Experimental Plan Research Articles

Optimal design of experiments in the context of machine-learning inter-atomic potentials: improving the efficiency and transferability of kernel based methods

Abstract Data-driven machine learning (ML) models of atomistic interactions are often based on flexible and non-physical functions that can relate nuanced aspects of atomic arrangements to predictions of energies and forces. As a result, these potentials are only as good as the training data (usually the results of so-called ab initio simulations), and we need to ensure that we have enough information to make a model sufficiently accurate, reliable and transferable. The main challenge stems from the fact that descriptors of chemical environments are often sparse, high-dimensional objects without a well-defined continuous metric. Therefore, it is rather unlikely that any ad hoc method for selecting training examples will be indiscriminate, and it is easy to fall into the trap of confirmation bias, where the same narrow and biased sampling is used to generate training and test sets. We will show that an approach derived from classical concepts of statistical planning of experiments and optimal design can help to mitigate such problems at a relatively low computational cost. The key feature of the method we will investigate is that it allows us to assess the quality of the data without obtaining reference energies and forces—a so-called offline approach. In other words, we are focusing on an approach that is easy to implement and does not require sophisticated frameworks that involve automated access to high performance computing.

Hybrid approach for parametric optimization of wire-electrochemical spark micromachining of borosilicate glass

This work intends to implement a hybrid strategy for the multiobjective optimization of a wire-electrochemical spark micromachining (WECSMM) process, integrating the Taguchi technique and response surface approach. Initially, the optimum level of process variables, such as, thickness of workpiece, feed velocity of wire, concentration of electrolyte, and applied voltage, are evaluated using the characteristic loss function of Taguchi. After the process variables are optimized, the response surface model is built and refined using the central values that represent the best values. An experimental plan for borosilicate glass slicing was carried out during WECSMM, utilizing the L9 Taguchi design process. For simultaneous optimization, the two attribute criteria like surface roughness ( Ra) and material removal rate (MRR) have been chosen. When comparing the outcomes of a single strategy with the hybrid approach, the results demonstrate a significant increase in both quality aspects. As contrasted to Taguchi Methodology (TM), the couple approach was shown to increase MRR by 192% and lower Ra by 10%, respectively.

An experimental approach for dimensional tolerance analysis using 3D printed parts

Abstract In 2D or 3D tolerance analysis, a dimension chain involves a complex propagation of random deviations from individual parts to the controlled assembly requirement. This can be calculated by setting up complex mathematical models, possibly with the help of CAD-based software tools. The paper studies the feasibility of an alternative approach, which uses measurements on assemblies of 3D printed parts to estimate the coefficients of a linearized error propagation model. The analysis is structured as a designed experiment, where each dimension is varied in two levels resulting in two different printed parts. The experimental plan consists of building assemblies from selected combinations of parts and measuring the assembly dimension on each combination. Among the possible designs of the plan, the paper compares two methods based on finite differences and least squares. The comparison includes both simulations with randomly generated dimension chains and physical tests on simple cases. The results show that a least squares plan allows a significant improvement in the accuracy on the estimation of model coefficients compared to a finite difference plan, with just a marginally higher number of assembly combinations. However, dimensional and geometric deviations in the 3D printing process are shown to play a critical role, and criteria are suggested to reduce or compensate them.

Machine learning analysis of rivaroxaban solubility in mixed solvents for application in pharmaceutical crystallization

This study investigates the use of machine learning models to predict solubility of rivaroxaban in binary solvents based on temperature (T), mass fraction (w), and solvent type. Using a dataset with over 250 data points and including solvents encoded with one-hot encoding, four models were compared: Gradient Boosting (GB), Light Gradient Boosting (LGB), Extra Trees (ET), and Random Forest (RF). The Jellyfish Optimizer (JO) algorithm was applied to tune hyperparameters, enhancing model performance. The LGB model achieved the best results, with an R2 of 0.988 on the test set and low error rates (RMSE of 9.1284E-05 and MAE of 5.85322E-05), surpassing other models in predictive accuracy and generalizability. Parity plots confirmed the LGB model’s close alignment between predicted and actual solubility values, highlighting its robust performance. Furthermore, 3D surface plots and partial effect plots demonstrated LGB’s capacity to model solubility across different solvent systems, capturing complex interactions between T, w, and solvent effects. Finally, the LGB model predicted maximum solubility at a temperature of 305.76 K and a mass fraction of 0.753 in a dichloromethane + methanol mixture, providing valuable insights for solubility optimization in solvent selection. This work underscores the effectiveness of the LGB model for solubility prediction, with potential applications in formulation and experimental planning.

