J. S. Sulzer, Gordon, K. E., Hornby, G. T., Peshkin, M. A., and Patton, J. L., “Adaptation to knee flexion torque during gait,” Rehabilitation Robotics, 2009. ICORR 2009. IEEE International Conference on. IEEE, pp. 713-718, 2009.
A set of bimetallic Pd−Cu/PVP (PVP = poly(N-vinylpyrrolidone)) colloids, with copper proportions ranging from 0 to 50 atom %, has been examined as catalysts in a batch reactor with flowing hydrogen for the reduction of aqueous nitrate and/or nitrite. The encapsulated Pd−Cu nanoparticles were characterized by powder XRD, TEM, EDX, and IR of adsorbed CO. A significant decrease in average particle diameter and changes in the Pd−Cu crystallinity occurred above ca. 30% copper content, and this transition corresponded with a significant increase in observed nitrate reduction rates. The strong dependence on composition suggests that specific Cun ensembles on the surface of the Pd−Cu nanoparticles are needed for effective nitrate-to-nitrite conversion. In contrast, nitrite reduction rates were only minimally enhanced by the presence of copper. Increasing pH had little effect on the nitrate reduction rates, but it strongly inhibited the rate of nitrite reduction. The requisite protonation of a palladium−nitrite surface intermediate is proposed.
In this work, the history of colloids in supercritical fluids in the last two decades and future directions in several promising areas are discussed. The primary focus of this article is on microemulsions and emulsions, although new developments are described involving protein colloids, electrostatic stabilization of inorganic particles and the use of CO(2) as an antisolvent for separation of metal colloids. The focus on the CO(2)-water interface is related to the fact that, historically, the studies of colloids in supercritical fluids began with microemulsions and emulsions, and then evolved to polymer latexes and inorganic dispersions. Moreover, many of the same types of stabilizers have been used for the various types of colloids. (C) 2008 Published by Elsevier B.V.
Ultrasound is a widely used modality with excellent spatial resolution, low cost, portability, reliability and safety. In clinical practice and in the biomedical field, molecular ultrasound-based imaging techniques are desired to visualize tissue pathologies, such as cancer. In this paper, we present an advanced imaging technique - combined photoacoustic and magneto-acoustic imaging - capable of visualizing the anatomical, functional and biomechanical properties of tissues or organs. The experiments to test the combined imaging technique were performed using dual, nanoparticle-based contrast agents that exhibit the desired optical and magnetic properties. The results of our study demonstrate the feasibility of the combined photoacoustic and magneto-acoustic imaging that takes the advantages of each imaging techniques and provides high sensitivity, reliable contrast and good penetrating depth. Therefore, the developed imaging technique can be used in wide range of biomedical and clinical application.