Multifactor Experiment Research Articles

Application of a dynamic model for regulating the hydrothermal regime in early potato cultivation in the Volgograd region

The article presents the results of research on the dynamics of development and water consumption of early potatoes, obtained from field observations in a multi-factor experiment, which formed the basis of the initial database of water adaptive regulation, temperature and food regimes based on simulation. The dynamic simulation model “POTATO” developed on this basis is aimed at displaying the processes of phenological development of potatoes and predicting crop yields during irrigation and fertigation. The model provides a forecast of the timing of the early potato development phenological phases, its yield depending on specific soil and weather conditions, as well as irrigation modes (sprinkling, drip and combined ones) and the level of mineral nutrition. The forecast of the dynamics of the culture phenological development allows to adjust the schedule of reclamation measures to regulate water and temperature regimes, taking into account current and forecast meteorological information. The simulation model allows to perform operational management of the hydrothermal and food regime of the agrocoenosis in order to obtain the planned yields. The developed method of regulating the hydrothermal regime based on the “POTATO” simulation model makes it possible to implement operational irrigation management and choose the optimal and cost-effective irrigation strategy.

Experimental investigation on the mechanical vapor recompression evaporation system coupled with multiple vacuum membrane distillation modules to treat industrial wastewater

• A multiple vacuum membrane distillation modules system (MVMD) was constructed. • A mechanical vapor recompression system coupled with MVMD was constructed. • An experimental study of the MVMD and MVR-MVMD systems was conducted. • Economic assessment of the MVMD and MVR-MVMD systems was made. • The MVR-MVMD system can save 79.24% energy than that of the MVMD system. Excessive population growth has increased the importances of industrial wastewater treatment as well as energy conservation. This paper presented an experimental study of a mechanical vapor recompression evaporation system coupled with multiple vacuum membrane distillation modules (MVR-MVMD) for energy saving in the wastewater treatment process. For this aim, the MVMD system was constructed to investigate the water production performance in the VMD process, and then the MVR was joined to the MVMD system to examine the energy-saving performance. The experiment results showed that: In the experiment of the MVMD system, an excellent water production performance was observed with the sodium chloride solution as evaporation object, and the parameters that significantly affected the water production performance were obtained as follows: feed temperature was the highest effect, and then permeate side pressure, feed flow rate, and feed concentration had the lowest effect through an orthogonal multi-factor experiment. In the experiment of the MVR-MVMD system, the specific heating energy consumption was 81.95 kWh t −1 , which could save 79.24% energy than that of the conventional MVMD system, at conditions of feed concentration of 5%, feed flow rate of 25 m 3 /h and membrane area of 200 m 2 . Finally, a detailed economic assessment had been made concerning the capital investment, operation, and environment costs compared to the MVMD system. From a long-term perspective, the MVR-MVMD system showed excellent economic performance comparable to the MVMD system.

Influence of hot pressing technological parameters on plywood bending properties

Different types of wood are used to manufacture of various wood products. In direct production processes, additional resources such as energy, adhesives, labor, etc. are also used. In line with sustainable environmental policies, all resources must be used more rationally, while simultaneously increasing the efficiency of the direct production processes. This research examined whether it is possible to reduce energy and labor resources in the technological process of hot pressing of birch plywood (nominal thickness 9 mm), by varying the holding time under pressure, pressure, and adhesive consumption. The Box-Behnken experimental design for a multifactor experiment was used to investigate the influence of technological parameters of plywood pressing. The highest strength in static bending both parallel and perpendicular to the plywood grain was achieved by pressing plywood with the following gluing parameters: highest pressing pressure, 3.2 MPa; minimal holding time under pressure, 9 minutes; and average phenol-formaldehyde adhesive consumption 150 grams per square meter.

