Thirty per cent of school districts in British Columbia do not ban smoking outright on school grounds, and in several instances, smoking is permitted in smoking pits, regardless of school district policy. While there is evidence to suggest that enforcing a tobacco-free environment for students does reduce adolescent smoking rates, the concomitant safety and discipline problems it creates for school staff and administration are demanding and complex, and may override concerns regarding student smoking. This study uses a qualitative approach to explore the meanings that students place on tobacco control policy and the impact that these meanings have on their own smoking behaviours. We found that students were surprised and concerned that smoking was permitted on school property and that it negatively impacted their own tobacco prevention/control/cessation attempts.

The water vapor transmission of fibers can be measured independent of any air space surrounding the fibers, by using sections cut from embedments of the fibers in polyacrylic resins. The rate of water vapor transmission, measured as the diffusion constant, is larger for cotton than for rayon, wool, nylon, or Dacron. The respective diffusion con stants are on the order of 134. 56. 39, 8 and 7 × 10 4 cm.2 sec., under the relatively moist conditions of the tests, between 54 and 93% relative humidity. White the possible influence of air in the lumen of cotton has not been completely evaluated, there is evidence that such influence has been reduced if not eliminated. How , ever, this same evidence indicates that the cotton fibers were in part in an altered condition as a result of the embedment. Even so, the results suggest that cotton is a good choice of fiber for high water vapor transmission along the fiber.

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The basic features of staple yarn structure which can vary in cotton yarns include those which depend on fiber factors such as fiber fineness, maturity, and staple length. Then there are mechanical processing factors, such as rate of carding, combing, and singeing, which affect fiber arrangement in or on the surface of the yarn. Finally, there are whole-yarn factors, such as twist, plying, and yarn fineness, which affect luster. These are discussed in three sections, which are presented together because of the use of experimental material which compares more than one type of factor at the same time. The results show that the three main means of improving luster by yarn structure factors are: ( 1) lowering of twist; ( 2) use of optimum plying twist, as shown by Adderley and Oxley ; ( 3) singeing to remove free surface fibers. Two additional structure factors, which, however, will not usually produce as great an effect on luster at the same cost, are: ( 4) using finer yarns; ( 5) combing.

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