Development of technology for obtaining tablets by double granulation method with Pipsissewa (Chimaphila Umbellata) extract

The use of the therapeutic potential of medicinal plants is currently considered a physiological method of prevention and treatment, which affects the normalization of metabolic processes and the restoration of the body's functional capabilities. Medicinal products created based on plants can be used for a longer period, including in the treatment of chronic diseases. The aim of the work is to select a technology to produce tablets containing wintergreen umbrella herb liquid extract, considering the pharmaco-technological properties of the resulting dosage form. Materials and methods. The objects of the study were pipsissewa herb liquid extract and experimental model samples of mixtures of this plant substance with excipients permitted for medical use. The research on the analysis of the liquid extract and pharmaco-technological indicators of test samples of tablet mass and tablets was carried out according to the methods of the State Pharmacopoeia of Ukraine (SPhU). Determination of the optimal technology for obtaining and quantitative composition of excipients of tablets from pipsissewa herb liquid extract was carried out using mathematical design of experiments (MDE) by the method of a four-factor experiment based on the Greco-Latin square. Results. The analysis of the liquid extract of pipsissewa showed the presence of 47.0±1.0 % of extractive (dry residue) substances. It was determined that the use of Liquid-Solid technology in the technology of obtaining tablets with plant extract based on the amorphous form of magnesium aluminometasilicate (Neusilin US2) requires the use of a combined approach that will ensure the quality of the finished product. During experimental studies, the use of three interrelated production strategies was proposed. In the process of applying the proposed strategy, it was determined that microcrystalline cellulose effectively performs the function of an adsorbent and filler; the consistency of the mixtures significantly depends on the ratio of MCC 101:extract. It was investigated that the use of double granulation will allow for the increase of the amount of active ingredient in the granulate without changing the volume of MCC 101, which will allow for the achievement of a higher extract content in the finished tablets. The use of double granulation technology can also ensure uniform distribution of the active ingredient and maintain the necessary flowability of the mixture for subsequent tabletting. The use of mathematical, experimental planning in the development of double granulation (drying) technology and the composition of excipients based on studies of the fluidity of the tabletting mass; attrition, disintegration, resistance of tablets to crushing, and organoleptic indicators became the basis for the development of the composition of the medicinal product in the form of tablets containing pipsissewa liquid extract. Conclusions. The adsorption property and its influence on the tabletting process of the synthetic amorphous form of magnesium aluminometasilicate (Neusilin US2) and microcrystalline cellulose 101 (MCC 101) were determined when using these substances as a carrier for pipsissewa grass liquid extract. The possibility of conducting a double granulation process using microcrystalline cellulose 101 (MCC 101) according to a given amount of liquid extract was proven. Using mathematical planning of the experiment, the drying conditions of the granulate and the quantitative composition of excipients were selected

Optimizing the Ventura Nozzle for Abrasive Jet Plant

Pneumatic abrasive surface treatment is an integral part of many technological processes used for applying coatings, performing repair or doing a restoration work, etc. The operation efficiency of the pneumatic abrasive plant is characterized by several factors. The main factor is the time of surface treatment of the material. The faster the surface treatment, the higher the treatment efficiency since a large amount of compressed air and abrasive material is required for the operation of a pneumatic abrasive plant. The efficiency of the pneumatic abrasive plant is most affected by the operating nozzle, the design of which defines the characteristics of the air-abrasive mixture. The operating nozzle is designed to form a jet and increase the speed of the working flow consisting of continuous and dispersed phases. The effect on the geometric dimensions and design of the nozzle can be varied by its characteristics. The operating characteristics of the nozzle are its main parameters that define the processing time of the material surfaces, in particular the speed of the working mixture at the nozzle outlet, the mass flow rate of the dispersed and continuous phases, the reaction force of the jet, and the value of contact stresses on the processed surface caused by the jet impact. The purpose of this research is to optimize the geometry of the operating nozzle of the pneumatic abrasive plant. The implementation of the set goal is ensured by using the plan of the full factorial experiment, performing a series of numerical studies using the ANSYS software package. The obtained data are verified on a special experimental stand designed for studying the operating nozzles of the pneumatic abrasive plant. Based on the obtained research data we can give practical recommendations for the design of operating nozzles used for the abrasive jet processing of material surfaces.

