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Kenneth S. Suslick - One of the best experts on this subject based on the ideXlab platform.
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Single Bubble perturbation in cavitation proximity of solid glass hot spot versus distance
Physical Chemistry Chemical Physics, 2014Co-Authors: Darya Radziuk, Helmuth Mohwald, Kenneth S. SuslickAbstract:A systematic study of the energy loss of a cavitation Bubble in a close proximity of a glass surface is introduced for the first time in a low acoustic field (1.2–2.4 bar). Single Bubble sonoluminescence (SBSL) is used as a tool to predict the temperature and pressure decrease of Bubble (μm) versus surface distance. A glass as a model system is used to imitate the boundary conditions relevant for nano- or micromaterials. SBSL preequilibrated with 5% argon is perturbed by a glass rod with the tip (Z-perturbation) and with the long axis (X-perturbation) at a defined distance. From 2 mm to 500 μm argon-SBSL lines monotonically narrow and the effective emission temperature decreases from 9000 K to 6800 K comparable to multiple Bubbles. The electron density decreases by two orders of magnitude in Z-perturbation and is by a factor of two higher in X-perturbation than the unperturbed cavitating Bubble. The perturbed Single Bubble sonoluminescence pressure decreases from 2700 atm to 1200 atm at 2.4 bar. In water new non-SBSL SiO molecular emission lines are observed and OH emission disappears.
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temperature nonequilibration during Single Bubble sonoluminescence
Journal of Physical Chemistry Letters, 2012Co-Authors: David J. Flannigan, Kenneth S. SuslickAbstract:Single-Bubble sonoluminescence (SBSL) spectra from liquids having low vapor pressures, especially mineral acids, are exceptionally rich. During SBSL from aqueous sulfuric acid containing dissolved neon, rovibronic emission spectra reveal vibrationally hot sulfur monoxide (SO; Tv = 2100 K) that is also rotationally cold (Tr = 290 K). In addition to SO, excited neon atom emission gives an estimated temperature, for neon, of several thousand Kelvin. This nonequilibrated temperature is consistent with dynamically constrained SO formation at the liquid-vapor interface of the collapsing Bubble. Formation occurs via collisions of fast neon atoms (generated within the collapsing Bubble) with liquid-phase molecular species in the interfacial region, thus allowing for a mechanistic understanding of the processes leading to light emission.
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molecular emission and temperature measurements from Single Bubble sonoluminescence
Physical Review Letters, 2010Co-Authors: Kenneth S. SuslickAbstract:Single-Bubble sonoluminescence (SBSL) spectra in H 2 O show featureless continuum emission. From an acoustically driven, moving Bubble in phosphoric acid (H 3 PO 4 ), we observe very strong molecular emission from excited OH radicals (∼310 nm), which can be used as a spectroscopic thermometer by fitting the experimental SBSL spectra to the OH A 2 Σ + -X 2 Π rovibronic transitions. The observed emission temperature (T em ) ranges from 6200 to 9500 K as the acoustic pressure (P a ) varies from 1.9 to 3.1 bar and from 6000 to >10000 K as the dissolved monatomic gas varies over the series from He to Xe.
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Plasma conditions during Single Bubble sonoluminescence.
Journal of the Acoustical Society of America, 2009Co-Authors: Kenneth S. Suslick, David J. FlanniganAbstract:There is a remarkable lack of experimental data on the conditions created during cavitation Bubble collapse. Indeed, only recently has strong evidence of plasma formation been obtained during Single Bubble cavitation. Here we have determined for the first time the plasma electron density and the ion broadening parameter during Single‐Bubble sonoluminescence and examined them as a function of acoustic driving pressure. We find that the electron density spans four orders of magnitude and can exceed 10×1021/cc (which is comparable to the densities produced by intense laser‐induced inertial confinement fusion experiments, e.g., the NOVA ICF laser at Livermore) with effective plasma temperatures ranging from 7000 to more than 16 000 K. At the highest acoustic driving force, neutral Ar lines can no longer be used as spectroscopic reporters due to the extent of ionization and to leveling of the population of states. Accounting for the temporal profile of the sonoluminescence pulse suggests that the ultimate cond...
