Optical Emission Spectroscopy of Abnormal Glow Region in Nitrogen Plasma

Optical emission spectroscopy of the active species in N₂ plasma is carried out to investigate their concentration as a function of discharge parameters such as filling pressure (2.0–7.0 mbar), source power (100–200 W) and gas flow rate (50–300 mg/min). The primary motivation of this work is to obtain reliable information about the concentration of the active species of N₂ plasma, which play an important role in plasma surface nitriding processes. Emission intensity from the selected electronic excited states of molecular and atomic species is evaluated as a function of discharge parameters to investigate their concentration. The emission intensity ratio I(N₂⁺)/I(N₂) and I(N⁺)/I(N) of the electronic transitions is also evaluated as a function of discharge parameters to investigate the relative dependence of their concentrations. It is observed that the concentration of the active species of N₂ plasma is strongly affected by the filling pressure and source power whereas flow rate has no significant effect. An increased occurrence of N₂⁺ molecular ions in comparison with N₂ molecules, and N⁺ ions in comparison with N atoms is observed with source power whereas decreased occurrence of N₂⁺ molecular ions in comparison with N₂ molecules, and N⁺ ions in comparison with N atoms is observed with the rise in filling pressure.     

Influence of additives on the clouding behavior of amphiphilic drug solutions

The present work focuses on the clouding phenomenon in an amphiphilic drug [amitriptyline (AMT), which is a tricyclic antidepressant] solution. A 50-mM AMT solution prepared in 10 mM of sodium phosphate (SP) buffer was taken where the cloud point (CP) was found to decrease with increasing pH. The same CP decreasing trend (with pH increase) followed in the presence of a fixed concentration (50 mM) of added salts [NaBr, and tetra-n-butylammonium bromide (TBuAB)]. The addition of increasing amounts of quaternary bromides (tetramethylammonium bromide, tetraethylammonium bromide, tetra-n-propylammonium bromide, TBuAB, and tetra-n-pentylammonium bromide) to 50 mM of AMT solution (prepared in 10 mM of SP buffer) caused continuous increase in CP, which was found to be dependent upon the alkyl chain length of that particular salt. The similar type of CP increase was also observed in the presence of conventional (cetyltrimethylammonium bromide and tetradecyltrimethylammonium bromide) and gemini surfactants [bis(hexadecyldimethylammonium)hexane, bis(hexadecyldimethylammonium)pentane, and bis(hexadecyldimethylammonium)butane]. The overall behavior was discussed in terms of electrostatic interactions, micellar growth, and mixed micelle formation.     

Effect of some trace elements on the nucleic acid metabolising enzymes level of germinating wheat seeds

Wheat seeds were grown in the presence and absence of some trace elements like Co, Cu, Fe, Mn, Mo and Zn in non-toxic limits. The level of enzyme activities involved in nucleic acid metabolism were measured by spectrophotometric methods. The level of certain RNA metabolising enzymes increased manyfold in trace element-treated seeds, while the level of AMP-deaminase was increased manyfold in Co-treated seeds.     

Deposition of Diamond-like Carbon Films using Graphite Sputtering in Neon Dense Plasma

This paper reports the deposition of diamond-like carbon (DLC) films on Si <100>, using a low energy (1.45 kJ) dense plasma focus assisted sputtering of graphite insert at the tip of the tapered anode. The substrates are placed in front of the anode at different axial and angular positions and are exposed to multiple focus shots. The information regarding the DLC structure is acquired by using Raman spectroscopy. The spectra are characterized by two broad bands known as “G-band” and “D-band”. The results point towards the formation of DLC films with both sp³ (diamond like) and sp² (graphite like) domains. In X-ray diffraction (XRD) pattern, no additional peak is observed except a peak at 2θ = 69° which corresponds to the silicon (Si) substrate. The intensity of Si peak is reduced after treatment indicating the deposition of amorphous carbon. Scanning electron microscopy (SEM) results demonstrate that the smoothness of the film increases with increasing the substrate angular positions with respect to the anode axis. Energy dispersive X-ray (EDX) analysis reveals that the films deposited at lower axial and angular positions are thicker which is complemented by the cross-sectional views of the films.     

