The oxidation of iron (II) sulphide

Journal of Thermal Analysis and Calorimetry - The oxidation in air and oxygen of iron (II) sulphide Fe1?x S was studied using TG, DTA, X-Ray powder photography and chemical analysis. A...     

Melting temperature of lead and sodium at high pressures

We have redetermined the melting temperature of lead and sodium as a function of pressure in a new pressure cell made up of low strength materials. Many of the anomalies reported in a prior determination of the melting curve of lead have largely disappeared. The slope of our new melting curve for lead is in close agreement with the slope computed from thermochemical data.One new curve for sodium differs only slightly from the prior published curves.     

NON-INVASIVE TECHNIQUE FOR OBTAINING FLUORESCENCE EXCITATION AND EMISSION SPECTRA IN VIVO

An intensified photodiode array forms the heart of a sensitive spectrophotofluorometry system that permits the rapid and non-invasive determination of fluorescence emission spectra in the skin of living, non-anesthetized animals. Using this system, we found it possible to obtain good emission and excitation spectra of the material responsible for the weak red fluorescence that characterizes normal mouse skin, and to follow the biosynthesis and subsequent clearance of protoporphyrin IX in the skin of non-anesthetized mice that had been given various doses of the porphyrin precursor 5-aminolevulinic acid.     

A novel closo-type metallaundecaborane, [1,1-(PPh3)2-2,5-(OEt)2-1-RuB10H8], and its relationship to the ‘isocloso’ series of metallaborane clusters

The new ruthenaundecaborane [(PPh₃)₂RuB₁₀H₈ (OEt)₂] may be considered as an eleven-vertex member of a previously unrecognised series of metallaboranes which are formally derived by the single capping of an arachno-type (rather than a nido-type) cluster geometry with a metal centre which can be thought of as contributing four orbitals to the cluster bonding schemes.     

Development of high quality carrier materials for field delivery of key microorganisms used as bio-fertilisers and bio-pesticides

High quality inoculants used as bio-fertilisers and bio-pesticides depend on having high concentrations of the microorganism(s), long shelf-life and a formulation appropriate for field delivery. To maintain the microorganisms in a viable state, commercially available carrier materials are typically based on milled peat, clays, rice, bran, seeds, or other complex organic matrices. To manufacture a high quality microbial product, it is essential that the carrier material is pre-packaged and pre-sterilised. This allows for non-competitive multiplication and maintenance of the microorganisms in a nutrient rich environment. This paper reports on the efficacy and problems inherent in the sterilisation of complex carbon-based carrier materials such as peat. Resident microbial survivors of gamma irradiation doses in excess of 50 kGy, commonly Gram positive spore-formers such as Bacillus or actinomycetes were consistently observed.     

Quasiliving Carbocationic Polymerization. XVII. Synthesis Of Poly (Styrene-β-Isobutylene-β-Styrene)

Poly(styrene-b-isobutylene-b-styrene) has been synthesized by sequential carbocationic polymerization under quasiliving conditions at -90°C. The quasiliving synthesis was effected by first continuously and slowly condensing gaseous isobutylene (IB) to a bifunctional initiating system (p-dicumyl chloride/TiCl₄) dissolved in a hexane-methylene chloride (60:40 v/v) mixture. After the quasiliving polyisobutylene (PIB) sequence had reached a desired molecular weight, styrene (St) was continuously and slowly added to produce the polystyrene (PSt) sequence. The products consisted of the target triblock. However, due to initiation by impurities and possibly to chain transfer to both IB and St, it also contained diblocks and small amounts of homopolymers. While the latter could be removed by selective fractionation, the triblocks and diblocks could not be separated. The mechanism of quasiliving polymerization leading to PIB/PSt blocks is discussed.