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plasma line emission during Single Bubble cavitation
Physical Review Letters, 2005Co-Authors: David J. Flannigan, Kenneth S. SuslickAbstract:Emission lines from transitions between high-energy states of noble-gas atoms (Ne, Ar, Kr, and Xe) and ions (Ar(+), Kr(+), and Xe(+)) formed and excited during Single-Bubble cavitation in sulfuric acid are reported. The excited states responsible for these emission lines range 8.3 eV (for Xe) to 37.1 eV (for Ar(+)) above the respective ground states. Observation of emission lines allows for identification of intracavity species responsible for light emission; the populated energy levels indicate the plasma generated during cavitation is comprised of highly energetic particles.
David J. Flannigan - One of the best experts on this subject based on the ideXlab platform.
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temperature nonequilibration during Single Bubble sonoluminescence
Journal of Physical Chemistry Letters, 2012Co-Authors: David J. Flannigan, Kenneth S. SuslickAbstract:Single-Bubble sonoluminescence (SBSL) spectra from liquids having low vapor pressures, especially mineral acids, are exceptionally rich. During SBSL from aqueous sulfuric acid containing dissolved neon, rovibronic emission spectra reveal vibrationally hot sulfur monoxide (SO; Tv = 2100 K) that is also rotationally cold (Tr = 290 K). In addition to SO, excited neon atom emission gives an estimated temperature, for neon, of several thousand Kelvin. This nonequilibrated temperature is consistent with dynamically constrained SO formation at the liquid-vapor interface of the collapsing Bubble. Formation occurs via collisions of fast neon atoms (generated within the collapsing Bubble) with liquid-phase molecular species in the interfacial region, thus allowing for a mechanistic understanding of the processes leading to light emission.
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Plasma conditions during Single Bubble sonoluminescence.
Journal of the Acoustical Society of America, 2009Co-Authors: Kenneth S. Suslick, David J. FlanniganAbstract:There is a remarkable lack of experimental data on the conditions created during cavitation Bubble collapse. Indeed, only recently has strong evidence of plasma formation been obtained during Single Bubble cavitation. Here we have determined for the first time the plasma electron density and the ion broadening parameter during Single‐Bubble sonoluminescence and examined them as a function of acoustic driving pressure. We find that the electron density spans four orders of magnitude and can exceed 10×1021/cc (which is comparable to the densities produced by intense laser‐induced inertial confinement fusion experiments, e.g., the NOVA ICF laser at Livermore) with effective plasma temperatures ranging from 7000 to more than 16 000 K. At the highest acoustic driving force, neutral Ar lines can no longer be used as spectroscopic reporters due to the extent of ionization and to leveling of the population of states. Accounting for the temporal profile of the sonoluminescence pulse suggests that the ultimate cond...
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plasma line emission during Single Bubble cavitation
Physical Review Letters, 2005Co-Authors: David J. Flannigan, Kenneth S. SuslickAbstract:Emission lines from transitions between high-energy states of noble-gas atoms (Ne, Ar, Kr, and Xe) and ions (Ar(+), Kr(+), and Xe(+)) formed and excited during Single-Bubble cavitation in sulfuric acid are reported. The excited states responsible for these emission lines range 8.3 eV (for Xe) to 37.1 eV (for Ar(+)) above the respective ground states. Observation of emission lines allows for identification of intracavity species responsible for light emission; the populated energy levels indicate the plasma generated during cavitation is comprised of highly energetic particles.
