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Bubble Formation: A Bibliography

Description: Bubble phenomena have been given a new meaning with their study in relation to the kinetic behavior of reactors. Prior to their study in relation to physics, the bulk of work on bubble phenomena concerned naval engineering problems of behavior in cavitation and water entry behavior. This bibliography is intended to fill the need of the reactor physicist as well as the naval engineer. An attempt has been made to include all available references on bubble phenomena and associated effects. A subject index has been purposely omitted. It is felt that the breakdown in content headings is sufficient to ascertain areas of interest. There will be overlapping of headings and to find all possible entries, a search through the headings may be desirable. To increase the usefulness of this bibliography the location of an abstract has been cited wherever possible following the reference. Classified reports are included; however, their titles contain no classified information. Sources used in compiling this bibliography are: Chemical Abstracts, Industrial Arts Index, Applied Mechanics Review, Nuclear Science Abstracts, the AEC Abstracts of Classified Literature, the AEC card catalogs available at Atomics International, and the bibliographic services of Armed Services Technical Information agency. (auth)
Date: June 30, 1958
Creator: Bloomfield, M.; McElroy, W.N. & Skinner, R.E.
Partner: UNT Libraries Government Documents Department

Rise of Air Bubbles in Aircraft Lubricating Oils

Description: Note presenting measurements of the rates of rise of small air bubbles, up to 2 millimeters in diameter, at room temperature in an undoped oil, in the same oil containing foam inhibitors, and in an oil containing lubricating additives. The apparent diameter of the air bubbles was measured visually through an ocular micrometer on a traveling telescope. A method is derived to calculate the thickness of the liquid shell which would have to move with the bubbles in the doped oils to account for the abnormally slow velocity.
Date: February 1950
Creator: Robinson, J. V.
Partner: UNT Libraries Government Documents Department


Description: Vortex breakdown is simulated by a three dimensional Lagrangian method using vortex filaments. The filaments are approximated by vortex elements and their velocity is computed by a Biot-Savart type law of interaction. The numerical calculations show the development of an axisymmetric bubble with a recirculation zone and resemble in many respects the results obtained in the physical experiments on vortex breakdown.
Date: October 1, 1978
Creator: Prete, Vincenza Del
Partner: UNT Libraries Government Documents Department

Implications for the Cryogenic Fielding of Leaking Beryllium Capsules

Description: In this paper we show that the ambient temperature measured leakage time constant, {tau}{sub RT}, is related to the leakage at cryogenic temperature, R{sub C}, by R{sub C}= 0.23{rho}{sub DT}V{sub sh}/ {tau}{sub RT} where {rho}{sub DT} is the density of cryogenic DT vapor, and V{sub sh} is the internal volume of the shell. We then calculate the size of voids that may result from leakage at the Be/DT interface, depending upon the number of leakage sites and {tau}{sub RT}. Even for the slowest leakers the potential void growth is excessive. Reasons that voids have not been seen in DT layering experiments to date include the lack of a technique to see isolated micronish bubbles, however possible mechanisms preventing void formation are also discussed.
Date: February 20, 2007
Creator: Cook, R
Partner: UNT Libraries Government Documents Department

Mechanisms of gas precipitation in plasma-exposed tungsten

Description: Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).
Date: May 1, 2012
Creator: Kolasinski, R. D.; Cowgill, D. F.; Donovan, D. C. & Shimada, M.
Partner: UNT Libraries Government Documents Department

Vessel-Spanning Bubble Formation in K-Basin Sludge Stored in Large-Diameter Containers

Description: The K Basin sludge to be retrieved and stored in the large diameter containers (LDCs) contains some fraction of uranium metal that generates hydrogen gas, which introduces potential upset conditions. One postulated upset condition is a rising plug of sludge supported by a hydrogen bubble that is driven into the vent filters at the top of the container. In laboratory testing with actual K Basin sludge, vessel-spanning bubbles that lifted plugs of sludge were observed in 3-inch-diameter graduated cylinders. This report presents a series of analytical assessments performed by the Pacific Northwest National Laboratory to address the potential for the generation of a vessel spanning bubble in the LDCs. The assessments included the development and evaluation of static and dynamic bubble formation models over the projected range of K Basin sludge physical properties. Additionally, the theory of circular plates was extrapolated to examine conditions under which a plug of sludge would collapse and release a spanning bubble.
Date: March 1, 2002
Creator: Terrones, Guillermo & Gauglitz, Phillip A.
Partner: UNT Libraries Government Documents Department


