摘要:

Phase equilibria measurements have been made for a 1:1 ethylene-propylene system in the critical temperature region by means of an equilibrium apparatus described by Holder and Maass (3). The critical density of the system was found to be 0.230 gm. per cc. and the critical temperature 58.30° ± 0.05 °C. For mass-volume ratios greater than 0.230, at constant volume, the temperature of liquid disappearance was lower than 58.30 °C., while for mass-volume ratios less than 0.230, the temperature of liquid disappearance was higher than 58.30 °C. With stirring, the phase compositions and phase densities of the liquid and vapour phases were shown to become equal at the critical temperature, whereas in the absence of stirring the attainment of equilibrium is slow and uncertain. The results are discussed on the basis of the liquid persistence theory (5), and the vapour-liquid dispersion theory (1, 9).

ISSN:1923-4287    

DOI:10.1139/cjr41b-029

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

In a search for an adequate preservative for gill nets many attempts were made to synthesize a plastic in the fibres of the twine. The resulting strands in no case possessed such requisite properties as sufficient flexibility and wearing qualities. Strands, treated with a solution of chlorinated pale crepe rubber, to which a plasticizer, dibutyl phthalate, and a bactericide were added, were found, by tensile strength measurements, to prolong the life of the twine in the sea. The strands had the necessary degree of flexibility, and their wearing quality was improved greatly.Tests made by commercial fishermen on sections of net, treated according to the formula recommended, confirm in large measure the laboratory and sea immersion experiments. They report, among other findings, that the net was easier to handle, remained clean, caught an equal catch of fish as the untreated sections, and that the knots did not slip. The strength of the treated net after a summer's fishing, the fishermen found, was only slightly greater than that of the untreated net. This result was not at all in accord with the laboratory tensile strength measurements made on twine after several weeks of sea immersion. An examination of the knots revealed that this difference is due undoubtedly to the fact that the preservative did not penetrate sufficiently into the knots. Nets are now being manufactured from the treated twine; this is expected to overcome the difficulty and increase considerably the life of the net under fishing conditions.

ISSN:1923-4287    

DOI:10.1139/cjr41b-030

出版商:NRC Research Press    

年代:1941

数据来源: NRC