Adsorption of doxorubicin on the surface of magnetically sensitive nanocomposite Fe3O4/Al2O3/С

Fe3O4/Al2O3/С nanocomposite was synthesized and characterized by a complex of physicochemical methods. The completeness of carbonization was confirmed by the method of TPD MS, and the results of TEM, EDX and changes in the values of the specific saturation magnetization proved the formation of the structure of Fe3O4/Al2O3/С by the type of core-shell. According to the results of potentiometric studies, the characteristics of acid -basic centers were quantitatively and qualitatively assessed. The adsorption of Doxorubicin (DOX) on the surface of Fe3O4/Al2O3/С was performed and the adsorption process depending on the contact time, pH of the solution and DOX concentration was studied. The experimental results of kinetic studies were analyzed for compliance with of Boyd, Morris-Weber and Elovich the theoretical models, models of pseudo-first and pseudo-second orders. Langmuir and Freundlich isotherm models were used to model adsorption processes. Under the conditions of the experiment (pH = 5) active basic centers (С = 8.46⋅10−5 mol⋅g−1, Кі = 1.296⋅10−5 (рК = 4.887)). Adsorption processes occur by a mixed diffusion mechanism, limiting processes are intraparticle diffusion and chemisorption processes of molecular and ionic forms of DOX. The highest correlation coefficient was r2 = 0.971, the correlation of theoretical and practical values of the adsorption capacity (A mg g−1) indicates the possibility of using the Freundlich model to describe the adsorption of DOX on the surface of Fe3O4/Al2O3/C. Desorption processes practically do not occur at pH 7.4 (change of value A from 30.56 to 30.12 mg g−1, which is − 1.83%), at pH 5 percent of desorbed DOX is higher − 2.88% (change in value A from 30.21 to 29.51 mg g−1)

ЭЛЕКТРОННОЕ УПРАВЛЕНИЕ ТОПЛИВОПОДАЧЕЙ ДИЗЕЛЬНОГО ДВИГАТЕЛЯ НА ОСНОВЕ ПРОГРАММНОГО ПИД-РЕГУЛИРОВАНИЯ

The article presents a schematic diagram of the Euro-3 diesel engine electronic control and describes hard- and software platform of the high pressure fuel pump pneumatic actuator control that allows to realize the concept of electronic fuel supply control of diesel engine KamAZ-740. The strategic dependence beetwen the angular position of fuel pump governor lever and the angular position of electronic accelerator pedal were put on the basis of electronic control concept. Implementation of this dependence was carried out by applying a modulated PWM signal with determined duty cycle by the controller to the coil proportional solenoid valve, which is responsible for the amount of air pressure in the working chamber of the power air cylinder, connected by articulated-type to the governor lever of the high pressure fuel pump. In this case, the feedback control by position of governor lever of the high pressure fuel pump was introduced in the control circuit, but engine crankshaft speed control was carried out using a software continuous PID governor. Developed strategy gives possibility to track the deflection  of control parameter from a predetermined value by real-time and almost instantly, to make a control action on actuators to eliminate this deflection, while providing a minimum time of transition. Governor’s setting (proportional, integral and differential component) performed empirically using the classical Ziegler – Nichols method, based on the analysis of the safety factor of automatic control system. The results of calculating the coefficients of proportional integral-differential regulator and oscillograms HIL experiment on testing the proposed diesel engine throttle control strategies using visualization CoDeSys V2.3 are given in activity.Представлена принципиальная схема электронного управления дизельным двигателем внутреннего сгорания стандарта Euro-3, описана программно-аппаратная платформа пневматического привода регулятора топливного насоса высокого давления, позволяющая реализовать электронное управление топливоподачей дизельного двигателя КамАЗ-740. В основу концепции электронного управления положена стратегическая зависимость углового положения рычага регулятора топливного насоса высокого давления от углового перемещения электронной педали акселератора. Реализацию указанной зависимости осуществляли путем подачи модулированного широтно-импульсного сигнала определенной скважности от контроллера на обмотку пропорционального электромагнитного клапана, отвечающего за величину давления сжатого воздуха в рабочей полости силового пневмоцилиндра, шарнирно соединенного с рычагом регулятора топливного насоса высокого давления. При этом в цепь управления вводили обратную связь по положению рычага регулятора топливного насоса высокого давления, а управление оборотами коленчатого вала двигателя осуществляли с использованием программного ПИД-регулятора непрерывного действия. Разработанная стратегия дает возможность в режиме реального времени отследить отклонение регулируемого параметра от заданной величины и практически мгновенно выработать управляющее воздействие на исполнительные механизмы для устранения этого отклонения, обеспечивая минимальное время переходного процесса. Настройку параметров регулятора (пропорциональной, интегральной и дифференциальной составляющих) производили эмпирическим путем с использованием классического метода Циглера – Никольса, основанного на анализе запаса устойчивости системы автоматического регулирования. Приведены результаты расчета коэффициентов пропорционального интегрально-дифференциального регулятора, а также осциллограммы полунатурного эксперимента по апробации предложенной стратегии управления топливоподачей дизельного двигателя с использованием средств визуализации CoDeSys V2.3

ELECTRONIC CONTROL FOR FUEL SUPPLY OF DIESEL ENGINE ON THE BASIS OF PROGRAMMABLE PID-REGULATOR

The article presents a schematic diagram of the Euro-3 diesel engine electronic control and describes hard- and software platform of the high pressure fuel pump pneumatic actuator control that allows to realize the concept of electronic fuel supply control of diesel engine KamAZ-740. The strategic dependence beetwen the angular position of fuel pump governor lever and the angular position of electronic accelerator pedal were put on the basis of electronic control concept. Implementation of this dependence was carried out by applying a modulated PWM signal with determined duty cycle by the controller to the coil proportional solenoid valve, which is responsible for the amount of air pressure in the working chamber of the power air cylinder, connected by articulated-type to the governor lever of the high pressure fuel pump. In this case, the feedback control by position of governor lever of the high pressure fuel pump was introduced in the control circuit, but engine crankshaft speed control was carried out using a software continuous PID governor. Developed strategy gives possibility to track the deflection  of control parameter from a predetermined value by real-time and almost instantly, to make a control action on actuators to eliminate this deflection, while providing a minimum time of transition. Governor’s setting (proportional, integral and differential component) performed empirically using the classical Ziegler – Nichols method, based on the analysis of the safety factor of automatic control system. The results of calculating the coefficients of proportional integral-differential regulator and oscillograms HIL experiment on testing the proposed diesel engine throttle control strategies using visualization CoDeSys V2.3 are given in activity