Search

The article solves the problem of thermal injury of seeds of grain crops during drying, which are capillaryporous bodies. It is hypothesized that the use of a vacuum in the drying chamber reduces the risk of thermal stress. In this regard, the article studies the effect of a vacuum inside the drying chamber on the diffusion of moisture inside the seeds. Seeds are complex materials in which moisture has different bonds with dry matter. During the working process, the drying speed in the surface layers and inside the seeds occurs at different speeds. As a result, drying stresses occur, which cause cracks on the surface of the seeds. Based on the solution to the differential diffusion equation with an absorbing screen as a boundary condition, the condition for drying without thermal stresses is found. Experimental verification of theoretical studies is carried out on a specially made experimental setup on the example of corn seeds. The effect of thermal stress on seed viability is determined by laboratory germination. Experimental studies confirm the adequacy of theoretical statements. Thus, when drying the seeds of grain crops, which are capillary-porous bodies, there is a limit value of rarefaction, above which cracks appear on the surface of the seeds due to different drying rates on the surface and inside. For drying seeds of grain crops without thermal stresses, it is necessary to consider not only the heating temperature but also the rarefaction in the drying chamber, which should be close to the limit value.

A mathematical description of the movement of caryopses in the composition of the components of grain material (CGM) on the surface of a stepped vibrating feeder is given when CGM is introduced into the aspiration channel of the separator under the action of vibrations on the CGM. The trajectories of movement of grains on the surface of the vibrating feeder with different sizes were obtained. The obtained equation of the movement of seeds under the action of vibrations makes it possible to determine the dependence of the speed of movement of the material in the CGM layer on a number of factors: the geometric parameters of the vibrating feeder, the angle of material feeding, the initial kinematic mode of the grain material, the indicator of the kinematic mode of the vibrating feeder, and the friction coefficient of the CGM. The process of movement of grain material on the stepped surface of the vibrating feeder has been substantiated, which makes it possible to determine the rational parameters of introducing the CGM into the aspiration channel of the separator and uniform distribution in the channel with the subsequent possibility of its fractionation. The dependence of the function of the flow rate of grain material on the stepped surface of the vibrating feeder is obtained, which makes it possible to determine the parameters of the distribution of grain material over the sectional area of the aspiration channel of the separator. The estimation of the absolute speed of grain material movement on the stepped surface of the vibrating feeder is made on the basis of a mathematical model constructed by hydrodynamic analogy, which in turn predetermines the analysis of the recombination of caryopses along the thickness of the vibrated layer of grain material. According to the established mathematical models, graphical dependences of the absolute speed of movement on time, the trajectories of the array of particles, the calculated trajectories of particles of grain material, which are fed into the pneumatic channel under initial conditions, were built.

The article examines the study of the separation of grain materials in pneumatic channels with an artificially generated distribution of air velocity in the cross-section channel to determine the rational form and parameters of the material supply and options for grain material separation into fractions. The regularities of the weevil movement were theoretically investigated and established in the form of mathematical models of the dynamics of the movement of a solid particle in airflow, which differ from the known ones by taking into account the action of lateral forces, the concentration of the material, and the use of a power-law and an artificially formed exponential law of air distribution facilitated to increase the differences (splitting) trajectories of caryopses by 20 %. The solution of the system of nonlinear differential equations with initial conditions is performed in the Mathcad software environment in the form of trajectories of the grain in the air flow. It allows calculating their trajectories, which differ in windage coefficients and determine the rational values of the parameters of pneumo-gravity and pneumo-inertia separators. Using the obtained dependencies for the development of air separators contributes to determine the initial speed of entry and the direction of entry of the kernels into the airflow, as well as to determine the trajectories of material movement in the air channels with the bottom unloading of material.

In this paper, we present a hybrid refractive-diffractive lens that, when paired with a deep neural network-based image reconstruction, produces high-quality, real-world images with minimal artifacts, reaching a PSNR of 28 dB on the test set. Our diffractive element compensates for the off-axis aberrations of a single refractive element and has reduced chromatic aberrations across the visible light spectrum. We also describe our training set augmentation and novel quality criteria called “false edge level” (FEL), which validates that the neural network produces visually appealing images without artifacts under a wide range of ISO and exposure settings. Our quality criteria (FEL) enabled us to include real scene images without a corresponding ground truth in the training process.

