[en] This is a short review of some recent results in interface science which were made possible by the use of synchrotron radiation surface crystallographic techniques. (A.C.A.S.)

[en] South Africa's mineral industry is put into perspective by Gian Rossi, who here examines its composition and analyses the importance of the Republic as a major supplier. South Africa's mineral policy, economy and transportation are also shortly discussed

[en] The results of a round robin on commercial high grade concentrated HNO₃ are presented. Selected trace metals - Fe, Cu, Cr, Mn, Zn and Cd - were determined by five laboratories, all using electrothermal atomic absorption spectrometry, without any sample pretreatment. Ten determinations of each impurity were carried out weekly on five 1 liter bottles lasting 12 weeks. Additional semiquantitative results were obtained by spark source mass spectrometry at the beginning and at the conclusion of the round robin. Although the results could be judged satisfactory as a whole, none of the three main scopes of the round robin could be considered as being fully achieved, these scopes being: feasibility of analyzing the sample without any preliminary chemical treatment, consistency of data from different laboratories, variation of impurity level over a period of time, due to the container walls

[en] The book discusses the use of radioisotope methods in the diagnosis of salivary gland diseases. Anatomical and physiological features of the salivary gland are summarized and radiotracer deposition processes are described. Clinical applications of scintigraphy are detailed. The degree of functional impairment due to various inflammatory diseases is contrasted by means of semiquantitative computerized methods with follow-up therapeutic results. Post-irradiatory involvement and possible functional recovery of salivary glands are also considered. The contents discussed are: Salivary Gland Physiology and Radioisotope Uptake. Radioisotope Study of Salivary Glands. Radioisotope Studies Under Normal Conditions. Survey of Radiographic Methods. Dosimetric Assessment. Conclusions and Index

No abstract available

[en] As the use of 'in vitro' and 'in vivo' radioisotope studies spreads more and more, many organizational and management problems arise. Hence an exact evaluation of current contamination levels and protection standards is very important for radiation-protection purposes. Environmental and personnel contamination levels in Nuclear Medicine Laboratories were recorded for four years and the results were evaluated by a computer-assisted method which furnished parameters such as the maximum permissible level of radioactivity at different timeintervals. They allow the health physicist to assess laboratory contamination levels as well as to classify radiation workers and places. A continuous 'monitoring' of radiation safety is possible in order to modify worker and/or laboratory classification as soon as possible, in close connection with possible changes in radiation hazards. This computer program applies equally well to other fields involving radioisotope use, such as industry, agriculture, etc. (Author)

[en] Short communication

[en] The optical absorption spectra of Yb and Eu near the 5p core level energy are understood by analyzing h nu dependent photoemission and experimental partial photoionization cross sections of the valence and 4f subshells. Resonant photoemission of the top of the valence band, and L-edge X-ray absorption show that the highest partial density of states (DOS) in the Fermi level region is of d character, (occupied and unoccupied). An intense constant kinetic energy electron emission structure turns on at the 5p/sub 3/2/ threshold of Yb and Eu, and is interpreted as the decay channel of a dynamical excitation process involving collapse of a localized 5d screening orbital when the 5p core hole is created; this process is responsible of the sharp onset on the 5p/sub 3/2/ optical absorption of the divalent rare earth metals. 20 references, 11 figures

[en] Loosening, infection and the presence of heterotopic bone are the most frequent and serious late complications of total hip replacement. Radioisotope methods enable the surgeon to follow-up post-therapy course as early and exactly as possible and sometimes to make differential diagnosis between infected and loose prosthesis. From the diagnostic standpoint, increased radioisotope uptake around the prosthesis component persisting or rising later than the 8th month after surgery is an index of complication. Bimonthly or quarterly examination starting from the 8th month after hip arthroplasty is the best way to follow-up total hip replacement. When femoral shaft, trochanters and acetabulum fail to show any increased activity, this indicates that no complication is present. (author)

No abstract available