Investigation of the Influence of Ultrasound Action on Diffusion Processes in an Explosion-Welded Bimetal System Cu-Al during Heat Treatment

The influence of ultrasound on the main regularities of the formation and growth of the diffusion zone at the interlayer boundary of an explosion-welded layered composite material of Al-Cu systems is investigated. It is proved that the effect of ultrasound contributes to the reduction of the latent period of the nucleation of intermetallic phases at the interlayer boundary, lowers the temperature of the beginning of the eutectic transformation (by about 10 ° C), but at the same time does not affect the phase composition of the diffusion zone as a result of homogeneous reactions at the boundary of contact of solids. It has been established that the thickness of the diffusion zone, with the duration of the supplied acoustic vibrations, ensures the absence of cracks in the diffusion zone, leading to delamination of the material, increases by 30-40% at a fixed temperature of intense diffusion.

Image-Guided Drug Delivery to Tumors using Ultrasound-Activated Perfluorocarbon Nanoemulsions as Drug Carriers

It is still not known which mode of ultrasound action - thermal or mechanical - plays the predominant role in ultrasound mediated drug delivery. This project will combine results from two powerful imaging modalities, MRI and RFP imaging, to better understand and quantify the major effects. Several experimental variables will be tested in vivo using RFP-transfected pancreatic cancer MiaPaCa2 subcutaneous tumors grown in nude mice, providing information to better understand the mechanisms involved in ultrasound-mediated drug delivery.

The interaction of a rising bubble and a particle in oscillating fluid

This article considers the interaction of a rising bubble and a sedimenting fine particle in an incompressible viscous liquid under vibrations (ultrasound). The particle is subject to Stokes, Basset and buoyancy forces, and average force due to the inhomogeneity of the pulsating field. It is shown that the main contribution to the average force is made by interference of the external field and the field caused by the monopole mode of bubble oscillations. The interaction force is the attraction of the particle to the bubble. It is found that even weak vibrations lead to considerable increase of the effective cross-section of particle capture by the bubble. The evaluation of the efficiency of the flotation process exposed to an ultrasound action is discussed.

Effect of Ultrasound Action Modes on the Oxidation Resistance of Ni-Nd2O3 Nanocomposite Coatings

The Ni-Nd2O3nanocomposite coatings were prepared by electrodeposition with different modes of ultrasound action. The surface morphology and co-deposited Nd2O3content of Ni-Nd2O3nanocomposite coatings were analyzed by scanning electron microscopy (SEM). The microstructure of Ni-Nd2O3nanocomposite coatings after oxidation was examined. The oxidation resistance of the coatings prepared by different electrodeposition methods was comparatively investigated. The results show that the content of Nd2O3nanoparticles greatly influences the oxidation resistance of nanocomposite coatings. The nanocomposite coating has an excellent oxidation resistance with the increased content of Nd2O3nanoparticles. Meanwhile, Nd2O3nanoparticles and ultrasound can significantly affect the microstructure and the oxidation resistance of Ni-Nd2O3nanocomposite coatings. The Ni-Nd2O3coating prepared by electrodeposition with dual-frequency ultrasound action has finer grains and denser structure and exhibits a superior oxidation resistance compared with the other coatings.