Processing Of Experimental Data Research Articles

Pengaruh Jumlah Penumpang dan Durasi Buka Tutup Pintu Terhadap Perubahan Suhu (Studi Kasus: Kereta Inspeksi PPI Madiun)

The inspection train is specialized equipment used for examining railway tracks, transporting personnel, and carrying work equipment. The inspection train must be equipped with operational tools, monitoring equipment, and work comfort equipment. One of the comfort equipment is air circulation control, which should provide comfort to the personnel while working. Factors influencing the air temperature inside the inspection train include the number of passengers and duration of door opening. This research employs the Design of Experiment data processing method, with the data analyzed using a 2-factor factorial design experiment, with the assistance of Minitab software to understand the influence of the number of passengers and the duration of door opening-closing on temperature changes inside the inspection train. The result obtained from Minitab analysis indicate that the number of passengers has a significant influence on temperature changes inside the inspection train, accounting for 5.2% of the variation. On the other hand, the duration of door opening-closing does not have a significant effect on temperature changes. Additionally, the interaction between the number of passengers and the door open-close duration does not have a significant influence on temperature changes inside the PPI Madiun Inspection Train.

On phase correspondence between chemical oscillations in liquid Belousov-Zhabotinsky mixture filling catalyst-containing matrix and resulted gel's chemomechanical oscillations

We investigated phases and phase differences between coupled mechanical and chemical self-oscillations running in two kinds of newly synthesised chemomechanical gels. Processing of experimental data was model-free and it was based on spectral and wavelet approaches of the theory of dynamical systems. It was applied to samples of different sizes and compositions (Ru- and Fe-based gels). It was revealed that the Ru-based gels demonstrate a faster mechanical response to the redox changes of the Ru-moiety coupled to the Belousov-Zhabotinsky chemical reaction than the Fe-based gels. This demonstrated a significant phase difference between the redox changes of the Fe-moiety and the mechanical oscillations. Special attention was paid to the phase-coupling features for averaged higher harmonics, which are significant due to the high degree of nonlinearity of the chemomechanical oscillatory process.

Results of experimental research of the process of forming reinforced concrete products by the centrifugation method

The method of conducting an experimental study of the process of forming reinforced concrete products is disclosed. The key factors influencing the quality indicators of the product being formed are defined and considered. On the basis of the conducted active, factorial experiment, a regression equation was compiled, graphical dependences of the influence of these factors on the process were obtained, rational parameters of the centrifugation process were determined, which are decisive in the manufacture of reinforced concrete products by the centrifugation method. Based on the results of laboratory experiment data processing, recommendations were developed for optimizing the operating parameters of industrial equipment for forming reinforced concrete products by the centrifugation method. Problem. When forming reinforced concrete products by the centrifugation method, some problems may arise, uneven distribution of the mixture in the mold body and of reinforcement, formation of voids or cracks, insufficient compaction of the mixture. If the parameters of the centrifugation process are not properly controlled, the quality of the products may vary, which may lead to deviations from specifications and standards. Problems with the deformation of the molds after forming the product can lead to damage to the product or difficulties in its removal. Goal. Based on the results of the conducted factorial experiment, recommendations are developed regarding the rational parameters of the process of forming columns of reinforced concrete supports for power transmission lines by the centrifugation method in the conditions of an operating technological line. Methodology. The basis of the research is the method of conducting a planned factorial experiment with further statistical processing of the obtained results using a computer program. Results. Based on the processing of the obtained results of the conducted factorial experiment, the following recommendations are suggested regarding the rational parameters of the process of forming reinforced concrete pillars for power lines by the centrifugation method in the conditions of an operating technological line.