Develop a mathematical model and calculated analytical dependences to determine the trajectories and parameters of grain movement on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator. They are based on the methods of mathematical modeling and theoretical mechanics with the application of the equations of motion of a material point under the variable action of vibrations. Theoretical research was conducted using mathematical analysis and modeling theory. The research results are processed using elements of probability theory and mathematical statistics using application packages. A mathematical description of the movement of grains of grain material components (GMC) on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator under the conditions of vibration on the GMC. The trajectories of grains on the surface of the vibrating feeder with different size are obtained. The obtained equation of motion of the particle under the action of vibrations allows to determine the dependence of the velocity of the material in the vibrated fluidized bed on a number of factors: geometrical parameters of the vibrating feeder, feed angle, initial kinematic mode of grain material, kinematic mode of the vibrating feeder and friction coefficient. The process of grain material movement on the flat surface of the vibrating feeder is described, which allows to determine the rational parameters of material introduction into the aspiration channel of the separator for its further fractionation. The dependence for the function of the grain flow rate on the flat surface of the vibrating feeder is obtained, which allows to determine the parameters of the grain material distribution by the cross-sectional area of the aspiration channel of the separator. The velocity of grain material on the flat surface of the vibrating feeder is estimated on the basis of a mathematical model constructed by hydrodynamic analogy, which in turn determines the analysis of grain recombination by the thickness of the vibrated liquid layer of grain material.

Annotation Purpose. Refinement of the mathematical description for calculating the movement of particles of sunflower material in the working gap of the threshing-separating device of the plot combine. Methods. Theoretical studies were carried out on the basis of the analysis of the dynamics of the movement of particles of sunflower material relative to the surface of a closed-type drum of a selection combine. Results. A mathematical description of the movement of particles of sunflower material in the working gap of the threshing-separating device of a selection combine with a closed drum is given. The dependence of the speed of movement of material particles on the initial speed of material feeding has been established. The dependence of the particle velocity on the radius of the closed-type drum of the selection combine has been established. The dependence of the speed of movement of the mass of sunflower material under the action of a closed-type drum of a selection combine on the coefficient of friction of the material is obtained. Conclusions. The obtained theoretical dependences of the speed of movement of the mass of sunflower material in the working gap of the threshing device of the selection harvester make it possible to substantiate the rational design and technological parameters of the closed-type threshing drum. Keywords: closed drum, speed, movement, coefficient of friction, plot combine, sunflower.

The purpose of research to formulate a mathematical description of the movement of components of grain material in pneumatic channels with artificially formed distribution of air velocity in the cross section of the channel to improve the quality of separation (trajectory divergence) of grain material components. The article considers studies of grain separation in pneumatic channels with artificially formed air velocity distribution in the cross section of the channel, to determine the rational form and parameters of material supply and options for separation of grain material into fractions. The regularities of grain motion in the form of mathematical models of the dynamics of solid particle motion in air flow are theoretically investigated and established, which differ from those known in that they take into account the action of lateral forces, material concentration, and the application of power law and artificially formed exponential air distribution law) trajectories. The solution of the system of nonlinear differential equations with initial conditions is made in the MathCad software environment in the form of grain motion trajectories in air flow, allows to calculate their motion trajectories that differ in sailing coefficients and determine rational values of pneumogravity and pneumoinertia parameters. Using the obtained dependences for the development of air separators, it is possible to determine the initial velocity of entry and direction of entry of grains into the air stream, as well as to determine the trajectories of the material in the air ducts with lower material unloading. Conclusions: 1. Theories of grain motion are theoretically investigated and established in the form of mathematical models of solid grain motion dynamics in air flow, which differ from those known in that they take into account the action of lateral forces, material concentration, and the application of power and artificial exponential law (splitting) of grain movement trajectories by 20%. 2. The solution of the system of nonlinear differential equations with initial conditions is made in the MathCad software environment in the form of grain motion trajectories in the air stream, which allows to calculate their motion trajectories differing in sailing coefficients and determine rational values of pneumogravity and pneumoinertial separators.

