Open Access Original Research Article

Influence of Tyre’s Dimensional Characteristics on Tyre-Pavement Noise Emission

A. Kumar, A. Tandon, S. Paul, A. Singla, S. Kumar, P. Vijay, U. D. Bhangale

Physical Science International Journal, Page 124-137

Road Traffic Noise is causing huge socio-economic losses to the nations all around the world by lowering the quality of life and property values. India, poised with the annual projected automotive industry growth of 12% to 15% for 2011-12 and ever increasing traffic on its roads draws serious concern related to traffic noise pollution. The noise associated with tyre-pavement interaction is known to be a major component of traffic noise. The paper addresses the influence of dimensional characteristics of tyres i.e. tyre section width and overall tyre diameter on the noise emission associated with tyre-pavement interaction. The principle focus of the study was to identify a conceivable trend showing not only the effect of tyre dimensions on tyre-pavement noise but also the extent of the influence. The tyres used for the study belong to C1 Class of tyres as per United Nations Economic Commission for Europe Regulation 30 (UNECE R30). For each set of tyres, the dimensional characteristics were first recorded and then the Coast-By Noise Measurement method in accordance with ISO-13325(2003) was employed to evaluate the tyre-to-road sound pressure emission level [SPL in dB (A)] on two different test sites. Based on the data obtained, a detailed analysis was carried out and the relation between tyre-pavement noise emission and said dimensional characteristics was established. The results were found to indicate that the on both test surfaces (rough), the tyre-pavement noise increases with increase in tyre section width and decreases with increase in overall tyre diameter. Plausible reasons in support of the results obtained were then identified and discussed.

Open Access Original Research Article

TEM and XAS Study of Silver Nanoparticles Formed in Phaseolus vulgaris

J. Parra Berumen, E. Gallegos-Loya, E. Orrantia-Borunda, A. Duarte-Moller, C. González-Valenzuela

Physical Science International Journal, Page 138-147

The phytoremediation can be used to recover precious metals like gold, silver, platinum and palladium, indicating that there is a wide opportunity for use it as a remediation technology in mining. The alfalfa alive was used to reduce the silver and forming silver nanoparticles Ag (0). The plant Phaseolus vulgaris (beans) was used to form silver nanoparticles through bioreduction of Ag (I) to Ag (0) in the living plant. Two groups of plants were used. One group of plants grew at garden soil and the other in cotton. In both cases, a solution of AgNO3 was added initially in a concentration of 0.01M then the concentration was changed to 0.1mm. The samples were analyzed with X-Ray Absorption Spectroscopy (XAS) at the Stanford Synchrotron Radiation Laboratory (SSRL) and later with Transmission Electron Microscopy (TEM). Analyzing the media of cultivation in soil and cotton and also in the roots of the plants, silver was found as silver oxide (AgO). In stem and leaves silver was found as Ag (0). The XAS spectra were adjusted for more accurate results. The plant has the ability to reduce the valence of silver and form nanoparticles. The TEM images show that the average particle size is 18 nm, showing in various forms and a greater number of them in the leaves of plants grown in soil.