Synthesis and characterization of new synthetic oxygen carriers. A kinetic study of the reaction of the binuclear iron(III)–copper(II) complex with H<Subscript>2</Subscript>O<Subscript>2</Subscript>

New oxygen carriers have been synthesized by the interaction of the Cu^II/Ni^II derivative of the bis(5-nitroindazolyl)methane complex with 14-membered 1,8-dihydro-1,3,6,8,10,13-hexaazacyclotetradecane (M-mac), where M=Fe^III, Ni^II, Co^II, to yield binuclear complexes. These complexes have been characterized by physico-chemical methods: elemental analysis, i.r., ¹H-n.m.r., ¹³C-n.m.r., 2D cosy n.m.r., e.p.r., u.v.–vis. spectroscopy and cyclic voltammetry. A representative binuclear Fe^III–Cu^II complex was chosen to interact with H₂O₂ to elucidate the mechanistic pathway of oxygen binding in solution spectrophotometrically, and also by cyclic voltammetry. Hydrogen peroxide exhibits two mechanisms for binding, either (i) homolysis or (ii) heterolytic cleavage. The mode of H₂O₂ binding can be hazardous in (i) due to the threat of oxidative damage to the cellular structure, proteins and metabolites, or eco-friendly as in (ii) which produces innocuous products such as water and dioxygen. This study aims to combat the problems associated with H₂O₂ binding in nature by producing a parallel study on model compounds.     

On Jordan Triple Higher Derivable Mappings on Rings

Let R be a ring and \({\mathbb{N}}\) be the set of all non-negative integers. A family of maps \({D=\{d_n\}_{n \in\mathbb{N}}}\) is said to be Jordan triple higher derivable if \({d_n(aba)=\sum \nolimits_{p+q+r=n} d_p(a)d_q(b)d_r(a)}\) holds for all \({a,b \in R}\), where d ₀ = I _R , (the identity map on R). In this paper, we determine Jordan triple higher derivable map on a ring R, which contains a nontrivial idempotent which is automatically additive. An immediate application of our main result shows that every Jordan triple higher derivable map becomes higher derivation on R.     

Applications of enantioselective carbolithiation of ortho-substituted beta-methylstyrenes

The enantioselective carbolithiation of ortho-substituted (E)-beta-methylstyrenes provides access to chiral lithiated intermediates with broad synthetic potential. Specifically, beta-methylstyrenes with o-aminomethyl, ether, and oxazoline groups have been employed in the synthesis of chiral aromatics and heteroaromatics such as isoquinolines, isoquinolinones, benzofurans, and isobenzofuranones.     

Poly (3,4‐ethylenedioxythiophene) γ‐Fe2O3 polymer composite–super paramagnetic behavior and variable range hopping 1D conduction mechanism–synthesis and characterization

The present paper reports the preparation of poly (3,4‐ethylenedioxythiophene) (PEDOT) ferrimagnetic conducting polymer composite by incorporation of ferrite particles in the polymer matrix by emulsion polymerization. Synthesis of PEDOT–γ‐Fe₂O₃ composite was carried out by chemical oxidative polymerization of EDOT with ferrite particles in the presence of dodecylbenzenesulfonic acid (DBSA) that works as dopant as well as surfactant in aqueous medium. The resulting conducting composite possesses saturation magnetization (Ms) value of 20.56 emu/g with a conductivity of 0.4 Scm^?1, which was determined by VSM and four probe technique, respectively. B‐H curve reveals that ferrimagnetic particles of γ‐Fe₂O₃ show super‐paramagnetic behavior at room temperature which was also observed in PEDOT–γ‐Fe₂O₃ composite. The resulting conducting ferrimagnetic composite shows microwave absorption loss of 18.7–22.8 dB in the frequency range of 12.4–18 GHz. Thermogravimetric analysis of the composite revealed that the composite is thermally stable up to 230°C. The characterization of the PEDOT–γ‐Fe₂O₃ composite was carried out using XRD and FTIR spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.