Topic
Surface tension
About: Surface tension is a research topic. Over the lifetime, 25410 publications have been published within this topic receiving 695471 citations.
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TL;DR: In this paper, the work carried out on pressure infiltration of packed ceramic particulate by liquid metals, mainly aluminum and its alloys, is reviewed and the main features of the technique and of the experimental procedures are first considered.
175 citations
TL;DR: In this article, the vertical component of the surface tension force on a body partly submerged in a liquid is shown to equal the weight of liquid displaced by the meniscus, and this was known for vertical axially symmetric bodies and for two-dimensional vertical plates.
Abstract: The vertical component of the surface tension force on a body partly submerged in a liquid is shown to equal the weight of liquid displaced by the meniscus. It is upward if the meniscus is depressed and downward if the meniscus is elevated. Previously this was known for vertical axially symmetric bodies and for two-dimensional vertical plates. The vertical component of the pressure force on the body is shown to equal the weight of liquid which would fill the volume bounded by the wetted surface of the body, a vertical cylinder through the waterline, and the original horizontal free surface.
175 citations
TL;DR: It is demonstrated that some of the matter of the model pulmonary surfactant can move in and out of the active monolayer, to keep the surface tension of the alveolar air/water interface constantly low over the range of area encountered upon breathing.
175 citations
TL;DR: A new model for contrast agents is developed, fitted in the linear regime, and successfully investigated its applicability for a wide range of operating parameters, showing that it can be used for characterizing different agents and designing new ones.
Abstract: A quantitative model of the dynamics of an encapsulated microbubble contrast agent will be a valuable tool in contrast ultrasound (US). Such a model must have predictive ability for widely varying frequencies and pressure amplitudes. We have developed a new model for contrast agents, and successfully investigated its applicability for a wide range of operating parameters. The encapsulation is modeled as a complex interface of an infinitesimal thickness. A Newtonian rheology with surface viscosities and interfacial tension is assumed for the interface, and a modified Rayleigh–Plesset equation is derived. The rheological parameters (surface tension and surface dilatational viscosity) for a number of contrast agents (Albunex®, Optison® and Quantison®) are determined by matching the linearized model dynamics with experimentally obtained attenuation data. The model behavior for Optison® (surface tension 0.9 N/m and surface dilatational viscosity 0.08 msP) was investigated in detail. Specifically, we have carried out a detailed interrogation of the model, fitted in the linear regime, for its nonlinear prediction. In contrast to existing models, the new model is found to capture the characteristic subharmonic emission of Optison® observed by Shi et al. (1999) . A detailed parametric study of the bubble behavior was executed using the ratio of scattering to attenuation (STAR). It shows that the encapsulation drastically reduces the influence of resonance frequency on scattering cross-section, suggesting possible means of improvement in imaging at off-resonant frequencies. The predictive capability of the present model indicates that it can be used for characterizing different agents and designing new ones. (E-mail: sarkar@me.udel.edu)
175 citations
TL;DR: Comparison with the liquid-vapor interfacial tensions of the model liquids studied here indicates that the surface free energies extracted for atomic-size cavities cannot be accurately identified with the macroscopic surface tensions of these systems.
Abstract: Observation of the size distribution of transient cavities in computer simulations of water, n-hexane, and n-dodecane under benchtop conditions shows that the sizes of cavities are more sharply defined in liquid water but the most-probable-size cavities are about the same size in each of these liquids. The calculated solvent atomic density in contact with these cavities shows that water applies more force per unit area of cavity surface than do the hydrocarbon liquids. This contact density, or "squeezing" force, reaches a maximum near cavity diameters of 2.4 angstroms. The results for liquid water are compared to the predictions of simple theories and, in addition, to results for a reference simple liquid. The numerical data for water at a range of temperatures are analyzed to extract a surface free energy contribution to the work of formation of atomic-size cavities. Comparison with the liquid-vapor interfacial tensions of the model liquids studied here indicates that the surface free energies extracted for atomic-size cavities cannot be accurately identified with the macroscopic surface tensions of the systems.
175 citations