Optimal design of multifactor experiments via grid exploration

We propose an algorithm for computing efficient approximate experimental designs that can be applied in the case of very large grid-like design spaces. Such a design space typically corresponds to the set of all combinations of multiple genuinely discrete factors or densely discretized continuous factors. The proposed algorithm alternates between two key steps: (1) the construction of exploration sets composed of star-shaped components and separate, highly informative design points and (2) the application of a conventional method for computing optimal approximate designs on medium-sized design spaces. For a given design, the star-shaped components are constructed by selecting all points that differ in at most one coordinate from some support point of the design. Because of the reliance on these star sets, we call our algorithm the galaxy exploration method (GEX). We demonstrate that GEX significantly outperforms several state-of-the-art algorithms when applied to D-optimal design problems for linear, generalized linear and nonlinear regression models with continuous and mixed factors. Importantly, we provide a free R code that permits direct verification of the numerical results and allows researchers to easily compute optimal or nearly optimal experimental designs for their own statistical models.

Minimal cost multifactor experiments for agricultural research involving hard-to-change factors

Multifactor experiments are very common in agricultural research. Randomizing run orders in multifactor experiments often witness in large number of factorwise level changes which will increase the cost and time of the experiments. Minimal cost multifactor experiments are such experiments where the cost of the experiment is minimum which can be achieved by choosing a factorial run order where the total number of factor level change is minimum as cost of the experiment is directly proportional to the number of level changes of factors. Here, a method of constructing minimal cost 2-level multifactor experiments with minimum number of factorwise level changes has been proposed. As for a same factorial combination, there may exist more than one minimally changed factorial run order, an exhaustive search was also performed to obtain all possible minimally changed run order for two level multifactorial experiments with three factors. Due to restricted randomization, adaption of these run orders may witness the effect of systematic time trend. Hence, the usual method of analysis may not be a feasible solution due to lack of randomization. Here, the analytical procedure of experiments using minimal cost multifactorial run order has also been highlighted based on a real experimental data. The work has been carried out at ICAR-Indian Agricultural Statistics Research Institute, New Delhi during 2019-20. The data from the real experiment used for explaining the analysis procedure has been collected from Climate Change Facility of ICAR-Indian Agricultural Research Institute farm, New Delhi, India based on experiments conducted during 2014-15.

Opimization of the main design and operating parameters of the micronization device

The article substantiates the main characteristics of the studied device of micronization in the processing of grain feed by the method of micronization. Here, an experimental micronizer that micronizes feed grain was taken as the object of research. A multi-factor experiment was also conducted to determine the optimal distance of the infrared lamp from the quartz glass and the optimal power of the light flux. The experiments were carried out on an experimental installation equipped with a “Legrand” dimmer, which allowed changing the radiation power of the lamps. For the experiments, a symmetrical Box-Bench plan was selected from a rotatable, composite second tier. The studies were conducted on wheat, barley and velamir.

Вплив технологічних факторів на якість антифрикційних покриттів

The conditions for the antifriction coatings formation during finishing antifriction non-abrasive treatment (FANT) are analyzed. The requirements for this kind of coatings and the main criteria for assessing their quality are noted. A relationship has been established between the quality of the coating obtained with FANT and the technological factors that determine the conditions for contacting the tool with the treated surface. It is proved that the shape and size of microroughnesses of the treated surface determine the efficiency of the microcutting process and filling the microcavities with the rubbed material. Technological factors influence on the coating quality was investigated during FANT by implementing a multifactor experiment, as a result of which a connection was established between the technological parameters of the process (total friction path, load on the tool), as well as the length of the supporting surface with indicators characterizing the coating quality. Statistical models were obtained for mass transfer of antifriction material, area (continuity) of the coating and surface roughness at natural values of the factors, which made it possible to establish the studied factors influence on the optimization parameters. The analysis of the experimental scattering graphs made it possible to clarify the nature of the factors changes and analyze their mutual influence on the optimization criteria. Taking into account the inversely proportional relationship of the optimization criteria, the achievement of their maximum values at the same time is impossible, therefore, the values are taken according to the final result of the FANT process. The range of the studied factors values is established, the regularities of their change are substantiated from the point of view of the selected optimization criteria. Determination the rational values of the FANT process technological parameters will improve the antifriction coatings quality obtained by a friction-mechanical method.

