We extend a theorem of Kist for commutative PP rings to principally quasi-Baer rings for which every prime ideal contains
a unique minimal prime ideal without using topological arguments. Also decompositions of quasi-Baer and principally quasi-Baer
rings are investigated.
The reduction of bulk and supported copper oxide was investigated using Constant Rate-Temperature Programmed Reduction (CR-TPR)
and conventional linear heating rate TPR. Linear heating profiles indicated that the reduction of supported samples was more
facile than that of the bulk oxide. CRTA results revealed that both supported and bulk oxide samples were reduced via a mechanism
involving a nucleation step and/or auto-catalysis. The increased reducibility of the supported samples is attributed to a
higher dispersion which provides a larger reactive surface area and a high concentration of defects at which reduction is
Analysis of very small particles can present problems. This paper describes the application of temperature programmed solid
insertion probe mass spectrometry (TP-SIP-MS), scanning electron microscopy and SEM X-ray microanalysis to the identification
of foreign particles present in an industrial product. The relative advantages and limitations of the techniques are discussed.
It is shown that TP-SIP-MS is a powerful tool for such work and complements the use of more conventional microanalytical methods.
Doppler broadening of a 477.6 keV line combined with a recoil of an excited Li nucleus is the characteristic of PGAA, which
leads to complicated gamma-ray spectrum which is difficult to analyze. For this solution, a modified algorithm for an automated
analysis of the Doppler-broadened peak spectrum is presented. The modified algorithm maintained the consistency of a Doppler-broadened
peak with the finest analysis algorithm used for a Gaussian gamma-ray peak analysis in the HYPERMET code.
Authors:G. Parkes, P. Barnes, E. Charsley, and G. Bond
This paper describes a new instrument for performing thermal analysis using microwaves both as a form of heating and as a
novel means of detecting thermally induced transformations in materials. Results are presented for a selection of processes
including decompositions, dehydrations and phase changes. The capability of the instrument to be coupled with ancillary techniques
such as EGA is also demonstrated.
The prompt k0,H factors for B, N, Si, P, S and Cl were determined relative to the 2223.25 keV gamma-line from the 1H(n,γ) reaction. The measurements were performed at the SNU-KAERI Prompt Gamma Activation Analysis facility, of which the background was greatly reduced recently by upgrading the detection system to a Compton suppressed g-ray spectrometer with a BGO/NaI(Tl) guard detector and by improving the shield geometry. From the measured prompt k0,H factors, the partial γ-ray production cross sections were determined using the latest cross section for H. The measured prompt k0,H factors were tabulated and compared with the other reported data.
Authors:E. Charsley, C. Stewart, P. Barnes, and G. Parkes
Sample controlled thermal analysis techniques such as constant rate transformation analysis or stepwise isothermal analysis,
where the transformation rate of the sample itself is used to control the experiment, are becoming increasingly important
. The measurements are normally carried out using changes in the sample mass, sample dimensions or in the evolved gas,
as the property used to control the experiment, and enable reactions to be studied in greater detail than is possible using
linear heating techniques. A new approach is described here where a thermomicroscopy system has been developed to enable the
intensity of the light reflected or transmitted by the sample to be used as the controlling signal .
Authors:E. L. Charsley, P. G. Laye, G. M. B. Parkes, and J. J. Rooney
The development of a new sample controlled thermal analysis technique based on a heat flux DSC is described. The performance of the system is demonstrated by studies on the decomposition of sodium bicarbonate and the oxidation of a copper impregnated carbon. The ability of the technique to study reactions which take place without a change in mass is illustrated by the curing of an epoxy resin with a polyaminoamide hardener.