Optical soliton and elliptic functions solutions of Sasa-satsuma dynamical equation and its applications

The Sasa-satsuma(SS) dynamical equation interpret propagation of ultra-short and femto-second pulses in optical fibers. This dynamical model has important physical significance.In this article, two mathematical techniques namely, improved F-expansion and improved auxiliary methods are utilized to construct the several types of solitons such as dark soliton, bright soliton, periodic soliton, Elliptic function and solitary waves solutions of Sasa-satsuma dynamical equation. These results have imperative applications in sciences and other fields, and constructive to recognize the physical structure of this complex dynamical model. The computing work and obtained results show the influence and effectiveness of current methods.     

Corrosion Inhibition Using Harmal Leaf Extract as an Eco-Friendly Corrosion Inhibitor

Extract of natural plants is one of the most important metallic corrosion inhibitors. They are readily available, nontoxic, environmentally friendly, biodegradable, highly efficient, and renewable. The present project focuses on the corrosion inhibition effects of Peganum Harmala leaf extract. The equivalent circuit with two time constants with film and charge transfer components gave the best fitting of impedance data. Extraction of active species by sonication proved to be an effective new method to extract the inhibitors. High percent inhibition efficacy IE% of 98% for 283.4 ppm solutions was attained using impedance spectroscopy EIS measurements. The values of charge transfer R_ct increases while the double layer capacitance C_dl values decrease with increasing Harmal extract concentration. This indicates the formation of protective film. The polarization curves show that the Harmal extract acts as a cathodic-type inhibitor. It is found that the adsorption of Harmal molecules onto the steel surface followed Langmuir isotherm. Fourier-transform infrared spectroscopy FTIR was used to determine the electron-rich functional groups in Harmal extract, which contribute to corrosion inhibition effect. Scanning electron microscopy SEM measurement of a steel surface clearly proves the anticorrosion effect of Harmal leaves.     

Transport and structural properties of polymerized AC60 (A = K, Rb) under zero and high pressure conditions

60 display transport properties vastly different from their unpolymerized counterparts. We here describe structural (X-ray diffraction and transmission electron microscopy) and dc resistivity measurements of polymerized AC₆₀ (A = K, Rb) at zero and high pressures. The structural and electronic properties are rich, and evidence is found for unusual phase transitions in both materials. Received: 28 October 1996/Accepted: 13 December 1996     

Direct Electrochemistry of Cytochrome P450 Reductases in Surfactant and Polyion Films

NADPH‐cytochrome P450 reductase (CPR) serves as electron donor for cytochrome P450 catalyzed monooxygenase reactions utilizing flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) as electron transfer cofactors. Here, stable films of human and rabbit CPRs with didodecyldimethylammonium bromide (DDAB), dimyristoylphosphatidyl choline (DMPC), and poly(diallyldimethylammonium) (PDDA) were made on pyrolytic graphite (PG) electrodes for comparative structural and electrochemical studies. CD and UV‐VIS absorbance spectra suggested that near native CPR conformation is retained in PDDA films, and some conformational changes occur in DMPC or DDAB films. Cyclic voltammetry of these films gave quasireversible pairs of peaks at average formal potential ?0.246±0.008 V vs. NHE. In human CPR‐DDAB (H‐CPR‐DDAB), a second pair of peaks at +0.317 V vs. NHE was found that depended strongly on identity of buffer and salt. Excepting H‐CPR in DDAB, films showed similar voltammetry, formal potentials, and k_s values. While CPR‐PDDA films had near native CPR structures, electrochemical parameters did not differ significantly from CPR‐DMPC films. The relative independence of film voltammetry from the influence of film materials for CPRs is in contrast with heme iron proteins that, while retaining near native structures, have formal potentials that depend significantly on identity of the film material.     

Elimination of chloride interference on arsenic speciation in ion chromatography inductively coupled mass spectrometry using an octopole collision/reaction system

Anion-exchange chromatography with inductively coupled plasma mass spectrometry (ICP-MS) is often used for the speciation of arsenic (As). In this work, either He or H₂ was introduced to the octopole collision/reaction cell to eliminate chloride (Cl⁻) interferences during As speciation by ICP-MS. Polyatomic species, ⁴⁰Ar³⁵Cl and ³⁸Ar³⁷Cl, which are formed in high chloride matrices interfere with the ICP-MS detection of ⁷⁵As. These interferences were reduced or eliminated by introducing He or H₂ to the collision/reaction cell, with some loss in sensitivity when compared to the standard mode (no gas). For example, the sensitivity of As(V) was 30.4 and 17.7% of that observed in standard mode when introducing He and H₂, respectively. Chloride interference was completely eliminated using a flow rate of 3.0 mL min^− 1 with H₂ as a reaction gas with detection limits in the range of 0.3-0.6 μg L^− 1. The developed method was applied to determination of arsenic species in waters containing high concentrations of chloride by following a simple procedure and without modification of the ICP-MS instrument.     

