Composites of polylactide containing graphite nanoplates as a filler in the concentration range 1–20 wt% were prepared in methylene chloride using the sonication technique. The thermal characteristics and phase transitions were studied by DSC and TGA methods. The temperatures and heats of glass transition, crystallization, and melting were determined, and the degree of crystallinity during primary and secondary heating was calculated. It is shown that the introduction of graphite nanoplates leads to an increase in the elastic modulus and a decrease in the breaking stress and elongation at break. These changes are especially pronounced at 20% GNP content in the composition, when the corresponding mechanical parameters are characteristics of brittle polymer systems. The study of the electrical properties of the composites showed that the percolation threshold in these materials is close to 7 wt%, which is significantly lower than in the case of spherical particles of comparable density. The SEM study of the filled composites showed a system of pores, which were apparently formed during the evaporation of solvent in the process of their preparation. Diverse structures of PLA/GNP composites films after hot pressure were established by the SEM method.
The object of research is the hardware-software complex of learning Braille. The research is aimed at the analysis of the use of the system of automatic change of modes of the hardware-software complex depending on the results of the user’s tasks.
As part of the development of the project for the implementation of hardware and software for the training of the visually impaired in Braille, there is a need to analyze the operation of the updated control system for the order of output of letters. The solution was a software bridge that connects devices to a remote database server via smartphones, where learning results are stored. To solve this problem, the algorithm for changing the modes of letter output was modified, the module of connection of the hardware and software complex with the phone was implemented, the file structure for information transfer to the database was developed.
After the introduction of updates in the hardware and software complexes of users, an analysis of the training was conducted. Statistics were collected according to the following parameters: selected language, type of game, correct and user answers, mode of output of letters, date-time of answer and operation of changing of the mode of output of letters. The analysis used data on the first and last states of the mode of output of letters for one day without reference to games and languages. The research was conducted over 30 calendar days for 100 users, but the data were reduced to 15 days, as some users were not study every day, and the day of study was taken.
The research showed a tendency to change learning to groups of letters of the highest complexity. Less than a third of users stayed at the first level, which provides for the next update of the software to collect data on the age of the user, because children under 5 years do not learn the letters of the third group of complexity.
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