Dynamic,Mechanistic, and Thermodynamic Modeling of Zn(II) Ion Biosorption onto Zinc Sequestering Bacterium VMSDCM

The surface of the bacterial cells before the biosorption of Zn(II) ion has been found rough, heterogeneous, and non‐crystalline together with tremendous protrusions and negatively charged functional groups. The bacterium was characterized as rod shaped with Gram‐negative type of cell wall structure. In reaction dynamics, pseudo‐second‐order kinetics with higher linear correlation coefficient (R²) ranging between 0.97 and 0.99, lower sum of square errors (SSE) (0.035–0.081) and chi (χ²) (0.0013–0.009) provided a better explanation of sorption of Zn(II) ion on bacterium surface as compared to pseudo‐first‐order model. The removal of Zn(II) was governed by both film and intra‐particle diffusion at onset and later stage of sorption of metal ion on the surface of bacterial cells. The R² (0.92–0.94) for intra‐particle diffusion model was quite higher with lower values of SSE (9.56–16.33) and chi (χ²) (11.26–19.65) against the Bangham's model. The positive value of ΔH (16.628 × 10^?6 kJ/mol) and ΔS (5320.90 kJ/mol/K) showed that the biosorption of Zn(II) ion across liquid phase on bacterial surface was endothermic with increased randomness at solid–liquid interface. The negative values of ΔG demarcated the whole process as spontaneous in nature. In the present work, the distribution coefficient was found to be > 0.5 at various temperature ranges. At the attainment of equilibrium, the residual concentration of Zn(II) ion in liquid phase was around 0.6 mg/L, which was much below the limit described by United States Environmental Protection Agency (USEPA), i.e. 5 mg/L.     

On the behaviour of the induction arrows over a buried conductive plate — a numerical model study

Two-dimensional numerical model calculations, employing a finite difference technique, are used to study the behaviour of the induction arrows, for a range of periods, for a conductive plate of (i) semi-infinite and (ii) finite width in uniform and layered resistive hosts. The results for the conductive plate at the surface of the host have application to a uniform-depth ocean, while the results for the plate buried at some depth in the resistive host have application to a conductive sill in a resistive Earth. The numerical results indicate that for a profile over the plate-host vertical interface the in-phase arrows for all periods and locations point towards the conductive plate, while the quadrature arrows at periods near the characteristic period of the model are oppositely directed on either side of the interface so as to point towards each other and towards the interface for nearby locations, both over the conductive plate and the resistive host. Further, the quadrature arrow undergoes a second reversal over the resistive host at a distance from the interface that is somewhat dependent on the period. Thus, at either side of the location of this second reversal, the quadrature induction arrows are again oppositely directed, but pointing away from each other, with the arrows near the interface pointing towards, and the more distant arrows pointing away from the conductive plate. The period range for the quadrature-arrow reversal is characteristic of conductivities and layer depths. The features of the quadrature-arrow sign reversals at and near the interface are in accordance with the earlier laboratory analogue model results of Hebert et al. for the Newfoundland coastal region and Nienaber et al. for a conductive plate in a resistive host.

It is suggested that in practice the sign reversal of the quadrature arrow may aid in locating a conductor-host interface, and that if the conductivity of the host is known, the maximum in the anomalous vertical magnetic field response may permit an approximate determination of the conductive-layer depth.     

Numerical simulation and optimization of CO2 sequestration in saline aquifers for vertical and horizontal well injection

With heightened concerns on CO₂ emissions from pulverized-coal (PC) power plants, there has been major emphasis in recent years on the development of safe and economical geological carbon sequestration (GCS) technology. Saline aquifers are considered very attractive for GCS because of their large storage capacity in U.S. and other parts of the world for long-term sequestration. However, uncertainties about storage efficiency as well as leakage risks remain major areas of concern that need to be addressed before the saline aquifers can be fully exploited for carbon sequestration. A genetic algorithm-based optimizer has been developed and coupled with the well-known multiphase numerical solver TOUGH2 to optimally examine various injection strategies for increasing the CO₂ storage efficiency as well as for reducing its plume migration. The optimal injection strategies for CO₂ injection employing a vertical injection well and a horizontal injection well are considered. To ensure the accuracy of the results, the combined hybrid numerical solver/optimizer code was validated by conducting simulations of three widely used benchmark problems employed by carbon sequestration researchers worldwide. The validated code is then employed to optimize the proposed water-alternating-gas injection scheme for CO₂ sequestration using both the vertical and the horizontal injection wells. The results suggest the potential benefits of CO₂ migration control and dissolution. The optimization capability of the hybrid code holds a great promise in studying a host of other problems in GCS, namely how to optimally enhance capillary trapping, accelerate the dissolution of CO₂ in water or brine, and immobilize the CO₂ plume.     

Visual interpretation of F.C.C. satellite data for channel migration and water logging conditions along Ghaghra and Terhi rivers in part of district Gonda and Bahraich,U.P.

The conventional visual interpretation of landsat Imagery is potentially the most useful remote sensing tool for the study of channel migration & water logging conditions at different time spans; which were earlier not easy due to non availability of suitable evidences. The present study brings out, in exact terms & the extent of the utility of the false colour and black and white landsat data. The application of the false colour scanning method is also useful remote sensing tool for the study of direct & indirect hydrogeological regime by visual interpretation technique. The spectrum are favourable for detection of surface phenomenon, which is associated with the subsurface ground water environment. An area of about 3,500 Sq.Km. of U.P. along left bank of Ghaghra river and right bank of Terhi rivers have been taken for the study. The paper was designed to evaluate the fluvial action and ground water environments with the help of repetitive landsat data in ten years. The fluvial action of Ghaghra and Terhi rivers have been mainly contributing to the development of hydrogeomorphological units which have given exact references regarding fluctuation in hydrogeomorphological units and water logging with hydrological response of the ground water environment, by using landsat data of 1975 & 1984. Further the direct relationship between remote sensing measurement and physical properties of hydrogeological environments is brought out in the maps.     

