Current-driven magnetization reversal dynamics and breather-like EM soliton propagation in biaxial anisotropic weak ferromagnetic nanowire

Nonlinear Dynamics - We investigate the effect of spin torque on the switching dynamics of magnetic solitons in a weak ferromagnetic nanowire under the influence of an electromagnetic wave (EMW)....     

The propagation of shape changing soliton in a nonuniform nonlocal media

Magnetization dynamics in uniformly magnetized ferromagnetic media is studied by using Landau-Lifshitz-Gilbert equation. The nonlinear evolution equation is integrable with site-dependent and biquadratic exchange interaction by means of Landau-Lifshitz （LL） equation which is well understood. In the present work, we construct the exact solitary solutions of the nonlinear evolution equation, particularly, we employ the modified extended tangent hyperbolic function method. We show the shape changing property of solitons for the given integrable system in the presence of damping as well as inhomogeneities.     

Modified extended tanh-function method and nonlinear dynamics of microtubules

We here present a model of nonlinear dynamics of microtubules (MT) in the context of modified extended tanh-function (METHF) method. We rely on the ferroelectric model of MTs published earlier by Satari? et al. [1] where the motion of MT subunits is reduced to a single longitudinal degree of freedom per dimer. It is shown that such nonlinear model can lead to existence of kink solitons moving along the MTs. An analytical solution of the basic equation, describing MT dynamics, was compared with the numerical one and a perfect agreement was demonstrated. It is now clearer how the values of the basic parameters of the model, proportional to viscosity and internal electric field, impact MT dynamics. Finally, we offer a possible scenario of how living cells utilize these kinks as signaling tools for regulation of cellular traffic as well as MT depolymerisation.     

Ultrasound assisted free radical polymerization of glycidyl methacrylate by a new disite phase-transfer catalyst system: A kinetic study

The kinetics of multi-site phase-transfer catalyzed free radical polymerisation of glycidyl methacrylate (GMA) using potassium peroxy disulphate (PDS) as water soluble initiator and newly synthesized 1,4-dihexadecylpyrazine-1,4-diium dibromide as multi-site phase-transfer catalyst (MPTC) has been investigated in ethyl acetate/water two phase system at constant temperature 65±1°C under nitrogen atmosphere and ultrasound irradiation conditions. The rate of polymerization increases with an increase in concentrations of GMA, PDS and MPTC. The order with respect to monomer, initiator and MPTC were found to be 1.0, 0.5 and 1.0, respectively. The comparative study reveals that the Rp of GMA determined in the presence of PTC combined with ultrasound has shown more enhancements in the activity than PTC alone. Based on the observed results a suitable mechanism has been proposed to account for the experimental observations and its significance was discussed.     

Stair and Step Soliton Solutions of the Integrable (2+1) and (3+1)-Dimensional Boiti-Leon-Manna-Pempinelli Equations

The multiple exp-function method is a new approach to obtain multiple wave solutions of nonlinear partial differential equations (NLPDEs). By this method one can obtain multi-soliton solutions of NLPDEs. In this paper, using computer algebra systems, we apply the multiple exp-function method to construct the exact multiple wave solutions of a (2+1)-dimensional Boiti-Leon-Manna-Pempinelli equation. Also, we extend the equation to a (3+1)-dimensional case and obtain some exact solutions for the new equation by applying the multiple exp-function method. By these applications, we obtain single-wave, double-wave and multi-wave solutions for these equations.     

New Rational Solutions for Relativistic Discrete Toda Lattice System

In the present work, we examine the soliton excitations in the relativistic Toda lattice model using the rotational expansion method, where the coupling between the lattice sites is varied. For specific choices of the coupling strength we proceed to analyze the nonlinear wave excitations arising in the model which are found to be dark, singular and periodic solitary wave profiles. These solitary wave profiles are admitted to show possible modulation in its amplitude.     

Development and evaluation of a highly sensitive rapid response enzymatic nanointerfaced biosensor for detection of putrescine

Putrescine (1,4-diaminobutane) a biologically active diamine has been found to be a valuable analyte for several clinical and analytical purposes. The present work deals with diamine oxidase immobilized on iron oxide nanoparticles for quantifying the amount of putrescine produced, by the decarboxylation of ornithine, which is converted into hydrogen peroxide by the enzyme diamine oxidase (DAO). This reaction can be quantified using electrochemical techniques, which forms the basis of this work. Iron oxide (Fe(3)O(4)) nanoparticles, synthesized using thermal co-precipitation, were chosen for immobilization of DAO due to its simple preparation procedure, high surface area and cost-effectiveness. The size of the particles was in the range of 25-35 nm and the enzyme was linked covalently by carbodiimide activation and confirmed using FT-IR. For detecting the hydrogen peroxide released in the reaction, a glassy carbon-working electrode coated with enzyme linked iron oxide nanoparticles was poised at +0.4 V versus an Ag/AgCl reference electrode and a platinum wire was used as the counter electrode. A step-wise increase in current was observed and linearity was obtained in the range of 2-8 nM, with 0.65 nM as the minimum detection limit and the response time was found to be 0.3 seconds. Ascorbic acid, a common interfering molecule in biological samples, did not interfere with the measurements indicating the high degree of specificity of the diamine oxidase-based nano-interfaced biosensor.     

Preparation of Feather Keratin Hydrolyzate‐Gelatin Composites and Their Graft Copolymers

With the aim of utilizing the Keratinous waste material, poultry feather, which is up till now discarded as a waste, was hydrolyzed to form keratin hydrolyzate (FH). As FH does not form a film, it was mixed with gelatin (G) and FH‐G composite was prepared in film form. FH‐G was further graft co‐polymerized with 2‐hydroxyethyl methacrylate (HEMA) to achieve better physico‐chemical properties for the resultant hydrogels. Percentage grafting studies and IR studies confirmed the grafting of PHEMA onto FH‐G. FH‐G‐PHEMA exhibited better mechanical properties compared to FH‐G and FH‐PHEMA. TG studies clearly indicated the grafting of HEMA onto FH and FH‐G. SEM (Scanning Electron Microscopy) pictures of FH‐G and FH‐PHEMA films exhibited brittle nature on their surface, whereas continuity and A smooth surface was observed on for the FH‐G‐PHEMA films.     

Facile epoxidation of alpha,beta-unsaturated ketones with cyclohexylidenebishydroperoxide

Cyclohexylidenebishydroperoxide was successfully used as the oxygen source for the oxidation of α,β-unsaturated ketones for the first time. The corresponding epoxides were obtained in excellent yields under the Weitz-Scheffer reaction conditions.