ENERGY ANALYSIS OF THE USE PHASE OF CONVENTIONAL TIRES COMPARED TO GUAYULE NR TIRES

ABSTRACT Guayule NR can be grown in the United States and offers a potentially more secure and sustainable alternative to the substantial Hevea NR that is imported from Southeast Asia. This paper presents the first rolling resistance and use-phase energy consumption estimates for guayule tires. The results of this study show that use-phase life cycle energy reductions can be achieved with NRs and that the rolling resistance coefficient (RRcnew) and reference service life (RSL) of the new tire are the critical parameters that pertain to energy and fuel efficiency. A tire's use phase accounts for approximately 86% of its life cycle energy consumption and thus is an important consideration in sustainability assessments. We calculated the use-phase energy consumption for two types of NR tires: a 100% guayule rubber tire and an experimental epoxidized NR tire. These two NR tires were compared against a conventional passenger tire made by Cooper Tire &amp; Rubber Company. The ISO product category rules for passenger tires were used to determine energy consumption, while relevant data were measured from concept tires built in collaboration with Cooper Tire &amp; Rubber Company. The results of this analysis showed that both experimental NR tires have improved use-phase energy consumption compared to conventional rubber tires. Although the epoxidized NR tire with low RRcnew consumes the least energy during the use phase, it is currently not being considered for commercial manufacture. The 100% guayule rubber tire shows a 6% reduction in energy consumption compared to the conventional rubber tire. Results of the sensitivity analysis showed a linear change in use-phase energy consumption with the relevant tire load and RRcnew and an inverse change with the average vehicle fuel efficiency and the RSL.</jats:p

Effectiveness of Nanoparticles in Enhancing Bond Strength in Adhesive Dentistry

Background: New opportunities for improving material qualities and clinical results have been created by the introduction of nanotechnology in dentistry. The ability of nanoparticles to strengthen the binding between adhesives used in restorative dentistry has drawn more attention. This is because successful and long-lasting dental procedures depend on strong adhesives. The purpose of this research is to determine if silica and zirconia nanoparticles may improve the bond strength of dental adhesives. Materials and Methods: The adhesive treatments applied to 60 removed human molars were separated into three groups at random: ordinary adhesive, adhesive combined with silica nanoparticles, and adhesive combined with zirconia nanoparticles. For both experimental groups, the nanoparticle concentration was normalized to 5% by weight. After being stored in distilled water at room temperature for 24 hours, the bond strength was assessed using a universal testing equipment. Results: There were notable variations across the groups based on the bond strength tests. The silica nanoparticle group had an improved binding strength of 30 MPa, compared to an average bond strength of 22 MPa for the traditional adhesive group. At an average of 35 MPa, the zirconia nanoparticle group showed the strongest bond. A statistical study verified that there were significant differences (P < 0.05) between each of the adhesives boosted with nanoparticles and the regular glue. Conclusion: Dental adhesives using silica and zirconia nanoparticles considerably improve binding strength over traditional adhesives. The exceptional binding strength of zirconia nanoparticles, in particular, raises the possibility of their practical use in adhesive dentistry to lengthen the lifespan of dental restorations