A New Algorithm for Wind-Vector Retrieval From Scatterometers

A new efficient algorithm for retrieving wind-vector solutions from scatterometers is developed based on a criterion of minimum normalized standard deviation (NSD) of wind speed derived from backscatter measurements using a geophysical model function (GMF). Its performance has been evaluated through simulations using QSCAT-1 GMF and the QuikSCAT observational geometry. The present algorithm, named the NSD algorithm, is found to be computationally more efficient (two to three times) besides being at par with the maximum-likelihood estimator (MLE) algorithm in terms of retrieval skill, retrieval errors, and distribution of solutions, on the basis of simulations as well as comparison of limited QuikSCAT-data-derived winds with National Centers for Environmental Prediction and European Centre for Medium-Range Weather Forecasts model winds. Simulation results and analysis of sample QuikSCAT data are presented.      

Drainage Analysis in a Part of the Brahmaputra Valley in Sivasagar District, Assam, India, to Detect the Role of Neotectonic Activity

An analysis of the drainage network of a part of Sivasagar district, Assam, India, is undertaken to reveal the role of neotectonic activity of the area. A number of fluvial geomorphic anomalies have been identified in the area. A prominent annular drainage anomaly is displayed by the major rivers—the Dikhu, Jhanzi, Namdang, Dorika and Disang, whose courses are carved in response to the ongoing tectonic deformation in the area. This study reveals that the development of topography and drainage system of the study area have been influenced by active subsurface geological structures. Formation of paleochannels, compressed meanders, reticulate streams, swamps, sagging of grounds, stream alignments, lineaments, knick points and abandonment of rivers as well as development of smaller drainage anomalies also substantiate the active nature of the subsurface structures.     

Impacts of tourism development on the physical environment of Mussoorie,a hill station in the lower Himalayan range of India

Tourism in mountainous regions is a significant source of revenue generation. However, it has also been associated with many adverse environmental consequences. This study aims at assessing the negative impacts of the incessant upsurge in tourism development on the physical environment of Mussoorie, a well-known mountain tourist destination in India. The impact indicators for the region were identified and assessed by qualitative and quantitative analysis of field observations. The observations indicated the aggravation of traffic congestion, atmospheric pollution, undisposed solid waste, water scarcity and infrastructure unavailability as the prevalent issues, especially during the peak tourist months. The extent of the consequential damage to the environment was evaluated by conducting an assessment of tourism-induced human disturbance on the natural landscape of the town. Slope, slope aspect, vegetation cover, road network and drainage network were incorporated as the determining landscape attributes to prepare thematic maps of landscape quality (perceivable intrinsic properties) and landscape fragility (vulnerability to anthropogenic disturbances) using GIS technique. An absorption capacity map was finally prepared to characterize the study area into regions of different conservation needs. The results identified the need for planning appropriate preservation strategies for different tourist places in the town. The study can be used by the policy makers for implementing the regulatory measures against potential disturbances due to mass-tourism.     

Early In-orbit Performance of Scanning Sky Monitor Onboard AstroSat

We report the in-orbit performance of Scanning Sky Monitor (SSM) onboard AstroSat. The SSM operates in the energy range 2.5 to 10 keV and scans the sky to detect and locate transient X-ray sources. This information of any interesting phenomenon in the X-ray sky as observed by SSM is provided to the astronomical community for follow-up observations. Following the launch of AstroSat on 28th September, 2015, SSM was commissioned on October 12th, 2015. The first power ON of the instrument was with the standard X-ray source, Crab in the field-of-view. The first orbit data revealed the basic expected performance of one of the detectors of SSM, SSM1. Following this in the subsequent orbits, the other detectors were also powered ON to find them perform in good health. Quick checks of the data from the first few orbits revealed that the instrument performed with the expected angular resolution of 12’ \(\times \) 2.5\(^\circ \) and effective area in the energy range of interest. This paper discusses the instrument aspects along with few on-board results immediately after power ON.     

Ramgarh,Rajasthan, India: A 10 km diameter complex impact structure

The Ramgarh structure is a morphological landmark in southeastern Rajasthan, India. Its 200 m high and 3.5–4 km wide annular collar has provoked many hypotheses regarding its origin, including impact. Here, we document planar deformation features, planar fractures, and feather features in quartz grains of the central part of the Ramgarh structure, which confirm its impact origin. The annular collar does not mark the crater rim but represents the outer part of a central uplift of an approximately 10 km diameter complex impact structure. The apparent crater rim is exposed as a low‐angle normal fault and can be traced as lineaments in remote sensing imagery. The central uplift shows a stratigraphic uplift of ~1000 m and is rectangular in shape. It is dissected by numerous faults that are co‐genetic with the formation of the central uplift. The central uplift has a bilateral symmetry along an SW‐NE axis, where a large strike‐slip fault documents a strong horizontal shear component. This direction corresponds to the assumed impact trajectory from the SW toward the NE. The uprange sector is characterized by concentric reverse faults, whereas radial faults dominate downrange. Sandstones of the central uplift are infiltrated by Fe‐oxides and suggest an impact‐induced hydrothermal mineralization overprint. The impact may have occurred into a shallow water environment as indicated by soft‐sediment deformation features, observed near the apparent crater rim, and the deposition of a diamictite layer above them. Gastropods embedded in the diamictite have Middle Jurassic age and may indicate the time of the impact.