Authentication of selected white wines by geographical origin using ICP spectrometric and chemometric analysis

An important aspect of assessing the authenticity of wines is its geographical origin. The aim of the work is to authenticate by geographical origin according to the data of the ICP-spectrometric and chemometric analysis of elemental "images" of wines produced from white grape varieties Chardonnay, Riesling and Muscat grown in four regions of the Krasnodar Territory, Russia. The difference in the contents of Al, Ba, Ca and Rb in wines was found depending on the variety, and Al, Ba, Rb, Fe, Li, Sr – depending on the region of grape growth. Different models of the experimental data processing were used for attribution of the produced varieties of wine to the area of the grape's growth. The criterion for the quality of the constructed models was the accuracy of the attribution of a wine variety to the area of the grape's growth (%). Analysis of the elemental analysis data of 153 wine samples showed that in terms of attribution accuracy, automated neural networks (100 %) are preferred among machine learning methods, followed by support vector machines (98.69 %) and general discriminant analysis (94.77 %). The applied mathematical models enabled the revealing of the cluster structure of the analyzed wine varieties and their attribution to the area of a grape growth with high accuracy. Sr, Li and Fe concentrations in wines were found as the dominating predictors in the constructed models for definition of the geographical origin of wines. The combination of ICP-spectrometric analysis data with the capabilities of statistical modeling of machine learning methods focused on large-dimensional data made it possible to successfully solve small-dimensional problems of the definition of the geographical origin of wines by their elemental composition and variety.

Justification Of The Technology Of Cavitation Massage Meat Delicates From Pork

The article discusses the methodology and results of experimental studies to determine the optimal modes of cavitation massaging of pork meat delicacies. It has been established that the use of this technology will significantly improve the technological and consumer properties of the finished product: looseness of meat fibers, improved juiciness and tenderness of meat, greater moisture-binding and water-holding capacity and, as a result, a greater yield of finished products (84% versus 75% provided by the standards). According to the results of the study, the optimal parameters of cavitation massaging were: ultrasound frequency 22 kHz, power 150 W. In the process of processing experimental data, a functional dependence of the cavitation massaging duration on the thickness of a piece of meat and the ultrasound power was obtained, which showed that the duration of the operation with the above parameters will be 4-5 minutes when using one-sided ultrasonic meat massagers or 2–2.5 minutes when using bilateral ultrasonic meat masseurs for a separate piece of pork with a thickness of 50-70 mm (carbonade, neck, loin). It was found that the thickness of the meat and the power of ultrasound have the strongest influence on the duration of the massaging operation.

ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ ВЛИЯНИЯ РАСТВОРОВ ЛИМОННОЙ КИСЛОТЫ НА СТЕПЕНЬ ИЗВЛЕЧЕНИЯ ПЕКТИНА ИЗ ФЕРМЕНТИРОВАННОГО СВЕКЛОВИЧНОГО ЖОМА

Pressed sugar beet pulp is a promising source of pectin. Currently, the growth of scientific and technological progress has made it promising to use such methods of controlled transformation of plant raw materials, in which the impact on the quality and yield of the target component is minimal, in contrast to the classic acid-alcohol method of producing pectin. Of greatest interest are biotechnological methods for extracting biologically active substances from plant materials, providing a higher yield while maintaining their properties. However, previous studies have established that during enzymatic hydrolysis-extraction of sugar beet pulp, about 50 % of pectin remains in the fermented sugar beet pulp. This necessitates research aimed at additional extraction of pectin from fermented beet pulp obtained as a result of enzymatic hydrolysis of pressed sugar beet pulp. The article resents the results of studies of the effectiveness of the influence of citric acid solutions on the degree of pectin extraction from fermented sugar beet pulp. Extraction of pectin from fermented sugar beet pulp was carried out under various conditions. When carrying out the extraction process, the extraction temperature was taken as constant factors – 55 ºC, the ratio (wt./vol.) fermented beet pulp: aqueous solution of citric acid equal to 1 : 10 and the intensity of mixing of the system, characterized by a stirrer rotation speed, equal to 0.33 s -1 . The concentration of an aqueous solution of citric acid and the extraction time were taken as variable factors, and the degree of pectin extraction was taken as a response function. Based on the results of mathematical processing of experimental data, an equation was obtained that adequately describes the effect of the concentration of an aqueous solution of citric acid and extraction time on the degree of pectin extraction. As a result of the studies, it was established that the optimal modes for extracting pectin from fermented beet pulp, ensuring a degree of pectin extraction of 10.81 %, are a concentration of an aqueous solution of citric acid of 0.33 % and an extraction time of 80 minutes. Key words: PECTIN-CONTAINING RAW MATERIALS, FERMENTED BEET PULP, PECTIN, CITRIC ACID, EXTRACTION DEGREE, EFFICIENCY

Efficient end-to-end simulation of time-dependent coherent X-ray scattering experiments.

