A number of materials, both biologic and alloplastic, have been used for nasal augmentation. Although biologic bone and cartilage grafts are associated with lower infection rates, they are also associated with long-term resorption and donor-site morbidity. Alloplastic materials, in particular silicone, have been associated in the literature with extrusion and infection but have the advantages of being affordable and easy to reshape with no requirement for harvesting autografts. A 10-year experience with silicone nasal augmentation documenting clinical experience, acute and long-term complications, and patient satisfaction was reviewed. All patients undergoing silicone augmentation rhinoplasty between July of 1985 and December of 1995 were reviewed. Preoperative nasal phenotype, operative data, and postoperative outcome were recorded. Long-term follow-up was undertaken using a telephone survey. There were 422 patients who underwent silicone nasal augmentation from July of 1985 to December of 1995. Only nine were men. The indications were for aesthetic nasal augmentation in 98 percent, and the majority (98 percent) were of South East Asian origin. Mean age was 26 (range 17 to 36), and 41 of the 422 patients had had previous nasal augmentation performed before presentation. Twenty-three patients (5.5 percent) had complications requiring removal of the implant within 30 days of surgery. These included displacement, prominence, hemorrhage, and excessive pressure in addition to obvious supratip deformity. On late follow-up, a further 18 patients (4.3 percent) had subsequent removal of the prosthesis. The most common reason for this was either displacement or over-prominence, more often judged by the surgeon than the patient. There were only two patients (0.5 percent) who had extrusion of the prosthesis. A total of 266 patients (63 percent) were contacted for a telephone interview. The majority of patients (84.2 percent) were satisfied with their nasal shape. Of the 42 patients (15.8 percent) who were not satisfied, 21 patients still wanted further augmentation of their nose. Photographic analysis of 198 patients showed a mean augmentation of 16.5 percent (range 4.0 to 27.5). Amount of augmentation correlated with preoperative nasal phenotype. Silicone nasal augmentation is a safe and effective procedure when used for moderate increases in nasal height. Contrary to previous reports, this series showed no associated infection. If the implant is shaped appropriately to the patient's nasal phenotype, the risk of extrusion may be reduced.
In this study, a range of carefully selected wool and cashmere yarns as well as their blends were used to examine the effects of fibre curvature and blend ratio on yarn hairiness. The results indicate that yarns spun from wool fibres with a higher curvature have lower yarn hairiness than yarns spun from similar wool of a lower curvature. For blend yarns made from wool and cashmere of similar diameter, yarn hairiness increases with the increase in the cashmere content in the yarn. This is likely due to the presence of increased proportion of the shorter cashmere fibres in the surface regions of the yarn, leading to increased yarn hairiness. A modified hairiness composition model is used to explain these results and the likely origin of leading and trailing hairs. This model highlights the importance of yarn surface composition on yarn hairiness.
This paper compares the hairiness of Solospun yarns with conventional ring spun worsted yams of the same specifications. A 24-spindles worsted ring spinning frame is used to spin the Solospun and conventional ring spun yarns at the same time, and yarn hairiness is measured. The total hairiness number ( Tp), the number of hairs longer than or equal to 3mm ( S3), the percentage of longer hairs in total hairs (100 S3/ Tp), and the total hair length per unit yarn length (K' ) are used to compare the hairiness of these yams. The results indicate that the Solospun yarn exhibits less hairiness in each of the hair length groups and has lower variations in yarn hairiness. The hair-length distribution of the Solospun yarn follows an exponential law just like conventional ring spun yams. There is a statistically significant difference between the Solospun and conventional ring spun yams for T p, S3, and K', but the difference in 1 00 S3 /Tp is not statistically significant for these yams. In addition, the Tp, S3, and K' values of the Solospun yarn decrease with twist increase and increase with spindle speed increase, but the 100 S3/T p values of the Solospun and conventional ring spun yarns in this study behave differently in that they are affected by twist level and spindle speed.
The spinning geometry of a ring frame plays an important role, and the twist triangle is the critical region in ring spinning. Changes in the spinning geometry may affect yarn properties. This paper examines the idea of ring spinning with a "diagonal" yarn path, and the effect of such a path on yam properties, particularly hairiness. Both "left diagonal" and "right diagonal" yam arrangements are tried on a 24-spindle Cognetex FLC worsted ring frame. The hairiness results obtained from the Zweigle hairiness meter show that the right diagonal yam path produces yams of lower hairiness than the conventional ring spun yarn in almost all the hair length groups. Yam evenness and tenacity are not as sensitive to the change in yarn path. The mean spindle speed at break is also tested, and there is some deterioration in spinning efficiency with the right diagonal yarn path, particularly at higher spinning speeds. Results from this study may help explain variations in yarns spun on poorly aligned ring frames.
The effect of yarn hairiness on energy consumption when rotating a ring-spun yarn package is investigated theoretically and experimentally. A theoretical model is developed to calculate the energy required to rotate hair fibers, based on hair length and number as well as package speed and size. A single spindle test rig is used to verify the theoretical prediction. The experimental results confirm the theoretical prediction that the package power increases with increased yarn hairiness level and spindle speed.In recent years, considerable research has gone into the development of a ring spinning theory [5-12, 16, 17] and studies of yarn hairiness [ 1-3. 15, 18-26]. While ring spinning has been a very important technology for staple yarns, it is also known for its high power consumption and low productivity. It is conceivable that power consumption in ring spinning could be exacerbated by any increase in the hairiness level of yams during the spinning process, because of the likely increase in air drag associated with rotating a hairy yam and yam package.In the only reported trial we could find in the literature [ 14], the power to rotate one frame package of continuous filament yarn was recorded. The package was then wrapped manually with one layer of heavy-count woolen yarn, and the power required was five times the initial result. This highlights the importance of yarn hairiness in energy consumption during ring spinning. But no one has yet attempted to quantify the effect of yarn hairiness on power consumption in ring spinning.In a normal ring spinning process, the total power consumption will include the power required to overcome friction between moving machine parts and to rotate the yarn package and yarn balloon, etc.[4]. In this paper, we consider the simple case of power consumption when rotating a single yarn package. We develop a power model to calculate increased power consumption due to increased hairiness of yarns on the package. We also conduct experiments to verify the power model. Theoretical BACKGROUND
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