Sirvi Autor "Pascuzzi, S." järgi

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An experimental investigation of performance levels in a new root crown cleaner
(2019) Bulgakov, V.; Pascuzzi, S.; Arak, Margus; Santoro, F.; Anifantis, A.S.; Ihnatiev, Y.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
For the purposes of carrying out field experiments using the vertical-type cleaner with its elastic cleaning blades to remove haulm residues from the crowns of standing roots, the programme for this process and the technique behind it have both been developed by basing the process on the measurement of the volume of haulm residues that are left on the root crowns after they have been cleaned by a cleaning tool that operates at pre-set values in terms of its translational velocity, its height above the soil surface, and its rate of revolution. In addition, the cleaner’s energy-and-force performance has also been determined. In this process, the new laboratory and the field experimental unit have been put together. The unit comprises a rearmounted root crown cleaner of the rotary type with a vertical axis of rotation. During the field experiments, the general-purpose tractor which carries it moves at a pre-set velocity as registered by the track measuring wheel; the general height of the cleaning tool’s position is set within the specified range by the use of two pneumatic feeler wheels that are equipped with adjustment mechanisms. The results of the completed investigations have been statistically processed with the use of the regression analysis and correlation analysis methods. On the basis of the developed multiple-factor experiment technique, empirical mathematical models have been generated in the form of regression equations for the process of cleaning the crown’s of sugar beet roots. In accordance with the results of the calculations, it has been established that the translational velocity of the implement has the greatest level of impact on the volume of haulm residue that remains on the spherical surfaces of root crowns after cleaning. The rate of rotation for the vertical cleaning rotor and its height above the soil surface which are controlled by the two pneumatic feeler wheels have a lesser effect on the process under consideration.
Experimental research into uniformity in spreading mineral fertilizers with fertilizer spreader disc with tilted axis
(2021) Bulgakov, V.; Adamchuk, O.; Pascuzzi, S.; Santoro, F.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
Improving the efficiency in the work process of mineral fertilizer dressing is a topical problem in today’s agricultural industry. The authors have developed a design of the fertilizer spreading tool with a tilted axis and carried out field experiment investigations on it. It has been established by the results of the investigations that the non-uniformity in the spreading of mineral fertilizers along the line of their departure from the fertilizer spreading tool with a tilted axis is most strongly affected by the disc rotation frequency. The obtained results provide for selecting the optimum parameters and modes of operation for the tool under consideration in the situation, when it is installed in fertilizer placing machines. Also, it has been established that increasing the spreading disc rotation frequency in such a tool from 600 to 800 rpm results in the growth of the effective range of mineral fertilizer spreading along the placing line at a level of 10.5 m. Increasing the disc’s angle of inclination to the horizontal plane to 20º results in the rise of the effective fertilizer spreading range at a level of the 48th tray (24 m) inclusive as well as the increase of the distance between the tool and the tray that contains the maximum share of the spread fertilizers (5.1%) to 24 trays (12 m). At a constant rotation frequency of the disc in the tilted-axis fertilizer spreading tool, in all its kinematic modes of operation, an increase in the angle of its disc’s inclination to the horizontal plane results in the rise of the indices representing the distribution of the mineral fertilizers over the trays along the line of their placing. The width of the mineral fertilizer spreading can be controlled by adjusting the rotation frequency of the disc in the tilted-axis fertilizer spreading tool, when it is set at an angle to the horizontal plane, similar to how it is done in state-of-the-art fertilizer placing machines with horizontally positioned discs in their centrifugal spreading tools. The rotation frequency of the disc in the tilted-axis fertilizer spreading tool has the most significant effect on the coefficient of variation incidental to the distribution of the mineral fertilizers along the line of their placing.
