Browsing Scholarly literature by Author "Valsangkar, A.B."
Now showing items 1-20 of 51
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A device for finer-scale sub-sectioning of aqueous sediments
Valsangkar, A.B. (Indian Academy of Sciences, 2007)A modified hand-operated mechanical device has been developed to facilitate precise sectioning of the aqueous sediment in a core liner. The device allows the core liner to remain vertical on the disk protecting physical, ... -
A simple device for subsectioning aqueous sediments from the box or spade corer
Valsangkar, A.B. (Taylor and Francis, 2015)A simple device has been developed to accomplish the requirement of precise thin subsections of the aqueous sediments at ease from the box or spade subcores. The device has been successfully tested onboard research vessel ... -
A special core liner for sub-sampling of aqueous sediments
Valsangkar, A.B. (Current Science Association, 2009)A portable and reusable special core liner (spcl) has been developed to accomplish real-time sub-sampling of aqueous sediments. Besides being revolutionary, inexpensive and user-friendly, the spcl is capable of collecting ... -
Alkaline phosphatase: An appraisal of its critical role in c-limited deep-sea sediments of central Indian Basin
Biche, S.U.; Das, A.; Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Naik, Sonali; Helekar, S.; Sharma, R.; Valsangkar, A.B.; LokaBharathi, P.A. (Taylor & Francis Group, 2017)Alkaline phosphatase (ALP) is a hydrolase that releases phosphate, a crucial nutrient supporting formation of many macromolecules. The oligotrophic sediments of Central Indian Basin (CIB) were examined for the extent of ... -
Bacterial response to contrasting sediment geochemistry in the central Indian Basin
Das, A.; Fernandes, C.E.G.; Naik, S.S.; Nath, B.N.; Suresh, I.; Mascarenhas-Pereira, M.B.L.; Gupta, S.M.; Khadge, N.H.; PrakashBabu, C.; Borole, D.V.; Sujith, P.P.; Valsangkar, A.B.; Mourya, B.S.; Biche, S.U.; Sharma, R.; LokaBharathi, P.A. (International Association of Sedimentologists, 2011)In order to investigate whether geochemical, physiographic and lithological differences in two end-member sedimentary settings could evoke varied microbe-sediment interactions, two 25 cm long sediment cores from contrasting ... -
Benthic disturbance and impact experiments in the Central Indian Ocean Basin
Sharma, R.; Nath, B.N.; Valsangkar, A.B.; Parthiban, G.; Sivakholundu, K.M.; Walker, G.A. (Taylor and Francis, 2000)As a part of the Environmental Impact Assessment studies for nodule mining, a long-term program has been initiated in the Central Indian Basin. Multidisciplinary studies on geological, biological, physical and chemical ... -
Clay as indicator of sediment plume movement in deep-sea environment
Valsangkar, A.B. (Indian Academy of Sciences, 2004)Future polymetallic nodules mining in the Central Indian Basin (CIB) will disturb not only the deep-sea sediments but also the benthic environment. Generation of voluminous sediment plume due to mining activity is unavoidable, ... -
Composition of macrobenthos from the central Indian Ocean Basin
Pavithran, S.; Ingole, B.S.; Nanajkar, M.; Raghukumar, C.; Nath, B.N.; Valsangkar, A.B. (Indian Academy of Sciences, 2009)The deep sea is well known for its high faunal diversity. But the current interest in its abundant polymetallic nodules, poses a threat to the little known benthic organisms surviving in this unique environment. The present ... -
Deep-sea polymetallic nodule mining: Challenges ahead for technologists and environmentalists
Valsangkar, A.B. (Taylor and Francis, 2003)Although, offshore mining for mineral wealth is not required at present, it may be the only alternative in the future due to the continuous growing demand for certain metals that have no or limited land deposits. Risk ... -
Distribution of grain size and clay minerals in sediments from the INDEX area, central Indian Basin
