No abstract

The influence of catalytic amounts of germanium tetrachloride on the copolymerization of vinyl acetate with acrylic acid and methacrylic acid in methanol is examined. It is shown that germanium tetra chloride exerts different effects on the formation rate, molecular mass characteristics, and composition of copolymers formed in these systems. For example, at a germanium tetrachloride to acrylic acid ratio of 0.02 (mol/mol), an alternating copolymer is formed, whereas in the case of methacrylic acid, a copolymer considerably enriched with methacrylic acid units is produced at the same ratio. The results are explained by different copolymerization mechanisms for both systems.

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The research performed is dedicated to the problem of energy efficiency analysis of modern delivery drones. 12 models are chosen to provide a statistical calculations of the average ratio of mass and flight range of the drone. The method of least squares is used to analyze trends. The conclusion is made that the most successful companies apply the similar ratio of mass and flight range. The most successful drones of such companies are able to carry from 1.3 to 2.27 kg of cargo and have a flight range from 10 to 24 km. That allows to judge about the energy efficiency of these devices.