Physical optics simulations for beamlines and experiments allow users to test experiment feasibility and optimize beamline settings ahead of beam time in order to optimize valuable beam time at synchrotron light sources like NSLS-II. Further, such simulations also help to develop and test experimental data processing methods and software in advance. The Synchrotron Radiation Workshop (SRW) software package supports such complex simulations. We demonstrate how recent developments in SRW significantly improve the efficiency of physical optics simulations, such as end-to-end simulations of time-dependent X-ray photon correlation spectroscopy experiments with partially coherent undulator radiation (UR). The molecular dynamics simulation code LAMMPS was chosen to model the sample: a solution of silica nanoparticles in water at room temperature. Real-space distributions of nanoparticles produced by LAMMPS were imported into SRW and used to simulate scattering patterns of partially coherent hard X-ray UR from such a sample at the detector. The partially coherent UR illuminating the sample can be represented by a set of orthogonal coherent modes obtained by simulation of emission and propagation of this radiation through the coherent hard X-ray (CHX) scattering beamline followed by a coherent-mode decomposition. GPU acceleration is added for several key functions of SRW used in propagation from sample to detector, further improving the speed of the calculations. The accuracy of this simulation is benchmarked by comparison with experimental data.

Effect of warm forming process parameters on 42CrMo4 skew rolled bar mechanical properties and microstructure

Skew rolling is a manufacturing process in which two or three rolls are used to reduce the diameter or modify the shape of a cylindrical workpiece, which is used to manufacture mechanical components such as shafts, rods or balls. Hot conditions are used to overcome limitations related to material ductility, residual stress and machine capacity. In this paper, the warm skew rolling (WSR) process of 42CrMo4 rods is modeled by the finite element method. The effects of forming parameters, namely initial temperature and roll rotational velocity, on the material strain rate, thermal properties, microstructure and hardness were analyzed. Simulation results were validated by experimental process data, while hardness tests and SEM-EBSD microscopy were used to assess mechanical properties and microstructure, respectively. The WSR resulting microstructure is different from the normalized ferritic–pearlitic initial one. The degree of spheroidization (DoS) of cementite increases with temperature. The maximum DoS of 86.5% occurs at the initial temperature of 750 °C, leading to the highest material softening. Rolling from lower temperatures favors grain fragmentation and the achievement of incomplete spheroidization, which, in combination with the highest proportion of high-angle boundaries, contributes to a higher hardness of the rods with respect to those rolled at higher temperatures. The highest reduction in hardness takes place at 750 °C and 30 rpm, leading to 209.4 HV1 (30.7% reduction) and 194.1 HV1 (35.7% reduction) in the near-surface and internal regions, respectively. The driving factor is the transformation of cementite precipitates into a spheroidal form characterized by the greatest degree of dispersion.

Алгоритм комп'ютерної обробки кінетичних залежностей відгуку газового сенсора з інтелектуальними компонентами

The purpose of the work is to develop an algorithm using intelligent components that will allow processing of experimental data of response kinetics of resistive gas sensors based on the algorithm of the model of the stretched exponential function of Kohlrausch-Williams-Watts, without operator intervention. The problems of implementing full automation of the information-measuring system for the study of the main characteristics of gas-sensitive sensors - the selection of the most informative time interval - are describe. The algorithm for processing the experimental kinetic dependence of the response of gas sensors based on the model of a stretched exponential function with intelligent components that allow choosing the most informative time interval from the processed kinetic dependences is present.

