48 research outputs found
Hydrogeochemical Assessment of Groundwater in Neyveli Basin, Cuddalore District, South India
In the light of progressive depletion of groundwater reservoir and water quality deterioration of the Neyveli basin, an investigation on dissolved major constituents in 25 groundwater samples was performed. The main objective was detection of processes for the geochemical assessment throughout the area. Neyveli aquifer is intensively inhabited during the last decenniums, leading to expansion of the residential and agricultural area. Besides semi-aridity, rapid social and economic development stimulates greater demand for water, which is gradually fulfilled by groundwater extraction. Groundwaters of the study area are characterized by the dominance of Na + K over Ca + Mg.HCO3 was found to be the dominant anion followed by Cl and SO4. High positive correlation was obtained among the following ions: Ca–Mg, Cl–Ca,Mg, Na–K, HCO3–H4SiO4, and F–K. The hydrochemical types in the area can be divided into two major groups: the first group includes mixed Ca–Mg–Cl and Ca–Cl types. The second group comprises mixed Ca–Na–HCO3 and Ca–HCO3 types. Most of the groundwater samples are within the permissible limit of WHO standard. Interpretation of data suggests that weathering, ion exchange reactions, and evaporation to some extent are the dominant factors that determine the major ionic composition in the study area
Irrigation Water Quality Assessment Using Water Quality Index and GIS Technique in Pondicherry Region, South India
The utility of groundwater, irrespective of its availability, is essential for mankind. The efficacy of the coastal aquifer’s groundwater quality for agriculture purpose in the Pondicherry region was gauged by their hydrochemistry. 44 groundwater samples were collected during 4 different seasons namely, pre-monsoon (PRM), southwest monsoon (SWM), northeast monsoon (NEM) and post-monsoon (POM). The samples were measured for physico-chemical parameters like pH, EC, TDS, Na, K, Ca, Mg, Cl, HCO3, PO4, SO4 and NO3. The spatio temporal variations of EC indicates that the coastal groundwater were relatively saline except during PRM. The suitability of groundwater for irrigation is evaluated through various water quality parametrs such as Electrical Conductivity (EC), pH, Na%, sodium absorption ratio (SAR), residual sodium carbonate (RSC) and permeability index (PI). Na%, SAR, PI and EC values were spatially interporlated and integrated to determine the regions suitable for irrigation purpose. The study infers that the groundwater of the study area is suitable for irrigation except few samples’ locations along the western part, as they have attained an alarming stage and they are unsuitable for irrigation. Thus, proper management strategy for irrigation water source has to be developed and a preventive management practice to address this issue has to be implemented
Identifying climate change information needs for the himalayan region: Results from the GLACINDIA Stakeholder Workshop and Training Program
Here we present results of a workshop designed to bring together stakeholders from different states of the Indian side of the Himalayan arc and an international group of climate scientists in order to discuss how climate change research for this region can be tailored toward the needs of local communities. The stakeholder workshop was jointly organized by the Jawaharlal Nehru University (JNU), New Delhi, India, and the Climate Service Center 2.0, Hamburg, Germany, within the framework of the multidisciplinary international research project GLACINDIA. The project focuses on the water-related effects of changes in glacier mass balance and river runoff in western Himalayas. Given the research focus of the GLACINDIA project, the initial focus of the workshop was on glacier-related hydrological information. During stakeholder interactions the resulting discussion covered a much broader range of urgent climate change information needs for the Himalayan region.publishedVersio
Stable isotopic signatures in precipitation of 2006 southwest monsoon of Tamil Nadu
Southwest monsoon (SWM) controls the majority ofthe agricultural activities in Tamil Nadu (TN), though the amount of rainfall received due to this is relatively less. The nature and behaviour of water vapour over TN reveal the other dynamic processes that are in operation during this period of the year. Hence, the stable isotope signatures of d 18O and dD obtained here were used to derive the first local meteoric water line for the State with SWM precipitation. The d-excess parameter was also used in conjunction and it was found that three dominant processes were in operation during this period: (i) vapours from southeast Arabian Sea, (ii) local evaporating vapours from inland tanks and (iii) vapours from the Indian Ocean
A two-domain folding intermediate of RuBisCO in complex with the GroEL chaperonin
The chaperonins (GroEL and GroES in Escherichia coli) are ubiquitous molecular chaperones that assist a subset of essential substrate proteins to undergo productive folding to the native state. Using single particle cryo EM and image processing we have examined complexes of E. coli GroEL with the stringently GroE-dependent substrate enzyme RuBisCO from Rhodospirillum rubrum. Here we present snapshots of non-native RuBisCO - GroEL complexes. We observe two distinct substrate densities in the binary complex reminiscent of the two-domain structure of the RuBisCO subunit, so that this may represent a captured form of an early folding intermediate. The occupancy of the complex is consistent with the negative cooperativity of GroEL with respect to substrate binding, in accordance with earlier mass spectroscopy studies. [Abstract copyright: Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.
Self- generated disorder and structural glass formation in homopolymer globules
We have investigated the interrelation between the spin glasses and the
structural glasses. Spin glasses in this case are random magnets without
reflection symmetry (e.g. - spin interaction spin glasses and Potts
glasses) which contain quenched disorder, whereas the structural glasses are
here exemplified by the homopolymeric globule, which can be viewed as a liquid
of connected molecules on nano scales. It is argued that the homopolymeric
globule problem can be mapped onto a disorder field theoretical model whose
effective Hamiltonian resembles the corresponding one for the spin glass model.
In this sense the disorder in the globule is self - generated (in contrast to
spin glasses) and can be related with competitive interactions (virial
coefficients of different signs) and the chain connectivity. The work is aimed
at giving a quantitative description of this analogy. We have investigated the
phase diagram of the homopolymeric globule where the transition line from the
liquid to glassy globule is treated in terms of the replica symmetry breaking
paradigm. The configurational entropy temperature dependence is also discussed.Comment: 22 pages, 4 figures, submitted to Phys. Rev.
Dynamic nuclear polarization and spin-diffusion in non-conducting solids
There has been much renewed interest in dynamic nuclear polarization (DNP),
particularly in the context of solid state biomolecular NMR and more recently
dissolution DNP techniques for liquids. This paper reviews the role of spin
diffusion in polarizing nuclear spins and discusses the role of the spin
diffusion barrier, before going on to discuss some recent results.Comment: submitted to Applied Magnetic Resonance. The article should appear in
a special issue that is being published in connection with the DNP Symposium
help in Nottingham in August 200
Superfluid rotation sensor with helical laser trap
The macroscopic quantum states of the dilute bosonic ensemble in helical
laser trap at the temperatures about are considered in the
framework of the Gross-Pitaevskii equation. The helical interference pattern is
composed of the two counter propagating Laguerre-Gaussian optical vortices with
opposite orbital angular momenta and this pattern is driven in
rotation via angular Doppler effect. Macroscopic observables including linear
momentum and angular momentum of the atomic cloud are evaluated explicitly. It
is shown that rotation of reference frame is transformed into translational
motion of the twisted matter wave. The speed of translation equals the group
velocity of twisted wavetrain and alternates with a sign
of the frame angular velocity and helical pattern handedness .
We address detection of this effect using currently accessible laboratory
equipment with emphasis on the difference between quantum and classical fluids.Comment: 8 pages, 3 figures, accepted to publication Journ.Low Temp.Phy