Concentration-dependent electrochemical supercapacitive performance of Fe2O3

This work reports the concentration-dependent electrochemical supercapacitor performance change of electrodeposited Fe₂O₃ thin films. Structural elucidation and morphological evolution studies are operated in the first stage and in second, electrochemical supercapacitive performances are investigated. The maximum specific capacitance of 540 F/g at 2.5 A/g in 1 M KOH is obtained. The electric parameters including specific energy, specific power and coulomb efficiency are measured using charge/discharge technique and finally, electrochemical impedance measurement is examined for knowing the internal charge transfer resistance. An equivalent circuit associated with the cell, with required parameters, is also designed.     

Conformally symmetric anisotropic magnetospheres in general relativity

A class of exact analytical solutions of Einstein-Maxwell equations is obtained for static spheres of Maugin's anisotropic magnetofluid where the space-time geometry is assumed to admit a nonstatic conformai symmetry. These solutions are found by utilizing special physical considerations.     

[HDBU][HSO4]-catalyzed facile synthesis of new 1,2,3-triazole-tethered 2,3-dihydroquinazolin-4[1H]-one derivatives and their DPPH radical scavenging activity

Research on Chemical Intermediates - A simple and efficient protocol has been developed for the synthesis of new1,2,3-triazole-2,3-dihydroquinazolin-4[1H]-one (DHQ) conjugates(6a?j) via...     

Synthesis and characterization of processable polyamides containing polar quinoxaline unit in the main chain and evaluation of its hydrophilicity

Here we report a new five polyamides prepared via solution-phase polycondensation under Yamazaki-Higashi conditions to prove the suitability of this method. The synthesized polyamides were characterized by FTIR, ¹H-NMR, differential scanning calorimetry, thermogravimetric analysis, inherent viscosity, solubility and wettability tests. These polyamides were amorphous in nature and they are completely soluble in many organic solvents and they could easily be solution-cast into transparent, flexible films. The as-prepaired polymers showed excellent thermal properties. The glass transition temperatures of these polymers are in the range of 251–274?°C under nitrogen atmosphere. The decomposition temperature in nitrogen for a 10% weight-loss temperature is more than 744?°C, and char yield at 900?°C ranged from 43 to 56% in nitrogen. Water contact angles were also tested to know the hydrophilicity of the polyamide films. As-synthesized polyamides showed smallest quantact angles indicating hydrophilic surface.     

A novel route of synthesis of WS2 thin film and its characterization

WS₂ thin films have been deposited by chemical deposition technique using citric acid as a complexing agent at 343 K. X-ray pattern shows that crystalline nature with hexagonal- and orthorhombic-mixed phase. The films show that good optical properties high absorption and band gap value was found to be 1.31 eV. The specific conductivity of the film was found to be in order of 10⁻³ (Ω cm)⁻¹.     

Multiresidue analysis of multiclass plant growth regulators in grapes by liquid chromatography/tandem mass spectrometry

A selective and rapid multiresidue analysis method is presented for simultaneous estimation of 12 plant growth regulators (PGRs), namely, auxins (indol-3-acetic acid, indol-3-butyric acid, and naphthyl acetic acid), cytokinins (kinetin, zeatin, and 6-benzyladenine), gibberellic acid (GA3), abscisic acid, and synthetic compounds, namely, forchlorfenuron, paclobutrazole, isoprothiolane, and 2,4-dichlorophenoxy acetic acid (2,4-D) in bud sprouts and grape berries at the development stages of 2-3 and 6-8 mm diameters, which are the critical phases when exogenous application of PGRs may be necessary to achieve desired grape quality and yield. The sample preparation method involved extraction of plant material with acidified methanol (50%) by homogenization for 2 min at 15000 rpm. The pH of the extract was enhanced up to 6 by adding ammonium acetate, followed by homogenization and centrifugation. The supernatant extract was cleaned by SPE on an Oasis HLB cartridge (200 mg, 6 cc). The final extract was measured directly by LC/MS/MS with electrospray ionization in positive mode, except for 2,4-D, GA3, and abscisic acid extracts, which required analysis in negative mode. Quantification by multiple reaction monitoring (MRM) was supported with full-scan mass spectrometric confirmation using "information-dependent acquisition" triggered with MRM to "enhanced product ionization" mode of the hybrid quadrupole-ion trap mass analyzer. The LOQ of the test analytes varied between 1 and 10 ng/g with associated recoveries of 80-120% and precision RSD <25% (n = 8). Significant matrix-induced signal suppression was recorded when the responses for pre- and postextraction spikes of analytes were compared; this could be resolved by using matrix-matched calibration standards. The method could successfully be applied in analyzing incurred residue samples and would, therefore, be useful in precisely deciding the necessity and dose of exogenous applications of PGRs on the basis of measured endogenous levels.     

XRD and bulk magnetic studies on Ni-Cd and Ti doped Ni-Cd ferrites

For the ferrites Ni _x Cd_1–x Fe₂O₄ (x=0.3, 0.4,1) the lattice parameter, grain size, electrical resistivity, initial permeability, Curie temperature and squareness of the magnetization curve were measured. The results are discussed in terms of the model of the canted spin structure taking into account the domain structure of the polycrystalline ferrite.