FACTOR ANALYSIS OF THE THERMAL SCHEME OF CHP WITH SUPER CRITICAL STEAM CYCLE ON THE BASIS OF EXERGY METHOD

The most promising direction of CHP modernization is the introduction of power units on supercritical steam parameters. Increasing steam parameters is one of the most effective ways to increase the efficiency of a CHP plant. Thus, the development of the concept of thermal schemes turbines for supercritical steam parameters, taking into account the characteristics of their operation at the existing CHP Ukraine is an actual scientific problem. The solution to this problem will make it possible to replace or modernize the power generating equipment that has exhausted its resource with modern power units that meet world economic and environmental standards. The method of exergy analysis is adapted to the study of thermal schemes of CHP plants with supercritical steam cycle. As an example of application of a method the exergy analysis of the power plant working on the one-stage thermal scheme is carried out. Within the framework of the proposed method, a thermodynamic and topology-exergetic model of the power plant is created. Based on the topology-exergetic model the indicators of thermodynamic efficiency of the power plant operating on supercritical parameters of steam are determined. It is proposed to apply the theory of experiment planning in exergy analysis of the thermal circuit of a CHP. With the involvement of this theory, a multifactor numerical experiment was conducted to determine the impact on the exergetic efficiency of the thermal scheme of CHP of the main determining variable factors, such as adiabatic and thermal efficiency of the plant, as well as the operating parameters. The generalized equation of functional interrelation of exergetic efficiency of system and exergetic efficiency of elements of thermal scheme of CHP is received. The proposed equation can be used as a tool for further training of neural networks and their application both in the design and in the diagnosis of energy efficiency of CHP. According to the results of the factor analysis, a rather high conservatism of the considered one-stage scheme of CHP to the change of the varied parameters was revealed. This indicates the presence of more rigid structural links between the elements, which is generally a positive aspect of the reconstruction.

Влияние отношения высот кругов в комбинированном инструменте на шероховатость шлифованной поверхности

The impact of the height ratio of fine-grain abrasive disks and coarse grinding ones included in a combined tool upon roughness of the surface ground is considered. There are drawn dependence diagrams of the arithmetic mean deviation of the ground surface profile in the function of independent factors of the process. On the basis of the multi-factor experiment carried out there is defined a ratio of heights of grinding disks mentioned ensuring a minimum value of the micro-geometry of the surface worked.

Warming and elevated CO2 intensify drought and recovery responses of grassland carbon allocation to soil respiration.

Photosynthesis and soil respiration represent the two largest fluxes of CO2 in terrestrial ecosystems and are tightly linked through belowground carbon (C) allocation. Drought has been suggested to impact the allocation of recently assimilated C to soil respiration; however, it is largely unknown how drought effects are altered by a future warmer climate under elevated atmospheric CO2 (eT_eCO2 ). In a multifactor experiment on managed C3 grassland, we studied the individual and interactive effects of drought and eT_eCO2 (drought, eT_eCO2 , drought×eT_eCO2 ) on ecosystem C dynamics. We performed two in situ 13 CO2 pulse-labeling campaigns to trace the fate of recent C during peak drought and recovery. eT_eCO2 increased soil respiration and the fraction of recently assimilated C in soil respiration. During drought, plant C uptake was reduced by c. 50% in both ambient and eT_eCO2 conditions. Soil respiration and the amount and proportion of 13 C respired from soil were reduced (by 32%, 70% and 30%, respectively), the effect being more pronounced under eT_eCO2 (50%, 84%, 70%). Under drought, the diel coupling of photosynthesis and SR persisted only in the eT_eCO2 scenario, likely caused by dynamic shifts in the use of freshly assimilated C between storage and respiration. Drought did not affect the fraction of recent C remaining in plant biomass under ambient and eT_eCO2 , but reduced the small fraction remaining in soil under eT_eCO2 . After rewetting, C uptake and the proportion of recent C in soil respiration recovered more rapidly under eT_eCO2 compared to ambient conditions. Overall, our findings suggest that in a warmer climate under elevated CO2 drought effects on the fate of recent C will be amplified and the coupling of photosynthesis and soil respiration will be sustained. To predict the future dynamics of terrestrial C cycling, such interactive effects of multiple global change factors should be considered.

