We used x-ray tomography to characterize the geometry of all bubbles in a liquid foam of average liquid fraction phi(l) approximately 17% and to follow their evolution, measuring the normalized growth rate G=V(-1/3) dV/dt for 7000 bubbles. While G does not depend only on the number of faces of a bubble, its average over f-faced bubbles scales as G(f) approximately f - f(0) for large f's at all times. We discuss the dispersion of G and the influence of V and phi(l) on G.
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http://dx.doi.org/10.1103/PhysRevLett.99.058304 | DOI Listing |
World J Gastroenterol
February 2025
Department of General Surgery, Azienda Sanitaria Locale (ASL) Lecce, Casarano 73042, Lecce, Italy.
Treatments for low degree hemorrhoids (I-III degree) are numerous and so are their counterparts for higher degrees. These treatments present nebulous differences in terms of indications and outcomes among techniques. Methods previously abandoned due to side effects and long-term results have recently rejoined the mainstream due to recent peculiar modifications: Hemorrhoidal sclerotherapy is enjoying a new age of interest due to the use of the foam form of polidocanol, which is more effective than the liquid one.
View Article and Find Full Text PDFJ Phys Chem B
March 2025
School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 Sichuan, China.
This study examines the foams generated by three surfactants: sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and sodium lauryl polyoxyethylene ether sulfate (AES). By analyzing the hydrogen bond at the gas-liquid interface, the research provides novel insights into the mechanisms by which surfactants stabilize foams. Surfactants adsorb at the gas-liquid interface, establishing hydrogen bonds with water molecules while simultaneously retarding the structural relaxation of water-water hydrogen bonds within the hydration layer.
View Article and Find Full Text PDFLangmuir
March 2025
School of Resources and Environment, Shandong University of Technology, Zibo, Shandong 255000, China.
Foam stability critically determines the efficiency of the mineral flotation process. Although the mixed amine Gemini surfactant/anionic surfactants exhibit excellent flotation performance, atomic-level investigations of the mechanism of their impact on foam stability remain limited. This study employs molecular dynamics simulations to investigate the self-aggregation behavior of mixed amine Gemini surfactant/sodium oleate (NaOl) systems with varying spacer chain lengths at the air/water interface.
View Article and Find Full Text PDFJ Expo Sci Environ Epidemiol
March 2025
Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
Background: Perfluoroalkyl substances (PFAS) are stable chemicals used in various applications. PFAS exposure has been associated with lower birth weight and immunological effects in children, and limited evidence further suggests adverse neurodevelopmental effects. Previous studies show that PFAS cross the placental barrier during pregnancy leading to prenatal exposure of the fetus.
View Article and Find Full Text PDFJ Chem Phys
March 2025
Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.
Magnesium atoms in liquid helium have been hypothesized to form a metastable foam structure, in which a layer of helium atoms surrounds each magnesium atom, inhibiting their coalescence into a compact cluster. This conjecture is based on the weak interaction between the magnesium atoms themselves and with the helium atoms and was used to explain observations in femtosecond two-photon ionization experiments by different groups. However, this theory is incongruent with previous infrared spectroscopic observations, indicating the formation of tightly bound clusters when different atoms and molecules combine inside liquid helium.
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