LL-GNN: Low Latency Graph Neural Networks on FPGAs for High Energy Physics

This work presents a novel reconfigurable architecture for Low Latency Graph Neural Network (LL-GNN) designs for particle detectors, delivering unprecedented low latency performance. Incorporating FPGA-based GNNs into particle detectors presents a unique challenge since it requires sub-microsecond latency to deploy the networks for online event selection with a data rate of hundreds of terabytes per second in the Level-1 triggers at the CERN Large Hadron Collider experiments. This article proposes a novel outer-product based matrix multiplication approach, which is enhanced by exploiting the structured adjacency matrix and a column-major data layout. In addition, we propose a custom code transformation for the matrix multiplication operations, which leverages the structured sparsity patterns and binary features of adjacency matrices to reduce latency and improve hardware efficiency. Moreover, a fusion step is introduced to further reduce the end-to-end design latency by eliminating unnecessary boundaries. Furthermore, a GNN-specific algorithm-hardware co-design approach is presented which not only finds a design with a much better latency but also finds a high accuracy design under given latency constraints. To facilitate this, a customizable template for this low latency GNN hardware architecture has been designed and open-sourced, which enables the generation of low-latency FPGA designs with efficient resource utilization using a high-level synthesis tool. Evaluation results show that our FPGA implementation is up to 9.0 times faster and achieves up to 13.1 times higher power efficiency than a GPU implementation. Compared to the previous FPGA implementations, this work achieves 6.51 to 16.7 times lower latency. Moreover, the latency of our FPGA design is sufficiently low to enable deployment of GNNs in a sub-microsecond, real-time collider trigger system, enabling it to benefit from improved accuracy. The proposed LL-GNN design advances the next generation of trigger systems by enabling sophisticated algorithms to process experimental data efficiently.

중등 화학 예비 교사를 대상으로 한 원격 제어 ‘산-염기 적정’ 실험 활동의 개발과 효과 탐색

Objectives This study aims to develop experimental activities using remote-control technology and apply them to prospective middle school chemistry teachers to explore the potential of the developed 'acid-base titration' chemistry inquiry experiment as a new experimental method.
 Methods The participants, consisting of 20 prospective teachers majoring in chemistry education from a university in the central region, engaged in a 4-session experiment where they remotely operated equipment, observed chemical experiment situations, and collected real-time data. Subsequently, based on their remote-controlled experiment experiences, surveys and semi-structured interviews were conducted to assess participants' experiences related to inquiry, alleviation of isolation, and a sense of realism in online settings.
 Results Remote-controlled experiments were divided into 'remote control of equipment' and 'remote control of data processing.'Remote control of equipment' involved sending signals to experimental devices through Blynk, wirelessly transmitting these signals to operate laboratory equipment. 'Remote control of data processing' allowed participants to use remote control functions to store and process experimental data in an Excel file. The developed remote-controlled inquiry experiment program in this study (1) provided prospective middle school chemistry teachers with experiences of basic inquiry functions such as observation and measurement, as well as integrated inquiry functions such as data interpretation and conclusion derivation, even in online experimental situations; (2) confirmed real-time learner-centered interactions, including learner-learner interactions and learner-content/ interface interactions; and (3) demonstrated a high level of presence in terms of teaching, cognitive, and affective realism.
 Conclusions Despite being a remote-based experiment class, it was evident that providing prospective teachers with opportunities for experiences and interactions in scientific inquiry activities could alleviate isolation and enhance a sense of realism. This study is expected to offer insights into designing and implementing the entire process of inquiry teaching in an online context.

Cutting Edge High‐Throughput Synthesis and Characterization Techniques in Combinatorial Materials Science

AbstractThe Materials Genome Initiative is expected to accelerate the materials discovery and design by fundamentally changing the trial‐and‐error research paradigm. However, mass data from high‐throughput experiments is still essential for the revelation of rules and verification of theories. In fact, the development of combinatorial materials science is always on the strength of the upgrade and evolution of high‐throughput techniques in each stage, especially high‐throughput materials synthesis and characterization. Herein, this review summarizes the high‐throughput synthesis methods for combinatorial materials libraries, especially the co‐deposition and masking techniques of thin‐film fabrication; and details the high‐throughput characterization methods for specific material properties and typical material categories, which comes down to the spectroscopy and microscopy techniques. It is considered that high‐throughput concepts will be the predominant lab experimentation in the future, along with advanced experimental techniques and convenient data processing procedures. Before that, more cooperation between multiple researchers from different fields should be conducted to complete the combinatorial materials research, since the high‐throughput technology covers multiple disciplines with a huge span.

