The article is devoted to the problem in diagnostic for axes of wheel sets of rolling stock at the railroad lines. It shows that the time counter method of magnetic powder control has low productivity and is characterized by high subjectivity and the impossibility of automating the control process. To eliminate these defects and improve the reliability for detection of defects on the surface of the stepped axis a method based on the using of fluxgate transducer is proposed. It was carried out the analysis of magnetic fields near the surface of the axles of wheel sets using the developed mathematical models, which made it possible to calculate both the defect fields and the stray field of the stepped surface of axis. Spatial and frequency selection of useful signals based on the analysis of information parameters of magnetic fields of stray of surface and subsurface defects and fields induced by the stepped surface of the magnetized axis is proved.
Purpose. This work involves the development of a numerical model for the calculation of areas of thermal damage to people in the event of solid propellant burning at the industrial site. Methodology. An equation expressing the law of energy conservation was used to solve the problem of determining the areas of thermal shock of people at the industrial site. A potential flow model was used to calculate the airflow velocity field in the presence of buildings at the industrial site where an emergency occurs. The numerical solution of the two-dimensional equation for the velocity potential is derived using the Liebmann method. This numerical model takes into account the uneven velocity field of the wind flow that is formed near industrial buildings. An implicit difference splitting scheme was used to numerically solve the energy equation. The physical splitting of a two-dimensional energy equation into a system of one-dimensional equations describing the temperature transfer in one coordinate direction has been carried out previously. At each splitting step, the unknown temperature value is determined by an explicit point-topoint computation scheme. Based on the numerical model built, the code using the FORTRAN algorithm language is created. Findings. Based on the developed numerical model, a computational experiment was conducted to evaluate the risk of thermal damage to people at the industrial site where solid propellants are produced. The dangerous areas for personnel are identified. Originality. An efficient numerical model has been developed to calculate the zones of thermal pollution in case of solid propellant burning. Practical value. Based on the developed mathematical model, a computer program was created, which allows performing serial calculations for determining the zones of thermal damage during emergencies at the chemically hazardous objects. The mathematical model developed can be used to design an emergency response plan for chemically hazardous objects.
The article presents the results of the phenomenological analysis of the flow of aggregate processes under conditions of anaerobic fermentation, examines the differences that accompany them in the brewing and alcohol industries. The estimation of energy potentials is carried out, recommendations of their use are offered. Firstly,it is formulated the position on the formation of the gas-liquid medium formed as a result of synthesis of CO 2 and the formation of a dispersed gas phase. It is indicated on the existence of the high-altitude gradient for saturation of the liquid phase on СО 2 because of the expense of hydrostatic pressure. The estimated data are also provided.
The article presents the results of investigations of the influence of the relations of geometric parameters of the liquid and gas phases on the dynamics of parameters of anaerobic fermentation. It allows to assess the prospects of using internal energy resources, improving and creating new technologies.Phenomenological generalizations of theoretical positions that are in accordance with the laws of Archimedes, Henry, Pascal and the principle of superposition were used in the study for determining the motive factors and factors of resistance in the processes of saturation and desaturation of culture media. On the basis of the material balance, the possibility of evaluating the relations of the two material flows of CO 2 synthesized in the process of anaerobic fermentation is shown. The first one relates to the dissolved carbon dioxide in the liquid phase, and the second one is formed in a sealed, ingenious volume. The relationship between the pressure of the gas phase in the ingenious volume and the amount of dissolved CO 2 corresponds to Henry's law, as well as the solubility associated with hydrostatic pressure.The mathematical formalisations in the reflection of the pressures and influences on them of the relations of geometric parameters, the results of calculations and their graphical interpretations, from which there is a noticeable and important possibility of redistribution between the specified flows of CO 2 are shown. The latter is the basis for creating the energy potential of dissolved CO 2 in the liquid phase and simultaneously limiting the energy potential in the gas phase of the ingenious volume. The proposed mathematical models, related to the dynamics of reducing the concentrations of dissolved sugars relate to self-priming fermentation processes and allow us to move to estimating the energy potentials of circulatory circuits. It is shown that the energy potential of the latter in the form of CO 2 pressures is proposed to be used in desaturation modes with the subsequent transfer of the liquid phase to the unsaturated state due to the forced increase of pressure in the gas phase to activate fermentation processes with a decrease in the mass transfer resistance at the interface between the surfaces of the yeast cells and the liquid phase.
Мета дослідження – здійснити порівняльний аналіз особливостей планування фізичного навантаження фізичної підготовки та визначити рівень фізичної підготовленості дівчат 10–12 років, які займаються боксом, на етапі початкової підготовки першого та другого року тренувань. Були використані такі методи дослідження: аналіз та узагальнення літературних джерел та програмно-нормативних документів, педагогічний експеримент, педагогічні спостереження, контрольне тестування, методи математичної статистики. Організація дослідження. Дослідження здійснювалося на базі комунального позашкільного закладу «Дитячо-юнацька спортивна школа № 12» Дніпровської міської ради. У досліджені брали участь 43 спортсменки віком 10–12 років, які займались боксом. Оцінка рівня фізичної підготовленості здійснювалася за контрольними тестами, які прописані в програмі ДЮСШ. Результати дослідження. На етапі початкової підготовки в процесі підготовки дівчат, які займаються боксом, пріоритетною стороною є загальна та фізична підготовка спортсменок (перший рік тренувань складає 188 годин, другий – 261 годин). Визначення рівня фізичної підготовленості на початку та наприкінці першого та другого року тренувань дозволило встановити достовірний приріст розвитку фізичних якостей при р ˃ 0,05-0,001. Однак необхідно звернути увагу на підбір засобів та методів, спрямованих на розвиток швидкісних здібностей у дівчат 10–11 років та витривалості у дівчат 11–12 років, виходячи за рамки рекомендацій, наведених у програмі ДЮСШ. Висновки. Результати дослідження свідчать про ефективність засобів на методів фізичної підготовки, наведених у програмі ДЮСШ. Рекомендується розглянути питання включення до програми тестів з оцінки функціональних можливостей організму дівчат 10–12 років. Це пов’язано з тим, що, по перше, дівчата даного віку перебувають у препубертатному періоді статевого дозрівання, по друге, отримані дані дозволять дати більш повну інформацію про адекватність планування інтенсивності фізичних навантажень.
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