Modifizierung von Faseroberflächen durch die permanente Fixierung supramolekularer Komponenten,Teil 1: Grundlagen

A new conception for modification of textile surfaces by permanent fixation of supramolecular components is explained. The principle of selective complexation is illustrated. Cyclodextrins, aza crown ethers, calixarenes, cyclotriveratrylenes and fullerenes are mainly suggested as suitable ligands for that procedure. The chemical structure and the complexation behaviour of the substances are described. Some surface properties which may be obtained with the ligands are especially emphasized.     

Modifizierung von polymeroberflächen zur erhöhung der zelladhäusion

After implantation a stable bond between the implant and the surrounding tissue is required. Therefore a high cell adhesion of the polymer surface of the implant must be achieved. Depending on the treatment time of a polydimethylsiloxane foil with oxygen plasma, the cell adhesion can be improved. FT-IR spectroscopy and ESCA analysis were used to characterize the surface modification. The cell spreading and cell adhesion increase with increasing hydrophilic character of the polymer surface after plasma treatment. A pronounced correlation was found between the efficiency of DNA and protein content, characterizing cell growth, and the spreading of the cells. Polydimethylsiloxane, Glow-Discharge, Surface Modification, Cell Adhesion, Cell Proliferation.     

Reinigbarkeit von Oberflächen in der Lebensmittelindustrie durch Flüssigkeitsstrahlen

The influence of properties of product contact surfaces on cleanability is widely discussed in the food processing and pharmaceutical industry. In the present work stainless steel surfaces of different surface roughness, surface energy and electrokinetic properties were subject to organic soiling in order to study the influence of surface properties on cleanability. As food model test soils gelatinized starch and whey protein were chosen. The cleaning was realized by means of water jets from a flat fan nozzle.     

Phasengrenzflächen in Blasenströmungen – Teil 3: Koaleszenzhemmung

The first part of this contribution [1] presents the population balances, i.e., balance equations for the numerical density of the bubbles in the individual bubble fractions. They are solved approximately by an analytical approach. There results a straightforward balance equation for the average bubble volume. This equation can be solved analytically for simple fields of flow. For complex fields of flow it has to be solved by a numerical approach. The result obtained is the bubble volume at any time and place averaged from the size distribution of the bubbles. This permits calculation of the local size distribution of the bubbles with the aid of the approximate analytical solution. In the second part of this contribution [2], this balance equation is extended to cover large gas volumes. Large bubbles and gas plugs then occur. These possess a very small interfacial area relative to their volume. They have high rise velocities and thus short residence times in the flow. They therefore participate to only a slight extent in mass and energy transfer and have to be considered, for example, in calculation of the conversion on a chemical reaction or the mode of action of an evaporator. The calculations are performed for pure liquids and compared with the authors' own and other experimental results. The liquids used industrially are generally mixtures of substances. In such liquids the coalescence behavior deviates significantly from that in pure liquids. The influence on coalescence and thus on the interfacial area is examined in the present paper.     

Schälung von Rapssaat durch definierte Verformung Teil II: Untersuchungen zum Schälverhalten

Dehulling of Rapeseed by Definite Deformation, Part II: Investigations on Dehulling Behaviour In continuation of results presented in the earlier communication on the disintegration behaviour of rapeseed, the findings on the disintegration of the seed after deformation in the rolls are reported. With the aim to determine the optimum spacing between the rolls, the extent of disintegration after a single passage at constant spacing is compared with that for passages at varying spacings. If one considers that the seed meat has to be deoiled by percolative extraction, effort should be made to obtain high proportions of coarse particles of the meat. The optimum spacing which ensures high capacity, low recycling, and no thawing of the meat particles is S = 0.6 mm.     

Schälung von Rapssaat durch definierte Verformung Teil I: Untersuchungen zur Saatanatomie

Dehulling of Rapeseed by Definite Deformation, Part I: Investigations on the Anatomy of the Seed In order to achieve an intensive utilization of high quality rapeseed in the future, an improvement in the quality of rapeseed meal is attempted via dehulling prior to oil extraction for the sake of reduction of its crude fiber content. A method is proposed, by which a well-defined deformation of rapeseed is accomplished within two stationary surfaces. The present communication records the anatomical characteristics of rapeseed. It is shown, that a reproducible disintegration of the seed can be expected if the seed is broken carefully. Various types of disintegration are explained. Using a schematic model, the dehulling of rapeseed in rolls is discussed. In a critical analysis of the problem, the aims and the conditions are summarized.     

Verfahren zur Konditionierung von Rohgasen — Teil 3: Konditionierung durch Dosierung von Feststoffen,Flüssigkeiten oder Gasen

The operating performance of plant for removal of particulates from gases can be positively influenced by crude gas conditioning and other additive measures. These processes involve introduction of additional material or additional energy into the plant. Set goals are the reduction of particle emissions, reduction of operating costs, adaptation to new boundary conditions, or the opening up of new applications for the separators concerned. In the third of three surveys, conditioning by dosage of solids, liquids, or gases is considered. Precoating, heterogeneous condensation, particle formation by gas phase reaction, and other fundamental aspects are of relevance in this context. The possibilities and effects of additive dosage in the cases of wet separators, electrostatic separators, and filtering separators are presented, discussed, and — wherever possible — assessed with regard to practical relevance.     

Kunststoffe in der Milchwirtschaft — eine kritische Studie,V. Mitteilung: Zur Reinigung und Desinfektion von Kunststoffoberflächen 2. Teil: Hygienische Beschaffenheit von Kunststoffoberflächen und ihre Folgen

Plastics in the Milk Industry — A Critical Study, V. Communication: Cleansing and Disinfection of Plastic Surfaces 2nd Part: Hygienic State of Plastic Surfaces and Their Consequences Plastic articles, meant for repeated use in direct contact with food-stuffs can permanently establish themselves, only if success is achieved in maintaining plastic appliances and parts clean and germ-free without much difficulty. Because in some respects the properties of the plastics deviate from those of hitherto employed materials of construction, the former set specific requirements on cleansing agents and cleansing processes. The cleansing solutions for the plastics must be physico-chemically more effective, in order to overcome the strong adhesion of fatty impurities. Since it is basically doubtful, whether polyolefines without adverse effects can at all be employed for repeated use in direct contact with fat-containing milk products, intensive trials should be made with plastics having lower affinity for fat.     

Mikroverfahrenstechnik: Komponenten – Anlagenkonzeption – Anwenderakzeptanz – Teil 3

Microtechnology: Components – Plant Concepts – User Acceptance Many activities over the last five or so years have focussed on the thus far underdeveloped field of carrying out reactions on small scales. Due to the rapid development of new components, this paper touches on recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous size difference between the microchannels and the fluid periphery of possible components this is not just a technical question, it touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development, are questions that are addressed here with respect to the big industrial interest in microreactors.