Similar pipeline experiment and disaster control emergency plan of updraft airflow fire in mine

Based on the engineering example of Linsheng coal mine, this paper uses TF1M3D computer simulation platform to systematically analyze the process of smoke flow spreading and air flow disorder disaster from the perspective of the whole mine network, and puts forward corresponding plans and measures. A small scale similar experiment was carried out to study the updraft flow fire in the mine. Through the analysis of the collected experimental data, the variation law of the air volume of the fire source in the main air path, side branch road and total air path with different air volume and the variation characteristics of the temperature at the monitoring point with time were obtained under different air volume conditions, and the critical air volume was fitted as 1.65 m3·s− 1. The CAD digital stereoscopic model of Linsheng mine was established, and the TF1M3D simulation platform was used to simulate the mine fire under normal ventilation condition. The preset fire source point of the conveyor belt roadway in the first west district of Linsheng coal mine was used to observe the change of air volume during the fire process.The smoke flow reversal phenomenon would occur when the fire occurred in the first west district. The reversed smoke flow will flow to the 503 face and cause contamination. In order to inhibit the reversal of smoke flow, the emergency plan is proposed to increase the number of fan rotation and set fire doors in appropriate places, which can effectively inhibit the diffusion of smoke and improve mine disaster resistance.

Study on the Mechanism of Energy Dissipation in Hemispherical Resonator Gyroscope.

The hemispherical resonator gyroscope is a gyroscope based on the principle of Coriolis vibration, widely used in inertial measurement systems of spacecraft. This article decomposes the gyroscope into two parts: the resonator shell and the gyroscope head, establishes the energy dissipation mechanism of the gyroscope, and conducts experimental verification. Firstly, based on the working principle of the gyroscope, a mechanical analysis model of the hemispherical resonator gyroscope head with a resonator spherical shell containing quality defects under second-order vibration state was established. The unbalanced force applied by the resonator spherical shell to the hemispherical resonator gyroscope head was analyzed, and the energy transfer path and dissipation mechanism from the spherical shell to the hemispherical resonator gyroscope head were explained. Finally, through the constructed testing platform, the circumferential quality factor test of the hemispherical resonator gyroscope before and after assembly was completed according to the designed experimental plan, and the consistency between theory and experimental phenomena was verified experimentally.

Optimization of Ingredients in Polystyrene Waste-Based Adhesive for Wood-to-Wood Bonding Using Experimental Planning

In this study, an adhesive was prepared using waste polystyrene foam for wood-to-wood bonding. The effects of natural rubber (NR) and methylene diphenyl diisocyanate (MDI) content on adhesion were investigated. NR modifies polystyrene, acting as a plasticizer to address its hardness and brittleness, while MDI functions as a curing agent for the adhesive system. Characteristics such as the viscosity and wettability of the liquid adhesive were determined. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were employed to evaluate the properties and structure of the resulting adhesive films. The bonding ability between two wood plates using this adhesive was evaluated through tensile shear strength and impact strength. An experimental plan was devised to identify the optimal content of NR and MDI, providing the highest tensile shear strength and impact strength of the bond. The research revealed that the highest tensile shear strength achieved was 3.87 N/mm² at 16.468% NR and 7.882 phr MDI, while the highest impact strength reached 15.352 kJ/m² with NR and MDI contents of 16.079% and 7.620 phr, respectively. The experimental planning models demonstrated a good fit for predicting tensile shear strength and impact strength.

Exploring the Photocatalytic Efficiency of Gold Nanoparticles Deposited on Ni-Al-Zr-Layered Double Hydroxides for Selective Glucose Oxidation.