Optimization of culture conditions of <italic>Isochrysis galbana</italic> by response surface method

<italic>Isochrysis galbana</italic> has the advantages of small size and fast reproduction. It has become one of the main micro-algae with great potential for green sewage treatment technology under the new concept. Because of its high nutritional value, it is often used as bait in the artificial breeding of bivalve shellfish such as <italic>Meretrix meretrix</italic>, <italic>Solen grandis</italic>, <italic>Sinonovacula constricta</italic> and so on. Response surface method is a combination of statistics and mathematics. It not only has the interaction in the orthogonal experiment, but also can use the mathematical model to get the functional relationship between the response and each variable, so it is an effective method to further predict the combination of all variable factors and get the optimal response surface value to solve scientific and production problems. Specific growth rate refers to the increased biomass of single-celled organisms per unit mass per unit time, which is an important parameter reflecting the growth rate of single-celled organisms such as microalgae and bacteria. The specific growth rate can not only accurately reflect the specific growth rate of microalgae in a certain time period, but also can comprehensively reflect the dynamic changes of the balance between microalgae growth and mortality. In order to optimize the culture conditions of <italic>Isochrysis galbana</italic>, using the method of experimental ecology and response surface (Box-Behnken mode), different experimental groups with different temperatures, salinities and initial inoculation levels were set up. Single factor experiment and multifactor experiment (Box-Benhnken model) were constructed to obtain the specific growth rate of <italic>Isochrysis galbana</italic>. Results showed that: 1) In a certain range of temperature, salinity and initial inoculation level, the specific growth rate of <italic>Isochrysis galbana</italic> increased first and then decreased with the increase of various factors; 2) The optimization of culture conditions of <italic>Isochrysis galbana</italic> respectively were: temperature 26.38 ℃, salinity 26.61, and initial inoculation level 1.29×10⁶ cell·mL^-1,and the maximum specific growth rate of <italic>Isochrysis galbana</italic> was 0.44 d^-1. The model conclusion data is available and can be applied to the actual production process.Our results could provide scientific basis for laboratory culture and large-scale propagation of <italic>Isochrysis galbana</italic>.In this paper, taking the specific growth rate of <italic>Isochrysis galbana</italic> as an index, the optimum conditions of suitable temperature, salinity and initial inoculation level were optimized by response surface method to provide scientific basis for laboratory culture and large-scale breeding of <italic>Isochrysis galbana</italic>.

INVESTIGATION OF SUBSTRATE MIXING PROCESS IN ROTATING DRUM REACTOR

The results of the research on the influence of the drum type reactor design-technological parameters and the substrate`s physical-chemical parameters on the substrate`s components mixing evenness, that influence the quality of the received compost, are presented in this paper. By the method of the multifactor experiment rational values of the drum rotation speed, the blades (mounted on the inner drum surface) angle and the substrate`s moisture content are defined at which the components distribution homogeneity in the substrate reaches maximal value. The abovementioned, in turn, provides high compost quality by the agrichemical indices. The recommendations are given to pick the design parameters and operational modes of the drum type reactor.

Research and Development of MEMS Accelerometer's Sensor

Currently, MEMS accelerometers are one of the most promising areas in the inertial sensor industry. The design and study of MEMS accelerometers structures is associated with solving problems of mathematical physics. Also, a very important task is to comply with the technological route, including carrying out such operations as deep etching of silicon. This article describes the modeling of the developed geometric model of the sensitive element MEMS accelerometer. The calculations were carried out, which showed that the developed structure is efficient. As a result of the study of the Bosch process using methods for planning multifactor experiments, the modes of deep etching of silicon were optimized. Prototypes of sensitive element MEMS accelerometers have been produced.

