Krefting, Dagmar

[["dc.bibliographiccitation.artnumber","174301"],["dc.bibliographiccitation.issue","17"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","91"],["dc.contributor.author","Krefting, D."],["dc.contributor.author","Mettin, Robert"],["dc.contributor.author","Lauterborn, Werner"],["dc.date.accessioned","2018-11-07T10:35:26Z"],["dc.date.available","2018-11-07T10:35:26Z"],["dc.date.issued","2003"],["dc.description.abstract","Single bubble sonoluminescence (SBSL) is realized in air-saturated water at ambient pressure and room temperature. The behavior is similar to SBSL in degassed water, but with a higher spatial variability of the bubble position. A detailed view on the dynamics of the bubbles shows agreement between calculated shape stability borders but differs slightly in the equilibrium radii predicted by a mass diffusion model. A comparison with results in degassed water is done as well as a time resolved characterization of bubble oscillation, translation, and light emission for synchronous and recycling SBSL. The formation of streamer structures is observed in the same parameter range, when bubble nuclei are present. This may lead to a unified interpretation of SBSL and multibubble sonoluminescence."],["dc.identifier.doi","10.1103/PhysRevLett.91.174301"],["dc.identifier.isi","000186138300024"],["dc.identifier.pmid","14611352"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45096"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","American Physical Soc"],["dc.relation.issn","0031-9007"],["dc.title","Single-bubble sonoluminescence in air-saturated water"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1918"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","The Journal of the Acoustical Society of America"],["dc.bibliographiccitation.lastpage","1927"],["dc.bibliographiccitation.volume","112"],["dc.contributor.author","Krefting, D."],["dc.contributor.author","Mettin, Robert"],["dc.contributor.author","Lauterborn, Werner"],["dc.date.accessioned","2018-11-07T09:53:20Z"],["dc.date.available","2018-11-07T09:53:20Z"],["dc.date.issued","2002"],["dc.description.abstract","Sonoluminescing single bubbles driven simultaneously by two harmonic frequencies were recently reported to increase the maximum light output up to a factor of 3 with respect to single mode excitation. In this paper, experimental and numerical results on single-bubble sonoluminescence (SBSL) in an air/water system using the fundamental mode of 25 kHz and the second harmonic at 50 kHz are presented. The region of light emission is mapped in the three-dimensional parameter space spanned by the two driving pressure amplitudes and their relative phase. Good agreement was seen between measured light output, maximum bubble radius, and stability boundaries and the numerical model which is based on spherical bubble oscillations regarding diffusive and shape stability. The maximum brightness was enhanced by a factor up to 2.5 with respect to single mode SBSL. However, long-term measurements reveal great variation of the emission at fundamental mode driven SBSL and of the boost factor reached with two frequencies. The overall brightness maxima of both excitation methods within a period of several hours turn out to show little difference. (C) 2002 Acoustical Society of America."],["dc.identifier.doi","10.1121/1.1509427"],["dc.identifier.isi","000178870100017"],["dc.identifier.pmid","12430803"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36312"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Acoustical Soc Amer Amer Inst Physics"],["dc.relation.issn","0001-4966"],["dc.title","Two-frequency driven single-bubble sonoluminescence"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","119"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Ultrasonics Sonochemistry"],["dc.bibliographiccitation.lastpage","123"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Krefting, D."],["dc.contributor.author","Mettin, Robert"],["dc.contributor.author","Lauterborn, Werner"],["dc.date.accessioned","2018-11-07T10:49:32Z"],["dc.date.available","2018-11-07T10:49:32Z"],["dc.date.issued","2004"],["dc.description.abstract","Cleaning and erosion of objects by ultrasound in liquids are caused by the action of acoustic cavitation bubbles. Experiments have been performed with respect to the erosive effect of multibubble structures on painted glass surfaces and on aluminium foils in an ultrasonic standing wave field at 40 kHz. High-speed imaging techniques have been employed to investigate the mechanisms at work, in particular bubble interaction and cluster formation near and at the object surfaces. It was found that different prototype bubble structures can contribute to the erosion process. Some are bound to the surface, which seems to act as a bubble source