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11.
— The fish Colisa fasciatus, Saccobranchus fossilis and Notopterus notopterus were exposed to phenol, pentachlorophenol and dinitrophenol at four pH levels, i. e. 4.6 + 0.12, 6.0±0.14, 7.3 ±0.10 and 8.8 ±0.13, to evaluate the effect of pH on the toxicity of these chemicals. — A change in pH from 7.3 ± 0.10 to 6.0 ± 0.14 increased toxicity to a certain degree while a change from 7.3 ± 0.10 to 4.6 ± 0.12 potentiated the toxicity of phenol, pentachlorophenol and dinitrophenol 5.05, 19.30 and 22.33 times, respectively for Notopterus notopterus, 3.59, 4.39 and 4.73 times, tespectively for Colisa fasciatus and 3.04, 4.68 and 5.85 times, respectively for Saccobranchus fossilis. — A change in pH from 7.3 ± 0.10 to 8.8 ± 0.13 has a protective effect on the toxicities.  相似文献   
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13.
In Jabalpur area about 18 m to 45 m thick Lameta Formation is stratigraphically divisible into five lithounits namely, Green Sandstone, Lower Limestone, Mottled Nodular Beds, Upper Limestone and Upper Sandstone. Having differentiated lithofacies constitution and here grouped as facies associations, these units are intensively burrowed and sparingly fossiliferous. Ichnogenera including Arenicolites, Calycraterion, Fucusopsis, Laevicyclus, Macanopsis, Ophiomorpha, Paleomeandron, Rhizocorallium, Stipsellus, Thalassinoides and Zoophycos are recovered from the Lower Limestone, Mottled Nodular Beds and Upper Limestone associations of the Lameta Formation of Jabalpur area.Among these, Arenicolites, Calycraterion, Laevicyclus, Ophiomorpha, Rhizocorallium, Stipsellus and Thalassinoides belong to mixed Skolithos and Cruziana ichnofacies and indicate sandy backshore to sublittoral condition of deposition. Additionally rhyzocretes, some times chertified, are also present in different parts of the Lameta Formation. Ichnofacies assemblage supported by sedimentological information suggests that the Lameta Formation of Jabalpur area was deposited in coastal marine settings where sediments were subaerially exposed intermittently.  相似文献   
14.
Shillong basin, one of the Purana basins of the Indian peninsula is situated in the central and eastern parts of the Shillong plateau of NE India. Metasedimentary and metavolcanic rocks of the basin are of Mesoproterozoic age and lithostratigraphically belong to Shillong Group (erstwhile Shillong series) comprising Lower Metapelitic Formation (LMF) and Upper Quartzitic Formation (UQF). A long, persistent, faulted and tectonically attenuated conglomerate known as Nongkhya-Sumer-Mawmaram-conglomerate separates these two formations. In the present work, quantitative strain analyses of the pebbles of Sumer, Nongkhya and Mawmaram conglomerates of Ri-Bhoi and West Khasi Hills districts of Meghalaya are carried out using manual and computerized programmes. Eight different techniques for intrapebble, interpebble and bulk rock strain estimation are applied and results are compared systematically. Sumer and Mawmaram conglomerates bear the testimony of broadly flattening type of deformation (0 < k < 1) while Nongkhya conglomerate shows constriction type (1 < k < α). The change in strain ellipsoid shape from Nongkhya to Mawmaram area is accompanied by a change of fabric from S < L to L < S tectonites. Affinity of rotational strain is more in Nongkhya conglomerate as compared to Sumer and Mawmaram conglomerates. The compactness of pebbles is high in case of Nongkhya conglomerate and low to moderate in Sumer and Mawmaram conglomerates indicating high strain in Nongkhya conglomerate (northeastern part of Shillong basin) relative to Sumer and Mawmaram conglomerates (southwestern part of Shillong basin). Thus strain magnitude increases from SW to NE direction of the Shillong basin.  相似文献   
15.
