NOPR Collection:

Distribution of rare earth elements in the inner shelf sediments, off the southwest coast of India

2016-12-01T00:00:00Z

Title: Distribution of rare earth elements in the inner shelf sediments, off the southwest coast of India Authors: Jayaprakash, C.; Sajeev, R.; Kumar, A. Anil Abstract: Shallow part of the seafloor adjoining the coast of Kerala is mostly covered by silty clay and clayey silt, from north of Quilon to Kasaragod. Sand dominate the shallow seafloor south of Quilon as well as the deeper part of inner shelf from Vizhinjam to Ponnani. Concentrations of Rare Earth Elements were determined in the surface sediments within the inner shelf off the coast of Kerala. ΣREE content in surface sediments varies between 9.15 mg. kg^-1 and 319.66 mg. kg^-1. Distribution pattern suggests higher concentration of REE in the inner shelf sediments off southern Kerala, between Ponnani and Vizhinjam. Sediments off northern Kerala have lower REE. ΣLREE ranges between 5.61 mg. kg^-1 and 306.31 mg. kg^-1 and is more in the southern sector. ΣHREE in inner shelf sediments is very low ranging between 2.91 mg. kg^-1 and 36.8 mg. kg^-1. REE in coastal sediments off Kerala is closely related to heavy mineral content. LREE is mostly contributed by detrital monazite, apatite and sphene in the fine fractions and HREE by detrital zircon, garnet, amphibole and pyroxene. Sediments from southern and central sectors show enrichment in ΣLREE compared to PAAS. There is a depletion in La, Ce and Pr in the shelf sediments from the northern sector and remaining LREE in this sector show enrichment. HREE is enriched in the central and northern sectors and depleted in the southern sector compared to PAAS. Page(s): 1623-1630

Stomach content analysis of Cobia Rachycentron canadum (Linnaeus, 1766) from North West coast of in India

2016-12-01T00:00:00Z

Title: Stomach content analysis of Cobia Rachycentron canadum (Linnaeus, 1766) from North West coast of in India Authors: Sajeevan, M.K.; Kurup, B. Madhusoodana Abstract: The present study is an attempt to understand the composition of the gut contents of Cobia inhabiting in Indian waters. Eleven groups of marine organisms were found in the stomach of Cobia. Fishes dominated the gut contents of male cobia, whereas crabs dominated the guts of female Cobia. Results illustrated seasonal variation on the preferential food. Cobia mainly fed on the prey available in the ecosystem and this point towards the opportunistic feeding behavior of the species. Analysis on the variation of gut contents in different life history stages showed that the share of marine organisms other than fishes were more in the guts of juveniles than that of adults. Page(s): 1631-1637

Chlorine dioxide as antifouling biocide results in reduced Trihalomethanes in condenser effluents at a coastal power station

2016-12-01T00:00:00Z

Title: Chlorine dioxide as antifouling biocide results in reduced Trihalomethanes in condenser effluents at a coastal power station Authors: Rajamohan, R.; Venugopalan, V. P.; Natesan, Usha Abstract: Biofouling control in coastal power stations is generally achieved through the use of chlorination. However, chlorine reacts with natural organic matter, leading to the formation of several chlorinated by-products such as trihalomethanes (THMs). Environmental discharge of THMs is of concern, as these compounds have been reported to be carcinogens and mutagens. Usage of chlorine dioxide as an alternative biocide is an effective way of controlling biofouling. This paper compares the formation and distribution of THMs in the cooling water discharge of a coastal power plant operating on the east coast of India under conditions of chlorination and chlorine dioxide addition. It is shown that use of chlorine dioxide as an alternative biofouling control agent results in reduced THMs formation and environmental release. Page(s): 1638-1644

Forest landscape connectivity change analysis in the Yangtze River basin by multi-temporal satellite data

2016-12-01T00:00:00Z

Title: Forest landscape connectivity change analysis in the Yangtze River basin by multi-temporal satellite data Authors: Huang, Pujiang; Du, Fengjiao; Yang, Shuo; Liu, Chang Abstract: This study selected the highly urbanized Wuhan city in the Yangtze River basin as a research area, and used the Landsat 5 TM images from 1990 and the Landsat 7 ETM+ images from 2000 and 2010. These images were combined by using the graph-based integral index of connectivity (IIC), probability of connectivity (PC), and the importance value of the patch to analyze the spatial and temporal dynamic change of the Wuhan urban forest. Results showed the increasing area and the widening Wuhan forest. However, for the past 20 years, their patch structure has been uneven, and composed of several small and super-large patches. The IIC and PC of Wuhan forest tended to increase slightly, whereas the connectivity level of urban forest remained low. The value of the importance of the patch and its range are increasing. Some of its characteristics indicated north is better than south, rural is higher than urban, and the main urban area is lesser than the urban area. Page(s): 1645-1651