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plasma formation and temperature measurement during Single Bubble cavitation
Nature, 2005Co-Authors: David J. Flannigan, Kenneth S. SuslickAbstract:The phenomenon known as Single-Bubble sonoluminescence (SBSL) has been the focus of intense investigation since it was discovered 15 years ago, leading to predictions that extreme temperatures are reached within the cavity at extreme compression. Conditions, some have controversially claimed, that could even lead to nuclear fusion. The lack of features in the typical SBSL spectrum has made it difficult to establish what is happening within the Bubble. But now, using concentrated sulphuric acid as the medium subjected to acoustic treatment, Flannigan and Suslick have obtained the most intense sonoluminescence yet seen. This provides plenty of spectral information — most importantly, evidence for temperatures as high as 15,000 K — indicating that the collapsed Bubble has a hot plasma core. Single-Bubble sonoluminescence (SBSL1,2,3,4,5) results from the extreme temperatures and pressures achieved during Bubble compression; calculations have predicted6,7 the existence of a hot, optically opaque plasma core8 with consequent bremsstrahlung radiation9,10. Recent controversial reports11,12 claim the observation of neutrons from deuterium–deuterium fusion during acoustic cavitation11,12. However, there has been previously no strong experimental evidence for the existence of a plasma during Single- or multi-Bubble sonoluminescence. SBSL typically produces featureless emission spectra13 that reveal little about the intra-cavity physical conditions or chemical processes. Here we report observations of atomic (Ar) emission and extensive molecular (SO) and ionic (O2+) progressions in SBSL spectra from concentrated aqueous H2SO4 solutions. Both the Ar and SO emission permit spectroscopic temperature determinations, as accomplished for multi-Bubble sonoluminescence with other emitters14,15,16. The emissive excited states observed from both Ar and O2+ are inconsistent with any thermal process. The Ar excited states involved are extremely high in energy (>13 eV) and cannot be thermally populated at the measured Ar emission temperatures (4,000–15,000 K); the ionization energy of O2 is more than twice its bond dissociation energy, so O2+ likewise cannot be thermally produced. We therefore conclude that these emitting species must originate from collisions with high-energy electrons, ions or particles from a hot plasma core.
Yuri T. Didenko - One of the best experts on this subject based on the ideXlab platform.
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Chemical control of Single Bubble cavitation
Journal of the Acoustical Society of America, 2003Co-Authors: Yuri T. Didenko, Kenneth S. SuslickAbstract:Sonochemistry would be ideally studied with a Single Bubble with known size pulsating in known acoustic pressure field. Single Bubble cavitation provides the means to make such studies. The promise that Single Bubble cavitation brought to the quantitative measurements of chemical activity of cavitation, however, has not been previously fulfilled due to the very small amount of reacting gas within a Single Bubble (typically
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the energy efficiency of formation of photons radicals and ions during Single Bubble cavitation
Nature, 2002Co-Authors: Yuri T. Didenko, Kenneth S. SuslickAbstract:It is extremely difficult to perform a quantitative analysis of the chemistry1,2 associated with multiBubble cavitation: unknown parameters include the number of active Bubbles, the acoustic pressure acting on each Bubble and the Bubble size distribution. Single-Bubble sonoluminescence3,4,5,6,7 (characterized by the emission of picosecond flashes of light) results from nonlinear pulsations of an isolated vapour-gas Bubble in an acoustic field. Although the latter offers a much simpler environment in which to study the chemical activity of cavitation, quantitative measurements have been hindered by the tiny amount of reacting gas within a Single Bubble (typically <10-13 mol). Here we demonstrate the existence of chemical reactions within a Single cavitating Bubble, and quantify the sources of energy dissipation during Bubble collapse. We measure the yields of nitrite ions, hydroxyl radicals and photons. The energy efficiency of hydroxyl radical formation is comparable to that in multiBubble cavitation, but the energy efficiency of light emission is much higher. The observed rate of nitrite formation is in good agreement with the calculated diffusion rate of nitrogen into the Bubble. We note that the temperatures attained in Single-Bubble cavitation in liquids with significant vapour pressures will be substantially limited by the endothermic chemical reactions of the polyatomic species inside the collapsing Bubble.
