13C CP MAS NMR and 29Si MAS NMR were used to characterize silylated montmorillonites and to estimate the extent of the silylation reaction. Indirectly-detected proton relaxation times of the intercalated surfactant were measured in both silylated and non-silylated clay systems to monitor the dynamics of intercalated species. A greater degree of mobility in the silylated montmorillonites was found. The lack of NMR information resulting from paramagnetic interaction brought about by structural Fe(III) ions was considered. The resulting broadening can prevent the estimation of the trans/gauche conformer ratio of the intercalated surfactant alkyl chain.

We investigate the impact of receiving a public pension on total expenditures, food expenditures, and private transfers of the elderly in South Korea. Using a natural experiment that occurred in 1999, we are able to explore the impacts of a large public pension program expansion which newly incorporated people who had been self-employed, unemployed, and out of the labor force. We find that receipt of a public pension did not allow the elderly to increase total expenditures or food expenditures because the expansion of public pensions largely crowded out financial transfers from adult children and/or own siblings.

The well-known Tschirnhausen transformation, , eliminates the second term of the polynomial xn + axn-l + …. By a mere repeated application of this transformation, one can decide whether a given element of k[[x,y]] is prime (irreducible) or not. Here K is an algebraically closed field of characteristic 0. A generalised version of Hensel's Lemma is developed for the proofs. The entire paper can be understood by undergraduate students.

The following paper defines a new type of ordering of higher level on a commutative ring. This definition allows the set of all orderings of level n to be given a topology which we show is consistent with the topology of the real spectrum.