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An investigation was carried out into external-Coanda Effect flares designed by British Petroleum International plc. The phenomenon of interest was breakaway of an under expanded axisymmetric curved wall jet from the guiding surface due to high blowing pressure. A survey of investigations of similar flows suggested very complex jet fluid dynamics. Strong cell structure including shock waves was present giving bulk and discrete compression and bulk dilatation. More expansion was imposed by the radial velocity components. Wall curvature and a rear-facing step added further significant influences. The combination of these factors is known to produce highly non-linear turbulence, and this constitutes a major difficulty for the application of computational methods to the flare. In view of the amount of resources required to eliminate the problems of using a Navier-Stokes code, an economical approach was adopted, matching the Method of Characteristics to various simplified models and an integral boundary layer. In the experimental work, a planar model of the flare was contructed and studied using a wide range of methods in order to achieve accuracy and provide comparability with other work. An axisymmetric model was designed and investigated in a similar manner, so that the influence of this geometry could be clearly distinguished. A full-scale flare was subjected to a restricted range of tests to compare the laboratory results with the industrial application. The results from all the experiments demonstrated good correspondence. The main conclusion was that amalgamation of separation bubbles is crucial for breakaway. These are present long before breakaway, and are strongly reduced by decreasing the cell scale, adding a rear-facing step and axisymmetry, which leads to improved breakaway performance. Although the computational methods did not prove robust enough for all design purposes, they did permit significant insights into the mechanism of breakaway.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Dentistry Johannesburg, 2013 / The aim of this study was to test various alternating sequences of sodium hypochlorite (NaOCl), anolyte solution, and EDTA for their ability to remove the mineralised portion of the smear layer, and to destroy bacteria. Forty-eight single canal teeth were collected and randomly divided into six groups, prepared to working length, sterilized and inoculated with Enterococcus faecalis. The irrigation protocols were as follows: Group 1 (four roots) 3ml sterile distilled water, Group 2 (four roots) 3ml 6% sodium hypochlorite, Group 3 (ten roots) 3ml 6% sodium hypochlorite followed by 3ml 18% EDTA, Group 4 (ten roots) 3ml 6% sodium hypochlorite followed by 5ml anolyte solution, Group 5 (ten roots) 0.5ml 6% sodium hypochlorite followed by 5ml anolyte solution followed by 3ml 18% EDTA and Group 6 (ten roots) 5ml anolyte solution followed by 3ml 18% EDTA. Sterile paper points were inserted into the canals after sterilization, inoculation and irrigation. Standard cultivation techniques were used to count the colony forming units of viable bacteria at each phase. The roots were split longitudinally and prepared for SEM evaluation. Two photomicrographs were randomly taken in the coronal, middle and iv apical thirds of each root and the number of patent dentinal tubules counted. The One-way ANOVA was used for statistical evaluation. The small sample size limited definitive conclusions but the results indicated that the coronal thirds of the roots showed better smear layer removal than the apical thirds, Sodium hypochlorite followed by EDTA showed the best smear layer removal. The various sequences of NaOCl, anolyte solution, and EDTA all had similar antibacterial results.

"This study examines atmospheric boundary layer over and around the Gulf of Mexico during return flow events. The locations investigated are on both the Texas coast and the Florida coast. Moreover, several inland stations such as Jackson (JAN), Mississippi and Shelby Co Airport (BMX), Alabama are added to the analyses to make some comparisons. In addition to examining the boundary layer structure of these coastal and inland stations, an attempt is made to investigate thermadynamic structure on the continental shelf of the Gulf of Mexico in terms of both synoptic analysis and model applications. Return flow events of the Gulf of Mexico are mainly examined by using a three dimensional Air Mass Transformation (AMT) model and a one-dimensional Planetary Boundary Layer (PBL) model. The models are intende for short-range weather forecasts of the temperature profiles in the lower atmosphere and the structure of the boundary layer"--Abstract. / Typescript. / "1996." / "Submitted to the Department of Meteorology in partial fulfillment of the requirements for the degree of Master of Science." / Advisor: Paul H. Ruscher, Professor Directing Thesis. / Includes bibliographical references.