Description: A wave equation for the pressure in a mixture of water and gas bubbles (such as found in the KEWB Reactor) is derived. The driving force may be either the production of additional bubbles or the growth of existent bubbles. Several illustrative solutions to the wave equation are found. (W.L.H.)
Date: May 25, 1960
Creator: Warner, C.
Partner: UNT Libraries Government Documents Department


Description: The problem of radiolytic gas diffusion into a bubble of fixed radius is solved. A constant source of radiolytic gas is assumed. The concentration of gas at the bubble surface is related to the pressure within the bubble by Henry's constant. (W. L.H.)
Date: July 15, 1960
Creator: Warner, C. III
Partner: UNT Libraries Government Documents Department

M-theory through the looking glass: Tachyon condensation in the E8 heterotic string

Description: We study the spacetime decay to nothing in string theory and M-theory. First we recall a nonsupersymmetric version of heterotic M-theory, in which bubbles of nothing -- connecting the two E_8 boundaries by a throat -- are expected to be nucleated. We argue that the fate of this system should be addressed at weak string coupling, where the nonperturbative instanton instability is expected to turn into a perturbative tachyonic one. We identify the unique string theory that could describe this process: The heterotic model with one E_8 gauge group and a singlet tachyon. We then use worldsheet methods to study the tachyon condensation in the NSR formulation of this model, and show that it induces a worldsheet super-Higgs effect. The main theme of our analysis is the possibility of making meaningful alternative gauge choices for worldsheet supersymmetry, in place of the conventional superconformal gauge. We show in a version of unitary gauge how the worldsheet gravitino assimilates the goldstino and becomes dynamical. This picture clarifies recent results of Hellerman and Swanson. We also present analogs of R_\xi gauges, and note the importance of logarithmic CFT in the context of tachyon condensation.
Date: September 20, 2007
Creator: Horava, Petr; Horava, Petr & Keeler, Cynthia A.
Partner: UNT Libraries Government Documents Department

Growth rate exponents of Richtmyer-Meshkov mixing layers

Description: The Richtmyer-Meshkov mixing layer is initiated by the passing of a shock over an interface between fluid of differing densities. The energy deposited during the shock passage undergoes a relaxation process during which the fluctuational energy in the flow field decays and the spatial gradients of the flow field decrease in time. This late stage of Richtmyer-Meshkov mixing layers is studied from the viewpoint of self-similarity. Analogies with weakly anisotropic turbulence suggest that both the bubble-side and spike-side widths of the mixing layer should evolve as power-laws in time, with the same power-law exponents and virtual time origin for both sides. The analogy also bounds the power-law exponent between 2/7 and 2/5. It is then shown that the assumption of identical power-law exponents for bubbles and spikes yields that are in good agreement with experiment at modest density ratios.
Date: January 13, 2004
Creator: Zhou, Y & Clark, T
Partner: UNT Libraries Government Documents Department

Feasibility of measuring 3He bubble diameter populations in deuterium-tritium ice layers using Mie scattering

Description: In this report, I assess the feasibility of using Mie scattering to quantify the diameter distribution of {sup 3}He bubbles in DT ice layers. Mie scattering methods are often used for He diameter m measurements of particulates in emulsions like pigments and ink products. These measurements suggests that similar techniques could be used to measure the distribution of {sup 3}He bubbles He in DT ice layers, which is important for NIF ICF capsules. To investigate the achievable performance of bubble diameter measurements using Mie scattering, I performed numerical modeling using exact analytical expressions.
Date: January 22, 2007
Creator: Izumi, N
Partner: UNT Libraries Government Documents Department

Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology

Description: This report summarizes the procedures used and results obtained in determining radial gas holdup profiles, via gamma ray scanning, and in assessing liquid and gas mixing parameters, via radioactive liquid and gas tracers, during Fischer Tropsch synthesis. The objectives of the study were (i) to develop a procedure for detection of gas holdup radial profiles in operating reactors and (ii) to test the ability of the developed, previously described, engineering models to predict the observed liquid and gas mixing patterns. It was shown that the current scanning procedures were not precise enough to obtain an accurate estimate of the gas radial holdup profile and an improved protocol for future use was developed. The previously developed physically based model for liquid mixing was adapted to account for liquid withdrawal from the mid section of the column. The ability of our engineering mixing models for liquid and gas phase to predict both liquid and gas phase tracer response was established and illustrated.
Date: July 31, 2002
Creator: Gupta, Puneet
Partner: UNT Libraries Government Documents Department