Development of a mathematical model and calculated analytical dependencies for determining the trajectories and parameters of grain movement in a vibro-fluidized layer of grain material components under the action of a pulsating air flow. They are based on the methods of deterministic mathematical modeling and theoretical mechanics based on the equations of motion of a material point at a variable air flow speed and the action of a pulsating air flow. Theoretical studies were carried out using the methods of mathematical analysis and modeling. The research results were processed using elements of the theory of probability and mathematical statistics using software packages; to determine the rational parameters of the process, the method of statistical experiment planning was used. A mathematical description of the motion of the grain material particles in a combined vibration-air separator under the action of a pulsating air flow of variable speed is given. The trajectories of motion of particles with different sizes are obtained. The obtained equation of motion of a particle under the influence of a pulsating air flow makes it possible to determine the dependence of the speed of movement of the material in a vibro-fluidized layer of grain material on a number of factors: the geometric parameters of the sieve-free sieve, the feed angle of the material, the initial kinematic mode of the material, the index of the kinematic mode of the sieve-free sieve, as well as the coefficient of windage of the grain. On the basis of theoretical studies, the possibility of separating particles of grain material into fractions according to aerodynamic properties with vibropneumatic loading of grain into the channel has been determined. The use of a pulsating air flow as a separating carrier, and taking into account the deflecting forces, made it possible to significantly increase the splitting of the trajectories and the criterion for dividing the grain into fractions.

Introduction: Herbal medicinal products are widely used for prevention and treatment of many diseases. Aim: The aim of our work was to study the parameters of grape leaves extraction on a laboratory extractor Timatic Micro. Materials and Methods: Towards achieving the goal, the tasks of determining the following factors influencing the grape leaves extraction were set: the degree of grinding and extraction time. Timatic Micro extractor was used for extraction. This contemporary technology is based on a double action of pressure – reduction of the pressure and percolation of biological material that intensifies extraction process. The extractant used was 40% ethyl alcohol as it provides maximum extraction of flavonoids and tannins. The extractor was set with standard parameters: compression - 2 minutes, decompression - 2 minutes. Results and Discussion: The degree of raw material depletion in the main biologically active substances of common grape leaves (tannins and flavonoids) significantly increases with decreasing the size of crushed grape leaves, and is the highest in the fraction less than 1 mm and is 69.93 %, 44.13% and 78.48% for extractives, tannins, and flavonoids, respectively (extraction time - 2 h). With increasing the time of extraction up to 4 h the yield of extractible substances increases by an average of 3%, but for 2 hours quite intensive extraction occurs, which gives high rates of raw material depletion. For obtaining the extract in the laboratory extractor Timatic, we have chosen as raw material a fraction of grape leaves of less than 1 mm and extraction time of 2 hours. Conclusion: The presented method has proven its reliability and efficiency in the extraction of substances in question.

Architectural aspects of exascale supercomputers are explored. Param-eters of the computing environment and interconnect are evaluated. It is shown that reaching exascale performances requires hybrid systems. Processor elements of such systems comprise CPU cores and arithmetic accelerators, implementing the MIMD and SIMD computing disciplines, respectively. Efficient exascale hybrid systems require fundamentally new applications and architectural efficiency scaling solutions, including: 1) process-aware structural reconfiguring of hybrid processor elements by varying the number of MIMD cores and SIMD cores communicating with them to attain as high performance and efficiency as possible under given conditions; 2) application of conflict-free sets of sources and receivers and/or decomposi-tion of the computation to subprocesses and their allocation to environment elements in accordance with their features and communication topology to minimize communication time; 3) application of topological redundancy methods to preserve the topology and overall performance achieved by the above communication time minimiza-tion solutions in case of element failure thus maintaining the efficiency reached by the above reconfiguring and communication minimization solu-tions, i.e. to provide fault-tolerant efficiency scaling. Application of these solutions is illustrated by running molecular dynamics tests and the NPB LU benchmark. The resulting architecture displays dynamic adaptability to program features, which in turn ensures the efficiency of using exascale supercomputers.