A divided spectrum balanced detection technique for intensity noise reduction in SAC OCDMA systems

In this paper we propose a simple divided spectrum balanced detection (DSBD) for spectral amplitude coding (SAC) optical code division multiple access (OCDMA) systems. SAC OCDMA systems are limited by phase induced intensity noise (PIIN), which is a signal dependent source of noise. Our proposed technique reduces the PIIN by dividing the spectrum of the signal into two or more, and detecting each spectrum by a different photodiode. The DSBD scheme reduces the detected optical power at photodetection, thus resulting in a higher mitigation of the PIIN. Theoretical results show that DSBD demonstrate noticeable improvement over traditional balanced detection technique, for example an up to 33% increase in the number of active users can be achieved, and at least 1 × 10⁻³ b/s Hz increase in the spectral efficiency is obtained. However, the SDBD is more complex and append more constrains on system components.     

Protein film electrochemistry of microsomes genetically enriched in human cytochrome p450 monooxygenases

This communication demonstrates direct electron delivery from electrodes to cyt P450 reductases in stable films ( approximately 100 nm thick) of genetically enriched CYP1A2 and CYP3A4 microsomes made by layer-by-layer assembly with polyions. Reversible voltammetry of films containing genetically enriched cyt P450 monooxygenase microsomes was shown to involve cyt P450 reductase by comparison with the pure rabbit reductase and by lack of characteristic reactions of iron heme enzymes, such as reaction of the FeII form with CO and catalytic electrochemical reduction of oxygen and hydrogen peroxide. The microsome films were activated electrochemically to catalyze styrene epoxidation, consistent with the pathway utilized in the human liver, although further work is required to establish this definitively.     

Synthesis and characterization of poly (indene‐co‐pyrrole) nanofibers

Nanofibers of poly (indene‐co‐pyrrole) (CInPy) have been synthesized, using a facile chemical oxidative polymerization reaction. The effect of copolymerization was examined in view of the individually synthesized homopolymer nanostructures of polyindene (PIn) and polypyrrole (PPy). Morphological details of CInPy, studied using scanning electron microscopy (SEM) and transmission electron microscopy, (TEM) reveal the appearance of dense cottony mess, comprising of fine fibers with an average diameter of 5–10 nm. Chemical structural analysis of CInPy, conducted using ultraviolet‐visible (UV‐Vis), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopic techniques, reveals that both PIn and PPy are involved in the formation of copolymer organization. Fluorescence properties of nanosized copolymer are observed in the blue region, with emission λ_max placed at 395 nm. Conductivity of copolymer nanofibers (2.4 × 10^?3 S/cm) is consistent with the morphology and thermal stability properties of integral homo‐polymers. Improved thermal stability and processability along with the enhanced optical and electrical properties of copolymer nanostructures outfit it as a better promising material in optoelectronic and light emitting nanodevices, with reference to nanosized PIn and PPy. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and characterization of polypyrrole nanofibers with different dopants

Nanostructures of polypyrrole (PPy) were synthesized in the presence of different dopants including hydrochloric acid (HCl), ferric chloride (FeCl₃), p‐toluene sulfonic acid (p‐TSA), camphor sulfonic acid (CSA), and polystyrene sulfonic acid (PSSA), using a simple interfacial oxidative polymerization method. The method is a reliable non‐template approach with relatively simple instrumentation, ease of synthesis, and economic viability for synthesizing PPy nanostructures. Morphology of synthesized PPy structures was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicate the formation of one‐dimensional (1D) nanofibers with average diameter of 75–180 nm. Energy dispersive spectrum (EDS) of the PPy nanofibers indicates the attachment of the dopants to the PPy backbone; the fact is further confirmed by the Fourier transform infrared (FTIR) spectra of PPy nanostructures. Thermal stabilities of the nanostructures explored using thermal gravimetric analysis (TGA) follow the order PPy‐p‐TSA > CSA > HCl > FeCl₃ > PSSA. It is noticed that the electrical conductivity (EC) of PPy nanostructures depends upon the nature of dopant (PPy‐p‐TSA > CSA > HCl > FeCl₃ > PSSA), PPy‐p‐TSA nanofibers showing the highest EC of 6 × 10^?2 Scm^?1. Copyright © 2009 John Wiley & Sons, Ltd.