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111.
112.
Leaching with Thiobacillus ferrooxidans has been used for selectively extracting Cu, Zn and Cd values from a PbS concentrate. The PbS is partly oxidized to the sulphate form. A scheme has been proposed for the recovery of the metal values from the leach liquor. 相似文献
113.
The dielectric constants and dielectric loss values of BeAl2O4 (chrysoberyl), MgAl2O4 (spinel), Be2SiO4 (phenacite), and Mg2SiO4 (forsterite) were measured at 1 MHz using a two-terminal method and empirically determined edge corrections. The results
are: chrysoberyl, κ′
a
=9.436, κ′
b
=9.071, κ′
c
=8.269; spinel, κ′
a
=8.18; phenacite, κ′
a
=6.28, κ′
c
=6.06; and forsterite, κ′
a
=6.867, κ′
b
=7.392, κ′
c
=6.739. The agreement between measured dielectric polarizabilities as determined from the Clausius-Mosotti equation and those
calculated from the sum of oxide polarizabilities according to αD(M2M′X4) = 2αD(MX)+αD(M′X2) is ~ 1.0%. 相似文献
114.
Stellite Remote Sensing is an emerging technique for observation of oceans. The important oceanic parameters, wave heights and wind speeds derived fron GEOSAT Altimeter data, are analysed in the present paper. Relation between wind speed and height of ‘sea waves’ are obtained for southwest monsoon, northeast monsoon and nonmonsoon seasons, and regression equations are arrived at for each case. Good correlation and high accuracy are observed for all the seasons. This assures the usage of remotely sensed data for oceanic studies. 相似文献
115.
The variational technique of data assimilation using adjoint equations has been illustrated using a nonlinear oceanographic
shallow water model. The technique consists of minimizing a cost function representing the misfit between the model and the
data subject to the model equations acting as constraints. The problem has been transformed into an unconstrained one by the
use of Lagrange multipliers. Particular emphasis has been laid on finite difference formulation of the algorithm. Several
numerical experiments have been conducted using simulated data obtained from a control run of the model. Implications of this
technique for assimilating asynoptic satellite altimeter data into ocean models have been discussed. 相似文献
116.
117.
Subramanian VEERASINGAM tamdoss VENKATACHALAPATHY Thirunavukkarasu RAMKUMAR 《国际泥沙研究》2014,29(1):11-23
Clay mineralogy, texture size and statistical analyses were carried out on surface sediments from the continental shelf of Chennai, Bay of Bengal, India. The purpose of this study is to characterize the clay mineral distribution and its relation to the hydrodynamics off Chennai to identify the sources and transport pathways of the marine sediments. Characterization of clay minerals in coastal sediments by Fourier Transform Infrared (FTIR) spectroscopy has provided the association of quartz, feldspar, kaolinite, chlorite, illite and iron oxides (magnetite and hematite) derived from river catchments and coastal erosion. Kaolinite, chlorite, illite, iron oxides, and organic matter are the dominant minerals in Cooum, and Adayar region. High quartz and feldspar zones were identified in Marina, which are being confined the sand zone and paralleling the coast. The strong relationships among the wave energy density, sand, quartz and carbonate revealed that wave induced littoral drift system play a dominant role in transportation and deposition of sediments in the Chennai coast. The sediment texture and minerals data are in agreement well with the previous results of hydrodynamics and littoral drift models in this region. Multivariate statistical analyses (correlation, cluster and factor analyses) were carried out and obtained results suggested that clay minerals and organic matter are trapped in silt and clay particles, whereas quartz, feldspar and carbonate are associated with sand particles. Results of sediment sources and transport processes from this study will be useful to predict the fate of the pollutants released from land or the potential change in sediment delivery to coastal areas. 相似文献
118.
Kwadwo Ansong Asante Tetsuro Agusa Reiji Kubota Hiroko Mochizuki Shuhei Nishida Suguru Ohta Annamalai Subramanian 《Marine pollution bulletin》2010,60(9):1560-1570
Trace elements (TEs) and stable isotope ratios (δ15N and δ13C) were analyzed in fish from deep-water of the Sulu Sea, the Celebes Sea and the Philippine Sea. Concentrations of V and Pb in pelagic fish from the Sulu Sea were higher than those from the Celebes Sea, whereas the opposite trend was observed for δ13C. High concentrations of Zn, Cu and Ag were found in non-migrant fish in deep-water, while Rb level was high in fish which migrate up to the epipelagic zone, probably resulting from differences in background levels of these TEs in each water environment or function of adaptation to deep-water by migrant and non-migrant species. Arsenic level in the Sulu Sea fish was positively correlated with δ15N, indicating biomagnification of arsenic. To our knowledge, this is the first study on relationship between diel vertical migration and TE accumulation in deep-water fish. 相似文献
119.
S. Chatterjee L. M. Pande S. K. Subramanian S. K. Saha C. J. Thampi 《Journal of the Indian Society of Remote Sensing》1990,18(4):15-23
Visual Interpretation of Landsat Imagery (TM-FCC) on 1∶250,000 scale covering 2410 sq km in a part of Mahandi Delta, Kataka district, Orissa was carried out for delineating the physiographic units. The major physiographic units identified and delineated were ‘Delta plain’ and ‘Coastal plain’. These units were further subdivided on the basis of image elements. The abstraction level attained was ‘Family’ based on Soil Taxonomy. The soils of the beach were classified as Typic Ustipsamments; old coastal plain as fine, Typic Haplaquept and coarse loamy Aquic Ustifluvent; Tidal flat as fine Typic Haplaquept and fine loamy Aquic Ustifluvent; mud flat as fine Typic Haplaquept; Levee-plain complex as Typic Ustipsamment and fine loamy Typic Ustorthent; old Delta plain as fine Udic Ustochrept and Aeric Haplaquept and recent delta plain as fine loamy and coarse loamy Typic Ustorthent. The soils are mixed in mineralogy and Isohyperthermic in temperature regime. 相似文献
120.
Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries 总被引:27,自引:0,他引:27
Monirith I Ueno D Takahashi S Nakata H Sudaryanto A Subramanian A Karuppiah S Ismail A Muchtar M Zheng J Richardson BJ Prudente M Hue ND Tana TS Tkalin AV Tanabe S 《Marine pollution bulletin》2003,46(3):281-300
Contamination of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT and its metabolites (DDTs), HCH (hexachlorocyclohexane) isomers (HCHs), chlordane compounds (CHLs), and HCB (hexachlorobenzene) were examined in mussels collected from coastal waters of Asian countries such as Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Far East Russia, Singapore, and Vietnam in 1994, 1997, 1998, 1999, and 2001 to elucidate the contamination status, distribution and possible pollution sources and to assess the risks on aquatic organisms and human. OCs were detected in all mussels collected from all the sampling sites investigated. Considerable residue levels of p,p(')-DDT and alpha-HCH were found in mussels and the concentrations of DDTs and HCHs found in mussels from Asian developing countries were higher than those in developed nations suggesting present usage of DDTs and HCHs along the coastal waters of Asian developing countries. On the other hand, lower concentrations of PCBs detected in mussels from Asian developing countries than those in developed countries indicate that PCBs contamination in mussels is strongly related to industrial and activities. To our knowledge, this is a first comprehensive report on monitoring OCs pollution in the Asia-Pacific region. 相似文献