Verfahren zur Anreicherung von Stearidonsäure

Preparation of Stearidonic Acid Concentrates Fatty acids of the n-3 series are precursors of the biochemical synthesis of prostaglandins which are known as inhibitors of blood platelet aggregation. The parent compound of this series, α-linolenic acid (ALA), is transformed to stearidonic acid C18:4 δ6.9, 12.15 (SA) by catalysis by the liver enzyme δ6-desaturase. SA is found in few natural materials such as fish oils and blackcurrent seed oil (BCO) and only at low concentrations. In this context the oil extracted from entrails of squids caught in warm-water seas is reported to present an interesting source of arachidonic acid with contents of up to 8%. A two-step procedure was developed for the preparation of SA concentrates with 15% SA was obtained by urea fractionation. Simultaneously the γ-linolenic acid (GLA) concentration was increased to 80%. Subsequent separation of SA from GLA was carried out by preparative HPLC yielding SA concentrates with a purity of ≧ 90%. These SA concentrates were used for a comparative investigation of the inhibiting effects of some polyunsaturated fatty acids such as GLA, ALA or eicosapentaenoic acid on blood platelet aggregation. It was found that, compared with the other fatty acids. SA inhibits more specifically the aggregation stimulated by thrombine.     

Verfahren zur Kristallisation aus Lösungen

Crystallization from solution . In general the processes occurring in crystallizers have previously been treated in only summary and phenomenological manner because only little was known about the joint action of the individual steps. An attempt has therefore been made, in the present survey, to examine the relationship between the physico-chemical properties of the relevant system, the process chosen, and engineering economics.     

Moderne Verfahren zur Beschichtung zementgebundener Untergründe

Modern Procedures for Coating of Cement Bound Grounds Still up to the middle of the sixties freshly prepared cement bound rough-casts and concrete surfaces were thought to be very critical grounds for painting. The effect of the high alcality of these grounds in connection with the residual humidity of the building and the influence of the weather was especially feared, which could cause saponification of the binding agent and destruction of inorganic colour pigments. Especially at concrete surfaces difficulties with adhesion of the paints on concrete were added, since at that time in building practice again and again pollution of the concrete surfaces by lagging oils and waxes occured. Defects by flaking off were the outcomes. Only when concrete pushed forward quickly in housing construction, where prefabricated building with prefabricated elements played a decisive role, special painting and coating systems were developed which allowed not only a durable protection of concrete, but moreover a colour fashioning. In the same measure as security in concrete painting was achieved, the difficulties in painting of cement containing rough-casts were solved. According to the state of the technic of today tested and well proved painting systems for coating of cement bound rough-casts and concrete are available.     

Über ein Verfahren zur Gewinnung von Lecithin-Fraktionen

A Process for the Recovery of Lecithin Fractions A plant for the fractionation of crude lecithin, such as soybean lecithin, sunflower lecithin and rapeseed lecithin is described in which ethanol, methanol or isopropanol is used as extracting solvent. In this context, the liquid liquid extraction and its relationship to the quality and yield of product are discussed. Technical problems involved in transport of miscella and solvent recovery are discussed with aid of diagrams, material data, consumption of utilities and a simple scheme of layout.     

Substratspezifische Stoff-Führung bei anaeroben Verfahren zur Methan-Gewinnung

Principles of material flow in anaerobic methane production processes . Rising prices of fossil energy are upgrading the importance of processes for generating fuels from organic wastes and from renewable biomass. Anaerobic digestion is a suitable approach for the production of fuel gas rich in methane from wet or liquid organic feedstock. Depending upon the biochemical characteristics of the digestion process and upon the physical conditions for an optimal mass transport, specific technical solutions have been found for treating typical substrates differing in chemical composition, digestability, and fluid mechanical behaviour; such substrates are waste water, sludges, and organic solids with a high liquid content. A survey is given on the principal systems now used for conducting material to be digested through the whole process and in particular through the bioreactor.