ИЗМЕНЕНИЕ ХИМИЧЕСКОГО СОСТАВА ЯЧМЕННОЙ МУКИ В ПРОЦЕССЕ ХРАНЕНИЯ РАЗЛИЧНЫМИ СПОСОБАМИ

The purpose of research is to study the influence of various conditions (type of packaging, storage method) on the chemical composition of barley flour during storage. Objectives: to analyze changes in the chemical composition of barley flour samples during storage using various packaging options and storage methods; to determine the presence of a statistically significant difference in terms of chemical composition between options and shelf life. The object of the study is barley flour produced according to TU 10.61.22-005-97623423-2018. Flour samples were stored at the Engineering Center of the Federal State Budgetary Educational Institution of Higher Education Krasnoyarsk State Agrarian University using various types of packaging. Samples of barley flour stored in bulk storage were selected for analysis at the enterprise. The analysis of the chemical composition of barley flour samples was carried out at the Research Testing Center of the Federal State Budgetary Educational Institution of Higher Education Krasnoyarsk State Agrarian University, statistical processing of experimental data was carried out using MS Excel programs. There is no separate federal-level regulatory document for barley flour in the field of standards for its production and quality control. During storage, the content of protein and sugar decreased, while the opposite process was observed in the content of starch and fat. There was a clear li-near increase in fat content during bulk storage, which may be due to greater access to atmospheric oxygen, which promotes fat oxidation. Statistically significant differences in fat content were identified between the container storage method for all packaging options and the bulk method, which allows us to indicate its advantage and note its importance for ensuring the purposes of long-term storage of the type of flour raw material in question.

Experimental study on the dissolution characteristics of ethane into oil‐based mud in complex oil and gas wellbore environments

AbstractAccurately determining the solubility of ethane in oil‐based mud is crucial for assessing the severity of gas kicks and implementing appropriate well control procedures. The key factors influencing the solubility of ethane gas in oil‐based drilling fluids include the content of base oil, pressure, temperature, and the viscosity of the drilling fluid. This study aims to test the solubility of high‐purity ethane in oil‐based mud under simulated downhole conditions in a 5000 m deep well. The test covers a temperature range of 40–140°C and a partial pressure range of 0.17–5.92 MPa. The effects of temperature, pressure, base oil content, and drilling fluid viscosity on the solubility of ethane are analyzed using various experimental data processing methods. The results show that the variation in ethane solubility with pressure and temperature is nearly linear within the specified ranges. Furthermore, the impact of pressure (1.24–2.78%/MPa) on solubility is approximately 50 times greater than that of temperature (−0.013 to −0.049%/°C) in oil‐based drilling mud. Additionally, ethane's solubility decreases as the drilling fluid's viscosity increases. The ethane solubility in 80% and 90% oil‐based muds is roughly 1.6 times and 2.0 times higher than in 70% oil‐based mud under the same testing conditions. Models for predicting ethane solubility have been developed using screening procedures and statistical regression. These models can be incorporated into gas–liquid flow models to analyze flow behavior during gas kicks.

