Suggestions for the quantitative X-ray microanalysis of thin sections of frozen-dried and embedded biological tissues

When a microregion in a thin section of frozen-dried and embedded tissue is analysed by the conventional electron-probe X-ray continuum-normalization method, the measured quantity is in mmol of element per kg of embedded specimen. As each microregion contains an unknown amount of embedding medium, this quantity generally lies indeterminately somewhere within the wide range between mmol of element per kg of hydrated tissue and mmol of element per kg of dehydrated tissue. However, if a ‘tag’ element is incorporated in the embedding medium, the contribution of the medium to the local continuum count in each probed field should be measurable, and the X-ray data may then unambiguously yield mmol of element per kg of dehydrated tissue. This result should not be affected by shrinkage on freeze-drying or by incomplete replacement of water by embedding medium. The same X-ray data can additionally provide estimates of mmol of element per unit volume, mmol of element per kg of hydrated tissue and local dry-mass fraction. However, these estimates are subject to errors due to tissue shrinkage, incomplete replacement of water and beam damage.     

Analysis of the effect of car size on accident injury probability using automobile insurance data

The Highway Loss Data Institute (HLDI) compiles injury and collision claim information from major insurance companies. These data have indicated that a disproportionately large number of injury claims are made for small cars. As a result, it might be concluded that small cars increase injury risk to their occupants. Recent advertisements by a major automobile manufacturer suggest a similar conclusion should be drawn from these data. In this paper it is shown that the apparent higher injury risk attributed to small cars can reflect the behavior of persons driving small cars. The number of injury claim accidents per collision claim accident is examined as an alternative measure of injury risk. Possible problems in interpretation are discussed.     

Chemicothermal treatment of 5KhNM die steel

Conclusions Of all of the tested forms of hardening with chemicothermal treatment single-phase boriding and chrome-vanadizing provide the best combination of service properties of 5KhNM steel.Kemerovo Technological Institute for the Food Industry. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 7–8, May, 1991.