The selectivity of the hydrogenation of linseed oil
We have invest igated the se lec t iv i ty of the hydrogenat ion of l inseed oil, which is a mix tu re of t r i g l y c e r ides of fatty acids of different degrees of unsaturat ion linolenic, l inoleic, and ole ic and sa tura ted fatty acids . Depending on the conditions of hydrogenat ing oils and fats , the p roce s s may go according to the following scheme , given in the l i t e r a tu re [1]:
Some additional notes on the kinetics and theory of fatty oil hydrogenation
Summary1.Equations are given for estimating from the composition of oil samples the relative reaction rates of the different unsaturated fatty acids in an oil subjected to catalytic hydrogenation.2.Application of the equations to data from the hydrogenation of cottonseed oil reveals that the ratio of reaction rates, linoleic acid to oleic acid, varies from about 4 to 1 in very non-selective to about 50 to 1 in very selective hydrogenation. Re-examination of analytical data on two series of linseed oils hydrogenated selectively and non-selectively showed the following relative reaction rates for oleic, isolinoleic (9: 10, 15: 16 octadecadienoic), linoleic, and linolenic acids, respectively: non-selective, 1, 2.5, 7.5, 12.5; selective, 1, 3.85, 31, 77. In the non-selective hydrogenation of the oil, 24% of the linolenic acid reacting went to linoleic acid, 65% to isolinoleic acid, and 11% directly to oleic acid. In the selective reaction the corresponding figures were none to linoleic acid, 54% to isolinoleic acid, and 46% to oleic acid. The behavior of soybean oil hydrogenated selectively was quite similar to that of linseed oil.3.The results are discussed in relation to the theory of catalytic hydrogenation. They indicate that the solution of hydrogen in the oil and the adsorption of unsaturated oil on the catalyst are the two steps which are controlling with respect to the reaction rate. It is suggested that the hydrogen pressure, the degree of hydrogen dispersion through the oil, the catalyst concentration, and the temperature all affect the selectivity of the reaction through their influence on the concentration of hydrogen in the reaction zone, with selectivity being favored by a low concentration.
Reconceptualizing Vagrancy and Reconstructing the Vagrant: A Socio-Legal Analysis of Criminal Law Reform in Canada, 1953-1972
This article explores significant reforms to the vagrancy section of the Criminal Code during the mid-to-late twentieth century. By locating the reforms within their unique social, political, and economic climates, I examine how they reconceptualized the offence of vagrancy and concomitantly reconstructed the vagrant as a social problem. The reforms played a seminal role in reducing the number of vagrancy offences, eventually leading to the demise of vagrancy in the criminal law. Yet, while the "vagrant" ceased to exist in the law, the law still continues to preserve vestiges of the vagrant in a highly gendered manner.