Synthesis and characterization of nanostructure hydrous iron–titanium binary mixed oxide for arsenic sorption

Synthesis of nanostructure hydrous iron–titanium binary mixed oxide (NHITBMO) had been reported by a simple method, and characterized by the X-ray diffraction (XRD), thermal analysis, transmission electron microscope (TEM), Föurier Transform Infrared (FTIR), surface area, and zero surface charge pH (pHzpc). The synthetic oxide was hydrated and microcrystalline with 77.8 m² g^?1 BET surface area. The particle size (nm) calculated using XRD peak table and TEM image was ~10–13 and 6–8, respectively. The pH_zpc value was 6.0 (±0.05) for the oxide. The NHITBMO showed pH dependent good sorption affinity for arsenic from the aqueous solution and, the Langmuir monolayer capacity (mg g^?1) was 80.0 and 14.6, respectively, for the As(III) and As(V). The pseudo-second order equation described the room temperature arsenic sorption kinetic data well. The minimum dose required was 1.6 g NHITBMO per L of water (As_total = 0.24 mg L^?1) to reduce the arsenic level below 0.01 mg L^?1 in batch treatment process.     

Centrifugal distortion analysis of difluoramine

The microwave rotational spectrum of difluoramine (NF₂H) has been analyzed in the frequency region 15–36 GHz involving rotational levels up to J = 19. The analysis gives refined rotational constants and all quartic centrifugal distortion constants. These constants have been used to predict additional Q-branch transitions of the molecule in the frequency region 5–95 GHz.     

Centrifugal perturbation in the microwave spectrum of nitric acid

The microwave rotational spectra of HNO₃ and DNO₃ have been analysed in the frequency region 5–50 GHz and up to J = 12. The analysis gives the effective rotational constants and all the quartic centrifugal distortion constants. These constants have been used to predict the transitions.     

Centrifugal distortion constants of the NGLT form of allylamine from microwave spectrum analysis

The centrifugal distortion analysis of the microwave spectrum of the N-gauche lone-electron-pair trans (NGLT) rotameric form of allylamine has been carried out in the frequency region 5–40 GHz and up to J = 29 in its ground vibrational state. The analysis gives effective rotational constants and all the quartic centrifugal distortion constants.     

Semimicrodetermination of mercury(II) and zinc(II) by precipitation from homogeneous solution,using cation generation technique

An efficient semimicro gravimetric method for the determination of mercury(II) and zinc(II) is presented. Potassium thiocarbonate (PTC) has been used as a source of sulfide and thiocarbonate ions affording clean precipitation from homogeneous solution and allowing the direct weighing of the precipitate when dry. The use of EDTA, ammonium tartrate, and PTC for masking of adverse ions in alkaline medium has afforded an efficient analytical separation of Hg(II) and Zn(II). The mean relative error is less than 1% in these estimations.     

D.c. drift and hot carrier effects on E.M. wave propagation in a current carrying bismuth2

This paper presents an investigation of d.c. drift and hot carrier effects on electromagnetic wave propagation in current carrying bismuth when the directions of the d.c. electric field, static magnetic field and of the propagation of waves are all along the trigonal axis. The anisotropic band structure and mass tensor of carriers have been taken into account. A generalised dispersion relation has been derived for a bismuth sample with arbitrary compensation. The enhanced heating of the carriers with a d.c. electric field causes a progressive decrease in the refractive index and the absorption coefficient; this effect is more pronounced in the case of upper band microwaves. The heating of the electrons is reduced by the presence of a static magnetic field while that of the holes is unchanged. The hot carrier effects in Faraday rotation and ellipticity for high frequency waves in bismuth have also been investigated.     

A quantum mechanics-based scoring function: study of zinc ion-mediated ligand binding

In this communication, we report the development of a novel quantum mechanics-based scoring function to predict free energy of ligand binding in the zinc metalloenzymes carbonic anhydrase (CA) and carboxypeptidase A (CPA). In particular, the AM1 method is used in conjunction with solvation modeling to predict the relative binding affinities of 18 CA and 5 CPA inhibitors. The effect of metal-ligand charge transfer is also discussed and shown to be different in CPA and CA, providing a further challenge to computing metalloenzyme binding affinities.