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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Laser pulse induced electrostrictive distortion of liquid micro-droplet.

January 1990 (has links)
by Poon Kai Lok. / Title also in Chinese. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 89-90. / LIST OF TABLES --- p.iv / LIST OF FIGURES --- p.v / ACKNOWLEDGEMENTS --- p.vii / ABSTRACT --- p.viii / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LASER PULSE INDUCED DEFORMATION OF DROPLET : PART I / Chapter 2.1 --- Curvature and surface tension on a deformed surface on the droplet --- p.6 / Chapter 2.2 --- Solution of the Navier-Stokes equation in the absence of viscosity --- p.8 / Chapter CHAPTER 3 --- GEOMETRIC OPTICS : CALCULATION OF INTERNAL INTENSITY / Chapter 3.1 --- Trace of a narrow light beam inside a droplet --- p.14 / Chapter 3.2 --- Intensity within droplet --- p.16 / Chapter 3.3 --- Mean intensity on the surface of a concentric sphere --- p.25 / Chapter 3.4 --- Intensity on the surface of the droplet --- p.28 / Chapter CHAPTER 4 --- PHYSICAL OPTICS : MIE SCATTERING / Chapter 4.1 --- "Formalism of Mie Scattering (Mie, 1908〕" --- p.35 / Chapter 4.2 --- Expression of Fl and its result --- p.39 / Chapter CHAPTER 5 --- LASER PULSE INDUCED DEFORMATION OF DROPLET : PART II / Chapter 5.1 --- Including viscosity --- p.50 / Chapter 5.2 --- Droplet deformation --- p.52 / Chapter 5.3 --- Discussion --- p.58 / Chapter CHAPTER 6 --- TWO FLUID PROBLEM / Chapter 6.1 --- Derivation and discussion of the equation of motion --- p.61 / Chapter 6.2 --- Calculated results --- p.65 / Chapter 6.3 --- The incompressibi1ity assumption --- p.73 / Chapter CHAPTER 7 --- CONCLUSION --- p.76 / APPENDIX A --- p.78 / APPENDIX B --- p.80 / APPENDIX C --- p.82 / APPENDIX D --- p.88 / REFERENCES --- p.89
2

Motion of a single optically levitated micro-droplet driven by morphology-dependent-resonances =: 由形態相關共振引起的光浮微水珠運動. / 由形態相關共振引起的光浮微水珠運動 / Motion of a single optically levitated micro-droplet driven by morphology-dependent-resonances =: You xing tai xiang guan gong zhen yin qi de guang fu wei shui zhu yun dong. / You xing tai xiang guan gong zhen yin qi de guang fu wei shui zhu yun dong

January 1996 (has links)
by Chan Chiu Wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves [68-69]). / by Chan Chiu Wah. / List of Tables --- p.i / List of Figures --- p.ii / Acknowledgments --- p.iv / Abstract --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Theory --- p.4 / Chapter 2.1 --- Radiation pressure on a droplet --- p.4 / Chapter 2.2 --- Laser levitation of a droplet --- p.7 / Chapter 2.3 --- Dynamic of a laser levitated spherical droplet --- p.9 / Chapter Chapter 3 --- Experiment --- p.11 / Chapter 3.1 --- Principle and calibration of the position sensor --- p.14 / Chapter 3.2 --- Measurement of the levitated laser beam waist --- p.16 / Chapter Chapter 4 --- Results and discussion --- p.18 / Chapter 4.1 --- Vertical motion due to MDRs --- p.22 / Chapter 4.2 --- Artifacts in the displacement --- p.26 / Chapter 4.3 --- Elastic scattering light intensity --- p.28 / Chapter 4.4 --- Effect of the size of beam waist --- p.31 / Chapter 4.5 --- Small size parameter droplet --- p.33 / Chapter Chapter 5 --- Conclusion and future outlook --- p.35
3

Modeling direct liquid injection into low pressure environments and plasmas /

Saraf, Iqbal Rashid, January 2008 (has links)
Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 86-87)
4

EXPERIMENTAL STUDIES OF DROPLET HEAT TRANSFER FROM HOT METAL SURFACES

Plein, Howard George January 1980 (has links)
The boiling of water droplets on hot metal surfaces is studied experimentally and mathematically in order to establish the conditions necessary for droplets to enter a film boiling mode. The subsurface temperature history within a plate undergoing droplet boiling on the surface is measured. A numerical model of the heat transfer in the plate is then used to deduce from these data the following characteristics of droplet boiling: (1) the effective heat transfer coefficient between water droplet and plate during the initial transient forming the spherical droplet, (2) the apparent time period needed to establish the droplet in the film boiling mode, and (3) the minimum plate surface temperature reached during the initial formation of the boiling droplet. The effective heat transfer coefficient, formation time, and minimum surface temperature are sufficient to develop a calculation method which predicts the minimum initial plate temperature necessary for a water droplet to enter film boiling. This numerical conduction model accounts for the influence of plate material, plate thickness, oxidation of the plate surface, the boundary condition on the plate lower surface, and the size of the droplet. The prediction method is successfully used to estimate the minimum film boiling temperature for brass, graphite, Pyrex, copper, aluminum, stainless steel, and Zircalloy II. The findings of the experiments and numerical studies are applied to the rewetting phase of a loss-of-coolant-accident in a light water reactor. This application, in turn, provides explanations for some of the phenomena observed in studies of the prequench heat transfer within rod bundles including the effect of multiple droplet impacts, and suggests possible reasons for some of the difficulties experienced in attempts to establish the effective rewetting temperature on reactor fuel rod surfaces.
5

