An Ultrasonic Sensor for Process Modeling and Proces Control of Ceramic Superconductors
This research demonstrates the feasibility of utilizing nondestructive ultrasonic sensors to monitor the effects of oxygen content, processing time and temperature on the resultant mechanical, structural, and electrical properties of high temperature ceramic superconductors. Ultrasonic velocity changes, as a function of processing time and temperature, have clearly been shown to indicate the transformation between orthorhombic and tetragonal phases in Y-Ba-Cu-O.
A Teflon pressure-transducer-specimen bond for ultrasonic measurements over a wide temperature range
Abstract A major limitation for the application of megahertz ultrasonic techniques to the study of the properties of solids is the problem of finding transducer-specimen bonds useful over a wide temperature range. A Teflon pressure bond has been developed and tested. It appears to overcome most of the problems, and promises to allow for many studies previously more difficult or impracticable.
Mucoadhesive Nanoparticles for Drug Delivery to the Anterior Eye
While the use of topical drops for the delivery of drugs to the anterior of the eye is well accepted, it is far from efficient with as little as 5% of the drug instilled on the eye actually reaching the target tissue. The ability to prolong the residence time on the eye is desirable. Based on the acceptability of 2-hydroxyethyl methacrylate based polymers in contact lens applications, the current work focuses on the development of a poly(2-hydroxyethyl methacrylate (HEMA)) nanoparticle system. The particles were modified to allow for degradation and to permit mucoadhesion. Size and morphological analysis of the final polymer products showed that nano-sized, spherical particles were produced. FTIR spectra demonstrated that the nanoparticles comprised poly(HEMA) and that 3-(acrylamido)phenylboronic acid (3AAPBA), as a mucoadhesive, was successfully incorporated. Degradation of nanoparticles containing N,N′-bis(acryloyl)cystamine (BAC) after incubation with DL-dithiothreitol (DTT) was confirmed by a decrease in turbidity and through transmission electron microscopy (TEM). Nanoparticle mucoadhesion was shown through an in-vitro zeta potential analysis.