Aging, expertise, and narrative processing.

In a study of how aviation expertise influences age differences in narrative processing, young and older pilots and nonpilots read and recalled aviation and general narratives. They chose referents for sentences referring to a protagonist or minor character mentioned 1 sentence (recent character) or 3 sentences (distant character) before this target sentence. All groups chose referents less accurately for sentences about distant and minor characters than about recent and protagonist characters, perhaps because these referents were less likely to be in working memory. Young readers and pilots were more accurate for distant and minor character target sentences in aviation narratives and recalled aviation narratives more accurately. Expertise did not reduce age differences. Expertise differences may reflect decreased demands on working memory capacity, and age declines may reflect reduced capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polarisation transformer on Ti:LiNbO3 with reset-free optical operation for heterodyne/homodyne receivers

Experimental results for an integrated-optical state-of-polarisation (SOP) controller device on Ti:LiNbO3 for continuous broadband optical operation, with small temperature sensitivity and the possibility of integration with polarisation- insensitive directional couplers, are presented.     

Zur optimierung der Polymerfraktionierung auf der Grundlage von Lösungsgleichgewichten in Lösungsmittel-Fällungsmittel-Systemen

The phase separation behavior of dilute polydisperse polymer solutions primarily depends on the partial concentration of each polymer component. So the equilibrium data obtained by turbidimetric titration with “calibration” fractions and their mixtures can be used for the construction of a solubility diagram (Claesson-diagram) which generally allows to describe fractionation processes. It can be shown that the characteristic features of precipitation fractionations can well be derived from the solubility diagram. This diagram then offers the possibility for a complete discussion of parameter variation (concentration, step of γ-variation, process-scheme, temperature, solvent/nonsolvent-system) on the efficiency of a fractionation step. On one hand these results correspond – as for the concentration variation – to well known experimentell experiences. On the other hand it is possible for the first time to give definite predictions for the influence of temperature and the solvent/nonsolvent system. The temperature selection can be shown to be inconsiderable for the separation effect. The usual characterization of solvents and nonsolvents as “good” or “poor” is absolutely insufficient, if not misleading, for there is no connection between these properties and the shape of the solubility diagram. Based on the analysis of the single parameters the optimum conditions for the preparation of narrow preparation of narrow precipitation fractions can be derived.     

Das spezifische Brechungsinkrement eines statistischen Methylmethacrylat/Benzylacrylat/Styrol-Terpolymeren

The specific refractive index increments of a random methylmethacrylate/ benzylacrylate/styrene-terpolymer and of the three corresponding homopolymers was measured in several solvents and at six different wavelengths. With the known terpolymer composition and the specific refractive index increments of the homopolymers the specific refractive index increment of the terpolymer is calculated by means of an equation formerly derived. Calculated and experimental values are compared.     

Zur kinetik der acrylnitril-polymerisation

The heterogeneous bulk polymerization of acrylonitrile initiated by AIBN has been studied by means of an improved dilatometric technique and a new method of analysis, where the initial reaction rate (v_w)₀ results from the intercept of a straight line in a \documentclass{article}\pagestyle{empty}\begin{document}$ \frac {\ln \left( 1 \hbox{---} {\rm U} \right)} {{\rm e}^{{- 0,5} {\rm k}_{\rm s}{\rm t} \hbox{---} 1}}$\end{document} versus t plot. It has been found that the initial reaction rate is proportional to the square root of the initial catalyst concentration S₀. The ratio of the rate coefficients of propagation and termination\documentclass{article}\pagestyle{empty}\begin{document}$\frac { {\rm k}_{\rm a} } { {\rm k}_{ {\rm w}^{2} } } $\end{document} could be calculated from the slope of a straight line passing through the origin in a plot of (v_w)₀ versus \documentclass{article}\pagestyle{empty}\begin{document}$\sqrt { {\rm S}_{0} }$\end{document} and yielded a value of 280 mol 1^?1.     

Messung der Selbstdiffusion im System Polystyrol-Benzol; Temperatur-, Konzentrations- und Molekulargewichtsabhängigkeit

Self-diffusion of benzene and polystyrene in the system benzene-polystyrene is studied by means of spin-echo-technique as function of temperature, concentration and polymer molecular weight. From the dependence of temperature the activation energies are calculated as function of concentration and molecular weight. The concentration dependence is discussed in terms of restricted diffusion and the Fujita Free-Volume-Theory. The computed free volume shows a significant maximum at 50°C. This effect may be attributed to a change in the mobility of the phenyl side groups of polystyrene and is vanishing with decreasing molecular weight. The free-volume-temperature curves are giving references to the glass transition.     

Zur oligomerenbildung bei der thermischen polymerisation von styrol

It is shown that in thermal polymerization of styrene four dimers and six trimers are formed by parallel occurring oligomerization reactions. With increasing temperature the rate of oligomerization increases more rapidly than the rate of polymerization. The relativ yields of the different oligomers depend on temperature, too.     

Struktur und eigenschaften von ABS-polymeren. IX. Quantitative untersuchungen zur morphologie von ABS-polymerisaten

The technological properties of ABS polymers largely depend on the structure of the elastomer phase as well as on the elastomer/thermoplast interface. The morphological structure of such polymers can be determined from electron micrographs of ultramicrotome sections – after selective contrasting of the polybutadiene phase – or of replicas of fracture surfaces after selective chemical degradation. The various ABS polymers are classified by their manufacturing processes and their morphologies and characterized by electron micrographs. The degree and place of grafting are of particular importance. The quantitative determination of the surface- and internal grafting is achieved by combining the determination of the degree of grafting (extraction), the evaluation of the results obtained on particle counting, and a morphometric process. It is demonstrated that the morphometric process can in general be applied for the quantitative determination of the contrastable component in two-phase polymers.     

Das Verhalten organischer Pigmente in Polymeren

The importance of colouring matter is of prime importance in the plastics industry. The individual behaviour of organic pigments in the various polymer materials necessitates, however, on the part of the plastics manufacturer a precise knowledge of ?which pigment for which plastic”?. For example, a well known Thioindigo pigment behaves very differently in various polymer materials : In polystyrene, depending on the concentration used, it is monomolecularly dissolved, in associated solution or present as undissolved particles. In PVC, however, the good migration fastness is indicative of the insolubility of the pigment in this medium and so it is not surprising that PVC is the ideal plastic medium for this pigment. The behaviour of organic pigments in polymers is largely a function of molecular structure, e. g. intermolecular H-bonds can cause a decrease in solubility of a pigment in a polymer material, which in turn results in improved migration fastness. This is demonstrated by the improved migration fastness of variously substituted β-hydroxy naphthoic acid arylamide derivatives. Many phenomena exist however, which as yet can only be explained on the basis of the crystal structure of the pigment particles, i. e. the presence of aggregates or agglomerates. Such a phenomenon is, for example, the dispersibility of pigments in polymers. Here pigment surface, wettability by polymer and intermolecular forces are all of importance. In general, the dispersibility is better the smaller the specific surface area, as is shown for a typical quinacridone pigment. The influence of the rate of wetting on dispersibility is demonstrated using polyethylene wax. A further effect, which demonstrates the intermolecular forces between pigment and polymer, is the way in which certain pigments influence the rate of crystallization of partly crystalline polymers. This itself is connected with the shape and size of the pigment particles embedded in the polymer material. Such effects are demonstrated by measurements on various polyethylene objects. The pigment in this case was a naphthalene tetra carbonic acid derivative in both cis and trans form with widely varying specific surface areas.