Experimental Stand Movable Module for Determining the Traction-Linked Properties of Wheel Engines and the Results of Laboratory Researches for Determining the Traction Force of Two-Wheel Tractors

Introduction. Farmers make extensive use of two-wheel tractors equipped with traction and drive interchangeable units. Two-wheel tractors are required to move evenly with minimal slip of the drive wheels on the soil. The tractive force on the drive wheels of the tillage unit is the decisive power factor in this case. An objective traction force value can be measured only by carrying out experimental studies. Materials and Methods. To determine the traction force on the drive wheels of the twowheel tractor, the design of the experimental stand was proposed and substantiated (RF patent for useful model No. 188610 “Movable module of the test stand”), and a methodology for planning and conducting a multifactor experiment to determine the traction force was developed. Results. As a result of the laboratory tests the calculation dependencies of the tractive force on the drive wheels of the Neva MB23-MultiAGRO Pro two-wheel tractor were obtained. Soil conditions, design and technological parameters, operating modes of the two-wheel tractor, and rolling resistance forces were taken into account. Discussion and Conclusion. The use of the developed regression models of the traction force under the condition of ensuring uniform movement with the minimum permissible slipping of the driving wheels of the two-wheel tractor on the soil will allow obtaining the permissible values of the two-tractor motion speed and form the zones of its most effective functioning.

Технология получения композиционных конгломератных порошков для плазменного напыления высокотемпературных защитных покрытий

Introduction. For parts of gas turbines operating under conditions of corrosion-erosion and intense wear, the most acceptable are compositions containing Ni, Co, Cr, Al, B, Y both in pure form and in the composition of compounds applied on the contact surface during thermal spraying. Modern integrated complexes obtained by combining dissimilar substances in the form of a single composition are promising. Such powders are obtained either by cladding or by conglomeration of finely dispersed starting components into a larger particle. The problem of developing and manufacturing plants for conglomeration of powders is urgent and practically important, since it makes it possible to obtain material for thermal spraying of coatings for high-temperature purposes. The aim of the work is to develop a technological scheme for obtaining powders of the required chemical composition with a given particle shape and size, intended for spraying high-temperature protective coatings. Materials and research methods. A technology is developed for the production of integrated powders for spraying coatings using the method of spray drying and subsequent sintering in vacuum or in an argon-hydrogen atmosphere, which avoids the loss of feedstock due to the return of fine and coarse fractions. A technology for preparing materials for spray drying and granulation is proposed. A gravity type aerodynamic classifier is designed and manufactured, which makes it possible to select automatically the powder fraction necessary for spraying the coating, as well as return the unwanted fraction for recycling. The morphology of the granular powder is determined using a TESCAN scanning electron microscope. The chemical composition of the resulting integrated complexes is determined by X-ray microanalysis on an OXFORD attachment. Results and discussion. The technological conditions for obtaining powders of a given size (40…100 µm) are established. It is shown that the shape of the conglomerate particles after spray drying is close to spherical. On the basis of a multifactor experiment, the optimization of the technological process for obtaining powders Ni-17Cr-10Al-1Y and Ni-22Cr-16Al-1Y with sizes up to 100 µm is performed. It is shown that when conglomerating powders with increased aluminum content (Ni-22Cr-16Al-1Y), it is necessary to take into account the exothermic reaction of nickel aluminide formation and dilute the mixture of initial components before sintering with the finished sintered powder. The resulting integrated complexes are characterized by high heat resistance; therefore they are designed and successfully used for plasma spraying of protective coatings for high-temperature purposes. Conclusions. A technology is developed for obtaining composite conglomerated powders Ni-17C-10Al-1Y and Ni-22Cr-16Al-1Y with particle sizes up to 100 µm and a shape close to spherical. A distinctive feature of this technology is that it avoids the loss of feedstock by returning fine and coarse fractions.

