The study aims to increase the efficiency of the use of the pipe-piston unit by ensuring the reliability of the measurement results based on the development of calibrating technique for the pipe-piston installation. Theoretical research is based on using the principles of system and process approaches. To solve the scientific problem, the fundamental provisions of statistical methods and experimental methods were used; methods of mathematical modeling of estimation of measurement uncertainties. Based on the results of the work, the normative document "Metrology. Installations of a standard pipe-piston. Calibration technique". The approach to controlling metrological characteristics of the pipe-piston installation, based on estimating the uncertainty of measurements during its calibration, was further developed. Application of the proposed approach allows one to control the metrological characteristics directly on site without disrupting the working product's accounting process and increasing the pipe-piston installation's efficiency by an increase in the reliability of measurements and ensuring repeatability.

The present study focuses on the comparative analysis of superparamagnetic iron oxide nanoparticles (SPIONs) characteristics with the TOPSIS method. The prediction of the characteristics of SPIONs is required for better manufacturing of these nanoparticles. Although the characteristics of these nanoparticles have been investigated, no research has been done on their comparison in order to determine which one of their surface functionalities would be more appropriate for their diverse applications. The objective of this study was to analyze the characteristics of SPIONs without or with surface charge with a prediction model and TOPSIS in order to determine the best nanoparticles. Moreover, the effect of inappropriate consideration of their cost criterion on their ranks was explored with the modified TOPSIS. This analysis showed that the characteristics of SPIONs such as antibiofilm activity, hemocompatibility, activity with hydrogen peroxide, rheological properties, and the labour of their chemical synthesis could affect their ranking. Neutral SPIONs, negatively charged SPIONs, and positively charged SPIONs were ranked as the first, second, and third candidates, respectively. However, the improvement of the activity of positively charged SPIONs with hydrogen peroxide showed an increase to 0,3 instead of 0,2, which resulted in a better rank of these nanoparticles in comparison with that of the same nanoparticles in the first analysis series. One of the advantages of this study was to determine the impact of the characteristics of SPIONs on their ranking for their manufacturing. The other advantage was getting the information for further comparative study of these nanoparticles with the others. The results of this work can be used in manufacturing engineering and materials science.

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

Reverse osmosis is an essential technological separation process that has a large number of practical applications. The mathematical simulation is significant for designing and determining the most effective modes of membrane equipment operation and for a deep understanding of the processes in membrane units. This paper is an attempt at systematization and generalizing the results of the investigations dedicated to reverse osmosis simulation, which was published from 2011 to 2020. The main approaches to simulation were analyzed, and the scope of use of each of them was delineated. It was defined that computational fluid dynamics was the most used technique for reverse osmosis simulation; the intensive increase in using of molecular dynamics methods was pointed out. Since these two approaches provide the deepest insight into processes, it is likely that they will further be widely used for reverse osmosis simulations. At the same time, for the simulation of the membrane plant, it is reasonable to use the models that required the simplest solutions methods. The solution-diffusion model appears to be the most effective and flexible for these purposes. Therefore, this model was widely used in considering the period. The practical problems solved using each of the considered approaches were reviewed. Moreover, the software used for the solution of the mathematical models was regarded.

Індекс рубрикатора НБУВ: Д234.11

Рубрики:

Сонячна (короткохвильова) радіація

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

The paper is devoted to the study of directions of application of combined systems for obtaining biofuels and biopolymers using electro-oxidative processes, namely electro-fermentation. In the course of the work, a step-by-step methodology of research is shown, and the relationship between different bioinformatic databases in their combined use is described, which made it possible to identify trends in electro-fermentation systems with the production of bio-based products. A review of possible electro-fermentation systems with major bio-product production was performed. The possibility of including anaerobic producers of organic acids, namely lactic acid, for the needs of biopolymerization, with bioinformatic databases was substantiated. The model of the process of anaerobic fermentation with the production of organic acids for biopolymerization has been formed. The analysis of bioinformatic databases showed that the strains Anaerotignum propionicum X2, isolated from silty bottom sediments, and Anaerotignum propionicum 19acry 3, isolated from an operating anaerobic reactor, have the most significant indicators of lactate productivity. The conditions for their cultivation with an indication of nutrient media and modification of their composition are considered.

The article is devoted to improving methods for designing a finite element model of rotor dynamics. For this purpose, numerical implementation of the authors' computer program "Critical frequencies of the rotor" was developed based on the computer algebra system MathCAD. As a result of the scientific work, a refined mathematical model of rotor dynamics using finite beam elements was created. This model considers the dependence of the radial stiffness characteristics of the bearing supports on the values of the critical frequencies. The reliability of the mathematical model was justified by the permissible differences of the obtained results within 2 % compared with the results of finite element analysis using the ANSYS software. The theorem was also proven by the mutual location of the spectra of the natural and critical frequencies. Overall, the proposed scientific approach reduces preparation and machine time compared to numerical modeling using the ANSYS software without losing the accuracy of the calculations.

