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Thesis (Ph. D.)--Columbia University, 1933. / Vita. Bibliography: p. 34.

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Tung oil, an important drying oil, is used in considerable amounts by the paint and varnish, linoleum, and electrical industries. At present domestic tung oil is obtained by mechanical expression. The cake which remains after expression has an oil content of from four to five per cent. Although the amount of domestic oil produced is a small part of the oil consumed in this country, tung oil shipments from China have ceased and the treatment of present and future domestic tung nut crops to obtain the maximum amount of oil most economically is a problem of considerable importance. Solvent extraction has proven more efficient and economical ln industries such as soybean and cottonseed oil extraction. It appeared feasible that tung oil might be extracted by analogous methods thus decreasing the loss of oil in the cake and increasing the efficiency and economy of tung oil production in the United States. First Soxhlet extractions of ground tung kernels were performed with ethyl alcohol, benzene, carbon tetrachloride, chloroform, hexane, and toluene. Of the flammable solvents, benzene extracted the most oil, 51.7 per cent. Hexane was next in oil extraction with 50.8 per cent. In the non-inflammable class, carbon tetrachloride extracted the most oil, 47.8 per cent. The compositions of non-inflammable mixtures of carbon tetrachloride with hexane and benzene were determined in a Cleveland open cup tester. A non-inflammable mixture of carbon tetrachloride-benzene (70 per cent and 30 per cent by volume respectively) was more economical than either a non-inflammable carbon tetrachloride-hexane mixture or carbon tetrachloride used alone. Consequently the carbon tetrachloride-benzene mixture was selected as the solvent to use in continuing the investigation. Higher extraction efficiencies were obtained for batch extractions at 22 deg. C. with raw tung kernels than with roasted tung kernels. The highest extraction efficiency was obtained with raw tung kernels at 40 deg. C. for a batch extraction of 90 minutes. Since the efficiencies of batch extraction are limited, preliminary investigations of the feasibility of using countercurrent extractors were made. These studies showed that the Allis-Chalmers and Ford type extractors were not applicable to the extraction of tung kernels with the carbon tetrachloride-benzene mixture since the tung kernels, as prepared, floated in the solvent mixture. The Allis-Chalmers extractor which depends upon the downward flow of the material being extracted against the upward flow of solvent would therefore not be suitable. Similarly the Ford type extractor would not be applicable because the solvent would have to travel downward against the natural tendency of the oil being extracted and the oil-solvent solution formed to flow upward since they would be lighter than the original solvent mixture. / Master of Science

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No description available.

Typescript. Thesis (Ph. D.)--University of Hawaii, 1938. Bibliography: leaves 150-158.

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La caractérisation de l'activité enzymatique des (phospho)lipases requiert des tests enzymatiques spécifiques, continus, utilisant des substrats lipidiques et adaptés au criblage à haut débit des activités et/ou des inhibiteurs de (phospho)lipases. Afin de développer de tels tests, la synthèse de glycérophosphatidylcholine (PC) estérifiée en position sn-1 et/ou sn-2 par l'acide alpha-éléostéarique (acide 9Z, 11E, 13E, octadécatriénoïque) a été effectuée. La triple insaturation conjuguée présente au sein de cet acide gras constitue un chromophore intrinsèque qui confère une forte absorption dans le domaine de l'ultra-violet à cet acide gras et aux lipides le contenant. Les PC contenant l'acide alpha-éléostéarique ont été adsorbées par « coating » au fond des puits d'une microplaque de titration. L'hydrolyse du substrat lipidique par une phospholipase A1 (PLA1) ou phospholipase A2 (PLA2), injectée dans le milieu réactionnel, est suivie en continu par l'augmentation de l'absorbance à 272 nm, due à la transition de l'acide alpha-éléostéarique de la phase adsorbée à la phase aqueuse. Des PC hétérogènes ont été synthétisées à partir de rac-glycidol pour effectuer un marquage sélectif de la PC par l'acide alpha-éléostéarique sur la position sn-1 (EOPC) ou sn-2 (OEPC). Pour empêcher la migration de la chaîne acyle, un lien éther non hydrolysable par les PLA1 ou PLA2 a été introduit sur l'autre position sn de la PC avec une chaîne alkyl (C18). Ces PC chimiquement définies ont permis d'élaborer une méthode de dosage en continu de l'activité enzymatique et discriminant les activités PLA1 ou PLA2, ce qui représente un caractère innovant par rapport à toutes les méthodes existantes / The characterization of the catalytic activity of (phospho)lipases requires specific assays, that are continuous, sensitive, use lipidic substrates and could be applied to high throughput screening. In order to perform these tests, several tailor-made alpha-eleostearic (9Z, 11E, 13E-octadecatrienoic acid) containing glycerophosphatidylcholines (PC) have been synthetized with the alpha-eleostearic acid at the position sn-1 and/or sn-2. The conjugated triene present in this fatty acid constitutes an intrinsic chromophore and, consequently, confers strong UV absorption properties of the fatty acid and the lipids harboring it. PC substrates were coated onto a microplate well and the phospholipase A1 (PLA1) or phospholipase A2 (PLA2) activity was measured continuously by the increase in absorbance, at 272 nm, due to the transition of alpha-eleostearic acid from the adsorbed to the soluble state. Moreover, two structured analogues of PC labeled at the sn-1 (EOPC) or sn-2 (OEPC) position with the alpha-eleostearic acid have been synthetized from rac-glycidol. A non-absorbing and non-hydrolysable by PLA1 and PLA2 O-ether alkyl(C18) was introduced at the other sn position to prevent intramolecular acyl chain migration during the synthesis and the lipolysis. These structured PC were coated onto a microplate and used in a continuous assay, to discriminate, with excellent accuracy, between PLA1 or PLA2 activities. The development of a sensitive enzymatic method using coated substrates analogues to natural lipid is a relevant improvement from current assays for measuring continuously (phosphor)lipases activities and/or their inhibitors due to the alpha-eleostearic acid UV spectroscopic properties