Address Energy Delivery Technologies Based on The Hybrid Electrodynamic Processes

An effective tool has been identified for transferring technologies for processing food raw materials onto the rails of the nano-eco-industry — these are hybrid processes in electrodynamic devices. The aim of the work is a comprehensive study of hybrid processes in microwave electrodynamic systems. To achieve the goal, an experimental stand was created, which made it possible to visually confirm the effects of mechanical diffusion and establish the influence of key parameters on the kinetics and energy of hybrid processes. The working section — a model of a capillary-porous structure — was a bundle of calibrated glass tubes. When processing experimental data, the dependences of the influence of field power, channel diameter, temperature, and beam orientation on the kinetics and energy of the hybrid process were obtained. The most significant result of the work is the use of certain modes of organizing hybrid processes to control the extraction process in electrodynamic devices of three types: volumetric, film and circulation. Tests of these structures confirmed the formulated hypotheses of the formation of a hybrid process. The importance of the work lies in the fact that it is shown that the effect of mechanical diffusion is most powerfully manifested in electrodynamic extractors of the circulation type and energy consumption in electrodynamic extractors of the volumetric type is 1.4 times lower, film extractors are 1.5 times lower, and circulation type ones are 1.9 times lower, than in devices of traditional design.

Deep learning-based data processing method for transient thermoreflectance measurements

Pump–probe thermoreflectance has been commonly applied for characterizing the thermal properties of materials. Generally, a reliable and efficient non-linear fitting process is often implemented to extract unknown thermal parameters during the pump–probe thermoreflectance characterizations. However, when it comes to processing large amounts of data acquired from similar structural samples, non-linear fitting process appears to be very time-consuming and labor-intensive to search for the best fitting for every testing curve. Herein, we propose to apply deep learning (DL) approach to nanosecond transient thermoreflectance technique for high-throughput experimental data processing. We first investigated the effect of training set parameters (density and bounds) on the predictive performance of the DL model, providing a guidance to optimize the DL model. Then, the DL model is further verified in the measurement of the bulk sapphire, SiC, diamond samples, and GaN-based multilayer structures, demonstrating its capability of analyzing the results with high accuracy. Compared to the conventional non-linear fitting method (such as Global Optimization), the computation time of the new model is 1000 times lower. Such a data-driven DL model enables the faster inference and stronger fitting capabilities and is particularly efficient and effective in processing data acquired from wafer-level measurements with similar material structures.

Frequency estimation of underwater acoustic targets based on improved FRI method

The line spectrum information of a ship’s radiated noise signal is often regarded as an important feature used to distinguish between targets. In this paper, an improved FRI (finite rate of innovation) method is proposed to estimate the low-frequency line spectra of the radiated noise from underwater acoustic passive targets under the condition of finite sampling points. First, a preliminary rough estimation of the frequency is performed using the Fourier transform. Then, the multichannel signal data are iteratively fitted based on the polynomial-ratio form model. The optimal estimation results are finally determined based on the residuals between the data and the model in the fitting process. Simulation experiments prove that compared with the original FRI algorithm, the method proposed in this paper can estimate line spectral frequency more efficiently under the condition of low signal-to-noise ratio (SNR), and can achieve fast convergence with shorter operation time. The experimental data processing results prove that the method can realize high-precision extraction of line spectrum information of ship noise.

EXPERIMENTAL STUDY OF THE INTENSITY OF COAL DUST REMOVAL

Problem statement. Industrial sites where coal storages are located are intensive sources of dust pollution of the environment. There is an important problem of assessing the intensity of dust removal into the atmospheric air from polluted areas. Knowledge of the intensity of dust removal into the atmospheric air makes it possible to scientifically assess the impact of contaminated sites on the pollution of the environment and work zones at industrial sites. The solution to this problem can be obtained experimentally. The purpose of the article. An experimental study of the value of the air flow velocity at which the detachment of dust particles from the surface with coal begins and their removal into the air and the determination of the intensity of the emission of coal dust from the contaminated surface. Methodology. The intensity of removal of coal dust from the contaminated area was studied experimentally in laboratory conditions. The research was conducted on coal samples from DTEK “Pavlohradvuhillya”, grade “ДГ. During the research, the velocity of the air flow at which the process of movement of dust particles along the emission source began and the velocity of “detachment” of dust particles and their removal from the emission source were determined. At the second stage of experimental research, the intensity of removal of coal dust from the polluted area was determined. Scientific novelty. The values of the air velocity at which the removal of coal dust particles from the contaminated area begins were determined experimentally. The regularity of the intensity of the removal of coal dust depending on the velocity of the air flow over the contaminated area was obtained. Practical significance. The obtained experimental data make it possible to determine under which weather conditions there is a risk of dust formation and the removal of dust into the atmosphere. The empirical dependence obtained by processing experimental data can be used for a scientifically based assessment of the level of pollution of working areas at industrial sites where there are coal storage facilities. Conclusions. The value of the velocity of the air flow at which the movement of dust particles on the contaminated surface begins, as well as the value of the velocity of the air flow at which the removal of dust particles into the air begins, was determined experimentally. The resulting empirical model can be used to estimate environmental damage due to dust pollution of atmospheric air.

