Toshifumi Yoshidome

Theoretical Treatment of New Particle Size Measurement Method Using Infrared-Attenuated Total Reflection Technique Combined with Sedimentation Phenomena and Its Application to Commercially Available Particle Samples

ABSTRACT Theoretical treatment was carried out for the new particle size measurement method using the infrared-attenuated total reflection (IR-ATR) technique combined with sedimentation phenomena. The theory constructed was applied to the size-distribution analyses of commercially available SiO2 particles. The simulations based on the equation obtained successfully reproduced the experimental IR-ATR results. The size distributions obtained from the reproduction procedures agreed with those from scanning electron microscopy (SEM) and optical microscope analyses.

Comparison of Tensile Fracture Behavior between Si-Ti-C-O Fiber Bundle (Yarn), Woven Fabric of Yarn and Laminated Composite of the Si-Ti-C-O Fabric / Mullite Filler / Polytitanocarbosilane System

A polytitanocarbosilane (20-30 mass%)-xylene solution was infiltrated into a porous laminated composite with 35-40 vol% Si-Ti-C-O fabric of 11 diameter fiber and 15-25 vol% mullite filler, and decomposed at 1000°C in an Ar atmosphere. This polymer impregnation and pyrolysis method was repeated 8 times to produce the composites of 76-82 % theoretical density. The yarn (662-765 filament / yarn), fabric and composite provided the following average strengths : 1240 MPa for the yarn; 768 MPa for the fabric; 117 MPa for the composite. The fracture probability of the yarn, fabric and composite was well fitted by the normal distribution function. The tensile strength of the composite was interpreted by the product of the effective fiber content, the Youngs modulus of the fiber and elongation of the composite.