Implementation of simultaneous performance of two technological operations with different machine-and-tractor units
(Estonian University of Life Sciences, 2022) Bulgakov, V.; Olt, Jüri; Pascuzzi, S.; Nadykto, V.; Kyurchev, V.; Mitkov, V.; Santoro, F.; Estonian University of Life Sciences. Institute of Forestry and Engineering
The gap between two technological operations should be minimal in the production environment. For this, special combined (multi-operational) machine-and-tractor units (MTU) are used. Their agricultural machines have sequentially installed working devices for various technological purposes. In the absence of such MTUs, single-operation units are used. Such units more often have different working widths. For their simultaneous operation in the same field, the first unit (for example, a sowing unit) must have a wider width than the second one (for example, a rolling one). In practice, the opposite case occurs more often when the first unit's working width is less than the second unit's working width. As a result, the first machine-and-tractor unit delays the work of the second one. This article aims to develop the algorithm for the simultaneous operation of two machine-and-tractor units of different field performance. The first of them (a sowing unit) has a working width of 3.6 m, and the second (a rolling one) is 6.1 m. As a result, the following has been established using the example of processing a field of 80 hectares: the second unit should start its work (i.e., rolling the crops) when the first one (sowing) has sown a certain area. According to the formula proposed in the article, the size of this area is 44 hectares. Under natural working conditions, the second unit (rolling) started its work after the first (sowing) unit has sown 44 hectares of the field area. As a result, both units have completed the entire area with a half-hour gap, i.e., practically simultaneously and without delay from each other.
Research into engineering and operation parameters of mineral fertiliser application machine with new fertiliser spreading tools
(2021) Bulgakov, V.; Adamchuk, O.; Pascuzzi, S.; Santoro, F.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The output capacity of the machine for top spreading the soil with solid mineral fertilisers can be raised by means of increasing its working width. The authors have carried out field trials and field experiment investigations with the MVU-8 granulated mineral fertilizer spreading machine equipped with two prototype units of the centrifugal fertiliser spreading tool, in which the axis can be tilted at different angles to the vertical line. In accordance with the results of the completed investigations, it has been established that setting the axial tilt angle of the centrifugal operating device in the fertiliser spreading tool within the range of 25–30° provides for achieving a productivity of the combined tractor-implement unit for applying mineral fertilisers at a level of 35–40 ha per working shift hour. The best performance in the fertiliser application with regard to both the working width and the fertiliser placing distribution uniformity is ensured at angles of inclination of the disc in the fertiliser spreading tool with respect to the horizontal plane within the range of 25–30°. At these angles, the uneven distribution of the fertiliser over the working width is equal to 19.2%, the uneven distribution of the fertiliser along the unit’s line of travel is equal to 8.9%, while the deviation in the dosage of the applied fertilisers from the set value is equal to 7.5%.
Research of the movement of agricultural aggregates using the methods of the movement stability theory
(2019) Bulgakov, V.; Kaletnik, H.; Goncharuk, T.; Rucins, A.; Dukulis, I.; Pascuzzi, S.
The theory of the movement stability is of crucial practical importance for mobile agricultural machines and machine aggregates, since it determines how qualitative and stable their performance is in a particular technological process. It is especially urgent To ensure stable movement for operation at high speeds of contemporary agricultural aggregates. The aim of this investigation is detailed examination of criteria for the stability assessment of a mechanical system used in agriculture, enabling their wide application in order to study the performance of the system in the case when it is affected by random forces that were not taken into account in the original model. The considered calculation methods and examples of their application make it possible to evaluate the performance of complex dynamic systems without numerical solution of complicated differential equations of the movement in the presence of external disturbances. The considered example of the stability determination of the movement of a trailed cultivator showed that this research method can be successfully used for practical purposes. Besides, a differential equation of disturbed movement has been composed for an actually symmetrical trailed agricultural machine with a particular mass, which moves at a constant forward speed under the impact of summary resistance force running along the symmetry axis of the cultivator and is applied at its centre of gravity. Reduced to normal Cauchy form, this equation was solved on the PC, which made it possible to determine immediately the conditions for stable movement of the trailed cultivator.
