Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

Background: A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(II)SO(4) solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents - triethanolamine, 2,3-dimercaptopropanol and a formaldehyde/acetone mixture - were used to determine quantities of aluminium, lead and zinc in a stepwise and selective manner. Results: The accuracy of the method was established by analysing glass certified reference material NBS 1412. The standard deviation of the measurements, calculated by analysing five replicates of each sample, was found to be less than 1.5% for the method proposed. Conclusion: The novelty of the method lies in its simplicity and accuracy afforded by there not being a need for a prior separation or instrumentation. The proposed method was found to be highly selective for the precise determination of aluminum, zinc and lead in the routine analysis of glass batch and allied materials

Effects of diabetes and hypertension on macrophage infiltration and matrix expansion in the rat kidney

BACKGROUND: In experimental models of diabetes mellitus, aggravation of renal injury by concomitant hypertension has been described. Inflammatory mechanisms contribute to renal damage in both diseases. We investigated whether hypertension and diabetes mellitus act synergistically to induce macrophage infiltration and matrix expansion in the kidney. METHODS: Insulin-dependent diabetes mellitus was induced by streptozotocin injections to hypertensive mRen2-transgenic rats (TGR) and normotensive Sprague-Dawley control rats. Quantitative immunohistochemical examination of kidney tissue sections was used to measure macrophage infiltration and matrix expansion. The expression of MCP-1, Osteopontin, RANTES, ICAM-1 and VCAM-1 was evaluated by real-time RT-PCR. The localization of MCP-1 was studied by immunohistochemistry. RESULTS: Macrophage infiltration was present in the kidney of normotensive diabetic rats. Hypertensive rats exhibited a more marked infiltration of macrophages, regardless of whether diabetes was present or not. Gene expression of ICAM-1, VCAM-1 and RANTES was unaltered whereas Osteopontin and MCP-1 were induced by hypertension. Immunoreactive MCP-1 was slightly increased in diabetic rat kidney podocytes, and more markedly increased in hypertensive animals. Glomerular matrix accumulation was induced by diabetes and hypertension to a similar degree, and was highest in hypertensive, diabetic animals. CONCLUSION: Diabetes mellitus caused a mild, and angiotensin-dependent hypertension a more marked infiltration of macrophages in the kidney. Combination of both diseases led to additive effects on matrix expansion but not on inflammation. Hypertension appears to be a much stronger stimulus for inflammation of the kidney than STZ diabetes, at least in mRen2-transgenic rats

Japan-Australian co-operative program on research and development of technology for the management of high level radioactive wastes, 1985 to 1998: final report.

The first five year phase (Phase I) of this Co-operative program commenced in 1985 as a consequence of technical and diplomatic discussions is the early 1980's. During Phase I, effective mechanisms of information transfer were established through personnel exchanges between JAERI and ANSTO, and a number of technical workshops. At the end of Phase I it was agreed that the Program should be extended into a second five-year period from 1990 to 1995, designated as Phase II. This latter phase was subsequently extended for a further three-year period from 1995 to 1998 to allow the collection of additional information on long-term accelerated damage tests and preparation of a final report. At the end of each phase of the Co-operative Program details results have been published in jointly-authored, formal documents. The key results, significance and recommendations of the entire Co-operative Program are summarised herein. The Co-operative Program has enhanced the excellent co-operative working relationship between the two institutions, and the arrangements developed under the original agreement should serve as a model for any other co-operative projects developed in the future. The main activities in the first phase of the Co-operative Program were the preparation, characterisation and subsequent testing of curium-doped Synroc containing simulated waste of the type produced by the PNC reprocessing facility at Tokyo in Japan namely JW-A containing elevated levels of Na. Here, the leach rates increased as a consequence of the radiation damage, due to (a) microcracking at a-doses corresponding to > 104 years of repository storage and (b) atomic displacements within the actinide-bearing phases, zirconolite and perovskite. At high doses, corresponding to > 3 x 104 years of storage, the former process led to leach rate enhancements of about a factor of 10 for Na and Ca, that were a further order of magnitude higher. Modifications to the Synroc composition were devised to prevent microcracking when the Na20 content of the Synroc exceeds ~ 1.5wt%. In the second phase of the Co-operative Program, comparative studies were carried out on Synroc containing Na-free PW-4b waste and in this case, after ~ 105 years of equivalent storage, Sr and Ca leach rates increased by a factor of 10, whereas the leach rate of Ba which is not contained in the actinide host phases did not increase with equivalent storage time. The density decrease due to radiation damage was less in samples stored at 200oC than at 30oC. Complementary studies on Cm-doped single-phase zirconolite and perovskite were carried out and studies on naturally-occurring zirconolites were initiated to provide insight into the long-term durability of zirconolite over geological time. In both phases of the Co-operative Program , the preparation of the Cm-doped samples was carried out in JAERI'S WASTEF facility at Tokai, with technical input and assistance provided by ANSTO where necessary. The results, described in greater detail in this report, have confirmed the potential of Synroc as a second-generation waste form