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Single Bubble sonochemistry and sonoluminescence
Journal of the Acoustical Society of America, 2001Co-Authors: Yuri T. Didenko, Kenneth S. SuslickAbstract:An isolated, Single vapor‐gas Bubble pulsating in a standing acoustic field can emit flashes of light. This peculiar phenomenon is known as Single Bubble sonoluminescence, SBSL. We find that these Bubble pulsations in water are accompanied with the formation of radicals and molecular products. In this paper, the yields of hydroxyl radicals and nitrite ions formed inside the Bubble were measured for the first time. The chemical and light efficiency of acoustic cavitation and the diffusion rate of nitrogen inside the Bubble during its pulsation were calculated using experimental data. The energy efficiency of OH radical formation by a Single Bubble is comparable to that in multiBubble cavitation. However, the energy efficiency of light emission is much higher for SBSL. The diffusion rate of nitrogen inside the Bubble is in good agreement with that predicted by the dissociation hypothesis. [Work supported by NAVY/ DARPA.]
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Molecular emission from Single-Bubble sonoluminescence.
Nature, 2000Co-Authors: Yuri T. Didenko, William B. Mcnamara, Kenneth S. SuslickAbstract:Ultrasound can drive a Single gas Bubble in water into violent oscillation; as the Bubble is compressed periodically, extremely short flashes of light (about 100 ps) are generated with clock-like regularity1,2,3,4. This process, known as Single-Bubble sonoluminescence, gives rise to featureless continuum emission4,5 in water (from 200 to 800 nm, with increasing intensity into the ultraviolet). In contrast, the emission of light from clouds of cavitating Bubbles at higher acoustic pressures (multi-Bubble sonoluminescence1) is dominated by atomic and molecular excited-state emission6,7,8,9,10,11 at much lower temperatures6. These observations have spurred intense effort to uncover the origin of sonoluminescence and to generalize the conditions necessary for its creation. Here we report a series of polar aprotic liquids that generate very strong Single-Bubble sonoluminescence, during which emission from molecular excited states is observed. Previously, Single-Bubble sonoluminescence from liquids other than water has proved extremely elusive12,13. Our results give direct proof of the existence of chemical reactions and the formation of molecular excited states during Single-Bubble cavitation, and provide a spectroscopic link between Single- and multi-Bubble sonoluminescence.
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multiBubble sonoluminescence spectra of water which resemble Single Bubble sonoluminescence
Physical Review Letters, 2000Co-Authors: Yuri T. Didenko, T V GordeychukAbstract:MultiBubble sonoluminescence (MBSL) spectra of water from cavitation clouds were collected in the presence of different noble gases and at different acoustic intensities. Results show that at high acoustic intensity and with xenon as a dissolved gas the emission of the OH* radical becomes indiscernible from the continuum. These spectra resemble Single-Bubble sonoluminescence (SBSL) spectra. It is concluded that the source of emission in MBSL and SBSL can be the same, the difference in spectra is due to the higher temperature inside the Bubble during SBSL.
Yasuo Iida - One of the best experts on this subject based on the ideXlab platform.
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theoretical study of Single Bubble sonochemistry
Journal of Chemical Physics, 2005Co-Authors: Kyuichi Yasui, Toru Tuziuti, Manickam Sivakumar, Yasuo IidaAbstract:Numerical simulations of Bubble oscillations in liquid water irradiated by an ultrasonic wave are performed under the experimental condition for Single-Bubble sonochemistry reported by Didenko and Suslick [Nature (London) 418, 394 (2002)]. The calculated number of OH radicals dissolving into the surrounding liquid from the interior of the Bubble agrees sufficiently with the experimental data. OH radicals created inside a Bubble at the end of the Bubble collapse gradually dissolve into the surrounding liquid during the contraction phase of an ultrasonic wave although about 30% of the total amount of OH radicals that dissolve into the liquid in one acoustic cycle dissolve in 0.1 micros at around the end of the collapse. The calculated results have indicated that the oxidant produced by a Bubble is not only OH radical but also O atom and H2O2. It is suggested that an appreciable amount of O atom is produced by Bubbles inside a standing-wave-type sonochemical reactor filled with water in which oxygen is dissolved as in the case of air.
