Effect of ferrocene on the structures and properties of epoxy-polyurethane composites

Effects of various ferrocene concentrations on the tensile strengths, elongations at break, and glass-transition temperatures of ferrocene-containing epoxy-polyurethane composite materials are studied. As shown by IR spectroscopy and X-ray diffraction analysis, ferrocene affects the structuring of epoxy-polyurethane composites via redistribution of intermolecular hydrogen bonds between amide, hydroxyl, and urethane groups of the polymer basis and formation of metal-polymer complexes between ferrocene and polar groups of the polymer carrier.     

Catalytic hydrogenation of pyridinium salts

Catalytic hydrogenation of polysubstituted pyridinium salts leads to piperidines and their condensed analogs The spatial properties and conformational properties of the saturated azaheterocycles have been determined by¹³C NMR spectorscopy. It was shown that hydrogenation of the pyridinium salts occurs stereoselectively to form cis isomers in most cases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 68–72, January, 1994.     

The effect of photoactivated transformations of Ag+ and Ag0 in silica fillers on their biocidal activity

Research on Chemical Intermediates - Ag and AgCu containing powdered silica fillers of polymers for medical applications have been synthesized using mechanochemical activation with a low content of...     

Population dynamics on random networks: simulations and analytical models

We study the phase diagram of the standard pair approximation equations for two different models in population dynamics, the susceptible-infective-recovered-susceptible model of infection spread and a predator-prey interaction model, on a network of homogeneous degree k. These models have similar phase diagrams and represent two classes of systems for which noisy oscillations, still largely unexplained, are observed in nature. We show that for a certain range of the parameter k both models exhibit an oscillatory phase in a region of parameter space that corresponds to weak driving. This oscillatory phase, however, disappears when k is large. For k = 3, 4, we compare the phase diagram of the standard pair approximation equations of both models with the results of simulations on regular random graphs of the same degree. We show that for parameter values in the oscillatory phase, and even for large system sizes, the simulations either die out or exhibit damped oscillations, depending on the initial conditions. We discuss this failure of the standard pair approximation model to capture even the qualitative behavior of the simulations on large regular random graphs and the relevance of the oscillatory phase in the pair approximation diagrams to explain the cycling behavior found in real populations.