Über den Einfluß der Grenzflächenspannung auf die Haftfestigkeit

The values of adhesion between four diffrent adhesive,and (i) steel substrates whose surface energy had been altered by adsorption, and (ii) several polymer having different surface energies, had been measured. The results show that the adhesion has a maximum value when the surface energy of the hardened adhesive is equals to that of the substrate, i.e. when the interfacial energy adhesive/substrate is a minimum. The adhesion of the adhesives to the polymer was much smaller than to the steel sprcimens and the dependence of the adhesion onm the interfacial energy was sharper in the case of the polymers. The decrease of the adhesion with increasing interfacial energy was fiund to be greater if the liquid adhesive wets the substrate badly than the steel speciman.     

Über den Einfluß synthetischer Tenside auf die Zusammensetzung der Hautoberflächenlipide

Influence of Synthetic Surfactants on the Composition of Skin Surface Lipids Twenty male persons were subjected to bath in a surfactant solution for 15 minutes each on 5 consecutive days. Before beginning and 3 days after the end of the experiment percent free fatty acids and triglycerides of the skin surface lipids were determined by thin-layer chromatography. It could be shown that the aforesaid treatment led to significant reduction of free fatty acids and increase of triglycerides. The significance of these findings on the therapy of Acne vulgaris and Seborrhoea oleosa capitis is discussed.     

Einfluß der Struktur auf die Unverträglichkeit von Polymergemischen in Lösung

The influence of polymer structure on the incompatibility in solution was investigated with combinations of 15 polyacrylates and polymethacrylates with different ester chain length. Small changes in polymer structure already cause an incompatibility in solution. In general it was found that the higher the difference in the carbon number the higher is the incompatibility. Furthermore there exists a dependence on the molecular weight of the polymer and on the nature of the solvent. Finally it was found that in contradiction to published data polyvinylacetate and polymethylacrylate are incompatible both, in dissolved and in solid state.     

Über den Einfluß der Lagerungsdauer auf die Aktivität des Ni-Katalysators

Storage Time Effect on the Activity of Ni-Catalyst The effect of long-time storage on the activity of Ni-catalyst on carrier passivated with fat was investigated. The catalyst was stored under normal conditions in the air for 5 years. Comparing the rate constants the following results were obtained. The activity of the long-term stored catalyst decreased depending on concentration (0.3-0.1% w/w Ni/oil) 6 to 14 fold for sunflower oil and 8 to 9 fold for olive oil (at the same Ni-level). By calculation of the rate constants of subsequent and parallel reactions it was found that the parallel reaction (linoleic acid → stearic acid) takes part on saturation of linoleic acid at a 13-15% level. The largest effect on activity decrease resulted from autoxidation reactions of the fat applied for passivation.     

Über den Einfluß der Begleitstoffe der Fettsäuren auf die Kinetik ihrer Hydrierung

Ta Influence of Concomitant Substances of Fatty Acids on the Kinetics of their Hydrogenation In the present paper the influence of concomitant substances of animal fats and their degradations components on the kinetics of the hydrogenation of free fatty acids of these fats was investigated. Our attention was directed to the balance of organic sulphur, phosphor and nitrogen compounds during high pressure splitting of fats, distillation of fatty acids and following hydrogenation. During the splitting process 70% of nitrogen and sulphur containing substances were degradated or removed, the content of phosphor containing substances didn't change basically. Another decrease of concomitant substances and their splitting products occurs during distillation of fatty acids. In the subsequent hydrogenation the content of phosphor containing compounds decreased significantly. Residual contents of amino acids and sulphur compounds were absorbed by the Ni-catalyst and contributed to the decrease of its activity. The effect of the confirmed substances on the decrease of its activity. The effect of the concomitant substances on the decrease of the hydrogenation velocity was confirmed by their addition to the fatty acids of sunflower oil after chromatographic isolation. This addition (concentration from 1 to 3%) lowered the reaction velocity up to 50%.     

Über den Einfluß der Hautoberflächenlipide auf Alkalineutralisationsfähigkeit und Alkaliresistenz der Haut

The Influence of Surface Lipids of Skin on Its Ability Towards Alkali Neutralisation and Its Alkali Resistance On 28 experimental persons, the alkali neutralisation time was determined by the method of Tronnier, and the alkali resistance was measured by the method of Burckhardt. Furthermore, the skin surface lipids were extracted with petroleum ether and determined gravimetrically. The composition of skin-surface lipids was determined by thin-layer chromatography. At short alkali neutralisation time, considerably more skin surface lipids were found than for the long periods. Any additional effect of the composition of skin surface lipids on the ability of skin towards alkali neutralisation could not be detected. No evidence on the significance of skin surface lipids towards alkali resistance was found.     

Über den Einfluß der Schichtdicke und der Oberflächenrauhigkeit auf die Glanzzahl von Wachsfilmen

Influence of the Thickness of Film and the Roughness of Surface on the Degree of Gloss of Wax Films With the help of a developed isotopic method film thicknesses of wax layers on different floorings were measured. The surface roughness was found out by a special apparatus. It could be shown that the degree of gloss of a wax film with respect to the substrate is also a function of film thickness and surface roughness of the substrate and each of the applied films.     