Confronting escalating challenges in energy security and environmental sustainability has intensified interest in renewable sources for fuels and chemicals. Among the most promising alternatives, sugars derived from biomass are emerging as a cornerstone in advancing an environmentally sustainable economy. Within this framework, the development of sunlight-driven carbohydrate oxidation is of significant interest, as it enables the production of a broad spectrum of high-value, bio-sourced chemicals through eco-friendly processes. Gold nanoparticles (Au NPs) immobilized on inorganic supports have demonstrated considerable potential in this area, although the methodology still requires further exploration. In this study, we explored the selective oxidation of glucose into the corresponding gluconic acid salt in presence of a novel Au/Ni-Al-Zr-layered double hydroxide (LDH) photocatalyst under standardized A.M. 1.5 G light illumination. To optimize the photocatalytic conditions, an experimental plan is herein proposed, highlighting the critical influences of both catalyst loading and pH. In optimal conditions, the Au catalyst demonstrated a high efficiency, achieving 87% glucose conversion and 100% selectivity towards gluconic acid in only 90 min. By means of long-pass filters to select the incident light energy to the photocatalytic reactor, we evidenced that the charge transfer processes were occurring from the Ni-Al-Zr LDH support to the gold nanoparticles, thus opening new directions towards further photocatalyst modifications. This work underlines the potential of Au/LDH materials for sunlight-driven photocatalysis and provides a pathway for the sustainable production of high-value chemicals from renewable biomass sources.

Dependence of wear intensity on the coating material of the hydraulic cylinder of the garbage truck’s sealing plate

The article is dedicated to the study of the influence of the coating material on the wear rate of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate. By means of a first-order planning of experiment with first-order interaction effects using the Box-Wilson method, an adequate dependence of the wear rate of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate on the coating material was determined. It is established that according to the Student’s criterion, among the studied factors of influence, the intensity of wear of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate is most affected by the iron content in the coating, the least – by the chromium content, and the nickel content affects only indirectly in interaction with the iron content. The response surfaces of the goal function – the intensity of wear of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate and their two-dimensional sections in the planes of the influence parameters are shown, which allow to clearly illustrate the specified dependence of this goal function on individual influence factors. The expediency of conducting further research to determine ways to further improve the wear resistance of the hydraulic cylinder of the mechanism of the garbage truck’s sealing plate is shown

METHODOLOGY OF EXPERIMENTAL STUDY OF LOCAL CONDITIONS OF NON-STATIONARY HEAT TRANSFER

The task of studying the conditions of heat exchange of a sprayed liquid – water with different concentrations of surfactants with a high-temperature surface has defined a number of problems that need to be solved. Two tasks: development of means for experimental study of non-stationary local conditions of heat exchange of a high-temperature surface with a sprayed liquid, taking into account the possibility of implementing a change in the level of determining factors in the range corresponding to their real values ​​in full-scale energy and metallurgy facilities, and the task of choosing a method for identifying the boundary conditions of heat exchange, from our point of view, are the main ones. Analysis of scientific publications and our own research have allowed us to establish that the central factor influencing local heat exchange conditions is the local irrigation density, which would be one of the factors for developing effective cooling systems, or for determining the thermal state of an object under various external influences. The next objective of the study is to investigate the intensity of heat exchange as a function of underheating of the sprayed liquid – water with different concentrations of surfactants at different local irrigation densities and surface temperatures. Since we are considering a multifactorial problem, modern requirements of the theory of experimental planning have made it possible to develop a methodology for experimental study of local conditions of non-stationary heat exchange, which will allow us to conduct a study of the boundary conditions of heat exchange as a function of the interrelated influence of the irrigation density, surface temperature, velocity and angle of impingement of the sprayed liquid onto the surface. The measurement technique we have developed will allow us to obtain reliable research results. Solving the inverse problem of heat conduction will allow us to establish the degree of influence of almost all factors noted as determining. It is obvious that in this case, studying the boundary conditions of heat exchange as a function of the speed of movement of a high-temperature surface results in a large independent problem.

