Structure-reactivity correlation in bromate oscillatory systems in aqueous-acetonitrile mixed medium

1993 ◽  
Vol 51 (2) ◽  
pp. 431-442 ◽  
Author(s):  
P. V. Lalitha ◽  
R. Ramaswamy
Keyword(s):  
Aqueous Acetonitrile ◽  
Oscillatory Systems ◽  
Mixed Medium

Study of Briggs Rauscher Oscillatory Reaction in Aqueous Acetonitrile Mixed Medium

1994 ◽  
Vol 59 (7) ◽  
pp. 1596-1605
Author(s):  
Punchayil V. Lalitha ◽  
Natesan Balasubramanian ◽  
Ranganathan Ramaswamy
Keyword(s):  
Mixed Media ◽  
Oscillatory Reaction ◽  
Oscillatory Behaviour ◽  
Cyanoacetic Acid ◽  
Aqueous Acetonitrile ◽  
Mixed Medium ◽  
Acetonitrile Concentration

The oscillatory behaviour of two new substrates namely, 2-thenoyltrifluoroacetone and cyanoacetic acid in the Briggs Rauscher (B-R) system was studied in detail employing a mixed medium: aqueous acetonitrile. The effect of acetonitrile concentration on the oscillatory behaviour is investigated. It is found that employing the aqueous organic mixed media is highly beneficial in the oscillatory study, enabling the study of water-insoluble substances.

The oscillatory Belousov–Zhabotinsky reaction with flavones in batch systems using aqueous–DMF mixed medium

1994 ◽  
Vol 72 (6) ◽  
pp. 1537-1540 ◽  
Author(s):  
G. Maya ◽  
P.V. Lalitha ◽  
R. Ramaswamy
Keyword(s):  
Aqueous Medium ◽  
Aqueous System ◽  
Water Soluble ◽  
Oscillatory Behaviour ◽  
Oscillatory Systems ◽  
Batch Systems ◽  
Mixed Medium ◽  
First Time ◽  
Belousov Zhabotinsky Reaction ◽  
Soluble Substrate

Oscillatory systems of the Belousov–Zhabotinsky type with flavones as substrates are described for the first time. Since quercetin and morin are water insoluble, a mixed medium containing DMF and water was used with one of the three catalysts Ce(III), ferroin, or Mn(II). The oscillatory behaviour of a water-soluble substrate (gallic acid) was studied in nine different aqueous–organic mixed media as well as in pure aqueous medium in the bromate–Ce(III) system. The results obtained from a catalyzed system with quercetin or morin as the substrate in an aqueous–organic mixed medium are in agreement with the accepted (FKN) mechanism for an aqueous system.

A Novel Approach to the Study of Briggs-Rauscher Reaction

1992 ◽  
Vol 57 (11) ◽  
pp. 2235-2240 ◽  
Author(s):  
Punchayil Velayudhan Nair Lalitha ◽  
Renganathan Ramaswamy
Keyword(s):  
Organic Solvent ◽  
Malonic Acid ◽  
Mixed Media ◽  
Oscillatory Behaviour ◽  
Present Communication ◽  
Oscillatory Systems ◽  
Novel Approach ◽  
Mixed Medium ◽  
Acidic Hydrogen

The Briggs-Rauscher reaction with substrates containing acidic hydrogen such as malonic acid, acetonyl acetone has been studied. The employment of mixed media involving an organic solvent and water enabled the study of water-insoluble substrates. The present communication reports the oscillatory behaviour of malonic acid in the iodate system in different mixed media (5 vol.% of the organic solvent) as well as the oscillatory behaviour of seven substrates in acetonitrile-water mixed medium of which two are new substrates hitherto unreported in any of the oscillatory systems.

scholarly journals Computational Analysis of Ca2+ Oscillatory Bio-Signals: Two-Parameter Bifurcation Diagrams

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 876
Author(s):  
Wieslaw Marszalek ◽  
Jan Sadecki ◽  
Maciej Walczak
Keyword(s):  
Equilibrium Points ◽  
Autonomous Systems ◽  
Cytosolic Calcium ◽  
Calcium Oscillations ◽  
Dynamical Model ◽  
Bifurcation Diagrams ◽  
Step Size ◽  
Oscillatory Systems ◽  
Two Parameter ◽  
Parameter Bifurcation

Two types of bifurcation diagrams of cytosolic calcium nonlinear oscillatory systems are presented in rectangular areas determined by two slowly varying parameters. Verification of the periodic dynamics in the two-parameter areas requires solving the underlying model a few hundred thousand or a few million times, depending on the assumed resolution of the desired diagrams (color bifurcation figures). One type of diagram shows period-n oscillations, that is, periodic oscillations having n maximum values in one period. The second type of diagram shows frequency distributions in the rectangular areas. Each of those types of diagrams gives different information regarding the analyzed autonomous systems and they complement each other. In some parts of the considered rectangular areas, the analyzed systems may exhibit non-periodic steady-state solutions, i.e., constant (equilibrium points), oscillatory chaotic or unstable solutions. The identification process distinguishes the later types from the former one (periodic). Our bifurcation diagrams complement other possible two-parameter diagrams one may create for the same autonomous systems, for example, the diagrams of Lyapunov exponents, Ls diagrams for mixed-mode oscillations or the 0–1 test for chaos and sample entropy diagrams. Computing our two-parameter bifurcation diagrams in practice and determining the areas of periodicity is based on using an appropriate numerical solver of the underlying mathematical model (system of differential equations) with an adaptive (or constant) step-size of integration, using parallel computations. The case presented in this paper is illustrated by the diagrams for an autonomous dynamical model for cytosolic calcium oscillations, an interesting nonlinear model with three dynamical variables, sixteen parameters and various nonlinear terms of polynomial and rational types. The identified frequency of oscillations may increase or decrease a few hundred times within the assumed range of parameters, which is a rather unusual property. Such a dynamical model of cytosolic calcium oscillations, with mitochondria included, is an important model in which control of the basic functions of cells is achieved through the Ca2+ signal regulation.

scholarly journals On controlling stochastic sensitivity of oscillatory systems

2013 ◽  
Vol 74 (6) ◽  
pp. 932-943
Author(s):  
I. A. Bashkirtseva ◽  
D. R. Nurmukhametova ◽  
L. B. Ryashko
Keyword(s):  
Oscillatory Systems ◽  
Stochastic Sensitivity
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