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71.
S. Thiagarajan A. Meena S. Anitha L. Rajendran 《Journal of mathematical chemistry》2011,49(8):1727-1740
A mathematical model of mediated bioelectrocatalysis is restudied in this paper. Here He’s Homotopy perturbation method is
implemented to give approximate and analytical solutions of steady-state non-linear reaction diffusion equation containing
a non-linear term related to Michaelis–Menten kinetics of the enzymatic reaction. Approximate analytical expressions for mediator
concentration and current have been derived for all values of saturation parameter α and reaction diffusion parameter k for the various types of boundary conditions. The Homotopy perturbation method which produces the solutions in terms of convergent
series, requiring no linearization or small perturbation. These analytical results are compared with numerical results (Matlab
program) and are found to be in good agreement. 相似文献
72.
Rekha?Goswami?ShresthaEmail author Suraj?Chandra?Sharma Kenichi?Sakai Hideki?Sakai Masahiko?Abe 《Colloid and polymer science》2012,290(4):339-348
Formation of wormlike micelles (WLMs) in an aqueous mixture of polyoxyethylene cholesteryl ether (ChEOn; where n = 20 and 30) and polyoxyethylene dodecyl ether (C12EOm; where m = 3 and 4) has been reported; rheological and small angle X-ray scattering (SAXS) measurements have been performed in the
micellar solutions of ChEOn as a function of C12EOm for the structural elucidation. When lipophilic cosurfactant, C12EOm is added to the micellar solutions of ChEOn, it favors the sphere-to-cylinder transition due to the penetration of C12EOm in the palisade layer of ChEOn micelle accompanying an increase in viscosity. When the concentration of C12EOm is increased, entangled network of WLMs is formed. A strong shear thinning has been observed in highly viscous samples indicating
the presence of transient networks. Such samples exhibited viscoelastic behavior and could be described by the Maxwell model
with a single stress relaxation mode. A maximum is observed in zero-shear viscosity-C12EOm plot. With further addition of C12EOm, viscosity declines and ultimately a phase separation occurs with the formation of turbid solution of vesicular dispersion.
This decline has been interpreted in terms of micellar branching induced by an increase in endcap energy, E
c (which is compensated by the formation of branch points, having a mean curvature opposite to that of endcaps). The C12EOm induced one-dimensional micellar growth has been confirmed by SAXS. 相似文献
73.
Suraj Chandra Sharma Rekha Goswami Shrestha Lok Kumar Shrestha Kenji Aramaki 《Colloid and polymer science》2008,286(14-15):1613-1619
Rheological behavior of viscoelastic wormlike micelles in an aqueous system of mixed sodium dodecyl trioxyethylene sulfate (SDES)–monolaurin (ML) is presented. Dilute aqueous solution of SDES has a high fluidity and follows Newtonian liquid-like behavior due to formation of small globular type of micellar structure. Addition of lipophilic nonionic cosurfactant ML to dilute or semidilute solution of SDES decreases the interfacial curvature of the aggregates favoring one dimensional micellar growth, and hence, viscosity increases. After a certain concentration of ML, the elongated micelles get entangled with each other leading to the formation of viscoelastic wormlike micelles. The viscoelastic solution follows Maxwell model of a single stress relaxation mode at low-frequency region. Further addition of ML decreases the viscosity of the solution due to formation of micellar joints in the network structure. The viscosity of the viscoelastic wormlike micelles decreases upon heating, and the system with poor viscoelastic character is observed at higher temperatures. 相似文献
74.
Nanostructured platinum-gold (Pt–Au) hybrid film modified glassy carbon electrode (GCE) was fabricated by electro-deposition
method in the presence of 2 × 10−4 mol l−1
l-cysteine. To examine the surface morphological analysis, the (Pt–Au) hybrid film were electrochemically deposited on transparent
semiconductor indium tin oxide (ITO) electrodes for scanning electron microscopy (SEM) and energy dispersive spectroscopy
(EDS) studies. From the SEM analysis, it was observed that the deposited nanoplatinum (250–400 nm) was formed as a cauliflower-shaped
structure with the gold nanoparticles (30–90 nm). The concentration variation of additive l-cysteine results in the formation of cauliflower-shaped platinum nanoparticles. Further, the Pt–Au hybrid film modified GCE
could be used for the detection of catecholamine neurotransmitters epinephrine (EP), norepinephrine (NEP) individually and
in the presence of ascorbic acid (AA) in pH 7 phosphate-buffered solutions (PBS). Furthermore, the proposed Pt–Au hybrid film
could be applied for the detection of epinephrine in injection solution and ascorbic acid from commercially available vitamin
C tablets. 相似文献
75.
