Geometrization of magnetohydrodynamic equations via lie groups

The equations of magnetohydrodynamics of a perfect fluid are classified with respect to the Coriolis parameter, and all essentially different solutions of rank one are indicated. The geometry of streamlines is discussed.     

Kinetics and mechanism of oxidation of 1,4-butanediol by chromium(VI) in acid perchlorate medium

Summary The kinetics of oxidation of 1,4-butanediol by chromium(VI) was studied in acid perchlorate medium and the oxidation product of the diol was identified as 4-hydroxybutanal. The kinetic rate law observed accounted for the complex dependence of the hydrogen ion k=(k₂K₁[H+]+k₃K₁K₂[H+]²)/(1+K₁[H]+) where k is the observed second-order rate constant.     

Surface and catalytic properties of Cu–Ce–O composite oxides prepared by combustion method

Surface and catalytic properties of Cu–Ce–O composite materials prepared by solution combustion method have been investigated. The materials are characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR) and electron paramagnetic resonance spectroscopy (EPR). The results of EPR and TPR show finely dispersed Cu²⁺ species on ceria matrix with low copper content. The Cu²⁺ species exists in the form of dimers and clusters which are not evident in XRD. In addition CuO is also present as small clusters which grow to larger size at higher Cu content. There is no evidence of CuO forming a solid solution with fluorite CeO₂ in combustion method. The Cu²⁺ species mostly appear on surface rather than in the bulk. Hydrogen peroxide decomposition kinetics has been carried out on Cu–Ce–O composite materials to investigate the effect of crystalline and well-dispersed copper oxide phases on CeO₂. From kinetic results, the catalyst materials can be grouped into highly dispersed as well as crystalline CuO phases present on CeO₂ matrix. Two parallel compensating lines for dispersed and crystalline CuO phases on CeO₂ are observed in ln A versus E_a plot indicating the compensation effect in H₂O₂ decomposition. This observation is consistent with XRD and EPR results.     

Synthesis, crystal structure determination, spectroscopic and electrochemical studies of trans-[Ru(PPh3)2(bbpH2)Cl]Cl·CHCl3·H20 (bbpH2=2,6-bis(benzimidazolyl) pyridine) – an infinite double columnar supramolecule in the solid state

The synthesis, crystal structure, redox and spectroscopic properties of trans-[Ru(bbpH₂)(PPh₃)₂Cl]Cl are reported. In the crystalline solvate trans-[Ru(bbpH₂)(PPh₃)₂cCl]Cl CHCl₃ H₂O, the molecular components are connected by strong intermolecular hydrogen bonding to form an infinite double column.     

Luminescence in ZnS: La and ZnS: (Mn,La) phosphors

The photo (PL) and electro (EL) luminescence in ZnS: MnLa and ZnS: La have been studied. The enhancement and quenching of emission bands have been observed on the simultaneous application of sinusoidal field and photons. The wave shape, voltage, frequency and temperature dependence of EL brightness have been reported. A study of the phosphorescence and thermoluminescence of these phosphors is also carried out and it is observed that the trap-depth changes slowly with temperature and activator concentration. An attempt has been made to calculate the trap depth by studying temperature dependence of EL brightness. The results are reported and discussed.     

Electric-field mapping of some anions and cations of adenine and guanine

Electric-field maps of certain anions and cations of adenine and guanine have been studied. The results are compared with those of neutral adenine and guanine. In all cases, the geometries were fully optimized using the MNDO molecular orbital method and the fields were computed using Mulliken charges. Reactivities and hydrogen-bonding pattern predicted by electric fields, including those of cations, are in satisfactory agreement with experiment. © 1993 John Wiley & Sons, Inc.     

Scalar variational analysis of single mode,graded-core,W-type fibres

A scalar variational analysis for the fundamental mode of a graded-core, W-type fibre based on single and two parameter trial fields has been presented. Comparison with the exact numerical results shows that the two parameter trial field estimates the propagation characteristics accurately.On study leave from Physics Department, G.M. College, Sambalpur-768004, India.