Program design of an online dynamic balancing system for grinding-wheel and spindle
For unbalance of grinding wheel and spindle system in high-speed grinding process, an online dynamic balancing program is proposed. Firstly unbalance factors during grinding process are analyzed, and vibration features excited by these centrifugal forces are defined. Based on these works, technologies on wheel-spindle online dynamic balancing are introduced, including sensor selection and setting, vibration signal and phase angle measurement, signal amplification and analog filtering, A/D conversion, digital filtering, unbalance solution, dynamic balancing device and its drive and control. Finally, a wheel-spindle online dynamic balancing program is designed, which will have a good engineering application prospect in CNC machine spindle system.
An Introduction to Holo-balancing Technique
This paper aims to provide an introduction to the holo-balancing technique. A detailed description of model separation, transfer matrix, computer aided simulation and genelic algorithm optimization technique is presented. The advantages of holo-balanc-ing technique are derived at the end.
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.