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71.
Soujan Ghosh Swati Chowdhury Subrata Kundu Sudipta Sasmal Dimitrios Z. Politis Stelios M. Potirakis Masashi Hayakawa Suman Chakraborty Sandip K. Chakrabarti 《Entropy (Basel, Switzerland)》2022,24(1)
We focus on the possible thermal channel of the well-known Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) mechanism to identify the behavior of thermal anomalies during and prior to strong seismic events. For this, we investigate the variation of Surface Latent Heat Flux (SLHF) as resulting from satellite observables. We demonstrate a spatio-temporal variation in the SLHF before and after a set of strong seismic events occurred in Kathmandu, Nepal, and Kumamoto, Japan, having magnitudes of 7.8, 7.3, and 7.0, respectively. Before the studied earthquake cases, significant enhancements in the SLHF were identified near the epicenters. Additionally, in order to check whether critical dynamics, as the signature of a complex phenomenon such as earthquake preparation, are reflected in the SLHF data, we performed a criticality analysis using the natural time analysis method. The approach to criticality was detected within one week before each mainshock. 相似文献
72.
This study was conducted in a continuous three-stage system of anaerobic (R1)-anoxic(R2)-aerobic (R3) reactors with synthetic
wastewater containing phenol (1000 mg/L), chemical oxygen demand (COD) (3000 mg/L), CN− (30 mg/L), SCN−(400 mg/L), and NH
4
+
-N (600 mg/L) as principal pollutants and well-acclimated heterogeneous microbial cultures. The final effluent was partially
returned to R2 with a recycle ratio of 1. Anaerobic stage served to detoxify the feed by removing up to 80% of cyanide. Complete
SCN− removal and denitrification could be achieved in the anoxic stage by utilizing phenol as an internal source of carbon. Nitrification
efficiency of 93% was obtained in the aerobic reactor. The results demonstrated that the three-stage system can give the desired
final treated effluent quality (0 mg/L of phenol, 0.2 mg/L of CN−, 210 mg/L of COD, and 20 mg/L of NH
4
+
-N) and that the NO
3
−
-N concentration can be lowered by a higher recycle ratio. 相似文献
73.
In this article, an assessment of surface structural heterogeneity in porous metal organic framework (MOF) structure has been demonstrated by employing the methane and carbon-dioxide adsorption isotherms data. The virgin MIL-101-(Cr) MOF was synthesized by the hydrothermal method and defects were induced in the MOF structure by doping with various alkali (K, Na, Li) cations. The synthesized MOFs were characterized by XRD, SEM, EDX and BET measurement techniques. In order to understand the defect induced surface heterogeneity by alkali cation dopants, the surface energy distributions for CH4 and CO2 adsorptions on MOFs were measured by Dubinin – Astakhov model equation. The surface heterogeneity is mainly controlled by the limiting uptakes of adsorbates, the polarizability of adsorbates and the adsorbate-adsorbent interaction energy. 相似文献
74.
Binita Ghosh Purushottam Chakraborty 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2010,4(3):518-524
Although electronics technologies have made great advances in device speed, optical devices can function in the time domain
inaccessible to electronics. In the time domain less than 1 ps, optical devices have no competition. Photonic or optical devices
are designed to switch and process light signals without converting them to electronic form. The major advantages that these
devices offer are speed and preservation of bandwidth. The switching is accomplished through changes in refractive index of
the material that are proportional to the light intensity. The third-order optical susceptibility, χ(3), known as the optical Kerr susceptibility which is related to the non-linear part of the total refractive index, is the nonlinearity
which provides this particular feature. Future opportunities in photonic switching and information processing will depend
critically on the development of improved photonic materials with enhanced Kerr susceptibilities, as these materials are still
in a relatively early stage of development. Different glass systems are now under investigation to increase their nonlinearity
by introducing a variety of modifiers into the glass-network. Ion implantation is an attractive method for inducing colloid
formation at a high local concentration unattainable by the melt-glass fabrication process and for confining the non-linearities
to specific patterned regions in a variety of host matrices. Recent works on metal-ion implanted colloid generation in bulk
fused silica glasses have shown that these nanocluster-glass composites under favourable circumstances have significant enhancement
of χ(3) with picosecond to femtosecond temporal responses. 相似文献
75.
