The sections of carbon black filled SBR composite materials, prepared by breaking in liquid nitrogen, was observed by SEM. The state of dispersion of carbon filler were characterized by two statistical processings: the distance method using Clark-Evans index CEI and the quadrat method using Morisita's I_δ value. Both were able to characterize the state of dispersion. The Morisita's I_δ value is more effective to characterize the state than CEI. The electrical conductivity of the composite materials were measured. The results were compared with these of the statistical analysis. The sudden increase in electrical conductivity with increasing carbon content was more adequately described by the Morisita's I_δ value method than the CEI method.

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The real tensile strength of polymeric materials is small remarkably for the reason of the fact that molecular chains do not work effectively in comparison with the ideal strength resulting from the interatomic covalent bonds of the main chains of polymers. It has been definitely shown based on cell division theory that the fracture of glassy polymers has occurred at near the mean value of density of effective molecular chains. The tensile strength of glassy polymers has been analyzed with a point of view of the change of the mean value of density of effective molecular chains, i.e. the mean value of ratio of contribution of those molecular chains to the tensile strength by use of polystyrenes as the model materials based on this fact.
The determining factors which produce an effect on the density of effective molecular chains are the factors resulting from the statistical properties of molecular chains, i.e. the conformational effect of molecular chains W_c, the directional distribution effect of molecular chains _Wd and the chain length distribution effect between the bonds of entanglements of molecular chains W_l. The density of effective molecular chains W_c is 0.213, W_d is 0.214 and W_l is 0.142. Calculated value of tensile strength of glassy polystyrenes is 5.76kg/mm² and indicates the sufficient agreement to the real data, i.e. 5_??_6kg/mm²

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A new approach to the evaluation of formation of paper sheet was performed by image analysis on digital image of mass distribution in the sheet.
To estimate the characteristics of variation in local mass density, the mass co-occurrence matrix was calculated from the digital image of mass density transformed from a soft x-ray image of the paper sheet. The matrix describes joint probability density distribution of mass density (local basis weight) of neighboring two points in the sheet (Fig. 1). The distribution patterns of joint probability density were classified into three types. These were dispersion in radial direction (type A), dispersion parallel to primary diagonal (type B), and dispersion perpendicular to primary diagonal (type C) in the matrix (Fig. 2). The parameters which describe the degrees of dispersion of types A-C quantitatively were also derived from the matrix (Table 1).
For handsheets and a commercial paper, coarseness and contrast of texture were expressed by the degree of type A dispersion. The amount of large flocks was expressed by the degree of type B dispersion, and contrast of fine texture and the amount of small flocks were expressed by the degree of type C dispersion (Fig. 3).

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It is well-known that Fibronectin (FN) has affinity to collagen. But the adsorption mechanism is not so clearly understood. Therefore, we examined adsorption behavior of plasma FN on collagen and various modified collagens.
The effect of chemical modification of the primary structure of collagen (methylation and succinylation) on FN adsorption was studied. The enrichment of positive charge on collagen increased the affinity to FN. The effect of the change in the secondary structure (gelatinaization) on FN adsorption was also evaluated. It was found that the change of the secondary structure of collagen increased the affinity to FN. In order to evaluate the activity of adsorbed FN's, cell-substrate adhesion activities of FN to mouse fibroblast (L-Cells) were compared among various collagens.
It was indicated that the secondary structure of collagen was important factor for the adhesion and spreading of fibroblast. However, spreading activity of FN on methylated collagen was not so high as other substrate.
The results suggest the possibility of adsorption control and activity control of FN by designing the structure of collagen. Immobilized FN on well-designed collagen matrices is very promising for cell culture system and hibrid artificial organs such as artificial skin.

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In a previous paper, we proposed a theoretical equation to predict the breaking behaviour of the yarn and discussed the effect of the breaking behaviour of the filaments on that of the yarn. Since this proposed equation has many parameters, the application of the equation to an actual yarn is very difficult. Therefore, an approximate equation is proposed in this work.
By using this new equation, the breaking behaviour of the yarn is discussed theoretically. Furthermore, the Monte Carlo Method was applied for the breaking behaviour of the yarn.
Following conclusions were obtained from the calculation by the approximation and simulation method.
1) The breaking stress and strain of the multi-filament yarn are proportional to the averages of those of the single filament in the yarn, respectively.
2) The breaking stress of the multi-filament yarn is inversely proportional to the coefficient of strain variation for the single filament.
3) The variation of strain at yield point for the single filament gives a negligible effect on the breaking stress and strain of the multi-filament yarn.
4) The breaking stress of the multi-filament yarn is directly proportional to the yield stress of the single filament, and the breaking stress of the multi-filament yarn is inversely proportional to the yield stress of the single filament.
5) The variations of stress at yield point for the single filament and initial Young's modulus give a negligible effect on the breaking stress and strain of the multi-filament yarn.

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The visual ratings on fastness of dyeings are influenced by many factors such as mental state of assessor, judging conditions, and so on. The variation factors of visual rating were examined. 307 sheets of stained cloth specimen were prepared by rubbing on 82 kinds of commercial clothing leather. The staining of the specimen was assessed with the Grey Scale by 26 assessors, making 7982 assessments in all.
The agreement between the average and individual ratings within ±0.5 rating grade was found to be about 94% for all assessments.
The formula which showed an extremely high correlation coefficient between the rating and the colour difference of the Grey Scale was proposed. The formula made it possible to calculate the rating of the stained specimen.
By comparing the visual and calculated ratings for all assessors, it was found that the assessors have an inherent rating criterion which gave good reproducibilities to their own assessments. However, the internal criterion differed from each other too greatly among assessors. The dispersion of visual ratings was broadened with increase in the colour difference of the stained specimen. This is mainly due to the difference in the internal rating criterion among assessors.
The difference threshold also increased with increase in the colour difference of the stained specimen. However, the difference threshold showed minor effect on broadening the dispersion of visual ratings.
The cloth grey scale was prepared for the purpose of decreasing the difference in the internal criterion among assessors. It should be noted that the dispersion of visual ratings is fairly improved by using the cloth grey scale.

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The effects of extension of wool fibers on the dyeing rate have been examined using C. I. Acid Orange 7 in an acidic dyebath. The apparent rate of dyeing increased with an increase of extension ratio. From the relationship between the relative dye exhaustion and the square root of dyeing time, it was found that the initial dyeing behavior which was remarkably affected by extension contributed to the increase of the apparent dyeing rate. The scanning electron micrographs of extended wool fibers showed that the cusps of the cuticle cells were curved upward and the gaps between cuticle cells were enlarged. Therefore, it seems reasonable that the increase of the initial dyeing rate is due to the rough and porous nature of the surface layer responsible to the morphological changes in the cuticle layer.

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Cotton fabric treated with the solution of poly (vinyl chloride) containing dispersed metalethylenediamine complexes (abbreviated as metal-(en)-PVC complexes). These samples were studied using the flammability test method JIS-L1091. After flame and glow, char length and char area of untreated cotton and cotton fabrics treated with metal-(en)-PVC complexes and PVC were evaluated. These results clearly indicate the metal-(en)-PVC complexes increases the flame retardance of cotton fabric.

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