The article discusses the process of low molecular rubber synthesis by the method of thermo-oxidative degradation as a controlled object. It was found that the control parameters affecting the degradation rate are the following: concentration of reaction initiator, temperature and mass concentration of the polymer. The main control parameters are the following: degree of degradation, quality of the resulting polymer and time of reaction. It was found that for effective control the process temperature and concentration of the initiator are to be stabilized in the vicinity of the predetermined value, and mass concentration is determined by dosage of initial components. In this case, the kinetics of the degradation process can be described as a linear function of time. I.e., the degree of degradation is linearly related to duration of reaction. Then, defining the initial quality of the polymer (its average molecular weight), the degradation process is performed till the time the predetermined value of degradation is reached.Since the initiator is consumed during the degradation, in order to stabilize its concentration, it is proposed to add the initiator into the reaction medium. We obtained a mathematical description that describes the kinetics of the process during continuous and divided feeding of the initiator, and dependency for calculating initiator feed rate. It has been shown that if the initiator is fed in a divided manner, linearity of degradation kinetics over time is ensured, which simplifies the technology of the process.Parameters of the approximating linear dependence of the kinetics of degradation have been determined. It has been shown that, even at the initial stage, the kinetics of degradation steadily tends to the linear asymptote. The asymptote's tilt angle depends on the constant of degradation rate (and consequently in the temperature of reaction) and on the initial concentration of the initiator. Degradation kinetics offset by the Y-axis depends on the initial molar concentration of the polymer. Thus, it is possible to control degradation rate by adjusting initial polymer concentration.
The article presents the results of the application of geographic information systems for environmental auditing, which allows you to monitor the ecological situation on the objects, food and chemical industries and to ensure environmental safety of natural and industrial areas. The authors propose a mathematical model that performs monitoring of environmental objects. The computational experiment is performed in Matlab for classifying the soil measurement conditions. The results of the analysis and the electronic cartograms constructed on their basis are used to predict the location of the points exceeding the parasitological indices in the soil. The assessment of the condition of the soil in different districts of the Voronezh city is made with the help of the created neural networks. The results are compared with the same indicators, measured in 2017. Data is taken from the information Bulletin «Evaluation of the influence of environmental factors on the health of the population of the Voronezh region on indicators of socio-hygienic monitoring». Information was prepared by the Office of Rospotrebnadzor in the Voronezh region. A study cited in the article was conducted at the Department of information and control systems of the Voronezh state University of engineering technologies. Geographic information system was built with the help of MapInfo software product. It can be used to simulate the environmental situation and to inform about its current state with the help of cartography. Thus, the geoinformation research method reviewed in this article allows predicting the emission of harmful substances into the environment and it can be used by regulatory agencies of the state authorities to control the environmental state of the territory.
Реферат. В работе рассматривается задача математического моделирования процесса термохимической деструкции. Для синтеза математической модели используется аппарат цепей Маркова. Предлагается рассматривать процесс деструкции как случайный процесс, при котором изменяется состояние системы, характеризующееся долей макромолекул в каждой фракции молекулярно-массового распределения. Интенсивности переходов из состояния в состояние характеризуют соответствующие скорости процессов деструкции для каждой фракции молекулярно-массового распределения. Процессами сшивки и полимеризации в данной работе пренебрегли, и принято, что существует вероятность перехода из любого состояния с низшим порядковым индексом (соответствующим фракции с более высокими молекулярными весами) в любое состояние с более высоким индексом (соответствующим фракциям с более низкими молекулярными весами). В качестве основы математической модели принята цепь Маркова с дискретными состояниями и непрерывным временем. В качестве среды моделирования использована интерактивная графическая среда имитационного моделирования MathWorksSimulink. Для оценки параметров математической модели были проведены экспериментальные исследования процесса деструкции полибутадиена в растворе. В качестве исходных данных для оценки ММР полимера использовались данные ГПХ раствора полибутадиена. Для численного поиска значений параметров минимизировалось среднеквадратичное отклонение расчетных данных от экспериментальных по каждой фракции и в заданные моменты времени. Результаты сравнения экспериментальных и рассчитанных по математической модели показали погрешность расчётов в среднем около 5%, что говорит о приемлемой ошибке оценки изменения долей фракций полимера в ходе процесса деструкции для рассматриваемого процесса и условий. Ключевые слова: термохимическая деструкция, цепь Маркова, математическое моделирование
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