Sea surface winds from the Oceansat-2 scatterometer (OSCAT) are important inputs to Numerical Weather Prediction (NWP) models. The Indian Space Research Organization (ISRO) recently updated the OSCAT retrieval algorithm in order to generate better products. An attempt has been made in this study to evaluate the updated OSCAT winds using buoy observations and the 6-hour short-term forecasts from the T574L64 model from the National Centre for Medium Range Weather Forecasting (NCMRWF) during the 2011 monsoon. The results of the OSCAT evaluation are also compared with those from the Advanced Scatterometer (ASCAT) on-board the Meteorological Operational Satellite-A (MetOp-A) which were evaluated in the same way. The root mean square differences (RMSDs) for wind speed and direction, are within 2?m?s?1 and 20° for both scatterometers. The RMSDs for OSCAT are slightly higher than those for ASCAT, and this difference may be attributed in part to the difference in frequency and resolution of the scatterometer payloads. The bias and standard deviation for ASCAT winds are also lower than those for OSCAT winds with respect to the model short-range forecast, and this can be attributed to the regular assimilation of ASCAT winds in the model.  相似文献   
16.
The Narippara area, which is nestled in the Banasuramala of Wayanad district, witnessed initiation of landslide, which was manifested in the form of curvilinear cracks running for a length of 170 m. In the event of continuous rainfall, these cracks may get reactivated, leading to a major landslide. This could affect the life and livelihood of a large number of families living downslope and could cause extensive damage to property. Extensive mining for building stones in this area has been a cause for much concern amongst the local population. This study aims at understanding the impact of quarrying on slope stability through geotechnical, geophysical and environmental impact assessment (EIA). Geotechnical analysis shows that the area is stable under dry condition but parts of the area are critical under wet and saturated conditions. Moreover, resistivity studies revealed that the cracks that had developed extend up to the bedrock and the suspected mechanism of failure will be translational in nature. EIA reveal that due to quarrying and mining operations, the possibility of land disturbances cannot be ruled out during the monsoon season. In the present study, an attempt is also made to suggest management strategies for mitigating further effects of landslides in this area.  相似文献   
17.
The basement gneiss of the Shillong plateau and the overlying rocks of the Shillong basin have been dissected by a number of mafic dyke swarms represented by older Proterozoic dolerite dykes and sills named as Khasi greenstone and the younger set of Cretaceous dykes. The older dolerites dykes of Shillong basin are partly metamorphosed and have undergone low-grade metamorphism compared to the fresh unmetamorphosed Cretaceous dykes dominantly exposed in the BGC of West Garo hills region. The Khasi greenstones are tholeiitic in composition and range from basalt to basaltic andesite. Most of the metamorphosed mafic dykes indicate continental nature with some amount of overlapping oceanic tectonic setting. Palaeomagnetic study of the metadolerite dykes show a direction of magnetization of Dm=29, Im=38 (α95 = 28.84; k = 48.33; N = 2) with a palaeolatitude of 21.3° N to the Indian sub-continent that clearly support the Proterozoic dyke/dyke swarm emplacement in the region. The magnetic carrier as inferred from IRM studies is magnetite in the range of psuedosingle to multi domain (MD) states with minor contribution from hematite.  相似文献   
18.
Mandal  Prantik  Srinagesh  D.  Vijayaraghavan  R.  Suresh  G.  Naresh  B.  Raju  P. Solomon  Devi  Aarti  Swathi  K.  Singh  Dhiraj K.  Srinivas  D.  Saha  Satish  Shekar  M.  Sarma  A. N. S.  Murthy  YVVBSN 《Natural Hazards》2022,111(3):2241-2260
Natural Hazards - Since the initial collision at 55&nbsp;Ma, rocks of the Indian crust below the Himalayas have undergone modification chemically and compositionally due to the ongoing...  相似文献   
19.
Mahmood  Shakeel  Rani  Razia 《Natural Hazards》2022,111(3):3053-3069
Natural Hazards - This study is an effort of people-centric geo-spatial exposure and damage assessment of 2014-flood in Upper Indus Plain (UIP). Community-based disaster risk management (CBDRM)...  相似文献   
20.
The problem of an axially-symmetric viscous fluid interacting with the gravitational field has been investigated. Exact solutions have been obtained for the pressure and density of the viscous fluid. Physical interpretation of the solutions in respect of the expansion factor, acceleration components reality conditions of the distribution, etc., have been made.  相似文献   
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