No abstract

The catalytic efficiency of modified nanodiamonds (MND) in reactions of interaction between organic compounds was demonstrated on the example of azocoupling reaction (hydrogen peroxide-4-aminoantipyrine-phenol). It was found that catalytic action of MND was caused by redox active metal ions of Fe and Cu located on the MND surface. The neutralization of the ions significantly decreased catalytic properties of MND.

The present study is devoted to developing a digital twin for a composite overwrapped pressure vessel (COPV) used in electric propulsion engines of spacecraft. The digital twin is used to predict the future behavior and performance of a real physical object based on the currently available information without carrying out expensive and time-consuming full-scale prototyping and testing. Multiscale approach is employed to link the macroscopic stiffness degradation and failure with a progressive damage evolution at the microlevel of composite. The computational models for the stress state and failure analysis at different scale levels are presented. Based on a comparative analysis of the traditional approach for assessing the load-bearing capacity of the COPV and its digital analogue, the advantages of the latter are shown as the predicted burst pressure is in good agreement with the experimental results.

The luminescent response of the enzymatic system of Armillaria borealis on the cold and hot extracts from cell-free culture liquids of Inonotus obliquus, Pholiota sp. and A. borealis was examined. The greatest influence on the light emission produced by the luminescent system of A. borealis was provided by the temperature at which the probes were prepared for assay. Boiling a culture liquid on water bath for a few minutes promoted a multifold increase in the luminescence. The results of luminescence assay suggest that the substance involved in the bioluminescent reaction in higher fungi is presented in culture liquids and mycelia in two forms. In one form, it is ready to interact with the enzymatic system and in the second form, it becomes accessible for the reaction after heat treatment. The pool of thermoactivated substance was found to be much large than the amount of the ready accessible one. We suggest that predecessors of hispidin, which is fungal luciferin precursor, are responsible for this phenomenon. They are not involved in bioluminescence at their original state and are converted into the substrate under the influence of high temperature.ARTICLE HISTORY