Kinetics and mechanism of oxidation of aromatic aldehydes by N-chlorosuccinimide in aqueous acetic acid

2044-2047Kinetics of oxidation of aromatic aldehydes by N-chlorosuccinimide (NCS) in the presence of HClO4 and NaCl in aqueous acetic acid medium is reported here. The observed rate of oxidation is first-order with respect to [NCS], [H+] and [Clˉ] . The order with respect to [aldehyde] is always zero. The rate is found to increase with decrease in the dielectric constant of the medium. Increase of ionic strength of the medium decreases the rate of oxidation. Addition of succinimide (>NH), has negligible effect on the rate of oxidation. The product of oxidation is the corresponding acid. Arrhenius and the activation parameters have been calculated. A suitable mechanism is also proposed

Kinetics of Oxidation of Cychlohexanol by N-Chloronicotinamide in Aqueous Acetic Acid Medium

Kinetics of oxidation o Cyclohexanol by N-Chloronicotinamide(NCN) in 50% V/V aqueous acetic acid mixture has been investigated in the presence of HCIO4 and NaCl. The observed rate of oxidation is first-order with respect to oxidation (NCN) and fractional-order with respect to cyclohexanol. A decrease in dielectric constant of the medium increases the rate. Addition of nicotinamide (NA), the reduction product of NCN, has a retarding effect an the rate of oxidation. Arrhenius and activation parameters are calculated. Kinetics of bromination1 and oxidation2,3 of saturated organic compounds by N-bromosuccinimide(NBS) have been received considerable attention. Kinetics and mechanism of oxidation of amino acids by NCN has been reported in aqueous acetic acid medium, we report herein the result of similar studies on the oxidation of cyclohexanol with NCN in aqueous acetic acid medium

Kinetics of Oxidation of Benzoin by N. Bromosuccinimide

Kinetics of Oxidation of Benzoin by N. Bromosuccinimide[NBS] 80% aqueous acetic acid has been investigated. The reaction follows first-order kinetics with respect to both[NBS] and [benzoin]. The effect of varying ionic strength and dielectric constant indicate the reaction is dipole-dipole type. Addition of succinimide(>NH), has a retarding effect on the rate of oxidation. The product of oxidation is benzil. By studying the effect of temparature on the reaction rate, the Arrhenius and the activation parameters have been calculated. A suitable mechanism has been proposed and a rate low explaining the experiment results is derived

Tahap Pengetahuan Guru Pendidikan Khas dalam Pengurusan Sosioemosi Murid Autisme

Guru perlu mempunyai pengetahuan dan kepakaran dalam menguruskan sosioemosi murid kecelaruan spektrum autisme agar mereka mampu belajar seperti murid lain. Kajian ini mengkaji tahap pengetahuan guru untuk mengenali tahap dan ciri-ciri sosioemosi murid autisme serta pengurusan sosioemosi mereka. Objektif kajian ini adalah untuk mengkaji  tahap pengetahuan guru mengenai ciri-ciri sosioemosi murid autisme, tahap pengetahuan guru mengenai tahap sosioemosi murid Autisme dan tahap pengetahuan guru mengenai pengurusan sosioemosi murid. Kajian dilaksanakan secara kuantitatif menggunakan borang soal selidik yang telah dijawab oleh  seratus orang responden. Dapatan kajian menunjukkan bahawa tahap pengetahuan guru mengenai pengurusan sosio-emosi, tahap perkembagan sosio emosi dan ciri – ciri sosio emosi murid autisme di sekolah adalah rendah. Diharapkan kajian ini dapat meningkatkan kefahaman pemegang taruh mengenai kepentingan pengetahuan guru dalam menguruskan sosioemosi murid autisme di dalam bilik darjah dan impaknya ke atas perkembangan murid autisme.     &nbsp

New Stability Criteria for Stochastic Takagi-Sugeno Fuzzy Systems With Time-Varying Delays

