Phycoremediation of cyanide from coke–oven wastewater using cyanobacterial consortium

Owing to the presence of several toxic pollutants such as cyanide, phenol, ammonium, coke–oven wastewater is being considered as hazardous stream and needs to be treated properly. In the present study, cyanobacterial consortium of Dinophysis acuminata and Dinophysis caudata, collected from East Kolkata Wetland, was used for the treatment of both synthetic cyanide solution and real coke–oven wastewater. The growth kinetics was studied considering nitrate as substrate. Since consortium showed growth in cyanide solution, a model was proposed considering both nitrate and cyanide as substrates. The simulated data match quite well with experimental ones. Two coke–oven wastewater samples were collected—untreated one from equalization tank and another from secondary clarifier effluent and treated with consortium separately. Lipid was extracted from biomass of native cyanobacterial consortium, biomass treated with raw coke–oven wastewater and biomass treated with secondary clarifier effluents. Fatty acid methyl ester of such lipid samples was analyzed using gas chromatograph.     

The Persistence of Warps in Spiral Galaxies with Massive Haloes

We study the persistence of warps in galactic discs in the presence of massive haloes. A disc is approximated by a set of massive rings, while a halo is represented by a conventional n -body simulation. We confirm the conclusion of Nelson &38; Tremaine that a halo responds strongly to an embedded precessing disc. This response invalidates the approximations made in the derivation of classical 'modified tilt' modes. We show that the response of the halo causes the line of nodes of a disc that starts from a modified tilt mode to wind up within a few dynamical times. We explain this finding in terms of the probable spectrum of true normal modes of a combined disc–halo system. The key physical point is that in each radial range the halo rapidly aligns with the disc, so calculations based on the assumption that, in the presence of a warped disc, the halo retains a regular spheroidal structure are based on a fatally flawed assumption.     

Evaluating Environmental Sensitivity of Arid and Semiarid Regions in Northeastern Rajasthan,India

Arid regions of Rajasthan in India are characterized by harsh environments, fragile ecosystems, and limited water resources and arable lands. Desertification is one of the major land‐degradation problems in these regions. Recent changes in the regional climatic regime and the low availability of water in this northwestern state of India, pose the threat of desertification in the agriculturally productive part of the state. This study aims to delineate the environmentally sensitive areas to desertification in the districts of Jhunjhunun and Sikar in Rajasthan, India. It uses geospatial data from various sources, and combines them to calculate an environmental sensitivity index (ESI), which will allow the quantification of the area's vulnerability to desertification. The study uses the analytical hierarchical process (AHP) to assign respective weights to individual factors for each index calculation. Land‐cover maps and socio‐economic data have been used to understand their relationship with ESI. Results showed that 13 percent and 45 percent of the study area are under highly sensitive and moderately sensitive zones, respectively. Mapping and monitoring of environmentally sensitive areas in such arid regions are critical to sustainable use and planning of natural resources namely water and land‐cover and are helpful in determining priority actions and their successful implementation.     

Bifurcations of dust ion acoustic travelling waves in a magnetized quantum dusty plasma

Bifurcation behavior of nonlinear dust ion acoustic travelling waves in a magnetized quantum dusty plasma has been studied. Applying the reductive perturbation technique (RPT), we have derived a Kadomtsev-Petviashili (KP) equation for dust ion acoustic waves (DIAWs) in a magnetized quantum dusty plasma. By using the bifurcation theory of planar dynamical systems to the KP equation, we have proved that our model has solitary wave solutions and periodic travelling wave solutions. We have derived two exact explicit solutions of the above travelling waves depending on different parameters.     

Chemical composition and palaeobotanical origin of Miocene resins from Kerala-Konkan Coast,western India

The terpenoid composition of resins from the Miocene lignite horizons from the Kerala-Konkan Coast, western India was analyzed by Curie-point pyrolysis-gas chromatography-mass spectrometry (Cupy-GC-MS). The major pyrolysates were cadalene-based bicyclic sesquiterpenoids including some C₃₀-C₃₁ bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family. These plants are typically supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period. The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch. These sesquiterpenoids which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in the western Indian region.     

Water Level Retrieval Using SARAL/AltiKa Observations in the Braided Brahmaputra River,Eastern India

In this study, water level retrieval over the Brahmaputra river was done using different retracking algorithms for the 40 Hz waveform data of SARAL/AltiKa satellite. Water level was retrieved at 10 different locations of the river to evaluate the performance and accuracy of Ka band altimeter over the braided river system. Different retracking algorithms such as ice-1, ice-2, threshold, and beta parameter were used to retrieve water levels. A correlation and error analysis between the in-situ and satellite altimetry derived river levels was carried out for all the stations. Performance and accuracy analysis has established that water level can be retrieved with less than 40 cm root mean square error (RMSE) for most of the braided reaches of the river. The statistical analysis have found that Beta parameter algorithm has performed best in most of the cases amongst the different retracking algorithms used in this study. The water levels derived from 10 different locations were used to generate water surface elevation profiles for the monsoon and nonmonsoon periods. The water levels and the water surface profiles derived from satellite altimetry indicate the potential use of altimeters for the parameterization and calibration of river hydrological, hydrodynamic and sediment transport models.     

Molecular fossils in Cretaceous condensate from western India

The present study reports the biomarker distribution of condensate belonging to the early Cretaceous time frame using gas chromatography–mass spectrometry (GC–MS). The early Cretaceous palaeoenvironment was inscribed into these molecular fossils which reflected the source and conditions of deposition of the condensate. The saturate fraction of the condensate is characterized by normal alkanes ranging from n-C₉ to n-C₂₉ (CPI-1.13), cycloalkanes and C₁₄ and C₁₅ sesquiterpanes. The aromatic fraction comprises of naphthalene, phenanthrene, their methylated derivatives and cyclohexylbenzenes. Isohexylalkylnaphthalenes, a product of rearrangement process of terpenoids, is detected in the condensate. Several aromatic sesquiterpenoids and diterpenoids have been recorded. Dihydro-ar-curcumene, cadalene and ionene form the assemblage of sesquiterpenoids which are indicative of higher plant input. Aromatic diterpenoid fraction comprises of simonellite and retene. These compounds are also indicative of higher plants, particularly conifer source which had been a predominant flora during the Cretaceous time.     

Probing the neutral fraction of the IGM with GRBs during the epoch of reionization

We show that near-infrared observations of the red side of the Lyα line from a single gamma-ray burst (GRB) afterglow cannot be used to constrain the global neutral fraction of the intergalactic medium (IGM),     , at the GRB's redshift to better than     . Some GRB sightlines will encounter more neutral hydrogen than others at fixed     owing to the patchiness of reionization. GRBs during the epoch of reionization will often bear no discernible signature of a neutral IGM in their afterglow spectra. We discuss the constraints on     from the   z = 6.3  burst, GRB050904, and quantify the probability of detecting a neutral IGM using future spectroscopic observations of high-redshift, near-infrared GRB afterglows. Assuming an observation with signal-to-noise ratio similar to the Subaru FOCAS spectrum of GRB050904 and that the column density distribution of damped Lyα absorbers is the same as measured at lower redshifts, a GRB from an epoch when     can be used to detect a partly neutral IGM at 97 per cent confidence level ≈10 per cent of the time (and, for an observation with three times the sensitivity, ≈30 per cent of the time).