Development of the superheated-liquid-droplet technique for measuring alpha decays in environmental samples

Pan, Lung-Kwan 05 1900 (has links)
No description available.
6

Behavior of water drops colliding in humid nitrogen

Park, Robert Watson, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
7

Heterogeneous condensation of the Lennard-Jones vapour onto nanoscale particles

2013 October 1900 (has links)
The heterogeneous condensation of a vapour onto a substrate is a key step in a wide range of chemical and physical process that occur in both nature and technology. For example, dust and pollutant aerosol particles, ranging in size from several microns down to just a few nanometers, serve as cloud condensation nuclei in the atmosphere, and nanoscale structured surfaces provide templates for the controlled nucleation and growth of variety of complex materials. While much is known about the general features of heterogeneous nucleation onto macroscopic surfaces, much less is understood about both the dynamics and thermodynamics of nucleation involving nanoscale heterogeneities. The goal of this thesis is to understand the general features of condensation of vapours onto different types of nanoscale heterogeneity that range in degree of solubility from being insoluble, to partially miscible through to completely miscible. The heterogeneous condensation of the Lennard-Jones vapour onto an insoluble nanoscale seed particle is studied using a combination of molecular dynamics simulations and thermodynamic theory. The nucleation rate and free energy barrier are calculated from molecular dynamics using the mean first passage time method. These results show that the presence of a weakly interacting seed has no effect on the formation of small cluster embryos but accelerates the rate by lowering the free energy barrier of the larger clusters. A simple phenomenological model of film formation on a small seed is developed by extending the capillarity based liquid drop model. It captures the general features of heterogeneous nucleation, but a comparison with the simulation results show that the model significantly overestimates the height of the nucleation barrier while providing good estimates of the critical film size. A non-volatile liquid drop model that accounts for solution non-ideality is developed to describe the thermodynamics of partially miscible and fully miscible droplets in a solvent vapour. The model shows ideal solution drops dissolve always spontaneously, but partially miscible drops exhibit a free energy surface with two minima, associated with a partially dissolved drop and a fully dissolved drop, separated by a free energy barrier. The solubility transition between the two drops is shown to follow a hysteresis loop as a function of system volume similar to that observed in deliquescence. A simple lattice gas model describing the absorption of mono-layers of vapour onto the particle is also developed. Finally, molecular dynamics simulation of miscible and partially miscible binary Lennard-Jones mixtures are also used to study this system. For all cases studied, condensation onto the drop occurs spontaneously. Sub-monolayers of the solvent phase form when the system volume is large. At smaller system volumes, complete film formation is observed and the dynamics of film growth are dominated by cluster-cluster coalescence. Some degree of mixing into the core of the particle is observed for the miscible mixtures for all volumes. However, mixing of the solvent into the particle core only occurs below an onset volume for the partially miscible case, suggesting the presence of a solubility transition similar to the one described by the thermodynamic model.
8

Numerical simulations of nucleation and growth phenomena

Monette, Liza January 1987 (has links)
No description available.
9

Numerical simulations of nucleation and growth phenomena

Monette, Liza January 1987 (has links)
No description available.
10

Cluster model analysis of exotic decay in actinide nuclei

Du Toit, Erasmus Johannes 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The binary cluster model is used to investigate the properties of exotic structures and decays in various nuclei. A simple method is described to choose the possible clusters forming within the nucleus, by assuming the nucleus consists of a mixture of up to four different core-cluster pairs. A phenomenological potential is then used, with optimized parameters, to describe the even-even 222-232Th nuclei within the binary cluster model, by calculating exotic decay half-lives, reduced electromagnetic transition probabilities, and energy spectra. After finding that all experimentally observed heavy ion emissions are predicted with the model and calculated structure observables are reproduced within good agreement of the experimentally measured values, the model was extended to include the even-even 230-234U, 236-240Pu and 222-224Ra nuclei. We found that almost all experimentally observed heavy ion emissions are predicted within the model with reasonable accuracy in the calculated halflives, and found good agreement in the other calculated structure observables. / AFRIKAANSE OPSOMMING: Die binêre bondel model is gebruik om die eienskappe van eksotiese strukture en verval in verskeie nukliedes te ondersoek. ’n Eenvoudige metode is gebruik om die moontlike bondels wat binne die nuklied vorm te kies, deur die aanname te maak dat die nuklied uit ’n mengsel van tot vier verskillende kern-bondel pare bestaan. ’n Fenomenologiese potensiaal is dan gebruik, met optimale parameters, om die ewe-ewe 222-232Th nukliedes met die binêre bondel model te beskryf, deur eksotiese verval halfleeftye, verminderde elektromagnetiese oorgangswaarskynlikhede, en energie spektra te bereken. Nadat daar gevind is dat alle vrygestelde swaar ione wat eksperimenteel waargeneem is deur die model voorspel word, en berekende struktuur waarneembares tot goeie ooreenstemming met die eksperimentele waardes produseer is, is die model uitgebrei om die ewe-ewe 230-234U, 236-240Pu en 222-224Ra nukliedes in te sluit. Daar is gevind dat byna alle vrygestelde swaar ione wat eksperimenteel waargeneem is deur die model voorspel word met redelike akkuraathied in die berekening van hul halfleeftye, asook dat daar goeie ooreenstemming tussen die berekende en eksperimentele waardes van ander struktuur waarneembares was.

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