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Patra A.,University of Burdwan | Sen B.,University of Burdwan | Sarkar S.,Durgapur Institute of Advanced Technology and Management | Pandey A.,Midnapore College | Chattopadhyay P.,University of Burdwan

A new series of hexacoordinated octahedral nickel(II) complexes of 2-(pyridin-3-ylmethylsulfanyl)phenylamine (L) formulated as [Ni(L) 4(X)2] (1-4) [where X = Cl- (1); NCO - (2); N3 - (3) and NCS- (4)] has been synthesised and characterised by physicochemical, spectroscopic tools. Details of structural study of complex 1 using single crystal X-ray crystallography showed that distorted tetragonal environment around nickel(II) ion has been satisfied by four pyridinic-N donors of four organic moieties (L) and two chloride ions. All the complexes are redox active and the electrochemical study of the complexes showed only cathodic Ni II/NiI redox couples in the range of -0.61 to -695 V versus Ag/AgCl. Interactions of 1 towards calf thymus-DNA by spectroscopic, viscosity-measurement and electrochemical study and towards bovine serum albumin (BSA) with the help of absorption and fluorescence spectroscopy were examined. Antibacterial activity of the complexes (1-4) studied by agar disc diffusion method showed the comparable inhibition activity of the nickel(II) complexes against some pathogenic bacteria namely Escherichia coli, Vibrio cholerae, Streptococcus pneumonia, Shigella sp. and Bacillus cereus. © 2013 Elsevier Ltd. All rights reserved. Source

Pal P.,National Institute of Technology Durgapur | Manna A.K.,Durgapur Institute of Advanced Technology and Management
Water Research

Investigations on solar-driven membrane distillation (SDMD) were carried out for removal of arsenic from contaminated groundwater. Three different types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polypropylene (PP) with surface area of 120×10-4m2 were used as flat sheet in a direct contact membrane distillation (DCMD) set up in a cross flow module. Effects of initial arsenic concentration in the feed, feed velocity, feed temperature and distillate inlet temperature on arsenic removal efficiency and flux were studied where temperatures of feed and distillate were found to have significant effect on the flux. Almost 100% arsenic separation was achieved without wetting membrane pore even after 120h of operation. The PTFE membrane with a flux of 49.80kg/m2h was found to the best one out of the tested membranes. The study shows that solar-driven DCMD can effectively separate arsenic from groundwater using a cross flow membrane module with PTFE hydrophobic membrane. © 2010 Elsevier Ltd. Source

Ghosh D.,Durgapur Institute of Advanced Technology and Management | Sinha M.K.,Indian Institute of Technology Guwahati | Purkait M.K.,Indian Institute of Technology Guwahati

Uniaxial and paste methods are widely used for the preparation of ceramic membranes. However, there is no specific guideline for considering a particular method to obtain the desired membrane properties. This paper elaborates a comparative performance analysis of ceramic membranes prepared by uniaxial and paste methods. Effects of sintering temperature on different membrane structural properties such as pore size distribution, average pore size, surface pore density and porosity were investigated in detail to characterize membranes prepared by both methods. It was seen that the mean pore size of the membranes prepared by paste method decreased from around 5.2μm to 1.6μm when sintering temperature was increased from 750°C to 950°C. The porosity and pore density were also decreased from 85 to 55 and 140 to 100, respectively for the said temperature change. Considering the raw material cost, the material cost of the membranes prepared by paste and uniaxial cold pressing methods were calculated at around 110US $m-2 and 135US$m-2, respectively. Prepared membranes were used in a hybrid technique (electrocoagulation followed by microfiltration) for the removal of fluoride from aqueous medium. © 2013 Elsevier B.V. Source

Sinha P.K.,Durgapur Institute of Advanced Technology and Management | Biswas A.K.,National Institute of Technology Durgapur | Majumdar B.,Jadavpur University
International Review of Mechanical Engineering

In the present investigation the distribution of mean velocity, static pressure and total pressure are experimentally studied on a C-shape diffuser of 40° angle of turn with an area ratio of 1.284 and centerline length was chosen as three times of inlet diameter. The experimental results then were numerically validated with the help of Fluent and then a series of parametric investigations are conducted with same centre line length and inlet diameter but with different area ratios varying from 1.25 to 2.0 and angle of turn 30° to 75°. The measurements were taken at Reynolds number 2.25 × 105 based on inlet diameter and mass average inlet velocity. Predicted results of coefficient of mass averaged static pressure recovery (48%) and coefficient of mass averaged total pressure loss (12%) are in good agreement with the experimental results of coefficient of mass averaged static pressure recovery (45%) and coefficient of mass averaged total pressure loss (11%) respectively. Standard k-ε model in fluent solver was chosen for validation. From the parametric investigation it is observed that for the increase in area ratio from1.25 to 2.0, static pressure recovery increases sharply but with the increase of angle of turn pressure recovery decreases steadily. The coefficient of total pressure loss almost remains constant with the change in area ratio and angle of turn for similar inlet conditions. © 2013 Praise Worthy Prize S.r.l. - All rights reserved. Source

Ghosh S.,Durgapur Institute of Advanced Technology and Management
IEEE Antennas and Wireless Propagation Letters

This letter proposes a planar modified circular ring antenna for ultrawideband (UWB) applications with band notch performance. By suitably adjusting the antenna parameters, a return loss of 10 dB is achieved over the desired frequency range (3.1-10.6 GHz) except the notch frequency band. The band-notched characteristic is achieved by introducing a tuning stub inside the ring monopole. The results for return loss and radiation pattern are simulated using electromagnetic simulator WIPL-D. The time domain behavior of the antenna in terms of the fidelity factor is evaluated using Computer Simulation Software (CST) transient solver. A prototype antenna is fabricated, and the simulated result for return loss is compared to the measured result. © 2010 IEEE. Source

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