Description: The complexities of bubble formation in liquids increase as the system size increases, and a photographic study is presented here to provide some insight into the dynamics of bubble formation for large systems. Air was injected at the bottom of a 28 feet tall by 30 inch diameter column. Different fluids were subjected to different air flow rates at different fluid depths. The fluids were water and non-Newtonian, Bingham plastic fluids, which have yield stresses requiring an applied force to initiate movement, or shearing, of the fluid. Tests showed that bubble formation was significantly different in the two types of fluids. In water, a field of bubbles was formed, which consisted of numerous, distributed, 1/4 to 3/8 inch diameter bubbles. In the Bingham fluid, large bubbles of 6 to 12 inches in diameter were formed, which depended on the air flow rate. This paper provides comprehensive photographic results related to bubble formation in these fluids.
Date: June 26, 2008
Creator: Leishear, R & Michael Restivo, M
Partner: UNT Libraries Government Documents Department

{open_quotes}Bubble fusion{close_quotes}: Preliminary estimates of spherical micro-implosions in cavitating liquids

Description: Liquids irradiated with intense ultrasonic waves can generate small cavities or bubbles. Upon nonlinear expansion to a state of disequilibrium, wherein the externally imposed hydrostatic pressure far exceeds that of entrapped non-condensable gas, these bubbles undergo a rapid and violent collapse. This collapse, if symmetric, can generate high pressures and temperatures through a number of possible mechanisms. The simplest and oldest explanation suggests a focusing of the kinetic energy of all the surrounding liquid onto the collapsing bubble and the subsequent heating of entrapped gases under either adiabatic or isothermal conditions. Although induced by externally imposed millisecond pressure oscillations, these collapses can occur on sub-microsecond timescales and are accompanied by picosecond light emissions; this combination of sound and light is called sonoluminescence. Recent explanations of observed high temperatures and picosecond radiation pulses accompanying such collapses are based on the interaction of multiple shock waves that are launched off the inward cavity wall. Other potential explanations invoke dipole emissions induced by intermolecular collisions or the release of Casimir energy when a dielectric hole is filled. Conjectures have been made that the processes responsible for sonoluminescence may be extended to generated conditions where thermonuclear fusion might occur. Such an achievement would extend scientific interest in sonoluminescence out of a purely chemical context to include the study of matter subjected to more extreme conditions. The main goal of this {open_quotes}scoping{close_quotes} study is to understand better conditions where deuterium-tritium fusion might be observed in conjunction with micro-implosions in cavitating liquids; prognoses of fusion application at this point are unintended.
Date: February 1, 1995
Creator: Krakowski, R.A.
Partner: UNT Libraries Government Documents Department


Description: The agglomeration of ultrafine-size coal particles in an aqueous suspension by means of microscopic gas bubbles was demonstrated in numerous experiments with a scale model mixing system. Coal samples from both the Pittsburgh No. 8 Seam and the Upper Freeport Seam were used for these experiments. A small amount of i-octane was added to facilitate the process. Microscopic gas bubbles were generated by saturating the water used for suspending coal particles with gas under pressure and then reducing the pressure. Microagglomerates were produced which appeared to consist of gas bubbles encapsulated in coal particles. Since dilute particle suspensions were employed, it was possible to monitor the progress of agglomeration by observing changes in turbidity. By such means it became apparent that the rate of agglomeration depends on the concentration of microscopic gas bubbles and to a lesser extent on the concentration of i-octane. Similar results were obtained with both Pittsburgh No. 8 coal and Upper Freeport coal.
Date: September 30, 1998
Partner: UNT Libraries Government Documents Department

