En la zona próxima a la costa del área de estudio, el movimiento de la arena a lo largo de la costa es debido a la acción de las olas y las corrientes. El movimiento del sedimento a lo largo de la línea de costa del área de estudio es principalmente gobernado por fuerzas asociadas a las olas entrantes a la costa y la disponibilidad de sedimentos en la zona. Esta investigación fue realizada para estudiar el movimiento del sedimento en relación a la actividad de las olas a lo largo de la costa. La dirección del transporte de sedimento a lo largo de la costa es mayor hacia el Norte que hacia el Sur. Las condiciones normales para el movimiento anual del sedimento se encuentran en aguas someras y en la playa. Las olas y la corriente de oleaje generan una deriva litoral de las arenas a lo largo de la playa y costa afuera. La erosión natural en el área de estudio (exepto Kanyakumari) entre Marzo y Octubre es debido a la prevalencia del gran oleaje desde la dirección Sur y Sureste. Introduction

In the nearshore zone ofpresent study area, the movement ofsand alongshore is due to the action ofwaves and currents. The sediment movement along the shoreline ofstudy area is mainly governed by the forces associated with the incoming wavesandtheavailabilityofsedimentswithinthearea. Thepresentinvestigationhasbeenmadeasanattempttoappreciate the sediment movement in relation to wave activity along the coast. The longshore sediment transport is higher in the northerly direction as compared to southerly direction. The normal condition is for and to be moved annually or more frequently in the shallows and on the beach. Waves and wave-driven currents cause longshore drift ofsand alongthe beach and offshore. The net erosive nature of the study area (except Kanyakumari) from March to October is due to the prevalence ofhigh waves from S and SE directions.

The present study was carried out to evaluate the antioxidant and antimicrobial activities of a methanol extract of Bauhinia racemosa (MEBR) (Caesalpiniaceae) stem bark in various systems. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of the methanol extract increased in a concentration-dependent manner. About 50, 100, 250, and 500 µg MEBR inhibited the peroxidation of a linoleic acid emulsion by 62.43, 67.21, 71.04, and 76.83%, respectively. Similarly, the effect of MEBR on reducing power increased in a concentration-dependent manner. In DPPH radical scavenging assays the IC50 value of the extract was 152.29 µg/ml. MEBR inhibited the nitric oxide radicals generated from sodium nitroprusside with an IC50 of 78.34 µg/ml, as opposed to 20.4 µg/ml for curcumin. Moreover, MEBR scavenged the superoxide generated by the PMS/NADH-NBT system. MEBR also inhibited the hydroxyl radical generated by Fenton's reaction, with an IC50 value of more than 1000 µg/ml, as compared to 5 µg/ml for catechin. The amounts of total phenolic compounds were also determined and 64.7 µg pyrocatechol phenol equivalents were detected in MEBR (1 mg). The antimicrobial activities of MEBR were determined by disc diffusion with five Gram-positive, four Gram-negative and four fungal species. MEBR showed broad-spectrum antimicrobial activity against all tested microorganisms. The results obtained in the present study indicate that MEBR can be a potential source of natural antioxidant and antimicrobial agents.