Polyvinylchloride stabilisation with organo-tin compounds—Part 1: Mechanism of the reaction of thioglycolate derivatives with allylic chlorine model compounds

Mixtures of the isomers 4-chloro-hex-2-ene and 2-chloro-hex-3-ene of different compositions were prepared in order to study their reaction with organo-tin thioglycolate. Whatever the initial composition of the mixture, the same composition of the isomeric products is obtained. This favours an ionic mechanism in which the rate-determining step is the formation of an allylic carbocation. The substitution reaction with free thioglycolate esters is more rapid than with the tin derivative. Thus, a second possible route for the stabilisation reaction can be proposed.     

Necessary and sufficient conditions on rates of convergence in the multidimensional central limit theorem

It is shown that the rate of convergence in the multidimensional central limit theorem and in its nonuniform version heavily depends on the behavior of the tails of the distribution of X₁.     

Automatic apparatus for the determination of carbon and hydrogen in organic compounds

A microanalytical determination of carbon and hydrogen in organic compounds is achieved by an original technique of coulometric titration in a nonaqueous medium. The apparatus, designed for the purpose, wholly automatic and monitored by a computer, makes possible the analysis of 23 samples without any intervention from the operator. Each analysis takes about 10 min and the precision of the method results in relative standard deviations of about 0.1 and 1% for carbon and hydrogen, respectively.     

Electronic density of states of high pressure liquid uranium from shock vaporization

Strong shock waves were used to compress and heat initially porous uranium plates to high pressures (≈10⁶atm) and temperatures high enough (some 10⁴K), that one should expect a dominant contribution of the electrons to the thermal state. Information about this contribution, which depends on the electronic density of states distribution D(E), is obtained by measuring the entropy in the shocked state on the basis of the shock vaporization technique. The results indicate that a considerable redistribution of the six valence electrons occurs when uranium is compressed and heated.     

Lifetimes of high-spin yrast states in 154Er

Lifetimes for high-spin levels (between about 10 and 30 ?) in ¹⁵⁴Er have been measured by the recoil-distance method. Non-collective, moderately collective and collective E2 transitions from states with lifetimes between at most 10 and 400 ps have been found. All available data on this nucleus are discussed within the framework of the oblate coupling scheme with the addition of collective degrees of freedom.     

Dual banach lattices and Banach lattices with the Radon-Nikodym property

We construct a separable dual Banach latticeE such that no non-trivial order interval of its dual is weakly compact. HenceE has the Radon-Nikodym property without being in some sense a dual in a natural way. The final draft of this paper was written while the author held a grant from NATO to visit the Ohio State University.