Synthesis of acridinedione derivatives as laser dyes

Synthesis of 9-alkyl, 10-alkyl, 9,10-dialkyl, and 10-aryl-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione (2a–r) are described as a new class of laser dyes. Reactions of diamines with methylene bis(cyclohexane-1,3-dione) yielded the respective bisacridinediones (3a–e). These dyes lase around 478–494 nm and are compared with the standard dye coumarin-102. © 1996 John Wiley & Sons, Inc.     

Observation of chimera patterns in a network of symmetric chaotic finance systems

The economic and financial systems consist of many nonlinear factors that make them behave as the complex systems. Recently many chaotic finance systems have been proposed to study the complex dynamics of finance as a noticeable problem in economics. In fact, the intricate structure between financial institutions can be obtained by using a network of financial systems. Therefore, in this paper, we consider a ring network of coupled symmetric chaotic finance systems, and investigate its behavior by varying the coupling parameters. The results show that the coupling strength and range have significant effects on the behavior of the coupled systems, and various patterns such as the chimera and multi-chimera states are observed. Furthermore, changing the parameters' values, remarkably influences on the oscillators attractors. When several synchronous clusters are formed, the attractors of the synchronized oscillators are symmetric, but different from the single oscillator attractor.     

Route to hyperchaos and chimera states in a network of modified Hindmarsh-Rose neuron model with electromagnetic flux and external excitation

Analyzing the chaos and bursting phenomenon of neurons has been of interest in the past decade. In this paper, we discuss an extended Hindmarsh-Rose neuron model by taking into consideration the slowly interacting cell phenomenon due to the calcium ions. In the extended model, we consider the effect of an external forcing current, and the electromagnetic coupling between the magnetic flux and the membrane potential of the neuron. We analyze the modified neuron model in the presence of periodic and quasi-periodic excitations. A more complex chaotic behavior (hyperchaos) is identified in the neuron model. The results also demonstrate the multistable nature, which was not explored earlier. To discuss the dynamical behavior of the modified neuron in a network, we construct a ring network of neurons and capture the spatiotemporal patterns of the neuron in the network, in the presence of different excitations.

     

Dynamical behavior and network analysis of an extended Hindmarsh–Rose neuron model

Nonlinear Dynamics - In this paper, the extended Hindmarsh–Rose neuron model, which considers the slow intracellular exchange of calcium ions between its store and the cytoplasm, is studied....     

Comparison of geometry dependent resistance models with conventional models for estimation of effective thermal conductivity of two-phase materials

The geometry dependent resistance models are used to estimate the effective thermal conductivity of two-phase materials based on the unit cell approach. The algebraic equations are derived based on isotherm approach for various geometries. The effective thermal conductivity of the above models are found and compared with experimental data with a minimum and maximum deviation of ±3.976 and ±19.55%, respectively. The present models are good agreement with experimental results.     

Velocity and strain-rate profiles in materials subjected to unlubricated sliding

This Letter focuses on the plastic response of a material, treated as a fluid, when subjected to sliding interactions. The analysis couples momentum conservation with material flow laws to predict velocity and strain-rate profiles that develop during sliding. The profiles depend on the strain-rate sensitivity. The spatial extent of the deformed zone is determined by strain-rate sensitivity, strength parameters, and the imposed sliding velocity.     

Highly regio- and chemoselective palladium-catalyzed three-component assembly of arylethylidene malononitriles,allylic chlorides,and allenylstannanes: a novel route to 1,7-enyne derivatives

[reaction: see text] An efficient method for the synthesis of 1,7-enyne derivatives via a palladium-catalyzed three-component assembly of arylethylidene malononitriles, allylic chlorides, and allenylstannanes is described.     

Sulfonated polyaniline network grafted multi-wall carbon nanotubes for enzyme immobilization, direct electrochemistry and biosensing of glucose

A new nanomaterial was prepared by grafting a layer of sulfonated polyaniline network (SPAN-NW) on to the surface of multi-walled carbon nanotube (MWNT) and effectively utilized for immobilization of an enzyme and for the fabrication of a biosensor. SPAN-NW was formed on the surface of MWNT by polymerizing a mixture of diphenyl amine 4-sulfonic acid (DPASA), 4-vinyl aniline (VA) and 2-acrylamido-2-methyl-1-propane sulfonic acid (APASA) in the presence of amine functionalized MWNT (MWNT-NH₂). The MWNT-g-SPAN-NW was immobilized with glucose oxidase (GOx) to fabricate the SPAN-NW/GOx biosensor. MWNT-g-SPAN-NW/GOx electrode showed direct electron transfer (DET) for GOx with a fast heterogeneous electron transfer rate constant (k_s) of 4.11 s^− 1. The amperometric current response of MWNT-g-SPAN-NW/GOx biosensor shows linearity up to 9 mM of glucose, with a correlation coefficient of 0.99 and a detection limit of 0.11 μM (S/N = 3). At a low applied potential of − 0.1 V, MWNT-g-SPAN-NW/GOx electrode possesses high sensitivity (4.34 μA mM^− 1) and reproducibility towards glucose.     

A novel approach to employ Li<Subscript>2</Subscript>MnSiO<Subscript>4</Subscript> as anode active material for lithium batteries

In the present paper, we describe utilization of cathode active material as anode active material, for example, Li₂MnSiO₄. The lithium manganese silicate has been successfully synthesized by solid-state reaction method. The X-ray diffraction pattern confirms the orthorhombic structure with Pmn2 ₁ space group. The Li/Li₂MnSiO₄ cell delivered the initial discharge capacity of 420 mA h g⁻¹, which is 110 mA h g⁻¹ higher than graphitic anodes. The electrochemical reversibility and solid electrolyte interface formation of the Li₂MnSiO₄ electrode was emphasized by cyclic voltammetry.