Seasonal sequestration capacity of chernozem under different agrotechnological impacts in agrocenosis
(Estonian University of Life Sciences, 2024) Bulgakov, V.; Gadzalo, I.; Pascuzzi, S.; Demydenko, O.; Holovach, I.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
The soil's sequestration capacity is primarily determined by the fine-dispersed fraction of the soil and strongly influences the properties and fertility level of the soil. To assess the sequestration capacity of C-CO2 humus in soil formation and fertility of typical chornozem (black soil), to identify the causes, rates, existing limits of the sequestration capacity decrease, it is important to study the seasonal dynamics of qualitative and quantitative indicators of humus state in time depending on the method of tillage and fertilization in agrocenoses of short rotation crop rotations in the central part of the Forest-Steppe region of Ukraine. During the research, a stationary field experiment was conducted to study the influence of methods of soil cultivation and fertilizer application on the sequestering capacity of chornozem. Laboratory studies were conducted to determine the content of humus and to calculate the seasonal reserves of absorbed carbon and phosphorus and to model the absorption capacity of chernozem. When processing with chisel plows and applying fertilizers, the increase in the C-CO2 reserve during the April-July period was +21 t ha-1 (0–0.2 m) and +36 t ha-1 a (0–0.3 m). Under moldboard plowing, the growth tended to increase by 1.52 times (0–0.2 m) and 1.25 times (0–0.3 m), but occurred at a lower quantitative level, and in the period July-September, the change in the humus C-CO2 stock was insignificant, indicating the predominance of C-CO2 sequestration processes in the summerautumn period with chisel plowing. With chisel plowing, the reserve of labile organic substances (LOS) in April exceeded the stock for plowing in the thickness of 0–0.3 m by 4.34–7.67 times (without fertilizers), 1.5–2.76 times (with fertilizers); in July - by 4.59–8.90 times (without fertilizers) and 1.32–3.16 times (with fertilizers); in September - by 4.52–4.04 times (without fertilizers) and by 1.11–1.93 times (with fertilizers), and the C-CO2 stock of the LOS compared to fallow land under chisel plowing without fertilizers in April, July, and September was 1.59–1.78 times, 2.31–3.29 times, and 1.4–1.78 times higher, and under fertilization - by 1.99–2.0, 1.86–4.50, and 1.7–2.6 times, respectively, depending on the seasons. Under fallow land maintenance, the seasonal dynamics of the C-CO2 stock of the LOS is subject to the seasonal dynamics of Porg(LOS). A direct strong correlation was found at the level of R = +0.89 ± 0.02; R2 = 79. In the period April-July, the decrease of Porg(LOS) stock in the thickness of 0–0.2 m was found to be 1.15 times, and in the thickness of 0–0.3 m - 1.1 times. From summer to autumn, the stock of Porg(LOS) was restored, and the stock in the thickness of 0–0.3 m increased by 1.10 times. Conclusions. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowingchiseling-fallow land, the cyclicality index under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality under plowing, which indicates the restoration of the CI. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowing-chiseling-fallow, the index of cyclicality under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality of plowing, which indicates the restoration of the ISC. However, the timing of changes in the Porg(LOS) stock indicates that in the series plowing-chiseling-fallow, chisel plowing is directed to fallow land by its seasonal cyclicality. The general regularity of seasonal cyclicality for all parameters of humus condition lies in the fact that a decrease in the values of ISC, as in fallow land or under moldboardless tillage, indicates the ordering of ISC, and an increase in the index of cyclicality to destruction, as under plowing.
Study of the controlled motion process of an agricultural wide span vehicle fitted with an automatic driving device
(Estonian University of Life Sciences, 2022) Bulgakov, V.; Olt, Jüri; Pascuzzi, S.; Ivanovs, S.; Kuvachоv, V.; Santoro, F.; Gadzalo, Ia.; Adamchuk, V.; Arak, Margus; Estonian University of Life Sciences. Institute of Forestry and Engineering
The aim of research is to analyse the process of the wide span vehicle motion on the treads of the permanent process track with the use of the traction method of turn. The completed studies have proved that the plane-parallel motion of a wide span vehicle solely with the use of the traction method of turn on the treads of the permanent process track requires a significantly smaller difference between the moments applied to the wheels on the right side and on the left side of the vehicle, as compared to that of a crawler tractor. This difference is in proportion to the width of its wheel base that has a relatively smaller length. It has been established that the use of solely tractionbased turn does not provide for the adjustment of the motion trajectory through the lateral (planeparallel) displacement of the fore-and-aft axis of the agricultural wide span vehicle. The oscillations in the lateral displacement of the agricultural wide span vehicle in the process of its motion are lowfrequency ones. The main variance spectrum of these oscillations is concentrated within the range of frequencies of 0–2 s −1. At the same time, the maximum transverse displacement of the agricultural wide span vehicle equal to 1.3 10−5 m N−1, occurs also at low frequencies. In view of the fact that the main variance spectrum of the oscillations of the tangential forces applied to the wheels on the left and right sides of the agricultural wide span vehicle is concentrated exactly within a low frequency range, only the high accuracy of the system using a laser beam can ensure its satisfactory steerability.
