E.p.r. studies on dichloromono(1-phenylamidino-o-alkylurea)copper(II) complexes. Evidence for field induced partial ordering in the solid state and some unusual features in solution

E.p.r. and optical absorption studies have been conducted on dichloromono(1-phenylamidino-o-alkylurea)copper(II) complexes (Alkyl = Me, Et, Pr, Bu or Pe). The e.p.r. spectra of solids, recorded at 300 K, confirmed the square-planar geometry with the unpaired electron in the dx ²–y ² orbital of copper. Magnetic field-induced partial molecular alignment has been observed in some of the polycrystalline samples when cooled in a magnetic field of 1 T at 77 K. E.p.r. spectra at 77 K in pyridine and DMF has shown axial ligation of solvent molecules (pyridine and DMF), whereas in MeOH and DMSO at least three structurally different Cu^II species have been identified. These features are consistent with differences in electronic absorption spectra in the powder and in solution.     

Dynamics of short fiber suspensions in bounded shear flow

We have studied the dynamics of non-colloidal short fiber suspensions in bounded shear flow using the Stokesian dynamics simulation. Such particles make up the microstructure of many suspensions for which the macroscopic dynamics are not well understood. The effect of wall on the fiber dynamics is the main focus of this work. For a single fiber undergoing simple shear flow between plane parallel walls the period of rotation was compared with the Jeffrey’s orbit. A fiber placed close to the wall shows significant deviation from Jeffrey’s orbit. The fiber moving near a solid wall in bounded shear flow follows a pole-vaulting motion, and its centroid location from the wall is also periodic. Simulations were also carried out to study the effect of fiber–fiber interactions on the viscosity of concentrated suspensions.     

Radiation effect on temperature distribution in three-dimensional Couette flow with suction or injection

A theoretical analysis of three-dimensional Couette flow with radiation effect on temperature distribution has been analysed, when the injection of the fluid at the lower stationary plate is a transverse sinusoidal one and its corresponding removal by constant suction through the upper porous plate is in uniform motion. Due to this type of injection velocity, the flow becomes three-dimensional. The effect of Prandtl number, radiation parameter and injection parameter on rate of heat transfer has been examined by the help of graphs. The Prandtl number has a much greater effect on the temperature distribution than the injection or radiation parameter.     

Lattice dynamic investigation of the Raman and infrared wavenumbers of orthorhombic R2BaNiO5 (R = Y,Gd) oxides in Immm structure

A short‐range force constant model has been applied to investigate the Raman and the infrared wavenumbers in R₂BaNiO₅ (R = Y, Gd) in their orthorhombic phase of space group Immm. Calculations of zone‐center phonons are made with seven stretching and four bending force constants. The force constants are evaluated by fitting nine Raman and two infrared modes. Two Raman modes are reassigned on the basis of group theoretical calculations. The calculated Raman and infrared modes show good agreement with the observed values. The infrared values are assigned for the first time in these oxides. Copyright © 2006 John Wiley & Sons, Ltd.     

Raman spectroscopy of the BC3 phase obtained under high pressure and high temperature

A direct transformation of the g‐BC₃ phase to a new diamond‐like d‐BC₃ phase was observed in a diamond‐anvil cell (DAC) at high temperature, 2033 ± 241 K, and high pressure, 50 GPa. Analysis of the peak positions of the d‐BC₃, B₄C, α‐boron, and the boron‐doped diamond leads to the conclusion that the positions of the peaks of the d‐BC₃ are more similar to the peak pattern of the boron‐doped diamond rather than that of boron carbide, α‐boron. Copyright © 2007 John Wiley & Sons, Ltd.     

Metal‐induced rearrangement of benzothiazoline ring: Synthesis and characterization of some new organoantimony(V) derivatives of N,O, and S atom containing schiff base ligands

Some new triphenylantimony(V) derivatives of Schiff bases having the composition have been synthesized by the equimolar reactions of Ph₃SbBr₂ with newly synthesized benzothiazoline ligands, (where R = C₆H₅(H₂L¹), 4‐BrC₆H₄(H₂L²), 4‐ClC₆H₄(H₂L³), 4‐CH₃‐OC₆H₄(H₂L⁴), 4‐CH₃C₆H₄(H₂L⁵)). The reaction proceeds with the rearrangement of benzothiazoline ring. All the derivatives have been characterized by elemental analyses, molecular weight measurements and their plausible structures have been proposed on the basis of IR and NMR (¹H and ¹³C) spectral studies. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:70–75, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20260     

Matching tyre size to weight, speed and power available for maximising pulling ability of agricultural tractors

The desirable weight-to-axle power ratio for agricultural tractors is determined by the necessity for the optimum utilisation of the available axle power to produce the required drawbar pull at a preselected slip. For a vehicle designed to operate in a given speed range, the weight-to-axle power ratio should be within a particular limit, so that a specific level of conversion efficiency can be maintained. In this paper attempts have been made to select suitable tyres for Indian two-wheel drive tractors operating in sandy clay loam soils on the basis of weight-to-power utiisation and maximum pull-to-optimum weight ratio at a preselected slip using the developed traction prediction equations. A comparison has also been made between the desired and actual weight on a single traction wheel and suitable tyre and tyre normally fitted in Indian two wheel drive tractors up to 35 kW.     

Preparation and Photocatalytic Performance of TiO2 Nanowire-Based Self-Supported Hybrid Membranes

Nowadays, the use of hybrid structures and multi-component materials is gaining ground in the fields of environmental protection, water treatment and removal of organic pollutants. This study describes promising, cheap and photoactive self-supported hybrid membranes as a possible solution for wastewater treatment applications. In the course of this research work, the photocatalytic performance of titania nanowire (TiO₂ NW)-based hybrid membranes in the adsorption and degradation of methylene blue (MB) under UV irradiation was investigated. Characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffractometry (XRD) were used to study the morphology and surface of the as-prepared hybrid membranes. We tested the photocatalytic efficiency of the as-prepared membranes in decomposing methylene blue (MB) under UV light irradiation. The hybrid membranes achieved the removal of MB with a degradation efficiency of 90% in 60 min. The high efficiency can be attributed to the presence of binary components in the membrane that enhanced both the adsorption capability and the photocatalytic ability of the membranes. The results obtained suggest that multicomponent hybrid membranes could be promising candidates for future photocatalysis-based water treatment technologies that also take into account the principles of circular economy.