摘要:

The formula for the computation of the fraction of the molecules in a gas that possess energy above a specified amount is simple when motion in only two directions is considered but becomes difficult to evaluate when three directions are considered. The ratio of the results for the two cases may be easily computed by means of the functionL(x), a table of which is given. The relations ofL(x) to the error function complementErfc(x), to the error functionErf(x), and to the Miller and Gordon functionF(x) are shown. An extension of the table ofF(x) is also given.

ISSN:1923-4287    

DOI:10.1139/cjr40b-017

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

A precision oscillating disc viscometer has been constructed with a view to studying viscosities of systems at the critical temperature and critical pressure. A new method of computing logarithmic decrements is described and a number of results obtained with ethylene are presented. Of particular interest is the transition in viscosity on an isochore through the critical temperature.

ISSN:1923-4287    

DOI:10.1139/cjr40b-018

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Determinations of the selenium content of 230 composites made up from 2230 individual samples of wheat grown from pure varieties on soils of known type over the whole of the wheat-producing area of the province of Saskatchewan are recorded. The composites were made on the basis of shipping point, wheat variety, and soil type. The maximum amount of selenium found was 1.5 p.p.m., this quantity being present in 10 of the 230 composites, representing 71 (3.2%) of the individual samples. The average found for all the samples analysed was 0.44 p.p.m. It is considered that the averaging that occurs on bulk handling of wheat for export would prevent the selenium content of export cargoes from exceeding materially this average concentration. This represents less than one-tenth of the minimum concentration found to affect the growth of young animals. Analysis of 80 individual samples from the composites containing the highest quantities of selenium showed that no sample contained selenium in concentration as high as the minimum affecting growth. Wheat grown on soil of glacial lacustrine origin predominated among the samples giving the higher selenium content.

ISSN:1923-4287    

DOI:10.1139/cjr40b-019

出版商:NRC Research Press    

年代:1940

数据来源: NRC