Madhumala Ghosh Devkumar Das Chandan Chakraborty Ajoy K. Ray 《Micron (Oxford, England : 1993)》2010,41(7):840-846
This paper aims at introducing an automated approach to leukocyte recognition using fuzzy divergence and modified thresholding techniques. The recognition is done through the segmentation of nuclei where Gamma, Gaussian and Cauchy type of fuzzy membership functions are studied for the image pixels. It is in fact found that Cauchy leads better segmentation as compared to others. In addition, image thresholding is modified for better recognition. Results are studied and discussed. 相似文献
76.
Dr. Aloysius Siriwardena Kiran Kumar Pulukuri Pancham S. Kandiyal Dr. Saumya Roy Dr. Omprakash Bande Dr. Subhash Ghosh Dr. José Manuel Garcia Fernández Dr. Fernando Ariel Martin Dr. Jean‐Marc Ghigo Dr. Christophe Beloin Dr. Keigo Ito Dr. Robert J. Woods Dr. Ravi Sankar Ampapathi Dr. Tushar Kanti Chakraborty 《Angewandte Chemie (International ed. in English)》2013,52(39):10221-10226
77.
AC Conduction and Time–Temperature Superposition Scaling in a Reduced Graphene Oxide–Zinc Sulfide Nanocomposite
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Koushik Chakraborty Poulomi Das Sankalpita Chakrabarty Dr. Tanusri Pal Dr. Surajit Ghosh 《Chemphyschem》2016,17(10):1518-1523
We report, herein, the results of an in depth study and concomitant analysis of the AC conduction [σ′(ω): f=20 Hz to 2 MHz] mechanism in a reduced graphene oxide–zinc sulfide (RGO–ZnS) composite. The magnitude of the real part of the complex impedance decreases with increase in both frequency and temperature, whereas the imaginary part shows an asymptotic maximum that shifts to higher frequencies with increasing temperature. On the other hand, the conductivity isotherm reveals a frequency‐independent conductivity at lower frequencies subsequent to a dispersive conductivity at higher frequencies, which follows a power law [σ′(ω)∝ωs] within a temperature range of 297 to 393 K. Temperature‐independent frequency exponent ′s′ indicates the occurrence of phonon‐assisted simple quantum tunnelling of electrons between the defects present in RGO. Finally, this sample follows the “time–temperature superposition principle”, as confirmed from the universal scaling of conductivity isotherms. These outcomes not only pave the way for increasing our elemental understanding of the transport mechanism in the RGO system, but will also motivate the investigation of the transport mechanism in other order–disorder systems. 相似文献
78.
Debadi Chakraborty Mohit Bajaj Leslie Yeo James Friend Matteo Pasquali J. Ravi Prakash 《ournal of non Newtonian Fluid Mechanics》2010,165(19-20):1204-1218
We compute the flow of three viscoelastic fluids (Oldroyd-B, FENE-P, and Owens blood model) in a two-dimensional channel partly bounded by a tensioned membrane, a benchmark geometry for fluid–structure interactions. The predicted flow patterns are compared to those of a Newtonian liquid. We find that computations fail beyond a limiting Weissenberg number. Flow fields and membrane shape differ significantly because of the different degree of shear thinning and molecular extensibility underlying the three different microstructural models. 相似文献
79.
Brotati Chakraborty 《Journal of luminescence》2009,129(1):34-39
The interaction of bovine serum albumin (BSA) with proflavin was investigated by spectroscopic tools like absorption and fluorescence spectroscopy as well as laser flash photolysis. Absorption spectroscopy proved the formation of ground-state BSA-proflavin complex. Proflavin was found to quench the intrinsic fluorescence of BSA via static quenching. High value of quenching constant suggested that energy transfer occurred from BSA to proflavin. Distance between the fluorophore in the protein and the ligand (proflavin) was evaluated. Binding constant and number of binding site were determined for proflavin-BSA interaction both in phosphate buffer (pH∼6.8) and in sodium dodecylsulphate media. The values of the thermodynamic parameters suggested that the key interacting forces are van der Waal's interaction and hydrogen bonding. Laser flash photolysis study reconfirmed the formation of complex between BSA and proflavin. 相似文献
80.
Rüdel A Hentges R Becker U Chakraborty HS Madjet ME Rost JM 《Physical review letters》2002,89(12):125503
The dynamics of the photoionization of the two outermost orbitals of C(60) has been studied in the oscillatory regime from threshold to the carbon K edge. We show that geometrical properties of the fullerene electronic hull, such as its diameter and thickness, are contained in the partial photoionization cross sections by examining ratios of partial cross sections as a function of the photon wave number in the Fourier conjugated space. Evaluated in this unconventional manner photoemission data reveal directly the desired spatial information. 相似文献