Valsangkar, A.B.; Ambre, N.V. (Taylor and Francis, 2000)The granulometry of 21 box core sediments from five selected sites in the Central Indian Basin (CIB) have been studied to understand the sediment size characteristics in the Pioneer area before the benthic disturbance ... -
Evidence for the formation of different-sized nodules by different accretionary processes
Valsangkar, A.B.; Karisiddaiah, S.M. (Taylor and Francis, 1993)Studies on different-sized polymetallic nodules from the Central Indian Ocean Basin reveal that chemical composition is largely related to the nodule diameter which show systematic decrease in Mn, Cu, and Ni content with ... -
First phase monitoring studies of simulated benthic disturbance delineating movement of fine particles in the Central Indian Basin
Valsangkar, A.B. (Taylor and Francis, 2005)Benthic disturbance due to future deep-sea polymetallic nodule mining would involve extensive sediment plume generation and resedimentation on the sea floor. In order to evaluate the effects of resedimentation on benthic ... -
Geochemistry of calcareous sediments from the SW Carlsberg Ridge: Evidence for deeper carbonate compensation depth
Valsangkar, A.B.; Ambre, N.V. (NISCAIR, CSIR, 1995)Concentration of Mn, Fe, Ni, Co, Zn, Ca, Mg, K, Al, Si, Ti, P and CaCO sub(3) show wide range for the calcareous sediments from SW Carlsberg Ridge (CR). Compared with the average pelagic clays, the CR sediments are enriched ... -
Geochemistry of calcareous sediments from the SW Carlsberg Ridge: Evidence for deeper carbonate compensation depth
Valsangkar, A.B.; Ambre, N.V. (NISCAIR, CSIR, 1995)Concentration of Mn, Fe, Ni, Co, Zn, Ca, Mg, K, Al, Si, Ti, P and CaCO sub(3) show wide range for the calcareous sediments from SW Carlsberg Ridge (CR). Compared with the average pelagic clays, the CR sediments are enriched ... -
Geochemistry of polymetallic nodules from the Central Indian Ocean basin
Valsangkar, A.B.; Khadge, N.H.; Desa, J.A.E. (Elsevier, 1992)Polymetallic nodules dredged at fourteen stations between 12 degrees-15 degrees S and 76 degrees-80 degrees E in the Central Indian Ocean Basin (CIOB) display wide variations in shape, size, texture, mineral phases and ... -
Geochemistry, factor analysis and clay mineral distribution of the sediments and relationship with the associated ferromanganese nodules from the SW Carlsberg ridge
Valsangkar, A.B.; Karisiddaiah, S.M.; Ambre, N.V. (Indian Association for Limnology and Oceanography, 1992)Calcareous clay and ooze from the southwestern Carlberg Ridge show wide range of concentrations in Si (4.62-23.88%), Al (1.63-7.98%), Ti (0.43-1.70%) and CaCO sub(3) (8.50-79.75%) and reveal association of the elements ... -
Geological and geophysical exploration along Carlsberg Ridge
Mudholkar, A.V.; Kodagali, V.N.; KameshRaju, K.A.; Valsangkar, A.B.; Ranade, G.; Ambre, N.V. (International Cooperation of Ridge-Crest Studies, 1997) -
Geomorphological and petrological observations along a segment of slow-spreading Carlsberg Ridge
Mudholkar, A.V.; Kodagali, V.N.; KameshRaju, K.A.; Valsangkar, A.B.; Ranade, G.; Ambre, N.V. (Indian Academy of Sciences, 2002)A 120-km-long section of the Carlsberg Ridge has been mapped with multi-beam bathymetry system (MBS). High-resolution bathymetric contour map generated with the MBS data shows well-defined axial valley bordered by steep ... -
Geotechnical characteristics of siliceous sediments from the Central Indian Basin
Khadge, N.H.; Valsangkar, A.B. (Current Science Association, 2008)Geotechnical properties and grain size analysis of surface sediments from the CIB showed silty clays of high porosity due to loose fabric of very fine particles, bioturbation and radiolarian tests. Their water content ... -
Heavy mineral placers off Kalbadevi Bay, Ratnagiri, Maharashtra
Valsangkar, A.B. (Macmillan, India, 2007)Sedimentological and heavy mineral studies were carried out for two offshore profiles in the Kalbadevi Bay, Ratnagiri, Maharashtra. The surface samples from the Bay were collected during pre- and post- monsoon period (i.e. ...