Mathematical justification of the optimal rate of selenium introduction into mixed feed for broiler chickens

In recent years, many countries worldwide have been revising the existing standards for introducing trace elements in mixed feed for high-performance crosses and poultry breeds, taking into account new scientific data. This also applies to Selenium, which is recognized as an indispensable biotic ultramicroelement according to the modern classification. The norms for introducing selenium into mixed feed for broiler chickens have specific differences and range from 0.1 to 0.5 mg/kg of feed, which are recommended in different countries and at other times. The reason for the disagreement is probably that the experiments were conducted under different conditions, against the background of different diets, on different poultry crosses, and using other selenium-containing compounds. In addition, the norms of selenium additives recommended by foreign and domestic scientists in mixed feed for broiler chickens are not always supported by mathematical calculations, and, in our opinion, they should be evaluated as indicative, requiring further justification and clarification depending on the regional characteristics of poultry feeding. Two scientific and economic experiments were conducted to determine the optimal rate of introducing selenium into mixed feed for broiler chickens, which lasted 42 days each. The study was conducted on broiler chickens of the Coob 500 cross. Selenium was additionally introduced into mixed feeds for broiler chickens of the experimental groups in doses of 0.2, 0.3, 0.4, and 0.5 mg/kg. Poultry in the control group did not receive Selenium supplementation. Statistical processing of experimental data obtained in two scientific and economic experiments, using graphical, variance, and regression analysis methods, allows us to conclude that the optimal dose of Selenium administration in mixed feed for broiler chickens should be considered 0.3 mg/kg. Feeding broiler chickens during the growing period of mixed feed enriched with Selenium in this amount contributed to a likely increase in their live weight in the first experiment by 7.8 % (Р < 0.001), in the second by 5.1 % (Р < 0.01), compared to the control group. Higher doses of Selenium (0.4 and 0.5 mg/kg) in mixed feed, as well as a lower dose (0.2 mg/kg), caused less intensive growth and lower live weight of broiler chickens of other experimental groups, compared to young animals fed mixed feed with the addition of selenium 0.3 mg/kg.

Experimental Investigation of the Soil-Water Characteristic Curves (SWCC) of Expansive Soil: Effects of Sand Content, Initial Saturation, and Initial Dry Unit Weight

Soil-water characteristic curve (SWCC) is an essential parameter in unsaturated soil mechanics, and it plays a significant role in geotechnical engineering to enhance theoretical analysis and numerical calculations. This study investigated the effects of key factors, such as the percentage of sand, initial degree of saturation, and initial dry unit weight, on the SWCC of expansive soil by measuring the matric suction using a pressure apparatus method. The empirical equation of SWCC was obtained using the Van Genuchten and Fredlung Xing models, and the processing of experimental data checks the fitting of the two empirical models. The findings revealed that the Fredlung Xing model fit the relationship between matric suction and volumetric water content of expansive soil better than the Van Genuchten model, indicating that the pressure apparatus approach’s experimental data are correct and acceptable. The study also found that the matric suction increased with decreasing percentage of added sand at the same volumetric moisture content, and the increase in initial dry unit weight increased the matric suction, with the water retention capacity decreasing significantly after adding 20% sand. Moreover, as the initial degree of saturation increased, the volumetric water content decreased, and the characteristic curves became identical when the initial saturation degree reached 90%. Finally, to minimize the water retention capacity of expansive soils, the study recommended adding a percentage of sand not less than 30% to the expansive clay sample.