Cation distribution in oxide fuels — a neutron scattering study

We use diffuse neutron scattering techniques to investigate cation ordering in the mixed oxide U/CeO_2?x — a model system for the oxide U/PuO_2?x. Our results show that there is little deviation from a random cation distribution at 10 or 20 mol% dopant concentration. Significant short-range order appears, however, to be present at 30 mol%. Experiments on samples prepared under reducing conditions suggest that vacancies have little effect on the cation short-range order, and thus cast doubt on the validity of models which assume dopant aggregation around vacancies.     

Identification and localization in tachistoscopic recognition: The effects of data- and resource-limitations.

Examined the effects of data- and resource-limits on mislocation and intrusion errors in a visual probe task. Mislocation errors were defined as responses to any letter that appeared in the test display but not in the position cued; intrusions were responses with letters that did not appear in the test display. Ss were 42 undergraduates with normal vision. Exp I manipulated the data-limits by changing both luminance and duration, and confirmed that decreasing stimulus energy increases intrusions and decreases the benefit of selective attention instructions. Exps II and III manipulated resource-limits by varying display size and the size of a defined subset of a display and showed that this manipulation primarily affected mislocation errors. Exp IV tested a minor point pertaining to the cue used in the previous studies. Results suggest that these errors may reflect 2 different processing operations, and that complete recognition of any visual stimulus involves both processes. (French abstract) (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hepatitis among plasma fractionation workers. An industry-wide study

An industry-wide survey of plasm fractionation facilities in the United States was conducted during 1973-74. Hepatitis was reported among the workers with varying degrees of plasma contact at all plant sites. For each of fourteen facilities in this investigation, field inspections disclosed: (1) numerous overt instances of employee-product contact: (2) inconsistent methodologic approaches at virtually all stages of the plasma fractionation process; (3) at low level of management and employee awareness regarding the potential bio-hazard identified; and (4) disparate examples of hepatitis surveillance and prophylaxis. Our data suggests that there is a high risk of hepatitis among plasma fractionation workers and, as such, much more attention needs to be focused on the reduction of health hazards within this industry.     

Salmonella carriage in an Irish pig herd: correlation between serological and bacteriological detection methods

Salmonella carriage in pigs represents a serious health problem that undoubtedly contributes to the spread of human disease. Thus, the efficient and reliable testing of farm animals for bacteria such as Salmonella is an important aspect of any efficient control strategy. Serological analysis of 15 meat juice samples detected antibodies against Salmonella in some. but not all, of the animals identified bacteriologically as harboring the pathogen, indicating a lack of correlation between the bacteriological and serological methods used for Salmonella detection. The results suggest that testing by enzyme-linked immunosorbent assay is appropriate at the herd level, with culture methods preferable for individual animal analysis. A novel culture protocol detected Salmonella in the cecal contents of 15 pigs, whereas a method based on the European Standard identified only 9 pigs as being Salmonella-positive. During the study, an unusual finding was the relatively high incidence of Salmonella London carriage in the pigs tested.     

Comparison of SeaWiFS measurements of the Moon with the U.S. Geological Survey lunar model

The Sea-Viewing Wide-Field-of-View Sensor (SeaWiFS) has made monthly observations of the Moon since 1997. Using 66 monthly measurements, the SeaWiFS calibration team has developed a correction for the instrument's on-orbit response changes. Concurrently, a lunar irradiance model has been developed by the U.S. Geological Survey (USGS) from extensive Earth-based observations of the Moon. The lunar irradiances measured by SeaWiFS are compared with the USGS model. The comparison shows essentially identical response histories for SeaWiFS, with differences from the model of less than 0.05% per thousand days in the long-term trends. From the SeaWiFS experience we have learned that it is important to view the entire lunar image at a constant phase angle from measurement to measurement and to understand, as best as possible, the size of each lunar image. However, a constant phase angle is not required for using the USGS model. With a long-term satellite lunar data set it is possible to determine instrument changes at a quality level approximating that from the USGS lunar model. However, early in a mission, when the dependence on factors such as phase and libration cannot be adequately determined from satellite measurements alone, the USGS model is critical to an understanding of trends in instruments that use the Moon for calibration. This is the case for SeaWiFS.     

Analysis of various numerical techniques applied to thin-wire scatterers

Several numerical schemes for solving Pocklington's and Hallén's equations for thin-wire scatterers are investigated. Convergence rates of solutions obtained from seven methods are given and reasons for different rates are delineated.     

X-Ray Microanalysis of ZrO2 Particles in ZrO2-Toughened A1203

Analytical electron microscopy of ZrO₂ particles in a zirconia-toughened alumina was performed. Significant solute heterogeneities in these particles were found but did not seem to affect the particle size dependence of M_s.