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A brief review of established methods shows that only with the Berthelot technique is it possible to see a finite volume of liquid in sustained mechanical tension. A short discussion of the practice and theory reveals two uncertainties with the conventional technique : that of the determination of a true filling temperature, and the influence of compliance by the glass on the tension developed. A description is then given of a modified apparatus with which these difficulties do not arise. The tube is formed into a coil which deflects sufficiently to indicate internal pressure or tension, and by monitoring these deflections with a distance meter a record of pressure/ tension against temperature can be made. The course of a typical run is shown from which the excess pressure, filling temperature and limiting tension may all be estimated with much greater precision than befoie. The orders of magnitude of the results obtained are indicated, and a possible influence of non-uniform gaseous supersaturation is suggested.

Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature (700 o C to 1100 o C) and chemical pre-treatment (NaOH and NH 4 Cl) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then reorganized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.