The article presents the importance of managing the flow of first-time patients in a dental practice. Three main areas of difference between the popular linear model of dental office operation on the market and the author's model of an integrated multi-specialist dental team were analyzed. Performance indicators for working with first-time patients illustrating the ability to manage the flow of patients in the office, communicate with patients, build patient awareness of oral health conditions, and harness patients' potential for treatment are presented and discussed. It was proven that with the fuller utilization of patients' potential for treatment, a noticeable effect is a simultaneous increase in the profitability of the dental practice, which, with an entirely ethical process based solely on diagnosed dental problems, makes both profitable.

Індекс рубрикатора НБУВ: К327.03-141

Рубрики:

Плавка сталі

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

Індекс рубрикатора НБУВ: Д234.11

Рубрики:

Сонячна (короткохвильова) радіація

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

The present study focuses on a new application of the TOPSIS method for the optimization of machine learning algorithms, supervised neural networks (SNN), the quick classifier (QC), and genetic algorithm (GA) for proteomic analysis. The main hypotheses are that the change in the weights of alternatives could affect the ranking of algorithms. The obtained data confirmed this hypothesis for their ranking. Moreover, adding labor as a cost criterion to the list of criteria did not affect this ranking. This was because candidate 3 had better fuzzy membership degrees than the two other candidates concerning their criteria. This work showed the importance of the value of the fuzzy membership degrees of the cost criterion of the algorithms in their ranks. The values of the fuzzy membership degrees of the algorithms used for proteomic analysis could determine their priority according to their score differences. One of the advantages of this study was that the studied methods could be compared according to their characteristics. Another advantage was that the obtained results could be related to the new ones after improving these methods. The results of this work could be applied in engineering, where the analysis of proteins would be performed with these methods.

The article is devoted to creating a refined computer model of the face packing seal (FPS) based on the solution of the two-way fluid-structure interaction (2-way FSI) problem. An approach to the average gap was proposed based on the micro-space's working medium leakage between the friction pair's roughness elements. Three FPS designs were studied, in which the following operating parameters were alternately changed: inlet pressure, load factor, stuffing box parameters, and friction coefficient. Young's modulus, Poisson's ratio, and the thickness of the annular plate at the bottom of the stuffing box were also changed. The model was created considering the actual geometry of the FPS. The shaft rotation was considered by applying the rotation condition on the wall of the fluid model. The calculation was carried out using the ANSYS Multiphysics software. The results of the calculations were presented in the form of graphic dependences with a comparison of the hydrostatic and contact pressure distributions over the friction pair width. The values of the magnitudes of leakage from the changing parameters were presented. Based on the obtained results, an optimal combination of parameters was evaluated for the most efficient design of the FPS.

The article considers the problem of machine learning of a wrist prosthesis control system with a non-invasive biosignal reading system. The task is solved within the framework of information-extreme intelligent data analysis technology, which is based on maximizing the system's information productivity in machine learning. The idea of information-extreme machine learning of the control system for recognition of electromyographic biosignals, as in artificial neural networks, consists in adapting the input information description to the maximum total probability of making correct classification decisions. However, unlike neuro-like structures, the proposed method was developed within a functional approach to modeling the cognitive processes of the natural intelligence of forming and making classification decisions. As a result, the proposed method acquires the properties of adaptability to the intersection of classes in the space of recognition features and flexibility when retraining the system due to the recognition class alphabet expansion. In addition, the decision rules constructed within the framework of the geometric approach are practically invariant to the multidimensionality of the space of recognition features. The difference between the developed method and the well-known methods of information-extreme machine learning is the use of a sparse training matrix, which allows for reducing the degree of intersection of recognition classes significantly. The optimization parameter of the input information description, the training dataset, is the quantization level of electromyographic biosignals. As an optimization criterion is considered the modified Kullback information measure. The proposed machine learning algorithm results are shown in the example of recognition of six finger movements and wrist.

The main idea was to solve the problem related to oil contamination of soil using bioremediation with bioaugmentation with modeled microorganism strains. The paper aimed to develop a bacterial consortium for petroleum hydrocarbon degradation during the biological treatment of oil-contaminated soils using electronic databases. The research methodology included an analysis of the mechanisms and metabolic pathways of petroleum hydrocarbon degradation and an assessment of the possible reaction modulus and enzymatic systems for the degradation of aromatic compounds. The taxonomic classification and review of oil compound transformation metabolic pathways were carried out using electronic KEGG, MetaCyc, and EzTaxon databases. The KEGG database was used to create a microbiological consortium of certain strains of bacteria that improved hydrocarbon degradation process performance. Identification of bacteria's complete genome using Island Viewer 4 allowed to create of a consortium of oil-destructive bacteria consisting of such strains: Pseudoxanthomonas spadix BD-a59, Rhodococcus jostii RHA1, Rhodococcus aetherivorans IcdP1, Pseudomonas putida ND6, Pseudomonas stutzeri 19SMN4, Pseudomonas fluorescens UK4, Acinetobacter lactucae OTEC-02, Bacillus cereus F837/76.7.9. The ratio between the mentioned strains of microorganisms in the consortium was set at 20 % : 20 % : 15 % : 10 % : 10 % : 5 % : 5 % : 15 %. This bacterial consortium for aromatic hydrocarbons was created according to the metabolic information of basic enzymatic systems and the predominant transformation of particular oil compounds using the BacDive database.