Über den Einfluß von Chlorkohlenwasserstoffinsecticiden auf Radikalreaktionen von Methyloleat

Effect of Chlorohydrocarbon-Insecticides on Radical-Reactions of Methyl Oleate Chlorinated hydrocarbons having insecticidal action accelerate the autoxidation of methyl oleate by way of shortening the period of induction phase. Measured on the basis of peroxide-formation, the aforesaid effect increases in the order DDT, DDE, heptachlor and heptachloro epoxide. Apart from the accelerating effect which is common to all the active substances studied, the differences with respect to number and nature of peroxides formed and their further conversion products indicate that the individual chlorohydrocarbons favour certain specific mechanisms in the autoxidation of methyl oleate. In this respect, similar behaviour was exhibited by related substances, such as DDT and DDE on one hand, and heptachlor and heptachloro epoxide on the other.     

Einfluß von Lösungsmitteln auf den Partikeldurchmesser von Dispersionen anionischer Polyurethanionomerer

Aqueous dispersions of anionic polyurethanes were prepared by reaction of polyethers, 1,6-hexamethylene diisocyanate, 1,2,4-benzenetricarboxylic acid anhydride and triethyl amine. Formation of the dispersion was achieved by phase reversal or by precipitation. Phase reversal occurred when the solution or the melt of the polymer was treated with water, while precipitation took place when the solution was stirred into water. The amount of acetone used has an effect on the mean particle diameter, D?_T, obtained by turbidity measurements. There was an optimal acetone concentration at which D?_T reached a minimum. A similar effect was observed when tetrahydrofuran, 2-butanone or acetonitrile were used as solvents instead of acetone. When the dispersion was formed by precipitation, only adequately diluted acetonic solutions formed colloidal dispersions, while concentrated solutions gave dispersions with a broad particle size distribution.     

Einfluß von thermophysikalischen Stoffdaten auf die Auslegung und den Betrieb von Destillationskolonnen

Influence of thermophysical data on the design and operation of distillation columns. It has become common practice in the petrochemical industry to utilize highly developed process simulators for the design of individual pieces of equipment or entire processes. Apart from actual model development, attention focusses on the calculation and use of efficient solution and converging algorithms in the development of such process simulators. Although frequent reference is made to the importance of the underlying material data in the literature and in practical applications there exist only scattered studies giving a suitable choice of the available substance data models and the sensitivity of the process variables to inaccuracy and uncertainty of the material data and the material data models. The present article illustrates the influence of material data (choice of model, sensitivity) for the example of the design and operation of distillation columns and several methods and recommendations are given for fast estimations. With the aid of appropriate examples, the influence of uncertainties in the underlying measured data and the phase equilibrium models on various process variables (plate number, reflux ratio, distillate and sump concentrations) is demonstrated.     

Einfluß polymerisathaltiger Schmieröle auf den Verschleiß von Verbrennungsmotoren

The wear protecting properties of motor oils containing oil soluble polymethacrylates were investigated by means of measuring the wear of the crankshaft bearings of internal combustion machines. From this results follows that lube oils containing enough polymer (up to 12%) give lower wear than straight mineral oils of equal viscosity. That means that polymethacrylate has a wear protecting effect which is more efficient than the thickening effect of the polymer. The efficiency of this effect depends on polymer content and on the molecular weight of the polymer. Furthermore, the results clearly show that the wear protecting effect of the polymethacrylate is strongly influenced by the solving properties of the base oil.     

Über den Einfluß von Licht auf den oxydativen Verderb von Speiseölen V: Reaktionskinetik

Influence of Light on the Oxidative Deterioration of Edible Oils V: Kinetics of Reaction A time law for the photochemical oxidation without the decomposition of hydroperoxides has been derived from the radical chain mechanism in the oxidation of edible oils. Quantum yield of the photochemical start reaction and of the chain length can be calculated from the experimental results for soybean oil in the first phase. Using these kinetic values as well as from the quantum yield of the brutto reaction it is proven that the first phase in the autoxidation of soybean oil does not proceed by autocatalysis. Autocatalytic oxidations, e. g. soybean oil in the second phase, sunflower oil, and peanut oil, are discussed on the basis of investigations on the oxidation rate as a function of absorbed quantum current. It is found that owing to the presence of antioxidants, the degree of unsaturation of oils alone is not responsible for the readiness with which the oil is oxidized.     

Über den Einfluß des Frittierens auf die chemische Zusammensetzung von Fisch-Frittierfetten

Effect of Frying on the Chemical Composition of Fats for Fish Frying If fats are heated upto 180° C in commercial frying plants with or without the material to be fried, corresponding chemical changes, depending on the period of heating occur. These changes are investigated by the methods commonly employed in food industry. Soybean oil and partially hydrogenated peanut oil were employed in these investigations. These two frying fats are very different as regards the degree of saturation of their fatty acids. Although these fats were subjected to more severe conditions than usually practiced in fish restaurants no detrimental physiological properties were found in both the fats after an observation period of two years.     

Einfluß der Zweiphasenströmungsbereiche auf die Trenneigenschaften von Siebböden

Influence of binary phase flow regimes on the action of sieve plates . Recognition of various flow regimes on sieve plates has greatly enhanced our understanding of the mode of action of these plates. When vapour flow dominates the liquid is dispersed into drops; this is the so-called ?droplet regime”?. In a second principal regime, liquid flow predominates and the vapour is dispersed into small bubbles; this is the ?emulsion regime”?. A transition region exists between these two principal regimes; it is called the ?mixed regime”?. The present paper attempts to demonstrate the relations between the flow regimes and the characteristics of sieve plates. It considers the structure of the binary phase layer, flow over the weir, axial mixing, entrainment of liquid, maximum loading (flooding), and efficiency.