International contact lens prescribing 2002

This paper presents our second annual survey of international contact lens prescribing trends. From January to March 2002, we analyzed contact lens prescribing habits in eight countries: Australia, Canada, Greece, the Netherlands, Norway, Singapore, the United Kingdom and the United States. With the exception of Norway and Singapore (545 and 390 surveys, respectively), 1,000 questionnaires were randomly sent out to a cross section of contact lens practitioners.

Improving fiber trapping with a contact surface during the ring twisting of two cotton yarns

In this study, a geometrical model was introduced to improve the hair trapping via a surface contacting the yarn-twisting triangle during ring twisting of two single yarns. The fiber-trapping improvement with the contact surface was analyzed theoretically. Then, single Ne 80 ring cotton yarns were used to produce two-ply yarns under different ring-twisting conditions, namely conventional twisting, dry twisting of yarns with a plane surface, wet twisting of yarns with a plane surface, dry twisting of yarns with a grooved surface, and wet twisting of yarns with a grooved surface. Plied yarn properties, including yarn hairiness, strength, and irregularity, were tested. The Student Newman Keuls (SNK) test and variation analysis were also carried out in the SPSS program to study the effect of different contact surfaces on related yarn properties; the significance level was 0.05 for the SNK test and variation analysis. The hairiness of plied yarns was significantly reduced when twisting with the plane or grooved surface, especially for the wet twisting cases. This corresponds well with our model on improving fiber trapping.