollar} formulation, which relates the mean concentration to the moments of the probability density function of the concentration. The …
An Empirical Determination Of The Electric Dipole Moment Function And Transition Probabilities Of Hydroxyl(Chi(2)Pi), David Norman Turnbull
An Empirical Determination Of The Electric Dipole Moment Function And Transition Probabilities Of Hydroxyl(Chi(2)Pi), David Norman Turnbull
Digitized Theses
Although intensity distributions derived from hydroxyl, OH({dollar}X\sp2\pi{dollar}), airglow observations are routinely used to determine rotational temperatures and vibrational level populations, the transition probabilities required to do so are in fact inadequately known. The set now in common use has come under attack both on theoretical grounds (because of the choice of theoretical dipole moment used in its derivation) and on experimental grounds (because of its failure to represent accurately measured intensity ratios).;An electric dipole moment function (EDMF) for OH has been derived by combining recent high precision measurements of the permanent dipole moments with laboratory and airglow intensity measurements, including …
Predicting Contaminant Concentration Values In Environmental Flows, Handson Yip
Predicting Contaminant Concentration Values In Environmental Flows, Handson Yip
Digitized Theses
A generic, small-time, asymptotic solution for the convective-diffusion equation was expressed as a three-dimensional, Hermite-polynomial expansion. This solution was used in a versatile scheme to describe mean values of concentration of contaminant in environmental flows. An analytical solution and a simple finite difference scheme was used to validate that scheme. The scheme was then used, with empirical information from the flow-field, to describe an elevated line and point source in a region of constant stress within a turbulent boundary-layer where detailed measurements of mean values of concentration of contaminant were used for comparison. The results from that comparison showed the …
Total Electron Content During Auroral Conditions, Richard John Niciejewski
Total Electron Content During Auroral Conditions, Richard John Niciejewski
Digitized Theses
Coordinated spectrophotometric and ionospheric electron content measurements were conducted during a variety of auroral conditions at Churchill, Manitoba for a total of 14 clear nights in November and December, 1984. Ground based narrow angle filter photometers measured the temporal history of 4278 and 6300 A emissions for a {dollar}2\sp\circ{dollar} wide, {dollar}100\sp\circ{dollar} long are containing the line of sight path to the polar orbiting HILAT satellite. Optical observations were begun 45 minutes prior to the satellite transit, at one half degree resolution along the long axis of the arc, with an average temporal resolution of seven seconds for each half degree …
Radar Auroral Echo Heights As Seen By A 398 Mhz Phased Array Radar Operated At Homer, Alaska, John Michael Ruohoniemi
Radar Auroral Echo Heights As Seen By A 398 Mhz Phased Array Radar Operated At Homer, Alaska, John Michael Ruohoniemi
Digitized Theses
Backscatter data collected with a 398 MHz phased-array radar operated at Homer, Alaska (59.72 deg N, 151.53 deg W) have been analyzed for information on the height of radar auroral echoing. Altitude was resolved through the variation of backscattered power with antenna beam elevation angle. The mean height of backscattering could be determined with an accuracy of 1-2 km over small ((TURN)20 x 20 km('2)) areas and short ((TURN)1 min) periods. In this thesis, the results are presented in the form of maps of the spatial distribution of echo height.;The data base encompassed approximately 40 hrs of observation carried out …
Thermal Plumes And Temperature Spectra In The Atmospheric Boundary Layer, Chia Luan Ting
Thermal Plumes And Temperature Spectra In The Atmospheric Boundary Layer, Chia Luan Ting
Digitized Theses
No abstract provided.
Internal Gravity Waves Of Tropospheric Origin, Michael John Curry
Internal Gravity Waves Of Tropospheric Origin, Michael John Curry
Digitized Theses
No abstract provided.
Satellite Measurements Of Irregularity Scale Sizes In The Inonosphere, Allan Farnell Dixon
Satellite Measurements Of Irregularity Scale Sizes In The Inonosphere, Allan Farnell Dixon
Digitized Theses
No abstract provided.
Combined Differential Faraday Rotation And Differential Absorption Measurements Of The Ionosphere, Charles Edward Livingstone
Combined Differential Faraday Rotation And Differential Absorption Measurements Of The Ionosphere, Charles Edward Livingstone
Digitized Theses
No abstract provided.