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Theoretical study of Single-Bubble sonochemistry
Journal of Chemical Physics, 2005Co-Authors: Kyuichi Yasui, Toru Tuziuti, Manickam Sivakumar, Yasuo IidaAbstract:Numerical simulations of Bubble oscillations in liquid water irradiated by an ultrasonic wave are performed under the experimental condition for Single-Bubble sonochemistry reported by Didenko and Suslick [Nature (London) 418, 394 (2002)]. The calculated number of OH radicals dissolving into the surrounding liquid from the interior of the Bubble agrees sufficiently with the experimental data. OH radicals created inside a Bubble at the end of the Bubble collapse gradually dissolve into the surrounding liquid during the contraction phase of an ultrasonic wave although about 30% of the total amount of OH radicals that dissolve into the liquid in one acoustic cycle dissolve in 0.1μs at around the end of the collapse. The calculated results have indicated that the oxidant produced by a Bubble is not only OH radical but also O atom and H2O2. It is suggested that an appreciable amount of O atom is produced by Bubbles inside a standing-wave-type sonochemical reactor filled with water in which oxygen is dissolved ...
Hyungdae Kim - One of the best experts on this subject based on the ideXlab platform.
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Single Bubble Boiling from an Artificial Cavity
Journal of Nanofluids, 2019Co-Authors: Saeid Vafaei, Hyungdae KimAbstract:Pool boiling heat transfer is an aggressive and complex phenomenon which needs to be simplified for a better understanding of the mechanism of Bubble growth and departure and how boiling heat transfer can be enhanced. Single Bubble boiling heat transfer is a simple version of boiling phenomenon which has been used to study the effective elements on pool boiling heat transfer. The purpose of the present review paper is to understand how to produce Single Bubble pool boiling on a heated substrate and investigate, how Single Bubble boiling phenomenon can be affected by geometry of cavities, cavity size, wettability, roughness, working fluid, subcooling, wall superheat, heat flux, gravity, etc. It was demonstrated that cylindrical cavities are capable to generate stable and continuous bubbling, small temperature fluctuation, low superheat with short waiting period. The cylindrical cavities can be manufactured very easily in small sizes which can be a good candidate to produce Single Bubble pool boiling. As heat flux increases, smaller cavities start becoming active. For a given depth, as cavity size increases, the Bubble growth rate and departure volume increase. Surface wettability is another complex and important factor to modify the Single Bubble boiling heat transfer. Wettability depends mainly on force balance at the triple contact line which relies on solid–liquid–gas materials. In case of hydrophobic surfaces, the triple line has tendency to move toward liquid phase and expand the radius of triple line, so the initiation of nucleation is easier, the waiting time is shorter, the downward surface tension force becomes bigger since radius of triple line is larger, the Bubble departure volume is higher and Bubble growth period is longer. The effects of the rest of main parameters on Single Bubble boiling are discussed in this paper in details. In addition, a theoretical model is developed to predict the liquid-vapor interface for the Single Bubble boiling. The theoretical model is compared with Single Bubble boiling experimental data and good results observed.
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an experimental method to simultaneously measure the dynamics and heat transfer associated with a Single Bubble during nucleate boiling on a horizontal surface
International Journal of Heat and Mass Transfer, 2014Co-Authors: Satbyoul Jung, Hyungdae KimAbstract:Abstract The heat transfer mechanisms of nucleate boiling are associated with how the liquid–vapor phase and the surface temperature are distributed and interact beneath a Single Bubble on a heated surface. A comparative analysis of the hydrodynamic and thermal behavior of a Single Bubble may contribute greatly to the understanding of nucleate boiling heat transfer. In this paper, a technique to simultaneously measure the liquid–vapor phase boundary, temperature distribution, and heat transfer distribution at a boiling surface is described. The technique is fully synchronized in time and spatially resolved, and is applied to explore Single-Bubble nucleate boiling phenomena in a pool of water subcooled by 3 °C under atmospheric pressure. The temperature and heat flux distributions at the boiling surface are quantitatively interpreted in relation to the distribution and dynamics of the dry and wet areas, the triple contact line, and the microlayer underneath the Single Bubble. The results show that intensive wall heat transfer during Single-Bubble nucleate boiling exactly corresponds to the extended microlayer region. However, the overall contribution of the microlayer evaporation to the growth of a Bubble is relatively small, and amounts to less than 17% of the total heat transport.
