Non contact wear measurement on pneumatic seals
Abstract An experimental methodology aimed at the evaluation of wear in pneumatic seals is presented. New equipment was designed and manufactured in order to measure the radial thickness of worn material on the sealing edge both axially and circumferentially, by means of a laser sensor, as well as to avoid the necessity of disassembling the seals. The methodology is intended as an instrument for a quick comparison of seal prototypes and is proposed as an alternative to those methods that globally quantify the wear of samples by measuring their loss of weight or volume. Results obtained on a NBR commercial lip seal are presented.
Experimental study of pneumatic seal extrusion
An experimental study of pneumatic seal extrusion is presented. Direct visual observations are made. An empirical formula for calculating extrusion based on the geometric characteristics of the sealing system is presented.
Single step formation of biocompatible bimetallic alloy nanoparticles of gold and silver using isonicotinylhydrazide.
Manufacturing nanoparticles with controlled physicochemical properties using environment-friendly routes have potential to open new prospects for a variety of applications. Accordingly, several approaches have been established for manufacturing metal nanoparticles. Many of these approaches entail the use of hazardous chemicals and could be toxic to the environment, and cannot be used readily for biomedical applications. In the present work, we report a single step bio-friendly approach to formulate gold (Au), silver (Ag), and Au-Ag alloy nanoparticles with desired surface corona and composition using isonicotinylhydrazide (INH) as a reducing agent. INH also functioned as a stabilizing agent by enabling a surface corona around the nanoparticles. Remarkably, within a single step INH could also provide a handle in regulating the composition of Au and Ag in bimetallic systems without any additional chemical modification. The physicochemical and surface properties of the different nanoparticles thus obtained have been examined by analytical, spectroscopic and microscopic techniques. Cell cytotoxicity (release of lactate dehydrogenase), cell viability and intracellular reactive oxygen species (ROS) assays confirmed that the Au, Ag, and Au-Ag bimetallic nanoparticles prepared with INH are biocompatible. Finally, the presence of organic surface corona of INH on the nanoparticles was found to impart nanozyme activity and antimycobacterial sensitivity to the nanoparticles.