Extraction of glucomannan from crude porang flour by acid hydrolysis and ethanol precipitation was studied. Effects of acid concentration, temperatures and time were investigated, kinetics model of the process was developed and the parameters were evaluated based on experimental data. New data on yield and purity of glucomannan under various conditions were obtained.
Being an objective element of the global economic system, international migration produces a significant impact on the performance of individual countries nowadays. The economic impact of international migration is driven by various factors, primarily the type of international migration (labour migration, refugee migration, family migration, or student migration) and the legislation of a receiving country which determines the ability of international migrants to interact with the host country’s economy and to produce the respective impact.
A comparative analysis of existing approaches to Cyber-Physical Systems simulation has been conducted. The intrinsic peculiarities of Cyber-Physical Systems have been reasoned and generalized. Thelimitations of available simulation tools have been pointed out. The approach to Cyber-Physical Systems design solutions checking on the basis of timed automata, UPPAAL integrated tool environment and Temporal Logic of Actions usage has been proposed.
Розглянуто найпотужніші та найпоширеніші засоби моделювання та прогнозування поширення вірусних захворювань, проаналізовано можливість їх застосування в умовах України та визначено напрям досліджень у галузі прогнозування та аналізу розвитку епідемій.
The main malfunctions that arise when operating a vehicle in Ukraine are the failure of the suspension elements and vehicle tires due to the poor condition of the most roads [11]. The car suspension elements soften the dynamic loads and smooth out the oscillations from the unevenness on the road while riding and provide a good stability and smoothness of the car ride.
Nowadays, the main method of machining the gears with a module in the range 1–25 mm, which are integral parts of modern machines, remains hobbing. Operations of the toothed crown processing determine the efficiency of the entire technological process of manufacturing gears. Thus, the time expenses and performance, the cost of the gears, and their final quality depend to a large extent on these indicators in operations of hobbing.
Outsourcing provides IT companies with a number of benefits and improves the financial and economic performance of their operations. The outsourcing market in Ukraine is developing fast, many types of outsourcing are used in various types of economic activity. Implementation of outsourcing as one of the most popular business models necessitates constant and well-coordinated cooperation with other business entities.
The article is devoted to computer modeling of the process of cavitation in liquid
mediums. The experimental researches of the regularities of the cavitation process was
conducted, dependences of changes in the parameters of the process efficiency on the
concentration of the solution and the frequency of vibration are shown. A solid– state model of
a laboratory vibration resonance electromagnetic cavitator in SolidWorks 2016 Educational
Edition software system was created. Based on the modeling of the cavitation process, the main
A model of hydro-erosion wear of sealing elements was constructed taking into account a set of parameters that reflect the physical properties of the fluid and the material of the sealing elements, as well as the design parameters of the valves. To determine the dependence of the rate of erosion wear on a complex of parameters, we use the π-theorem of similarity and the method of dimension analysis. An expression is given that determines the change in the thickness of the erosive fracture of the sealing surfaces in time.
The practice of operating multiple single-tuned filters in industrial power supply systems has shown that technological transformer capacitors in switching filters within the systems can cause the damage of filters. The most disturbing loads on the power supply systems are powerful AC arc furnaces. Static Var compensators used in the power supply systems contain multiple harmonic filters for harmonic mitigation and reactive power compensation.