Research for a Uniform Quality Grading System for Tires V. Effect of Environment on Tread Wear Rate

In tests with bias ply, belted bias, and radial commercial passenger car tires it was found that the rate of wear does not change as the tires are worn. It was also shown in a test which there were dry and wet periods that the same tires wore at a faster rate in the wet than in the dry. This observation was reinforced when a comparison of two tests run with duplicate sets of tires in January and June on the same course gave greatly different results; the greater rate of wear occurring in January when the course was continuously wet. Finally an explanation for the observation that tires wear faster on wet pavements has been proposed. The tire is more deformed passing through the contact patch on a wet surface than on a dry. In addition, the water, acting as a lubricant, reduces resistance to motion between surfaces of the cut rubber or the surface of the cutting asperity and the rubber.

Research for a Uniform Quality Grading System for Tires VI. Comparison of the Effect of Front and Rear Wheel Drive Vehicles on Projected Tread Wear of a Tire

The total number of miles that could be expected for a tire was projected and compared from a test involving two vehicles, one with a front axle drive and one with a rear axle drive. On the front axle drive vehicle the tires when changed by forward-X pattern each 1000 miles wore at twice the rate on the front wheels as on the rear; on the other vehicle they wore at about the same rate on both sets of wheels. The projected mileages for the tires on the two vehicles were 22,400 and 22,500 miles which is not appreciably different.

Research for a Uniform Quality Grading System for Tires. IV. Tread Wear

This research had as its objective the development of a test procedure for rating tires for tread wear. The results of preliminary experiments on roads of different composition and severity are discussed. The authors conclude that the course on which tires are to be rated should include several different pavements and a variety of maneuvers of unequal severity. Two courses, one near Bryan, Texas, and the other near San Antonio, Texas were designed on this principle. Eighteen brands of tires including bias, radial, and G78 belted bias tires were run on each course. The tires ranked in order of decreasing projected mileage on each course were highly correlated, although the mileages were not equal.

Immunotyping of different strains of Japanese encephalitis virus by antibody-absorption, haemagglutination-inhibition and complement-fixation tests

The immunological characteristics of 26 strains of Japanese encephalitis virus (JEV) isolated in Japan and Malaya between 1935 and 1966 have been investigated mainly by the antibody-absorption variant of the haemagglutination-inhibition test, and to a certain extent also by conventional haemagglutination-inhibition and complement-fixation tests. The antibody-absorption technique shows promise as a routine method for the immunotyping of JEV.At present, two immunotypes can be distinguished. One comprises 2 strains, Nakayama-NIH and I-58, and is designated as the I-58 immunotype. The other immunotype, JaGAr 01, comprises 17 strains which share the characteristics of the JaGAr 01 strain, including one subline of the Nakayama strain, Nakayama-Yakken. The Nakayama-RFVL strain was found to have the characteristics of both immunotypes. The I-58 immunotype differs more markedly from related arboviruses, such as the Murray Valley encephalitis virus and the West Nile Eg101 strain, than does the JaGAr 01 immunotype.Evidence is presented which suggests that a given JEV strain can change immunotype on repeated passage through mice.