The use of neighbourhood intensity comparisons, morphological gradients and Fourier analysis for automated precipitate counting & Pendell¨osung fringe analysis in X-ray topography

Crystal distortions modify the propagation of X-rays in single crystal materials, and X-ray topography can be used to record these modifications on a film thus providing images of the distributions and nature of defects, dislocations, strains, precipitates, etc. in semiconductors. Small variations of contrast, which often need to be analysed can be rendered invisible. Furthermore, artefacts in the films must be removed. This study examines the use of advanced image analysis techniques applied to a selection of X-ray topographs in section transmission mode: (i) the automated counting of oxygen-related precipitates and (ii) the enhancement of Pendell¨osung fringes. The technique also succeeds in removing unwanted features in the original x-ray topographs such as vertical streaking due to collimating slit phase contrast and strain features near the surface due to the presence of integrated circuit process strains

JTEC Panel report on electronic manufacturing and packaging in Japan

This report summarizes the status of electronic manufacturing and packaging technology in Japan in comparison to that in the United States, and its impact on competition in electronic manufacturing in general. In addition to electronic manufacturing technologies, the report covers technology and manufacturing infrastructure, electronics manufacturing and assembly, quality assurance and reliability in the Japanese electronics industry, and successful product realization strategies. The panel found that Japan leads the United States in almost every electronics packaging technology. Japan clearly has achieved a strategic advantage in electronics production and process technologies. Panel members believe that Japanese competitors could be leading U.S. firms by as much as a decade in some electronics process technologies

Neuroactive steroids in depression and anxiety disorders: Clinical studies

Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel

POST-IRRADIATION EVALUATION OF A PLATE-TYPE UOsub2sub 2 FUEL ELEMENT

The premature failure of fuel Element M22, which had six compartments of 0.100-in.-thick, 96% TD UO/sub 2/ + 6 wt% ZrO/sub 2/ fuel, was attributed to the large irradiation-induced solid volume swelling of the UO/sub 2/ fuels. This volume swelling was the result of incomplete homogenization during fabrication of the mixed and sintered U/sup E/O/sub 2/ and U/sup N/O/sub 2/ fuel s in Element M22. In addition, heavy hydriding of the Ni-free Zircaloy-2 cladding occurred in the relatively hot areas adjacent to the fuel and to a lesser extent at the external cladding surfaces. By postulation, H/sub 2/ was apparently formed by the radiolytic decomposition of water entrapped between fuel and cladding after formation of the initial cladding defect, and was absorbed by the cladding so rapidly that it could not diffuse adequately down the thermal gradient to the cold side of the cladding. The corrosion behavior of the cladding was as expected and did not contribute to the hydriding. Analysis of the CR-X-3 loop operating history indicates that no abnormal conditions external to Element M22 existed in the loop other than U from inpile intentionally defected fuel elements. (auth