Implications of TAE modes for the design of ITER

A simple mixing-length estimate of diffusion of alphas particles by toroidicity-induced shear Alfven eigenmodes (TAE) is used, in zero and one-dimensional models, to evaluate the importance of diffusion of meeting ignition requirements for ITER and other next-generation burning plasma experiments. It is found that, depending on a number of assumptions, diffusion could reduce that effectiveness of alpha heating in the core as much as an order of magnitude. However, the effect would be less if only alphas resonant with the Alfven waves diffuse. Also, in the Appendix it is argued that the mixing length diffusion formula, though qualitatively reasonable, may be an over estimate. 12 refs., 7 figs., 1 tab

Recent studies of nuclear and chemical properties of elements 103, 104 and 105

Information obtained since 1983 on the nuclear and chemical properties of element 103, the last on the actinide series, and elements 104 and 105, at the beginning of the transactinide series, is reviewed. Their chemical properties are compared with their lanthanide and lighter group 4 and 5 homologs and evidence for possible relativistic effects is discussed. The current knowledge of the nuclear properties of these elements and how these affect of the study of chemical properties is discussed. Some of the challenges involved in the study of short-lived isotopes which can only be produced an atom-at-a-time'' at an appropriate accelerator and the prognosis for future studies of these and still heavier elements are considered. 40 refs., 4 figs

Effects of partial occlusion on perceived slant difference

When two slanted surfaces are placed in proximity, the perceived slant difference between them is exaggerated. This effect has been called slant contrast. When a partial occluder is presented in front of the gap between them, the perceived slant difference between the surfaces is reduced. We refer to this reduction in perceived slant difference as stereo-slant assimilation. We investigated two properties of the occluder that might affect perceived stereo-slant difference. Three vertically aligned random-dot patterns were presented either with a partial occluder over the gaps between them or without it. Observers judged the perceived slant difference between the center pattern and two surround random-dot patterns that had the same slant. The perceived slant difference was reduced when the partial occluder was present. We varied stereodepth and slant of the occluder and found that the decreased perceived slant difference was not due to either of these. Note that the surfaces were all simulated and presented on a computer screen and the results may not apply to real surfaces. The effect of the occluder on perceived slant differences could have resulted from either a reduction of slant contrast or an increase of slant assimilation