Kolonneneinbauten für Vakuum-Rektifizierkolonnen unter besonderer Berücksichtigung der Fettsäurefraktionierung

Column Elements for Vacuum Rectification Columns with Special Consideration of Fatty Acid Fractionation Natural and synthetic fatty acids are rectified in vacuum columns due to their temperature sensitivity. Column elements should ensure low pressure drop per theoretical plate. Several column elements used in fatty acid fractionation are described. Umbrella shaped bell elements, ceramic packings and metallic rings are compared on the basis of literature data and authors' experimental data. The limiting capacities, efficiency of separation and pressure drop are considered as criteria for evaluation. A suitable approach in the choice of a column element for a particular separation is described with due consideration of contamination and corrosion.     

Fettsäure-Geradeausdestillation unter besonderer Berücksichtigung des Umweltschutzes und der Wirtschaftlichkeit I

Straight Distillation of Fatty Acids with Special Consideration of Environmental Safety and Economy This work shows that suitable layout and construction of individual units with due consideration of thermal and oxidative behavior of fatty acids permit to reduce the cost of operation and at the same time meet the requirements for environmental safety without additional expenditure. This shows that requirements for environmental safety need not necessarily be a handicap for plant construction. The straight distillation according to ACV-process is described which shows that the legal demands of the present day regulations and those expected in the near future can be fulfilled with practically no additional expenses.     

Hormonwirkungen auf die Haut unter besonderer Berücksichtigung der Steroid-Hormone

Action of Hormone on Human Skin with Special Consideration of the Steroid Hormones The action of various hormones on skin is outlined. Alterations of the skin due to such actions can also be caused by other medicaments. Parenteral or oral application of glucocorticoids lead to typical alterations of the skin, depending on the dose and duration of the treatment. If applied externally, the counteractions on the entire system are generally negligible, however, considerable local disorders, such as atrophy and striae can occur. The significance of the metabolism of androgens in the skin is discussed. The gestagens and the oestrogens, especially in the form of the “pill”, can cause typical pathogenetic alterations whose nature is yet unknown. Such actions can be reduced if the biological value of the anticonceptives in relation to “hormone-type” of the woman is taken into account.     

Zur fütterungsbedingten Variation des Milchfettes der Kuh unter besonderer Berücksichtigung von Regulationsmechanismen beim Fettstoffwechsel

Variations of Cow's Milk Fat as Affected by Feeding with Special Consideration of Regulation Mechanisms of Fat Metabolism Milk fat composition is highly affected by the conditions of feeding, which again may have considerable consequences for the quality of several dairy products. In order to establish possible variations in physical and chemical properties of the milk fat as depending on the nutritional status of the cow, a small herd of cows was successively subjected to different defined feeding conditions (barn feeding, pasture feeding, energy deficit). The investigations indicated that from barn feeding to pasture feeding to energy deficit the proportions of oleic acid and of long chain triglycerides increased and the proportions of short and medium chain fatty acids and triglycerides decreased. In spite of highly differing fat compositions relatively constant values for the viscosity and the average triglyceride molecular weight were obtained; also various characteristics from the melting and solidification curves were nearly identical. The solid/liquid ratios approached at higher temperatures. These results point to the existence of regulation mechanisms, in the course of which the flow and melting properties are kept within the required narrow ranges by an opposite behaviour of the proportions of short chain fatty acids and oleic acid. With pasture feeding, compared with barn feeding, all oleic acid isomers and linoleic acid increased, with energy deficit the proportions of these acids are at the low level of barn feeding. These results as well as the continuous decrease of the cholesterol content from barn to pasture to energy deficit are explained on the basis of the different pathways of fat metabolism; deficit are explained on the basis of the different pathways of fat metabolism; furthermore the proportions of trans C18: 1 acids are discussed in connection with the milk fat content. The milk fat globules are particularly large and unstable at the period of energy deficit. Consequently, quality deterioration of whipping cream (creaming, plug formation) and other dairy products (lipolysis) can be expected.     

Wachse mit hoher Dispergierfähigkeit unter besonderer Berücksichtigung ihrer Eignung für die Herstellung von Kohlepapierfarbmassen

Waxes Having High Dispersibility and Special Consideration of Their Suitability in the Manufacture of Colouring Masses for Carbon Paper Increasing amounts of waxes having fundamentally different chemical composition are being used as dispersion aids. In the manufacture of colouring masses for carbon papers, the materials used as vehicle of the colour and as dispersing agent for carbon black are hydrocarbons, wax acids and their natural esters. Whereas low-priced paraffins are mainly used for cheap carbon papers meant for a single use, carnauba wax is used for better quality carbon papers which can be used several times. The latter wax is especially suited because of its carbon black-dispersing and oil-binding properties. Since crude montana wax does not have these properties to such an extent as the carnauba wax, it was attempted to improve the carbon black-dispersing and oil-binding of montana wax by chemical synthesis. This was achieved by reacting crude montana wax with maleic anhydride and subsequent esterification of the reaction products with glycols. The results were successfully applied to the solution of problems involving dispersion of pigments and plastic additives.     

Toxikologie freier Radikale und Antioxidantien unter besonderer Berücksichtigung von Vitamin E

Toxicology of Free Radicals and Antioxidants with Specific Regards to Vitamin E By metabolic activation radicals of xenobiotics can occur in the body which may be toxic by reacting with oxygen. The oxygen radicals formed then react with cellular macromolecules. When reacting with lipids lipid peroxidation occurs. Antioxidants may either inhibit the formation of oxygen radicals or prevent lipid peroxidation. As examples carbon tetrachloride, adriamycin, paraquat and some carcinogens are dealt with. With some toxicity as well as lipid peroxidation are inhibited by vitamin E and other antioxidants. Furthermore, the toxicology of the antioxidants is discussed, because they are themselves transformed into free radicals. Whereas vitamin E has practically no toxic effects, some synthetic antioxidants show carcinogenic effects in animal experiments.     

Kostenoptimierung von Verbundfolien unter Berücksichtigung von Gasdurchlässigkeit und Steifigkeit

Optimization of the Cost of Wrapping Materials with Emphasis on the Permeability of Gases and the Stiffness A procedure is described for calculating optimum thicknesses of the individual layers of multi-layer wrapping foils that are used for packaging semi-solid goods. With a suitable combination of materials in various layers, the wrapping foil represents an optimum as regards the cost of raw material, the desired stiffness and gas permeability. Apart from the cost of raw material the E-modules, the permeability coefficients and the density of the materials involved have to be taken into account for the calculations. The validity of the equations employed in the procedure for optimization is demonstrated experimentally on an example of a wrapping material that consists of three layers. Predictability of this procedure is discussed on several examples.