Suraj Kumar Tripathy Jin-Nyoung Jo Hyeon-Min Song Yeon-Tae Yu 《Applied Physics A: Materials Science & Processing》2011,104(2):601-607
Ag@SnO2 core-shell nanoparticles dispersed in poly-(vinyl) alcohol films were fabricated on glass substrate by employing a dip-coating
technique. Synthesis of Ag@SnO2 nanoparticles with core-shell morphology is carried out by a soft-chemical technique in aqueous phase at 60°C. Formation
of core-shell structure is monitored by the red-shift of the surface plasmon band of Ag nanoparticles (from 390 to 410 nm)
in the UV-visible spectrum. These nanoparticles are deposited on the glass substrate. The structure and morphology of these
films were investigated by X-ray diffraction technique and field-emission transmission electron microscopy, respectively.
Optical properties of these pseudo-solids were studied by UV-visible spectroscopy. Surface plasmon spectrum of the core-shell
nanoparticles film remained unaltered with increase in the number of layers. However, silver nanoparticles films have shown
peak broadening and development of additional peaks with increase in the number of layers. Our investigations showed that
the surface plasmon band of the silver nanoparticles could be preserved by controlled deposition of the tin dioxide shell. 相似文献
76.
Euaggelos E. Zotos Wei Chen Md Sanam Suraj Rajiv Aggarwal Charanpreet Kaur 《Journal of Nonlinear Modeling and Analysis》2020,2(4):551-564
The scope of this work is to reveal, by means of numerical methods, the escape process in a Hamiltonian system with five exits which describes
the problem of rearrangement multichannel scattering. For determining the
influence of the energy on the nature of the orbits we classify starting conditions of orbits in planes of two dimensions. All the complex basins of escape,
associated with the five escape channels of the system, are illustrated by using
color-coded diagrams. The distribution of time of the escape is correlated with
the corresponding escape basins. The uncertainty (fractal) dimension along
with the (boundary) basin entropy are computed for quantifying the degree of
fractality of the dynamical system. 相似文献
77.
78.
Suraj P. Narula Sajeev Soni Meenu Puri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2714-2725
Disproportionation reactions between (CF 3 CH 2 O) 3 GeNHC 6 H 5 ? n F n and TiCl 4 in petroleum ether (40?60°C) at 0° to ?10°C give (CF 3 CH 2 O) 2 Ge(NHC 6 H 5 ? n F n ) 2 .2TiCl 4 and (CF 3 CH 2 O)Ge(NHC 6 H 5 ? n F n ) 3 . 2TiCl 4 adducts. However, complete disproportionation of (CF 3 CH 2 O) 3 Ge(NHC 6 H 5 ? n F n ) (n = 1,2) occurs at ?55 to ?60°C to give Ge(NHC 6 H 5 ? n F n ) 4 .3TiCl 4 . These complexes give double adducts on reactions with CH 3 NO 2 and CH 3 CN. All the products are characterized by elemental analyses and IR, 1 H, and 19 F NMR spectroscopy. A comparative disproportionation of the germanamines and analogous silanamines is discussed. 相似文献
79.
Suraj Chandra Sharma Lok Kumar Shrestha 《Journal of Dispersion Science and Technology》2013,34(4):577-581
The equilibrium, dynamic surface tensions, and surface dilatational elasticity of aqueous solutions of nonionic fluorocarbon surfactant are reported. The critical micellar concentration, CMC (0.023 mM) and equilibrium surface tension (24.6 m N . m?1) at CMC were measured by Wilhelmy plate method for aqueous solution of C8F17SO2N(C3H7)(C2H4O)nH (n=20), abbreviated as EF122A. The surface tension decay is slower for C8F17SO2N(C3H7)(C2H4O)nH (n=10) system, abbreviated as EF122B compared to the EF122A system over short time region, which indicates the slow transport of the surfactant molecules to the surface. The relaxation time for surface tension decay is estimated by fitting a series of exponentials to the dynamic surface tension data and it decreases with temperature for EF122A. Slow exchange of monomers between bulk and interface is reflected in the high elasticity value of the air‐liquid interface for EF122B compared with EF122A within measured frequency window (0.125–1.25 Hz). 相似文献
80.
Journal of Thermal Analysis and Calorimetry - This paper deals with the numerical solution of a multi-reaction model for the complex thermal history. The effect of thermal and kinetic parameters is... 相似文献