On the nature and structure of ‘niobic acid’ and its pyrolytic products : Part II : Correlation between the hydrates,the stoichiometric and the nonstoichiometric oxides of niobium(V)

The reported anomaly in the composition of the various hydrates of niobium(V) oxide as described in the literature has been rationalised and explained on the basis of the structure of isopolyniobic acid, H₈Nb₆O₁₉. The irreversible phase transition in the oxides, which they undergo when subjected to pyrolysis, has been interpreted. A general formula for the representation of the composition of the entire range of nonstoichiometric oxide phases, where O : Nb ratio varies from 2.33 to 2.50, has been derived on the basis of Nb₆O₁₅ as the ‘building block’.     

Immunologic aspects of leprosy with reference to extravascular immunoglobulins: their excretion profile in urine

An aliquot of 24-hour urine collected from leprosy patients was concentrated and examined for the presence of albumin, transferrin, IgG, IgA, IgM, IgD, D3, kappa and lambda light chains by the gel diffusion technic using respective monospecific antisera. Urinary protein excretion profile in lepromatous leprosy patients showed that while excretion of transferrin in the urine was negligible; that of IgG molecules, a substance of higher molecular weight, was significant. It is suggested that the immunoglobulins excreted in the urine may not be plasma-derived, but extravascular in origin. They are probably synthesized in the urinary tract. In the present study, out of 25 leprosy patients, 2 female patients having severe lepra reactions developed urinary tract infections. E. coli and Klebsiella were isolated from their urine. The urinary IgG levels in those two cases were found to be the highest in the series.     

An analysis of energy conservation possibilities in the residential sector in New Zealand

A model which simulates residential energy use in New Zealand until the year 2000 has been developed. This paper describes some of the energy conservation possibilities and their effect on energy use for space and water heating. an engineering analysis made to determine the effect of various factors on energy use for space heating is first described. the information gained from many computer simulations is used to develop a quantitative relationship between space heating energy and major determinants—climatic location, building type and intensity of use. Results from an engineering analysis of a water heating unit are used to establish the energy savings due to improved cylinder insulation and lower storage temperature. A solar space and water heating system is analysed to determine the fraction of total heating load that can be met by harnessing solar energy. the analyses demonstrate that the potential of conservation measures to reduce energy use can be substantial—by raising the insulation level on the building and on the water heating cylinder, by lowering the water storage temperature, and by installing an optimized solar heating system, the energy requirement can be reduced to 0·37 times what it is today for a typical uninsulated home.     

Sintering kinetics of pure and doped chromium oxide

The mechanism of sintering in chromium oxide in the presence of varying amounts of magnesium oxide in a firing condition that simulates a controlled reducing atmosphere has been investigated. The investigation is based on isothermal shrinkage measurements at different temperatures. The data suggest grain boundary diffusion to be the main process with evidence of vapour transport.