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Water is closely linked with all living beings and it is the source of all developments in the form of societal, cultural, rituals and religious beliefs. The river Cauvery is the only perennial river in Tamil Nadu and the water level is raised during rainy season. Out of 133 chapters in Thirrukkural, one of the famous Tamil literature, the second chapter itself deals with the importance of water management and the need for the water cycle. All most all the ancient Tamil literatures have evidenced of various water management practices which were carried out to manage the water throughout the year. Several thousand years ago, the olden civilizations were invented to consume the water flowing through the canals and drainages to the maximum extent. Various dynasty were ruled in India before 1000 years onwards and the emperors handled the water management in a systematic approach and managed the floods and droughts in an effective manner. Various structures like canals, dams and water diversion were built by the emperors for the effective utilization of rain water. This paper deals with the effective water management exercises practiced in more than 1000 old Chozha dynasty in Tamil Nadu. [ABSTRACT FROM AUTHOR]

One of the most important application of the VLF signals is that it contains possible information about the lithosphere-ionosphere coupling. In other words, in near future, it may be possible to predict seismic events by judging signatures of VLF signals. In this paper, we present the result of the monitoring of the VLF signals collected in the Malda branch of ICSP, located in Malda, West Bengal, for four years (2005, 2007-09) and we try to find out the co-relations, if any, between the ionospheric activities and the earthquakes. Here we use that VLF signals which are transmitted from the VTX station (18.2 KHz), located near Vijayanarayanam in Tamilnadu, about 2290 km away from the receiver. To find out the co-relation of the ionospheric activities with the seismic events such as earthquake, first we have to study the average signal throughout the year. For this, we plot the so-called standardized calibration curve using the four years data. Here we use a total of 481 no. of data. To establish the co-relation between the ionospheric activities and the seismic events, we use the data of the year 2008 and we found that the deviations of the anomalous data are co-related with the seismic event. We found that the highest deviation takes place one day prior to the seismic events. We also calculated the 'D-layer preparation time' (DLPT) and the 'D-layer disappearance time' (DLDT) for the data of 2008 and tried to establish the co-relation between the anomalous DLPT and DLDT with the seismic events, if any. We compare our result with the VLF signals received from other places. [ABSTRACT FROM AUTHOR]

Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials in Tiruvannamalai, city, have been collected randomly over the city. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. All samples under investigation are within the recommended safety limit when used as building construction. [ABSTRACT FROM AUTHOR]