Performance of solid state protonic battery with different cathodes

To establish the fact that the performance of a solid state battery is predominantly governed by the cathode, primary electrochemical cells were fabricated using FeH(SO₄)₂-xH₂O solid electrolyte having proton transport number close to unity (prepared by chemical route) taken in conjunction with five different cathodes MnO₂, PbO₂, V₆O₁₃, I₂ and TMAI iodine complex. Amongst these, better discharge characteristics along with thermodynamic and chemical stability of the cell were offered by TMAI iodine complex based cathode. Beside these, it provided short-circuit current, capacity and energy density of the order of 5 mA 4.5 mAh and 2.67 Wh/kg respectively due to the presence of highly active iodine, which is not free in TMAI compared to the cathode made of simply I₂. Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003.     

Simple algorithms for approximating all roots of a polynomial with real roots

We present a simple algorithm for approximating all roots of a polynomial p(x) when it has only real roots. The algorithm is based on some interesting properties of the polynomials appearing in the Extended Euclidean Scheme for p(x) and p′(x). For example, it turns out that these polynomials are orthogonal; as a consequence, we are able to limit the precision required by our algorithm in intermediate steps. A parallel implementation of this algorithm yields a P-uniform NC₂ circuit, and the bit complexity of its sequential implementation is within a polylog factor of the bit complexity of the best known algorithm for the problem.     

Timing and Spectral Studies of Pulsar EXO2030＋375

We report the results of timing and spectral analysis of the x-ray pulsar EXO2030＋375. The observations were made using the Rossi x-ray timing explorer space satellite. The spectral analysis is carried out for the flux of x-ray energy range 3-30 keV. The x-ray continuum spectra of proportional counter array could be represented by a two-component model, a power law with an exponential cutoff at higher energies and a blackbody. An iron line at about 6.4-6.6 keV was also detected.     

Novel spray reagents for plant pigments

Summary Paper chromatographic procedures involving the use of butanolacetic acidwater (415 v/v) as solvent and 1 % aqueous uranyl acetate or uranyl nitrate solution as spray reagent, have been developed for detection of plant pigments when present in amounts of at least 5 g each. Quinones, flavones and some of their O-glycosides having at least one hydroxyl group adjacent to carbonyl group, have been easily detected. The colour intensity has been found to increase in the case of compounds containing vicinal hydroxyl groups.     

Hydrocarbon group type analysis of petroleum heavy fractions using the TLC-FID technique

Hydrocarbon group type analysis is important in all conversion processes and in preparation of feed for these conversion processes so as to learn the selectivity of the different type of catalysts for product yield and quality. The use of the Mark 5 Iatroscan detector and the method reported here allowed for a rapid and quantitative hydrocarbon group type analysis of petroleum residues without prior separation of asphaltenes. SARA type analyses of petroleum residues have been performed by a three stage development using n-hexane, toluene and DCM (95%):MeOH (5%). The standard deviation and coefficient of variation in repeated measurements by this method were as low as 0.65 wt% or less and 3.5 wt% or less, respectively. The time required for analysis of 10 samples could be as short as 90 min.     

Titrimetric determination of certain mercaptans with mercuric chloride

A procedure is described for the semimicro determination of certain mercaptans, by means of their reaction with mercuric chloride. The acid liberated during the reaction is titrated with standard alkali after addition of sufficient potassium iodide to convert the surplus mercuric chloride into a stable soluble complex. The procedure has been applied to determine 0.12-1 mmole of these compounds; the results are accurate to within 0.5%.     

Stereoselective synthesis of alpha,alpha'-biprolines

A means to induce dehydrodimerization of Seebach's oxazolidinone (5), the stereochemical outcome of which is entirely temperature dependent, is described. The resultant dimers 3 and 4 are precursors to (R,R)-alpha,alpha'-biproline (1) and meso-alpha,alpha'-biproline (2), respectively. An organohypobromite and an iminium halide are proposed to serve as electrophiles in the reaction with the enolate of 5 to give 3 and 4, respectively.     

Thermal behaviour of 8-hydroxyquinoline complexes with nickel(II)/copper(II)/zinc(II) hydroxides

Thermal behaviour of M(OH)₂(8-HQ)₂ (M=Ni, Cu and Zn; 8-HQ=8-hydroxyquinoline) has been studied by dynamic TG and DTA methods in nitrogen atmosphere. The percent weights lost in different temperature range was calculated from TG curves. The mode of decomposition has been supported by endotherms observed in DTA curves of the respective compounds.