Über den Einfluß der Klimatisierung auf den Gehalt an Phospholipiden im gepreßten Rapssamenöl

The Conditioning Influence on the Content of Phospholipids in Pressed Rape Seed Oil The influence of the conditioning temperature and humidity of the rape seed which was to be conditioned, on the migration of phospholipids into raw oil was investigated. The increase of the humidity content from 6 to 8 wt.-% had an extent influence on the total content of the phospholipids. Thr increase of the temperature from 70°C to 80°C showed no essential influence, a further temperature rise up to 95°C led to an increase of phospholipids in oil of 1/3. The corresponding relations are of great importance for oil storage as well as for the balance of the yield and of the losses.     

Über den Einfluß von Sonnenblumen-Krankheiten auf das Samenöl und auf die Veränderungen der freien Fettsäuren

Influence of Sunflower Diseases on the Seed Oil and on Changes in Free Fatty Acids The relationships between the widespread sunflower diseases like peronospora, botrytis disease, etc. on reduction of yield as well as on the deterioration of the quality of oil were investigated. It can be seen from the results obtained that the damage caused by such diseases can be minimized by suitable measures like dressing of the seeds, appropriate nutrition, proper sequence of planting etc. However, the breeding of resistant varieties remains an important task. Promising results were obtained in this respect by the author on the basis of an artificial infection procedure carried out in pathological breeding grounds.     

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.     

Untersuchungen über den Einfluß von Sorte und Standort auf den Tocopherolgehalt verschiedener Pflanzenöle

Investigations on the Influence of Genotype and Location on the Tocopherol Content of the Oil from Different Oil-Crops Eight plant species have been cultivated on climatically differentiated locations as well as in phytotron trials, in order to determine the influence og genotype and environmental conditions on the tocopherol content of the oil. The tocopherol content has been related with the oil content of the seeds ami the part of the main polyenic fatty acid of the plant. Considering the genetic range of variation and the inheritance an increase of tocopherol content through breeding efforts seems likely. Especially oil plants which seeds can directly be consumed or which oil needs not to be refined, seem to be promissing. Concerning the environmental influence, biosynthesis of tocopherol was promoted by increased temperature. The negative correlation to the oil content of the seed could be due to the fact that oil plants of our climatic conditiones yield higher oil contents with low temperature.     

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 ernährungsphysiologischen Eigenschaften von Fisch-Frittierfetten

Effect of Frying on the Nutritional Properties of Fats for Fish Frying Experiments are reported in which especially the protein efficiency was determined in the feeding of albino rats with frying fats which were used in the industry. No correlation could be established between the chemical data and the results of animal experiments. For example, the frying fats which were used for a much longer period than the common industrial practice, did not show any injurious action on the growth and protein efficiency, although some of the chemical constants of the fats deviated considerably from those of the starting material. Considering the results obtained till now and in agreement with the instructional pamphlet of the public health authorities of Hamburg, it is recommended not to exceed a frying temperature of 180° C in the frying of fish and fish products and to fully replace the used frying fat with a fresh one once a week.     

Über den Einfluß von Licht auf den oxydativen Verderb von Speiseölen III: Abhängigkeit der Oxydationsgeschwindigkeit vom Sauerstoffpartialdruck und der Lichtintensität

Effect of Light on the Oxidative Deterioration of Edible Oils III: Effect of Partial Pressure of Oxygen and Intensity of Light on the Rate of Oxidation An apparatus is described for the measurement of oxygen consumption during oxidation of edible oils. Oxidation can be followed in this apparatus under the action of light of any desired intensity and spectral composition, and at various O₂-pressures. Sunflower, peanut and soybean oils were chosen as substrates. The characteristic curves representing oxygen uptake versus time during photo-oxidation showed an unique behaviour of soybean oil; its photo-oxidation proceeded in two phases. With decreasing pressures, a noticeable decrease in the rate of oxidation of the aforesaid oils is observed only at pressures as low as 10-20 mm Hg; up to this region the effect of oxygen pressure is insignificant. The effect of light intensity on the rate of oxidation shows for soybean oil a linear function in the first phase, and a square root function for sunflower oil, and peanut oil and for soybean oil in the second phase.     

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.     

Über den Einfluß von Licht auf den oxydativen Verderb von Speiseölen IV: Abhängigkeit der Oxydationsgeschwindigkeit von der Wellenlänge des eingestrahlten Lichts

Influence of Light on Oxidative Deterioration of Edible Oils IV: Dependence of Rate of Oxidation on Wave-Length of Incident Light A distinct decrease in the rate of oxidation with increasing wave-length is observed for soybean, sunflower and peanut oils when these oils are irradiated with various coloured lights having the same quantum-density. While studying the causes of this behaviour, pure absorption curves for the aforesaid oils were determined. Light of short wave was completely absorbed, whereas long-wave light was barely absorbed to any measurable extent. A considerable increase in quantum yield during oxidation occurs with increasing wave-length. Inspite of this, the oxidation of oils is catalysed most strongly by short-wave light, because the influence of pure absorption exceeds the increase in quantum yield. Pure absorption is therefore considered as the decisive factor with regard to the dependence of photooxidation on wave-length. Finally, the rate of oxidation, as determined in darkness, was found to increase with decreasing wave-length of light used for pre-oxidation of the oil.