An evaluation of machine guarding techniques for robot guarding
Abstract An increasing number of problems caused by the use of industrial robots should be expected due to the dramatically increasing population of robots today. In this paper, machine guarding functions and techniques are reviewed. The possibilities of transferring the concepts of machine guarding to robotic systems are then analyzed. The analysis shows that most of the guarding techniques are still applicable to industrial robots with modifications to accommodate differences. A set of guidelines for installing safeguarding devices is also presented. Research is need in the areas of guarding techniques for robotic cells, new sensor development, and sensor reliability, fusion, and coordination problems.
A model to predict and optimize machine guarding operator compliance activities in a bottling process plant: a developing country experience
Introduction. The accurate tracking, elimination and control of hazards are fundamentals in accident avoidance at operational machine guarding stations. This article develops a machine guard usage compliance model. Nonetheless, very few studies account for operator compliance to the usage of machine guards in workplaces. Methods. This article contributes by first building up a multiple regression (MR) model, and, second, proposing a novel integrated MR and Taguchi method (MR-TM) model that optimizes operator compliance to guard usage. The comparative significance of the diverse factors was appraised and examined via analysis of variance. Results. Bottling process data from Nigeria illustrate the effectiveness of the proposed model. The coefficient of determination (R 2 = 0.997) established the efficient predictive ability of the MR model. The significant variables are the number of functional guards and damaged guards, and the number of non-compliances (guards present and operational but not used) (p < 0.050). Simulated and field data variables exhibited good agreement (R 2 = 0.997). From the MR-TM model, the most significant result is the highest operator compliance for machine guard usage with mean and signal-to-noise ratio values of 269.28 and 48.60, respectively. Conclusion. This work provides safety managers with snapshot information for planning and control purposes.
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.