МОДЕЛИРОВАНИЕ СВЯЗИ КРУТЯЩЕГО МОМЕНТА ОБЪЕМНОГО ГИДРОПРИВОДА С ПАРАМЕТРАМИ ГИДРАВЛИЧЕСКОГО НАГРУЖАЮЩЕГО УСТРОЙСТВА

Currently, manufacturers for a reliable assessment of the technical condition of volumetric hydraulic drives use the dynamic test method, which allows you to determine the torque (braking) moment on the shaft of the tested hydraulic motor. There are difficulties in reliably determining the value of the developed torque (braking) moment. (Research purpose) The research purpose is in constructing a mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device. (Materials and methods) The article presents a hydraulic loading device that provides the necessary braking torque on the shaft of the tested hydraulic motor. Authors conducted one-factor and multi- factor experiments-dynamic tests of the new Sauer-Danfoss series 90 volumetric hydraulic drive using a hydraulic loading device. The torque (braking) was monitored using a non-contact digital torque sensor M 425 3-A datum electronics and a digital indicator with LCD display (Results and discussion) As a result of one-factor passive experiments, the factors influencing the optimization parameter and the ranges of their variation were determined. A mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device was obtained by a multi-factor active experiment. The article presents a complete planning matrix for a multi-factor active experiment, which reflects the sequence of all possible combinations of factors that affect the optimization parameter. The most significant factors affecting the value of the developed torque (braking) moment were: the pressure drop and the temperature of the working fluid in the hydraulic lines of the hydraulic loading device. (Conclusions) The mathematical model allows us to determine with high accuracy the developed torque (braking) of the volumetric hydraulic drive.

An Analysis of Multiple Variance for The Multivariate Split-Block Design

This paper studies an important type of multi-factor experiments designs called (Split-Blocks experiment Design). And we’re going to use the orthogonal matrix to convert the observation matrix. Also, we study the analysis of variance for the Multivariate split-Blocks design. And we discuss the test statistics for Lawley-Hotelling test, Roy’s Union-Intersection test and Walks, Lambda test.

Impact of basic tillage systems and fertilization on agrochemical indices of soil fertility in the right bank of the Forest-Steppe of Ukraine

The paper presents the results of stationary multifactor field experiment on study of the mutual impact of various systems of soil deep and surface tillage in combination with various levels of organic and mineral fertilizers application on crop rotation performance, as well as on a number of agrochemical indicators of black soil fertility. Researches were carried out as a stationary field experiment on the experimental field of Bila Tserkva National Agrarian University in 2013-2018. During the crop rotation in all the studied tillage methods, especially mouldboardless and disking tillage, the hydrolytic acidity of the arable layer increased with increase in fertilizer rates, and the amount of bases absorbed, saturation degree, level of exchangeable calcium and magnesium cations decreased, but in most cases these changes were not significant. Systematic mouldboardless and disking tillage enhance the topsoil heterogeneity in relation to agrochemical indicators of its fertility. Heterogeneity increases with increase in the level of applied fertilizers. With the mouldboard tillage during the crop rotation period at unfertilized areas, the largest part of humus loss in the arable layer is observed in the top, and the smallest - in its bottom parts; the opposite pattern was observed on fertilized areas at the highest rate. With mouldboardless and disking tillage, directly opposite patterns were observed in comparison with mouldboard tillage. An annual application of 8 t/ha of manure + N76P64K57 stabilizes the humus state of the arable soil layer when carrying out differentiated and disking tillage in crop rotation. Fertilization rate of 12 t/ha of manure + N95P82K75 for these tillage options a significant increase in humus and total nitrogen reserves is provided.

Toward a predictive theoretical model for osmolality rise with non-humidified incubation: a randomized, multivariate response-surface study.

