Zum enzymatischen Nachweis von Organophosphorinsecticiden

Zusammenfassung Zum Nachweis von Organophosphorinsecticiden auf Pflanzenmaterial werden zwei enzymatische Schnellmethoden beschrieben (pH-Test und colorimetrische Methode). Beide beruhen auf der Cholinesterasehemmung durch Organophosphorinsecticide. Bei dem pH-Test konnte keine Beeinflussung durch pflanzeneigene Inhaltsstoffe festgestellt werden, dagegen war die Störanfälligkeit bei der colorimetrischen Methode, besonders bei Kohlarten sehr stark, was auf Senföle zurückzuführen ist. Mit beiden Methoden werden die in der Höchstmengen-VO aufgeführten Organophosphor- und Carbamatinsecticide auch unter den niedrigsten zugelassenen Höchstmengen von 0,1 mg/kg Pflanzenmaterial erfaßt.

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On the enzymatic determination of organophosphoric insecticides

Summary Two rapid enzymatic methods are described (pH-test and a colorimetric method) for the determination of organophosphoric insecticides in plant materials. Both methods are based on the inhibition of choline-esterase by organophosphoric insecticides. Using the pH test, no influence of the plant ingredients was found, however using the colorimetric method, the tendency for disturbances, especially with cabbage varieties, was very strong because of mustard oil. By the application of the two methods it is possible to detect organophosphoric and carbamate insecticides in amounts of less 0.1 mg/kg plant material.

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Auszug aus der Dissertation von Miklós Nagy: Zum enzymatischen Nachweis von Organophosphorinsecticiden. Technische Universität München 1970.     

The reinitiation mechanism of HCl catalysis in PVC degradation

Summary The effect of HCl on the thermal degradation of PVC has been studied. Changes in UV and visible spectra and kinetics of HCl loss indicate that HCl is able to reinitiate the allyl-activated zip elimination by proton exchange with polyenes. Also polyene-consuming secondary reactions are accelerated by HCl.     

Image database

The notion of the image database is still unstructured. We examine recent work under this heading as well as related work in computer vision and conventional database technology. It appears that the principal difficulties in fusing the two disciplines are: the arbitrary nature of discrete representations of continuous scenes; and the lack of linear ordering in two dimensions. A possible solution to these problems is suggested.     

Flicker photometric sensitivity and chromatic adaptation in color-deficient and normal observers

Congenital red-green color deficients and observers with normal color vision were asked to make flicker photometric matches on a red background, on a green background, and with no background present. Adaptation had no effect on the matches made by color deficients, but clearly affected the matches of normal observers. There were small differences between the matches of different observers. We attempted to characterize these differences by fitting the R and G curves of Smith and Pokorny to the data. Two parameters, Λ_max and optical density, were varied to obtain the best fit. Extremely good fits were obtained, suggesting that individual differences can be characterized with these two parameters.     

Terrain visibility

Visibility indices, matrices, graphs, and maps are defined for digital elevation terrain models and their properties are established. Several potential applications of geometric terrain visibility in geographic information systems are presented. Direct applications include the location of observation points and hiding places, the determination of line-of-sight relay networks for microwave communications, scenic and hidden surface paths, and aids to navigation. Indirect applications allow inferences about physiographic terrain features: the mutual visibility among surface points yields considerable information about the landscape. The preservation of the visibility model also provides a check on data reduction (compression) in digital elevation models. Algorithms for computing terrain visibility on both triangulated irregular networks and rectangular grids are reviewed and experimental results from several sources are reported. It is shown that terrain visibility is invariant under certain projective transformations, and therefore relative elevations can be reconstructed from visibility maps.