in this case, while others also exist independently from the object. Cleaning and erosion effects at the pressure antinodes can vary strongly as they depend on the emerging bubble structures. These, in turn, seem to be substantially influenced by properties and the history of the surface. (C) 2004 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.ultsonch.2004.01.006"],["dc.identifier.isi","000221062200003"],["dc.identifier.pmid","15081967"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48453"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","4th Conference on the Applications of Power Ultrasound in Physical and Chemical Processing"],["dc.relation.eventlocation","Besancon, FRANCE"],["dc.relation.issn","1350-4177"],["dc.title","High-speed observation of acoustic cavitation erosion in multibubble systems"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","39"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Ultrasonics Sonochemistry"],["dc.bibliographiccitation.lastpage","42"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Appel, J."],["dc.contributor.author","Koch, P."],["dc.contributor.author","Mettin, Robert"],["dc.contributor.author","Krefting, D."],["dc.contributor.author","Lauterborn, Werner"],["dc.date.accessioned","2018-11-07T10:53:17Z"],["dc.date.available","2018-11-07T10:53:17Z"],["dc.date.issued","2004"],["dc.description.abstract","Filamentary formations of acoustic cavitation bubbles in an ultrasonic resonator are recorded by high-speed stereoscopic means. The bubble locations and motions are reconstructed in three dimensions, and a velocity distribution of bubbles is obtained. Experimental bubble trajectories are compared to a one-to-one simulation by a particle modeling approach which shows reasonable agreement. Such investigations are important for a better understanding of the mechanisms taking place in applications of intense ultrasound in liquids, and for verification and improvement of particle modeling of cavitation bubbles. (C) 2003 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/S1350-4177(03)00111-1"],["dc.identifier.isi","000186903400009"],["dc.identifier.pmid","14624986"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49325"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","Meeting on the Applications of Power Ultrasound in Physical and Chemical Processing (USound3)"],["dc.relation.eventlocation","PARIS, FRANCE"],["dc.relation.issn","1350-4177"],["dc.title","Stereoscopic high-speed recording of bubble filaments"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","670"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Journal of the Acoustical Society of America"],["dc.bibliographiccitation.lastpage","675"],["dc.bibliographiccitation.volume","120"],["dc.contributor.author","Krefting, Dagmar"],["dc.contributor.author","Toilliez, Jean O."],["dc.contributor.author","Szeri, Andrew J."],["dc.contributor.author","Mettin, Robert"],["dc.contributor.author","Lauterborn, Werner"],["dc.date.accessioned","2018-11-07T09:29:43Z"],["dc.date.available","2018-11-07T09:29:43Z"],["dc.date.issued","2006"],["dc.description.abstract","A microbubble in a sound wave oscillates in volume and translates unsteadily. The two motions are coupled. In large-scale simulations of the structure of bubble clouds driven by acoustic fields, it has been of significant convenience to decouple volume oscillations and translation, as an approximation. The errors of this decoupling approximation were considered in an earlier presentation [A. J. Reddy and A. J. Szeri, J. Acoust. Soc. Am. 112, 1346-1352 (2002)], in the parameter range of interest in medical ultrasound. In this work, the approximation is reexamined for a much broader range of driving frequencies and bubble sizes. Solving the equation of motion for linearly oscillating bubbles, it is found that even for weak acoustic forcing, the translation speed obtained with the decoupling approximation can be in error as much as 30% relative to the translation speed in the full equations. The error depends on the bubble size, the driving frequency, and the liquid properties. The results are presented in a form convenient for applications. The principal utility of the analysis is for bubbles in microgravity, or in normal gravity driven by a soundfield with a horizontal wave-number vector. (c) 2006 Acoustical Society of America."],["dc.identifier.doi","10.1121/1.2214132"],["dc.identifier.isi","000239835400014"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31113"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Acoustical Soc Amer Amer Inst Physics"],["dc.relation.issn","0001-4966"],["dc.title","Translation of bubbles subject to weak acoustic forcing and error in decoupling from volume oscillations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]