摘要:

Addition of 0.005–0.500% citric acid to refined peanut oil caused a marked retardation of the oxygen absorption by the oil at 100 °C. Conversely, oxygen absorption was accelerated by the addition of from 0.11 to 10.00 p.p.m. iron in the form of iron stearate. When iron and citric acid were added together, the accelerating effect of iron on oxidation was overcome when the molar ratio of citric acid to iron was about 23:1; with higher concentrations of citric acid, oxidation was retarded still further.With distilled methyl esters of the fatty acids of peanut oil, further purified by passage through a column containing activated carbon, citric acid addition alone had only a small effect. Addition of iron caused acceleration of oxygen absorption which was compensated for by suitable addition of citric acid. Addition of hydroquinone caused a retardation of oxygen absorption, and still further retardation occurred when citric acid and hydroquinone were added together. It was concluded that citric acid has the properties of both a metal deactivator and a synergist, but does not in itself function as an antioxidant.

ISSN:1923-4287    

DOI:10.1139/cjr50f-041

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The hydrostatic pressures that silicone-coated sintered glass plates will withstand before permitting the passage of water are recorded, and a rough constancy in the product of rupturing pressure and porosity is indicated. Application as check-valves to pass gases but not water is suggested.

ISSN:1923-4287    

DOI:10.1139/cjr50f-042

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

In estimating bacterial populations by the colony count method increased accuracy is obtained by using large numbers of replicates. The high cost of Petri plates makes this difficult in many laboratories. A simple spinner is described which utilizes cheap, easily obtained screw-capped bottles to substitute for Petri plates. The method has proved satisfactory in estimating numbers ofRhizobia, and has resulted in significant savings in the cost of glassware and media, and in incubator space.

ISSN:1923-4287    

DOI:10.1139/cjr50f-043

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The dynamic and static friction on ice, the hardness, and the resilience of natural and synthetic rubber tire compounds were measured. General relationships were found to exist between friction and hardness of the rubber, friction and ice temperature, hardness and temperature, hardness and age of the rubber, resilience and hardness. Extraction of the rubber had a variable effect.

ISSN:1923-4287    

DOI:10.1139/cjr50f-044

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Because of obvious complications it is too difficult to calculate the stresses in the cords of a tire. In this work the direct measurement of strains was undertaken. Two techniques will be discussed; (1) the measure of the increase in length of the cords in the outside ply, and (2) a radiographic technique in which the change in length of the cord elements, marked by steel wires, is followed by photographic methods. The measurements on a number of tires are presented. The cords in a tire are strained about 2% by the inflation pressure. When the tire is loaded some of the cords are thrown into compression and some into more tension. During the rotation of the tire the cords are thus subjected to a vigorous alternation of compression and tension (± 2%). At the same time the angles between the cords change by as much as two degrees. A few general applications are mentioned and their importance to the tire engineer is indicated.

ISSN:1923-4287    

DOI:10.1139/cjr50f-045

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr50f-046

出版商:NRC Research Press    

年代:1950

数据来源: NRC