Theoretical study on sieving of potato heap elements in spiral separator
(2019) Bulgakov, V.; Pascuzzi, S.; Nikolaenko, S.; Santoro, F.; Sotirios Anifantis, A.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
One of the principal problems in the harvesting of potatoes is the cleaning of the lifted heap from soil and plant impurities. The low quality in the performance of this harvesting work process operation is the main cause of the withdrawal from fields of considerable amounts of fertile soil. In order to facilitate choosing the optimal parameters for the new design of the spiral potato heap cleaning unit, a mathematical model of sieving the soil impurities through its cleaning spirals has been developed. The obtained analytical expressions have been solved with the use of a PC and the results have been used for plotting the graphic relations between the parameters of the examined process of a variable-mass body’s motion on the surface of a spiral, which have made it possible to select the optimal design and kinematic parameters of the spiral cleaning unit under consideration. The obtained graphic relations indicate that the rate of sieving in the spiral separator depends on many factors, including the initial mass, the design dimensions (spiral’s radius, helix angle etc.), the frictional properties of the surface, the angular parameters of the position of the potato heap elements on the spiral’s surface, and the angular velocity of the rotational motion of the spiral roll itself.
The theory of vibrational wave movement in drying grain mixture
(2020) Bulgakov, V.; Holovach, I.; Kiurchev, S.; Pascuzzi, S.; Arak, Margus; Santoro, F.; Anifantis, A.S.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
This paper outlines a theory that involves the vibrational wave transportation of bulk grain during the course of passing that grain under an infrared radiation source, in a working thermal radiation drying chamber, and using a vibrational wave transporter belt that has been developed by the authors of this paper. The main outstanding feature of the proposed design is the presence of mechanical off-centre vibration drives which generate the vibration in the working rollers at a preset amplitude and frequency, thereby generating a mechanical wave on the surface of the flexible transporter belt which ensures the movement of bulk grain along the processing zone which itself is being subjected to infrared radiation. A calculation method was developed for the oscillation system that is used in conjunction with the vibrational transportation of the grain mass, in order to be able to determine the forces that may be present in the vibrational system and to prepare the differential calculations for the movement of the vibrational drive’s actuators, utilising for this purpose Type II Lagrange equations. The solving of the aforementioned integral equations on a PC yielded a number of graphical dependencies in terms of kinetic and dynamic parameters for the vibrational system described above; the analysis of those dependencies provided a rational structural, along with kinetic and dynamic indicators. According to the results that were taken from theoretical and experimental studies on the functioning of the developed infrared grain dryer combined with a vibrational exciter, stable movement for its working roller takes place if the angular velocity of a drive shaft is changed within the range of between 50–80 rads–1 , whereas the amplitude of the indicated oscillations falls within the range of 3.0–4.0 mm. It has been discovered that a rational speed when transporting soy seeds during infrared drying falls between the range of between 0.15–0.60 cm s -1 , whereas the amplitude of the indicated oscillations falls within the range of 3.0–4.0 mm. An increase of this parameter within the stated limits increases the time that it takes to achieve the stage in which a constant drying soy speed is reached by more than 2.5 times (from 205 seconds to 520 seconds), stabilising the figure at a level of 520 seconds, which makes it possible to recommend a range of transport speeds of between 0.15–0.40 cm s –1 under infrared radiation for the seeds in order to achieve the required moisture content with a single pass of the produce on the wave transporter. With that in mind, the power consumption levels for the vibrational exciter do not exceed 50W, while the angular velocity of the drive shaft’s rotation falls within the range of between 100– 120 rads–1 . The results of the experimental study that has been conducted indicated that a rational transportation speed for the soy seeds on the wave transporter under infrared radiation is between 0.15–0.40 cm s –1.

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