Microplasma-assisted synthesis of CuO nanostructures for catalytic degradation of organic dyes under solar irradiation

Journal of Solid State Electrochemistry - In this research work, CuO nanostructures were synthesized using atmospheric pressure microplasma (AMP) electrochemical process. The synthesized CuO...     

Graft copolymerization onto jute fiber: Ceric ion-initiated graft copolymerization of methyl methacrylate

Graft copolymerization of methyl methacrylate (MMA) was carried out on both defatted and bleached jute fibers using ceric ammonium sulfate (CAS) as the initiator. In order to obtain the optimum condition for grafting, the effects of initiator concentrations, temperature, time of reaction, lignin content of jute, and the monomer concentration were studied. The maximum percent grafting and grafting efficiency were found to be 132% and 0.71, respectively. Kinetic studies showed that at 0.03M CAS, the reaction appeared to obey the second-order process. The activation energies were found to be 7.74 and 5.12 kcal/mole for defatted (lignin content, 15.7%) and chlorite-bleached jute (lignin content 10%), respectively. The activation energies of graft copolymerization of MMA onto jute fiber are compared with the energies of activation of graft copolymerization of acrylonitrile (AN).     

Bright and dark solitons in optical metamaterials

This paper addresses the dynamics of solitons in optical metamaterials. Both bright and dark soliton solutions are obtained. The ansatz method of integration is employed to extract the 1-soliton solutions to the governing equations. A couple of constraint relations are obtained in order for these solitons to exist. A few numerical simulations are also given to expose the dissipative effects.     

Mössbauer spectroscopic study of FeAl1−x Co x

We report the results of a Mössbauer study of the alloy sytem FeAl_1?x Co _x forx ≥ 0.3 at temperatures down to 83 K. Magnetic splitting is observed forx ≥ 0.35 at all temperatures. However, forx=0.3, no splitting is observed at room temperature, and superparamagnetic behavior occurs at LN₂ temperature. The magnetically split spectra are fitted each with a distribution of hyperfine fields and the average hyperfine field \(\bar B_{hf} \) as a function of temperature is obtained. The variation of \(\bar B_{hf} \) withT is explained using the model of magnetic clusters with collective magnetic excitations from which the saturation hyperfine field and the magnetic anisotropy energy for these clusters are obtained. Also, the results are discussed using the model of random atomic distributions, and the agreement between the calculated and the experimentally obtained distributions of hyperfine fields is found improve asx increases.     

Line shape parameters study of the 6p7p (<Superscript>1</Superscript>P<Subscript>1</Subscript>, <Superscript>3</Superscript>D<Subscript>1</Subscript> and <Superscript>3</Superscript>P<Subscript>1</Subscript>): Autoionizing resonances in barium

We report a systematic line shape analysis study of the 6p7p configuration based ¹P₁, ³D₁ and ³P₁ autoionizing resonances in barium using a Nd:YAG pumped dye laser system in conjunction with a thermionic diode ion detector. The even parity isolated autoionizing resonances have been approached via four intermediate states 6 snp ¹P₁ (6 ≤n ≤8) and 5d6p ¹P₁. A comparison of the Fano parameters of the resonance profiles reveals that the width of an autoionizing resonance is independent of the excitation path while the line profile parameter changes with the selection of different intermediate states.     

Flow control with plasma-based actuator in different velocity regimes: Momentum and heat transfer effects

In this study, control of the airflow by the direct current (DC) electrical discharge with bare electrodes has been investigated in different velocity regimes. The discharge characteristics of the plasma model are obtained numerically. An induced electrohydrodynamic (EHD) force on neutral flow was characterized based on momentum transfer from charged particles. The change in the incident flow parameters was studied by applying Navier–Stokes (N-S) equations, considering source terms arising from a weakly ionized plasma. The effect of the discharge on the low- and high-speed flow was simulated in this study. It was concluded that the changes of the velocity profile, airflow pressure, and oblique shock wave could be attributed to the EHD force from a nonthermal plasma to the incoming airflow. It was seen that the incident airflow is accelerated also by the induced EHD force. Our results show that the most important mechanism in the plasma-based flow control is the momentum transfer from the electrical discharge to the incident flow and that the gas heating has no significant role.     

Observation of B(0) --> D0pi(0) and B(0) -->D(*0)pi(0)

We have studied the color-suppressed hadronic decays of neutral B mesons into the final states D*0pi(0). Using 9.67 x 10(6) BB pairs collected with the CLEO detector, we observe the decays B( 0) --> D0pi(0) and B( 0) -->D(*0)pi(0) with the branching fractions BB( 0) -->D0pi(0)) = (2.74(+0.36)(-0.32) +/- 0.55)x10(-4) and BB( 0) -->D(*0)pi(0)) = (2.20(+0.59)(-0.52) +/- 0.79)x10(-4). The first error is statistical and the second systematic. The statistical significance of the D0pi(0) signal is 12.1sigma ( 5.9sigma for D(*0)pi(0)). Utilizing the B( 0) -->D*0)pi(0) branching fractions we determine the strong phases delta(I,D(*)) between isospin 1/2 and 3/2 amplitudes in the Dpi and D*pi final states to be cosdelta(I,D) = 0.89 +/-0.08 and cosdelta(I,D*) = 0.89 +/- 0.08, respectively.     

Laser-induced breakdown spectroscopic studies of marbles

We present laser-induced breakdown spectroscopic studies of variety of marbles extracted from Quetta region of Boluchistan, Pakistan using a Nd:YAG laser (532 nm) in conjunction with LIBS 2000 detection system. The emission spectra of Onyx (white spot) and Quetta Green Marble samples have been recorded as a function of laser irradiance. The elemental composition and their relative abundance in each sample are fond to be quite different. In Onyx (white spot), calcium dominates while in the Quetta Green marble magnesium is the dominant element. In addition the effect of the laser irradiance on the emission intensity, width and shift of the transition lines have been studied.     

Efficient and Mild Procedure for Reductive Methylation of Amines Using N‐Methylpiperidine Zinc Borohydride

A simple and efficient procedure for reductive methylation of primary and secondary amines using N‐methylpiperidine zinc borohydride (ZBNMPP), giving tertiary amines, is described. The reaction is carried out in methanol at room temperature under neutral conditions.     

Convenient Synthesis of Bis(indol)alkanes by Niobium(V) Chloride

Bis(indolyl)alkanes have been synthesized in excellent yields in the presence of a catalytic amount of niobium(V) chloride under solvent-free conditions.