This paper is concerned with the asymptotic stability issue for a class of stochastic Takagi-Sugeno (TS) fuzzy systems with time-varying delays. Then, by utilizing a delayfractioning method, the stochastic analysis theory combined with the matrix inequality technique, a new set of sufficient condition in terms of linear matrix inequalities is presented which ensures the asymptotic stability of the stochastic TS fuzzy systems with timedelays. The results obtained in this paper are delay-dependent in the sense that they depend on not only the lower bound but also the upper bound of the time-varying delay. Numerical examples are given to illustrate the effectiveness and less conservativeness of the obtained results

Exponential H-infinity filtering for discrete-time switched neural networks with random delays

This paper addresses the exponential H∞ filtering problem for a class of discrete-time switched neural networks with random time-varying delays. The involved delays are assumed to be randomly time-varying which are characterized by introducing a Bernoulli stochastic variable. Effects of both variation range and distribution probability of the time delays are considered. The nonlinear activation functions are assumed to satisfy the sector conditions. Our aim is to estimate the state by designing a full order filter such that the filter error system is globally exponentially stable with an expected decay rate and a H∞ performance attenuation level. The filter is designed by using a piecewise Lyapunov–Krasovskii functional together with linear matrix inequality (LMI) approach and average dwell time method. First, a set of sufficient LMI conditions are established to guarantee the exponential mean-square stability of the augmented system and then the parameters of full-order filter are expressed in terms of solutions to a set of LMI conditions. The proposed LMI conditions can be easily solved by using standard software packages. Finally, numerical examples by means of practical problems are provided to illustrate the effectiveness of the proposed filter design.Kalidass Mathiyalagan, Hongye Su, Peng Shi, and Rathinasamy Sakthive

Robust reliable sampled-data control for switched systems with application to flight control

Published online: 25 Sep 2015This paper addresses the robust reliable stabilisation problem for a class of uncertain switched systemswith random delays and norm bounded uncertainties. The main aim of this paper is to obtain the reliable robust sampled-data control design which involves random time delay with an appropriate gain control matrix for achieving the robust exponential stabilisation for uncertain switched system against actuator failures. In particular, the involved delays are assumed to be randomly time-varying which obeys certain mutually uncorrelated Bernoulli distributed white noise sequences. By constructing an appropriate Lyapunov– Krasovskii functional (LKF) and employing an average-dwell time approach, a new set of criteria is derived for ensuring the robust exponential stability of the closed-loop switched system. More precisely, the Schur complement and Jensen’s integral inequality are used in derivation of stabilisation criteria. By considering the relationship among the random time-varying delay and its lower and upper bounds, a new set of sufficient condition is established for the existence of reliable robust sampled-data control in terms of solution to linearmatrix inequalities (LMIs). Finally, an illustrative example based on the F-18 aircraft model is provided to show the effectiveness of the proposed design procedures.R. Sakthivel, Maya Joby, P. Shi and K. Mathiyalaga

Reliable mixed H-infinity and passivity-based control for fuzzy Markovian switching systems with probabilistic time delays and actuator failures

This paper is concerned with the problem of reliable mixed H∞ and passivity-based control for a class of stochastic Takagi-Sugeno (TS) fuzzy systems with Markovian switching and probabilistic time varying delays. Different from the existing works, the H∞ and passivity control problem with probabilistic occurrence of time-varying delays and actuator failures is considered in a unified framework, which is more general in some practical situations. The main aim of this paper is to design a reliable mixed H∞ and passivity-based controller such that the stochastic TS fuzzy system with Markovian switching is stochastically stable with a prescribed mixed H∞ and passivity performance level γ > 0 . Based on the Lyapunov-Krasovskii functional (LKF) involving lower and upper bound of probabilistic time delay and convex combination technique, a new set of delay-dependent sufficient condition in terms of linear matrix inequalities (LMIs) is established for obtaining the required result. Finally, a numerical example based on the modified truck-trailer model is given to demonstrate the effectiveness and applicability of the proposed design techniques.Rathinasamy Sakthivel, Subramaniam Selvi, Kalidass Mathiyalagan and Peng Sh