Assessment of evolutionary multi-objective optimisation algorithms for thermoplastic injection moulding in aluminium moulds

In order for a plastic part manufactured by the injection moulding process to be of the desired quality, it is necessary to maintain control of the process parameters. To increase productivity and reduce defects in parts, various studies have been carried out to propose and evaluate methods for determining injection parameters, which are based on the use of experimental planning techniques as well as the application of optimisation algorithms. This work proposes an experimental design with 6 injection parameters (mould temperature, melt temperature, injection time, percentage of volume filled, packing time and packing pressure) to determine the initial search space for the NSGA-II and MOEA/D optimisation algorithms in relation to the use of aluminium moulds. This procedure was used via a computer code described in the PYTHON programming language to determine the appropriate injection parameters for minimising part warpage and injection pressure. The results showed that an increase in compaction pressure is associated with a reduction in warpage and vice versa. It was observed that the NSGA-II algorithm showed a greater diversity of points on the approximate Pareto frontier compared to the MOEA/D algorithm. In the case of the proposed study, MOEA/D presented a more viable solution, determining a lower packing pressure, less warping of the part and a shorter cycle time. The NSGA-II algorithm required around 4 hours more computational time than MOEA/D.

Development and Characteristics of Infra-Lightweight Foamed Concrete

This research focuses on development of infra-lightweight foamed concrete with very low density. The first step is to manufacture stable preformed foam with optimizing the applied air and water pressure as well as the foaming agent dosage. Then, an appropriate mixing procedure of infra-lightweight concrete is developed. In the experimental plan, 8 different mixes are prepared and tested with different densities, 200, 300, 500, 600 kg/m3. Two values of w/c ratio are used, 0.6 and 0.4. A superplasticizer compatible with the foaming agent is used in the second case (w/c 0.4) in order to achieve the required workability. Compressive strength, thermal conducting and scanning electron microcopy (SEM) measurements have been measured in order to characterize the developed foamed concrete. The experimental results show that for infra-lightweight foamed concrete, the material density is the main parameter governing its compressive strength and thermal conductivity. The SEM observations provide evidences confirming the results of compressive strength and thermal conductivity. The role of w/c is insignificant on compressive strength and thermal conductivity of such type of concrete with very low density. The findings of this investigation revealed that infra-lightweight concrete with self-leveling ability, appropriate strength and different densities can be produce with giving more concern to the performed foam characteristics as well as the mixing technology.

Better power by design: Permuted-subblock randomization boosts power in repeated-measures experiments.

During an experimental session, participants adapt and change due to learning, fatigue, fluctuations in attention, or other physiological or environmental changes. This temporal variation affects measurement, potentially reducing statistical power. We introduce a restricted randomization algorithm, permuted-subblock randomization (PSR), that boosts power by balancing experimental conditions over the course of an experimental session. We used Monte Carlo simulations to explore the performance of PSR across four scenarios of time-dependent error: exponential decay (learning effect), Gaussian random walk, pink noise, and a mixture of the previous three. PSR boosted power by about 13% on average, with a range from 4% to 45% across a representative set of study designs, while simultaneously controlling the false positive rate when time-dependent variation was absent. An R package, explan, provides functions to implement PSR during experiment planning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Granite Dust and Silica Fume as a Combined Filler of Reactive Powder Concrete.

By volume, cement concrete is one of the most widely used construction materials in the world. This requires a significant amount of Portland cement, and the cement industry, in turn, causes a significant amount of CO2 emissions. Therefore, the development of concrete with a reduced cement content is becoming an urgent problem for countries with a significant level of production and consumption of concrete. Therefore, the purpose of this article is to critically investigate the possibility of using inert granite dust in combination with highly active silica fume in reactive powder concrete. The main physical and mechanical properties, such as the compressive strength at different curing ages and the water absorption, were studied using mathematical planning of experiments. The consistency and microstructure of the reactive powder concrete modified with granite dust in combination with silica fume were also analyzed. Mathematical models of the main properties of this concrete are presented and analyzed, and the graphical dependencies of the influence of composition factors are constructed. A more significant factor that affects the compressive strength at all curing ages is the silica fume content, increases in which to 50 kg/m3 lead to a 25-40% increase in strength at 1 day of age, depending on the granite dust content. In turn, an increase in the amount of granite dust from 0 kg/m3 to 100 kg/m3 in the absence of silica is followed by an increase in strength of 8-10%. After 3 days of curing, the effect of granite dust becomes more significant. Increases in the 28-day strength of 25%, 46% and 56% were obtained at a content of 50 kg/m3 of silica fume and 0 kg/m3, 100 kg/m3 and 200 kg/m3 of granite dust in concrete, respectively. It is shown that the effect of inert granite dust is more significant in combination with silica fume at its maximum content in the range of variation. The pozzolanic reaction between highly active silica and Ca(OH)2 stimulates the formation of hydrate phases in the space between the grains and causes the microstructure of the cement matrix to compact. In this case, the granite dust particles act as crystallization centers.