Star in a jar

Description: A sonoluminescing bubble has been modeled as a thermally conducting, partially ionized two-component plasma. The use of accurate equations-of-state, plasma physics, and radiation physics distinguishes our model from all previous models. The model provides an explanation of many features of single bubble sonoluminescence that have not been collectively accounted for in previous models, including the origin of the picosecond pulse widths and spectra. The calculated spectra for sonoluminescing nitrogen and argon bubbles suggest that a sonoluminescing air bubble probably contains only argon, in agreement with a recent theoretical analysis.
Date: August 11, 1997
Creator: Moss, W.C.; Clarke, D.B. & Young, D.A.
Partner: UNT Libraries Government Documents Department

Coal Cleaning by Gas Agglomeration

Description: The gas agglomeration method of coal cleaning was demonstrated with laboratory scale mixing equipment which made it possible to generate microscopic gas bubbles in aqueous suspensions of coal particles. A small amount of i-octane was introduced to enhance the hydrophobicity of the coal. Between 1.0 and 2.5 v/w% i-octane was sufficient based on coal weight. Coal agglomerates or aggregates were produced which were bound together by small gas bubbles.
Date: March 1, 1998
Creator: Shen, Meiyu; Abbott, Royce & Wheelock, T. D.
Partner: UNT Libraries Government Documents Department

Pressure effects on bubble-column flow characteristics

Description: Bubble-column reactors are used in the chemical processing industry for two-phase and three-phase chemical reactions. Hydrodynamic effects must be considered when attempting to scale these reactors to sizes of industrial interest, and diagnostics are needed to acquire data for the validation of multiphase scaling predictions. This paper discusses the use of differential pressure (DP) and gamma- densitometry tomography (GDT) measurements to ascertain the gas distribution in a two-phase bubble column reactor. Tests were performed on an industrial scale reactor (3-m tall, 0.48-m inside diameter) using a 5-Curie cesium-137 source with a sodium-iodide scintillation detector. GDT results provide information on the time- averaged cross-sectional distribution of gas in the liquid, and DP measurements provide information on the time and volume averaged axial distribution of gas. Close agreement was observed between the two methods of measuring the gas distribution in the bubble column. The results clearly show that, for a fixed volumetric flowrate through the reactor, increasing the system pressure leads to an increase in the gas volume fraction or ``gas holdup`` in the liquid. It is also shown from this work that GDT can provide useful diagnostic information on industrial scale bubble-column reactors.
Date: March 1, 1996
Creator: Adkins, D.R.; Shollenberger, K.A.; O`Hern, T.J. & Torczynski, J.R.
Partner: UNT Libraries Government Documents Department

Bubble Dynamics in a Superheated Liquid

Description: This report presents an extensive literature survey on bubble dynamics. Growth of a single spherical bubble moving in a uniformly superheated liquid is considered. Equations of motion and energy are presented in the forms that take into consideration the interaction between the motion and the growth. The fourth-order Runge-Kutta method is used to obtain a simultaneous solution of equations of motion and growth rate, and the solution is compared with available experimental results. Results for liquid sodium are presented for a range of pressures and Jakob numbers.
Date: September 1977
Creator: Sha, William T. & Shah, V. L.
Partner: UNT Libraries Government Documents Department

Mechanistic Studies of Improved Foam EOR Processes

Description: The objective of this research is to widen the application of foam to enhanced oil recovery (EOR) by investigating fundamental mechanisms of foams in porous media. This research will lay the groundwork for more applied research on foams for improved sweep efficiency in miscible gas, steam and surfactant-based EOR. Task 1 investigates the pore-scale interactions between foam bubbles and polymer molecules. Task 2 examines the mechanisms of gas trapping, and interaction between gas trapping and foam effectiveness. Task 3 investigates mechanisms of foam generation in porous media.
Date: January 5, 2005
Creator: Rossen, William R.
Partner: UNT Libraries Government Documents Department

Mechanistic Studies of Improved Foam Eor Processes

Description: The objective of this research is to widen the application of foam to enhanced oil recovery (EOR) by investigating fundamental mechanisms of foams in porous media. This research is to lay the groundwork for more-applied research on foams for improved sweep efficiency in miscible gas, steam and surfactant-based EOR. Task 1 investigates the pore-scale interactions between foam bubbles and polymer molecules. Task 2 examines the mechanisms of gas trapping, and interaction between gas trapping and foam effectiveness. Task 3 investigates mechanisms of foam generation in porous media.
Date: March 16, 2005
Creator: Rossen, William R.
Partner: UNT Libraries Government Documents Department