of magnetite, calcite dissociation and iron reduction. Additionally, the mutual influence
of technological parameters on certain stages of pellet production has been revealed.
The results of the study allow determining the influence of the principle parameters on
the pellets strength and the specific productivity as well as revealing the optimum
parameters of the pellets firing for the sake of ensuring the efficient operation of the
firing machine.
The thirty-fourth section “HIGH-FREQUENCY GENERATOR FREQUENCY
MEASURER ON YIG-RESONATOR”. In this article the meter of the frequency of a
high-frequency generator based on YIG-resonator is proposed: the principle of its
operation is analyzed, mathematical models analyzed, computer simulation is
performed, an example of application is given. The meter works with the generator in
the frequency fluctuation mode under any law of its change, as well as in the mode of
generation at a fixed frequency.
The thirty-fifth section “GAS CONCENTRATION TRANSDUCERS WITH
FREQUENCY OUTPUT SIGNAL BASED ON REACTIVE PROPERTIES OF
SEMICONDUCTOR
STRUCTURES
WITH
NEGATIVE
DIFFERENTIAL
RESISTANCE”. The paper presents the results of studies on the creation of frequency
microelectronic transducers of gas concentration based on autogenerator transistor
devices. In the proposed devices, the gas concentration is converted into a frequency
output signal. Such a conversion allows to remote all disadvantages of analog gas
sensors: low output voltage, low sensitivity, parasitic influence of measuring channels
on each other, instability in operation, need for amplifying devices and analog-digital
transducers by subsequent processing of measurable information. The paper considers
the mechanism of formation of the impedance of semiconductor gas sensors, in which
the active component is determined by the surface resistance, and the reactive
component is determined by the surface capacitance. The dependence of the magnitude
of the impedance on changes in the concentration of active gases characterizes the
essence of the gas-reactive effect of the sensors, which unambiguously changes the
output frequency of autogenerating gas transducers.
The thirty-sixth section “E-LEARNING SYSTEM BASED ON SOCIAL
NETWORK FRAMEWORK. USING NLP IN EVALUATING OPEN QUESTIONS”.
Current article describes possibilities of an internal e-learning system that allows
students to be aware of any urgent updates, useful information, and changes to schedule
regarding learning activity in university. Current e-learning situation in Kiev National
University of Ukraine compared to world tendencies is briefly mentioned in this article.
Possibility of social network for distant or partly distant students learning service
implementation as a social network with strict registration is reviewed. Motivational
mechanisms in a gamification framework, feedback advantages for teachers in a non-
anonymous way, examples of mobile devices usage in educational process for
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