The Influence of a Community Science Technology Learning Model Based on a Scientific Approach to Improve Science Learning Outcomes

The science and technology model is learning to teach science and technology in the context of experience and everyday life, focusing on societal issues, whether local, regional, national, or global, with science and technology components. Meanwhile, the scientific approach is an approach to learning science process skills. It uses a scientific approach where students are directed and guided in observing, asking, trying, reasoning, and building networks to disseminate the learning results obtained. Learning outcomes are a path to mastering knowledge or skills in a subject, usually indicated by test scores or numbers given by the teacher. Learning outcomes are obtained from learning to master knowledge, usually developed and shown by numbers. This research aims to determine whether implementing a science and technology learning model based on a scientific approach affects the science learning outcomes of grade IV students at SDN Pemongkong. Researchers are implementing technology in science learning at SDN 1 Pemongkong. Still, many obstacles exist, such as internet signals and technological stupors; only some have a laptop or cellphone. Therefore, the idea that emerged in this research was the use of technology that can be accessed by all students, namely the community science technology model based on a scientific approach, which is expected to improve student learning outcomes. The method used in this research is experimentation. This type of experimental research uses Quasi-Experimental Design or quasi-experiments. The experimental plan used in this research is a Nonequivalent Control Group Design. Hypothesis testing is carried out using uji t (independent samples test). Comparison of the average learning outcomes of the experimental class and the control class for the two classes experienced an increase compared to before learning; namely, the average value of the control class at the pretest 54.82 and increased to 73.10 after learning, while the average value of the experimental class is at posttest 58.07 and rose to 74.42 on posttest. The average learning outcomes are similar between the control class and the class experiment. However, the average learning outcomes of the experimental class are still higher than those of the control class. The class that was taught used the community science and technology learning model. Namely, two students got a score of 90 in the control class, and in the conventional class, only one got a 90. By hypothesis testing, face H0 accepted that the scientific approach-based community science and technology learning model influences the learning outcomes of class IV students at SDN 1 Pemongkong. In this case, it can be interpreted that the community science and technology learning model positively impacts student learning outcomes.

Effect of boron oxide and basicity on viscosity and crystallization onset temperature of СаО–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>–12%Cr<sub>2</sub>O<sub>3</sub>–3%Аl<sub>2</sub>O<sub>3</sub>–8%МgO slag system

The rapid growth of demand for stainless steel and, accordingly, its production, which occurred in the second half of the 20th century and continues till today, makes it necessary to conduct studies of the properties of oxide systems that will contribute to the improvement of metallurgical production technologies for such steel. Therefore, in this paper, using the method of simplex grids for experimental planning and vibration viscometry, a study was conducted of the effect of basicity and boron oxide content on the viscosity and crystallization onset temperature of slags of the СаО–SiO2–B2O3–12%Cr2O3–3%Аl2O3–8%МgO oxide system formed during the reduction period of the production of low-carbon stainless steel by the argon-oxygen decarbonization (AOD) process, which is currently the main method for producing corrosion-resistant steel. The introduction of boron oxide into AOD-slags is a possible solution to the problem of instability of the physical properties of slags during smelting, caused by the volatility of fluorspar fluorides, traditionally used as a flux, and compliance with increasingly stringent environmental requirements by eliminating the formation of toxic fluorine compounds. Based on the results of experimental studies of the viscosity of slags of the studied oxide system depending on the chemical composition and temperature, approximating mathematical models in the form of a reduced third-degree polynomial are constructed. Graphically, the results of mathematical modeling are presented in the form of “composition – property” diagrams, which allow quantitatively determining the effect of temperature and chemical composition of the slags under study on viscosity and their composition on the crystallization onset temperature. It is noted that at 1600 and 1650°C, an increase in the boron oxide content in the slag from 3.0 to 6.0% has a favorable effect on the fluidity of the formed slags in the basicity range of 1.0-2.5. For example, an increase in the boron oxide concentration from 3.0 to 6.0% ensures a decrease in the viscosity of the slags from 2.0 to 0.5 Pa s at a temperature of 1600°C and from 0.4 to 0.3 Pa s at a temperature of 1650°C in the region of increased basicity up to 2.0-2.5.