What factors associated with embryo culture techniques contribute to the rate of medium osmolality change over time in an embryo culture incubator without added humidity? The surface area-to-volume ratio of culture medium (surface area of the medium exposed to an oil overlay), as well as the density and height of the overlaying oil, all interact in a quantitative way to affect the osmolality rise over time. Factors such as medium volume, different oil types, and associated properties, individually, can affect osmolality change during non-humidified incubation. Several experimental designs were used, including simple single-factor completely randomized designs, as well as a multi-factor response surface design. Randomization was performed at one or more levels for each experiment. Osmolality measurements were performed over 7 days, with up to 8 independent osmolality measurements performed per treatment group over that time. For the multi-factor study, 107 independent combinations of factor levels were assessed to develop the mathematical model. This study was conducted in a research laboratory setting. Commercially available embryo culture medium and oil was used. A MINC incubator without water for humidification was used for the incubation. Osmolality was measured with a vapor pressure osmometer after calibration. Viscometry and density were conducted using a rheometer, and volumetric flasks with an analytical balance, respectively. Data analyses were conducted with several commercially available software programs. Preliminary experiments showed that the surface area-to-volume ratio of the culture medium, oil density, and oil thickness above the medium all contributed significantly (P < 0.05) to the rise in osmolality. A multi-factor experiment showed that a combination of these variables, in the form of a truncated cubic polynomial, was able to predict the rise in osmolality, with these three variables interacting in the model (P < 0.05). Repeatability, as measured by the response of identical treatments performed independently, was high, with osmolality values being ± 2 of the average in most instances. In the final mathematical model, the terms of the equation were significant predictors of the outcome, with all P-values being significant, and only one P-value > 0.0001. Although the range of values for the variables were selected to encompass values that are expected to be encountered in usual embryo culture conditions, variables outside of the range used may not result in accurate model predictions. Although the use of a single incubator type and medium type is not expected to affect the conclusions, that remains an uncertainty. Using this predictive model will help to determine if one should be cautious in using a specific system and will provide guidance on how a system may be modified to provide improved stability during embryo culture. This study was funded by Cook Medical. The author is a Team Lead and Senior Scientist at Cook Medical. The author has no other conflicts of interest to declare. N/A.

МОДЕЛИРОВАНИЕ СВЯЗИ КРУТЯЩЕГО МОМЕНТА ОБЪЕМНОГО ГИДРОПРИВОДА С ПАРАМЕТРАМИ ГИДРАВЛИЧЕСКОГО НАГРУЖАЮЩЕГО УСТРОЙСТВА

Currently, manufacturers for a reliable assessment of the technical condition of volumetric hydraulic drives use the dynamic test method, which allows you to determine the torque (braking) moment on the shaft of the tested hydraulic motor. There are diffi culties in reliably determining the value of the developed torque (braking) moment. (Research purpose) The research purpose is in constructing a mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device. (Materials and methods) The article presents a hydraulic loading device that provides the necessary braking torque on the shaft of the tested hydraulic motor. Authors conducted one-factor and multifactor experiments-dynamic tests of the new Sauer-Danfoss series 90 volumetric hydraulic drive using a hydraulic loading device. The torque (braking) was monitored using a non-contact digital torque sensor M 425 3-A datum electronics and a digital indicator with LCD display (Results and discussion) As a result of one-factor passive experiments, the factors infl uencing the optimization parameter and the ranges of their variation were determined. A mathematical model of the relationship between the developed torque (braking) moment of a volumetric hydraulic drive and the parameters of a hydraulic loading device was obtained by a multi-factor active experiment. The article presents a complete planning matrix for a multi-factor active experiment, which refl ects the sequence of all possible combinations of factors that affect the optimization parameter. The most signifi cant factors affecting the value of the developed torque (braking) moment were: the pressure drop and the temperature of the working fluid in the hydraulic lines of the hydraulic loading device. (Conclusions) The mathematical model allows us to determine with high accuracy the developed torque (braking) of the volumetric hydraulic drive.