No abstract

Flame-resistant clothing or fabrics against thermal exposure is a crucial requirement in order to ensure people survivability and to protect the structure. A model-based method was developed to evaluate the thermal performance of flame-resistant fabrics used in protective clothing. The skin simulant sensor is used to determine the heat flux at the skin simulant surface from the elevation of temperature of the skin simulant surface. The heat flux is then applied to a newly developed skin thermal wave model (STWM) instead of Pennes' model, which inherits some questionable physical and physiological aspects, and the Henriques burn integral is incorporated into the new model to predict the level of skin injury. Results of tolerance time from the Stoll criterion method are also compared with those from the Henriques method with two skin models (Pennes' model and STWM) by a thermal protective performance calorimeter. Deviations between the STWM and the traditional Pennes' equation imply that the STWM, which accounts for finite thermal wave propagation, may provide realistic predictions on burn evaluation. The comparison measurements show that the test results by the STWM correlated well with those obtained from the Henriques method with Pennes' model. Therefore, this test method provides a new technique to accurately and precisely characterize the thermal performance of flame-resistant fabrics.

Surface charging effects on etching profiles during silicon etching in a nonuniform plasma were investigated by scanning electron micrographs and plasma potential measurements. The distortion in ion trajectories caused by the surface charging was calculated by an ion lens simulator. A tilt in the etching profile was found in holes and trenches near a large etched area when an insulating mask such as photoresist or silicon dioxide was used. Ion trajectory calculations showed that this profile tilt was caused by the local electric field resulting from the potential difference between the charged mask surface and the electrically grounded silicon substrate. This profile result agrees well with gate oxide damage results which were also successfully explained by surface charging.

Surface charging effects on the etching profile defects during silicon (Si) and polycrystalline silicon (poly-Si) etching in non-uniform plasmas were experimentally demonstrated and their mechanisms were studied using an electrostatic ion trajectory simulator and a newly developed surface potential probe. Profile tilt and bowing were found in Si etching, while undercut and shouldering were observed in poly-Si etching. The trajectory simulation and the directly measured charging potential showed that these profile defects were induced by the potential difference between the etching materials and the charged insulating mask and were dependent on the mask patterns. The profile results agreed well with the gate oxide damage results which were also successfully explained by the surface charging.

A new class of organic conductors, mixed valence DIPS@. polyiodides. have been used as conductive addRives in reticulate doping c# polymers. Conductive films have been prepared using three modaications of the reticulate doping technique: a Standard one-step method (direct casting), a two-step method consisting d swelling the film containing molecularly dispersed DIPS@, polyiodldes, and a recently developed method in which oxidation d molecularly dispersed DIPS@. and simuitaneous crystallization of as polyiodides in situ I s induced by treatment d the pristine film containing the donor with 12/CH2C12 vapours. The first and the third methods have been found to be the most advantageous. Conductive films with additive concentrations as low as 0.5 wt% and conductivities d Me order of lo-' S an-' were obtained. In all three methcds, the best results have been obtained when lhe conductive network consisted o f the mast conducting DIPSb, 2.281 salt. Europ. Patent 0 134 026 Jeszka J K and Wacz A 1992 h!yn A&. EchnoL 3 139 Strzelecka H and Rivory J 1980 Matec Res. BUN. 15 897 and reierences therein. Albouy P A, Pouget J P and Strzelecka H 1987 Phys. Rev. B 35 173 and references therein. h e t L C, Reynolds G A, Schneider E M and Perlstein J H 1979 Solid Stare Commun 30 1 Gionis y Fugnitto R, Meyer G, Strzelecka H and Dubis J C 1982 Mol. Cyst. Liq. Cyst. 90 153 and references therein. Strzelecka 6 Vincente R, Ribas J, Legros J P, Cassow P, Petit P and Andre J J 1991 Polyhedmn 10 687 Wan A, Kryszewski M 1989 MakmmoL Chem. Suppl.