by Yongbao Xin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 113-117). / by Yongbao Xin. / ABSTRACT --- p.I / ACKNOWLEDGMENTS --- p.II / LIST OF FIGURES --- p.V / LIST OF TABLES --- p.VIII / CHAPTERS / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Turbulence: A Long-standing and Unsolved Problem --- p.1 / Chapter 1.2 --- Rayleigh-Benard Convection --- p.3 / Chapter 1.3 --- High Rayleigh Number Rayleigh-Benard Convection --- p.5 / Chapter 1.3.1 --- The Rayleigh number dependence of Nu --- p.6 / Chapter 1.3.2 --- Large-scale flow in RB convection --- p.7 / Chapter 1.3.3 --- Thermal plumes in the high Ra convection --- p.9 / Chapter 1.4 --- Velocity Field and Viscous Boundary Layer Measurement in Rayleigh-Benard Convection --- p.11 / Chapter 2. --- SETUP OF RAYLEIGH-BENARD CONVECTION --- p.14 / Chapter 2.1 --- The Convection Cells --- p.14 / Chapter 2.2 --- Built Up the Convection --- p.18 / Chapter 2.2.1 --- Preparations of fluid --- p.18 / Chapter 2.2.2 --- Procedures to have a stable convective state --- p.19 / Chapter 2.3 --- Measurements of the Nusselt Number --- p.22 / Chapter 3. --- VELOCITY MEASUREMENT IN RAYLEIGH-BENARD CONVECTION --- p.25 / Chapter 3.1 --- Dual-beam Incoherent Cross-correlation Spectroscopy --- p.25 / Chapter 3.1.1 --- Theory of the technique --- p.25 / Chapter 3.1.2 --- Experimental setup --- p.31 / Chapter 3.1.3 --- Calibration and applications of the technique --- p.34 / Chapter 3.1.4 --- Summary --- p.41 / Chapter 3.2 --- Velocity Measurement in Turbulent Rayleigh-Benard Convection --- p.42 / Chapter 3.2.1 --- Cross-correlation functions in turbulent convection --- p.42 / Chapter 3.2.2 --- Some experimental details --- p.43 / Chapter 3.2.3 --- Some issues to be concerned in the velocity measurement --- p.47 / Chapter 4. --- LARGE SCALE CIRCULATION IN RAYLEIGH-BENARD CONVECTION --- p.50 / Chapter 4.1 --- Large Scale Circulation in Cylindrical Cells --- p.50 / Chapter 4.1.1 --- "Large scale circulation in cells of AR =1,2，and 44" --- p.50 / Chapter 4.1.2 --- Flow pattern in AR = 0.5 cell --- p.55 / Chapter 4.1.3 --- Velocity profiles along vertical central axis --- p.57 / Chapter 4.1.4 --- Prandtl number dependence of the boundary layer properties --- p.61 / Chapter 4.2 --- Large Scale Circulation in Cubic Cell --- p.65 / Chapter 4.2.1 --- Large scale flows near the plate and near the sidewall --- p.65 / Chapter 4.2.2 --- Velocity profiles along the vertical axis --- p.68 / Chapter 4.3 --- Summary --- p.73 / Chapter 5. --- SCALING PROPERTIES OF THE BOUNDARY LAYER QUANTITIES --- p.75 / Chapter 5.1 --- Ra Dependence of Boundary Layer Properties --- p.75 / Chapter 5.1.1 --- Scaled velocity and standard deviation profiles at different Ra --- p.75 / Chapter 5.1.2 --- Scaling properties of the maximum mean velocityvm and the maximum standard deviation σm --- p.76 / Chapter 5.1.3 --- Scaling properties of the shear rate γv and the gradient of the standard deviation yσ --- p.80 / Chapter 5.1.4 --- Scaling properties of boundary layer thickness --- p.84 / Chapter 5.2 --- Aspect-ratio Dependence of Boundary Layer Properties --- p.87 / Chapter 5.2.1 --- AR dependence of vm(Ra) and σm(Ra) --- p.87 / Chapter 5.2.2 --- AR dependence of the shear rate --- p.89 / Chapter 5.2.3 --- AR dependence of the viscous boundary layer thickness --- p.89 / Chapter 5.2.4 --- Vertical motion of the coherent structures in AR = 0.5 cell --- p.92 / Chapter 5.3 --- Summary --- p.93 / Chapter 6. --- CONCLUSION --- p.96 / APPENDIX / Chapter A1. --- NUMERICAL ANALYSIS OF THE CORRELATION FUNCTION EQ. 315 --- p.100 / Chapter A1.1 --- Analysis with Gaussian PDF Distribution --- p.100 / Chapter A1.2 --- Definition and Properties of Erfc(x) --- p.101 / Chapter A1.3 --- The Variable of Erfc in Eq. 315 --- p.104 / Chapter A1.4 --- Difference of Peak Position and t0 --- p.105 / Chapter A2. --- LASER HEATING EFFECTS IN THE LIGHT SCATTERING EXPERIMENT --- p.106 / Chapter A 2.1 --- Introduction --- p.106 / Chapter A 2.2 --- Experimental Technique --- p.106 / Chapter A 2.3 --- Results and Discussion --- p.108 / Chapter A 2.4 --- Summary --- p.109 / REFERENCES --- p.113