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1

Erbium-doped fiber ring laser dynamical analysis for chaos message masking scheme

Ali S. Z., Islam M. K.

Optica Applicata

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2017

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Vol. 47, nr 3

395--410

EN

A detailed dynamical analysis of erbium-doped fiber ring laser cavity loss configuration for the chaos message masking scheme is carried out to optimize the generation of high quality chaos. A threefold increase in Lyapunov exponent implying higher security, and a significant increase in chaos bandwidth is achieved, both ideal for secure optical communication and nonlinear chaotic applications. The pulsed chaos is chaotic in a pulse time interval in addition to the amplitude resulting in better concealment of data pulses in a time domain. The chaos spectrum is a flat broadband and rich in spikes making spectral detection of a message more difficult. The range of five key parameters for which erbium-doped fiber ring laser retains its chaotic behaviour is also increased significantly reducing the effectiveness of a brute force attack to guess the erbium-doped fiber ring laser parameters. The chaos message masking scheme provides a higher security in comparison with additive chaos modulation scheme for implementation of chaotic optical communication using erbium- doped fiber ring laser. The security of a complete end-to-end chaotic optical communication system is tested by launching a spectral attack to estimate the message signal. The message signal clearly hides in a stronger chaotic signal and its spectral contents are not discernible.

2

Analgesic and anti-inflammatory activities of some transition metal schiff base complexes

Jesmin M., Islam M. K., Ali S. M. M.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 8

64--72

EN

Analgesic and anti-inflammatory activities of four transition metal complexes of a Schiff base derived from salicylaldehyde and glycine, viz. [N-salicylideneglycinato diaqua cobalt(II) dimer] (SGCo)2, [N-salicylideneglycinato-di-aqua-nickel(ll)dimer] (SGN)2, [N-salicylideneglycinato-aqua-copper(II)] (SGC) and [N-salicylideneglycinato diaqua zinc(II) dimer] (SGZ)2 were studied in swiss albino mice. 10 mg/kg (p.o) dose for each compound were selected throughout the research work. The analgesic activity was determined by acetic acid induced writhing and tail immersion methods. All such data were compared with standard drugs at the dose of 10 mg/kg (p.o. The anti-inflammatory activity of the test compounds was determined by the carragenan induced mice paw edema inhibition method.). Analgesic and anti-inflammatory activities of the test compounds at 10 mg/kg (p.o.) were quite comparable to those of standard drugs at 10 mg/kg (p.o.). All these compounds can be considered as potent analgesic and anti-inflammatory agents.

3

Antibacterial Activities of Some Transition Metal Schiff Base Complexes

Islam M.N., Shahriar S.M.S., Islam M.K., Jesmin M., Ali M.M., Khanam J.A.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 5

12-20

EN

A new series of four transition metal complexes of a Schiff base derived from salicylaldehyde and glycine, viz. [N-salicylidene glycinato diaqua cobalt (II) dimer] (SGCo)2, [N- salicylideneglycinato-di-aqua-nickel(ll)dimer] (SGN)2, [N-salicylideneglycinato-aqua-copper(II)] (SGC) and [N-salicylidene glycinato diaqua zinc(II) dimer] (SGZ)2 have been synthesized and characterized through a rapid, simple, and efficient methodology in excellent yield. These compounds were screened for in vitro antibacterial activities against six pathogenic bacteria, such as Shigella sonnei, Escherichia coli, Bacilus subtilis, Sarcina lutea, Staphylococcus aureus and Pseudomonas arioginosa. The antibacterial activity was determined by the disc diffusion method using DMSO as solvent. The results indicate that (SGC) compound exhibit a significant antibacterial activity, depending on the bacterial strain and (SGCo)2, (SGN)2 and (SGZ)2 compounds show a moderate sensitivity even with higher doses. All these compounds were found to possess cytotoxic effect.