Study of relaxor-like behaviour of laser ablated (Pb, La)Tio3 thin films

Lanthanum modified lead titanate (PLT) thin films are one of the potential candidates for the pyroelectric and memory applications due to their excellent dielectric, pyroelectric and ferroelectric properties. PLT thin films with 25 at.% of La were deposited on platinum coated Si substrates by the laser ablation technique. The phase transition studies were done in the temperature range of −40 to 150 °C as a function of frequency and ac field. A diffused phase transition with the shifting of the maximum dielectric permittivity (?_max) to higher temperatures with the increase of frequency and dielectric dispersion with frequency at the lower temperatures were observed. The variation of the temperature corresponding to maximum dielectric constant T_m, with frequency follows the Vogel-Fulcher relation, which is the characteristic of the relaxor-like behavior of the material. With the increase of ac drive, the T_max was shifted to lower value.     

Direct determination of cadmium in high-purity metals by flame atomic fluorescence spectrometry

Raschig rings used as a safety mechanism, to avoid critical reactions in solutions containing radioactive materials, are usually made of borosilicate glass. Since boron is the active neutron absorbing ingredient, it is important to determine the boron content in the Raschig rings at any given time. A method has been developed to determine rapidly the boron content of borosilicate glasses. Ion exchange and potentiometric measurement are used to determine boron as the tetrafluoroborate ion. The precision of the method is ±2.0 mV. The average difference between values of a wet chemical analysis and those of the potentiometric method is 7.7%.     

Extraction of uranium(IV) and uranium(VI) by primary and tertiary-amines from sulphate solutions

In developing a method for possible low level isotopic enrichment, which uses to advantage the equilibrium isotope effect observed during U(1V)-U(VI) electron exchange reaction in sulphate solutions, details of a solvent extraction process involving high concentration of a mixture of U(IV) and U(VI) and at low acid concentrations, are described. The extraction behaviour of uranium under these conditions is discussed. During the extraction with amines, U(IV) tended to get oxidised in sulphate solutions.     

Analytical application of embelin

Summary Embelin is employed as a reagent for the gravimetric individual estimation of alkaline earth metals and magnesium.

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Zusammenfassung Zur gravimetrischen Einzelbestimmung von Magnesium und den Erdalkalien wird Embelin als Reagens empfohlen.

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Part III: Z. analyt. Chem. 185, 216 (1962).     

An efficient, rapid and regioselective nuclear bromination of aromatics and heteroaromatics with NBS using sulfonic-acid-functionalized silica as a heterogeneous recyclable catalyst

A simple, efficient and rapid method has been developed for high-yielding regioselective nuclear monobromination of aromatic and heteroaromatic compounds using NBS in the presence of sulfonic-acid-functionalized silica at room temperature. The catalyst works under heterogeneous conditions and can be recycled.     

Protein crystal nucleation: is the pair interaction potential the primary determinant of kinetics?

Fundamental understanding of protein crystal nucleation facilitates crystallization of biological macromolecules for structure determination and control of crystal size distribution. In the studies presented here, nucleation kinetics of hen egg-white lysozyme crystals were measured at solution conditions that exhibited equal solubility by adjusting pH, temperature, or sodium chloride concentration. It was observed that solution conditions that lead to equal solubility resulted in equal nucleation rates and hence kinetic parameters. Since the solubility of globular proteins correlates with the osmotic second virial coefficient, B(22), an integral measure of the protein pair interaction potential, this observation indicates that the protein pair interaction plays a key role in determining nucleation kinetic parameters.     

Estimation of substituted phosphates such as dibutyl and monobutyl phosphates, based on their reaction with lanthanum-Xylenol Orange complex

Development of a new method for the estimation of substituted phosphates such as dibutyl phosphate (DBP) and monobutyl phosphate (MBP) is described in this paper. The method is based on the decolouration of lanthanum-Xylenol Orange complex by DBP and MBP at pH 5.