The estimation of desulphurization property of boron-containing slags of the reduction period of the AOD process

Now the main industrial method for producing stainless steel is smelting in an argon-oxygen decarburization (AOD) furnace, therefore the paper presents the results of thermodynamic modeling of the desulfurization process of low-carbon semi-finished stainless steel during the reduction period of AOD process by treating it with boron-containing slags. The use of boron oxide as a fluxing material instead of fluorspar reduces the environmental harm and decrease the viscosity of the formed slags. Using the simplex lattice method of experiment planning, a matrix was constructed containing 16 compositions of the oxide system СаО–SiO2–(3-6%)В2О3–12%Cr2O3–3%Al2O3–8%MgO with variable basicity of 1.0–2.5. Based on the generalization of the thermodynamic modeling results, approximating mathematical models in the form of a reduced third-degree polynomial were constructed. The adequacy of the models is verified by three control points not included in the experimental design matrix using the t-criterion at a significance level of 0.01. The results of mathematical modeling are presented graphically in the form of diagrams of the dependence of the equilibrium sulfur distribution on the slag composition at temperatures of 1600 and 1700°C. The constructed diagrams made it possible to quantitatively estimate the effect of temperature, basicity and boron oxide content on the equilibrium interphase distribution coefficient of sulfur. It is found that an increase in slag basicity from 1.0 to 2.5 in the considered range of boron oxide content (3.0–6.0%) improves the metal desulfurization process, ensuring an increase in the equilibrium interphase distribution coefficient of sulfur from 0.1 to 5.0–7.0 at temperatures of 1700 and 1600°C. It’s shown that the process of metal desulfurization in slags with low basicity of 1.05–1.15 is accompanied by a slight decrease in the sulfur content in the metal. At the same time, the concentration of boron oxide has virtually no negative effect on the process of metal desulfurization. Slags with increased basicity up to 2.0–2.5 have more favorable refining properties. The sulfur concentration in the metal during their formation decreases from 0.015 to 0.007–0.008%.

Development of a machine for cultivation and sowing of grain crops

BACKGROUND: When designing sowing machines, requirements are imposed to ensure soil preparation and sowing of grain crops as part of the implementation of energy-saving technology, since their productivity largely depends on these types of work. Thus, increasing the efficiency of sowing machines is an urgent task. AIM: – the development of a seeder design that allows, with maximum simplification of the design compared with analogues, reducing metal consumption and increasing the manufacturability of the product, both in production and in operation, to ensure the best conditions for the growth of crops and a significant increase in yield. In one pass, the seeder sows the main crop, small-seeded crop (binary component) and introduces mineral fertilizers, and can also be used when putting waste and fallow lands into circulation. METHODS: Methods of system analysis, mathematical modeling, and experiment planning were used in the development of the drill design. Experimental studies were conducted in the field and laboratory conditions in accordance with existing methods, using modern electronic and mechanical devices. Experimental data processing was carried out in the environment of the MathCAD system, Microsoft Office Excel. RESULTS: In contrast to known analogues, the proposed technical solution of the seeder simplifies the design, reduces the weight and improves the manufacturability of the product - on a simple frame welded in one plane from pipes, but free enough for the passage of crop residues and soil particles, on one side are installed stands with tines for mounting discs, and on the other - for mounting the hopper. The plane of attachment of tines for disc mounting is as close as possible to the soil surface, which reduced the load on the frame and reduced its material intensity. The seed drill-cultivator developed by the authors allows to realise all operations related to soil cultivation and sowing of grain crops Translated with DeepL.com (free version). CONCLUSIONS: The design solutions for the cultivator planter obtained by the authors simplified the design of the planter compared to its analogues, reduced its metal consumption, and therefore its weight, which makes it possible to use tractors of a smaller class with lower fuel consumption. The adjustment of the angle of attack of the discs has also been simplified, and the additional installation of baking powder has reduced the clogging of the seeder with crop residues and soil lumps.