Agricultural Engineering

A MEANS OF MEASURING SMALL CONCENTRATIONS OF DISSOLVED SUBSTANCES BASED ON A REFRACTOMETRIC SENSOR

2023-08-23T09:24:16+03:00

Determining the quantitative and qualitative composition of solutes is an important scientific and applied problem that arises in various fields of science and technology. However, in a number of practical problems there is a need to determine the concentration of substances whose mass (volume) fraction in the solution is quite small.

Common measurement methods, characterized by high speed and versatility are refractometric methods. Of particular interest among refractometric methods in the measurement of low concentrations of solutes is the method based on the use of the effect of surface plasmon resonance. The main advantages of this method are its high sensitivity and low weight of the sample used in the study. To date, the widespread use of this method of measurement is significantly limited by the lack of high-precision mathematical models of primary measuring transducers (sensors) implemented on its basis.

The main directions of refractometry development and its relevance in various spheres of human activity, such as science, technology, medicine and even the food industry, were considered in the work. As a result of the need to use the phenomenon of surface-plasmon effect, a detailed description of this phenomenon, its features, nature and practical application. The peculiarity of the interaction of radiation with gold nanofilms is considered.

A mathematical model of the refractometer based on the surface plasmon effect was developed. The adequacy of the obtained conclusions was confirmed by means of computer modeling and experimental research.

The design of a means of measuring small concentrations of dissolved substances, built on the basis of the described sensor, has been developed. It is shown that such a measuring tool will be characterized by relative simplicity of construction while preserving all the advantages of the refractometric measurement method.

The LAND COVER MAPPING OF TROPICAL FOREST AREAS USING SPOT IMAGE IN CENTRAL BORNEO

2023-10-30T11:47:19+02:00

Land cover is fundamental information that could be applied to understand the interaction between human activities and nature. This information could be derived from remotely sensed images. This study analyzes and compares tropical forested areas’ land cover (LC) classification results. In this study, we use a SPOT image as the primary input. The study was conducted in Central Borneo and covered 162.60 km². The image was processed using three algorithms, including NN-MLP, MLC, and ECHO Classifier, with three treatments (2×2, 4×4, and 6×6) sized block of pixels. The classification produces nine (9) land cover classes, i.e., Sparse vegetation area, Dense Vegetation area, Shrubland, Open Water Body, Open Land, Grassland, Mining Area, Pavement Area, and Palm Oil Area. The three algorithms can produce land cover maps with kappa and an overall accuracy value of more than 85%. However, NN-MLP has better accuracy than other algorithms (MLC and ECHO), with a kappa value of 90.72% and an overall accuracy of 93.88%.

THE INVARIANTS OF KINETICS OF STRUCTURAL ELEMENTS OF METAL SURFACES

2024-12-06T14:21:46+02:00

THE INVARIANTS OF KINETICS OF STRUCTURAL ELEMENTS OF METAL SURFACES

INCREASING THE WEAR RESISTANCE OF THE LOCOMOTIVE WHEEL CREST BY INTRODUCING AN ANTIFRICTION ADDITIVE INTO THE LUBRICANT

2024-12-06T14:28:48+02:00

Tests were carried out to determine the wear of the surface of the locomotive wheel rail using a Puma lubricant with a sulfonic additive, with an additive of a hydroquinone derivative and an organophosphorus compound and to determine the amount of diffusionally active hydrogen released in the system. The purpose of the work was to determine the wear of the rail material and analyze the lubricant with the selected additives. The principle of action of additives and the nature of their interaction with rubbing surfaces is analyzed. Additives have been identified that reduce surface wear, as well as an additive that best binds hydrogen. As a result of the work, it was revealed that the additives of the sulfo- and organophosphate compounds reduce the wear of the friction surface, and it is also shown that the organophosphate compound reduces the release of diffusionally active hydrogen into the system.

INVESTIGATION OF DYNAMICS OF THE PIPE ROBOT WITH VIBRATION DRIVE BASED ON CENTRIFUGAL FORCES

2024-12-06T15:22:16+02:00

Vibration drive based on centrifugal forces can be used as an exciter of vibrations in the structure of a pipe robot. In this paper, a pipe robot with vibration drive based on centrifugal forces is proposed and investigated. A dynamic model of the pipe robot is presented, and differential equations of motion are obtained. Model in which excitation is assumed to be of unlimited power is described and investigated as well. Typical graphical relationships for the investigated pipe robot with vibration drive based on centrifugal forces are obtained and presented. It is determined that the obtained results reproduce the main dynamic effects taking place during the motion of a pipe robot with vibration drive based on centrifugal forces.