Results Of Calculations Research Articles

Multi party confidential verifiable electronic voting scheme based on blockchain

The current electronic voting system ensures the confidentiality of the ballot but does not explicitly address the anonymity of the voter’s identity. The voting process is entirely managed by smart contracts, which diminishes the efficiency of contract execution and poses challenges for achieving large-scale voting. There is a lack of comprehensive explanation regarding the voting process and the verifiability of ballot information. This article introduces a multi-party secure verifiable electronic voting scheme based on blockchain technology. The solution uses IPFS distributed file system to alleviate the problem of limited block storage. The task allocation and vote counting processes are managed separately through management and computation contracts to improve efficiency. Ring signature technology is used to ensure the anonymity of voting identities. The vote counting process uses a key-sharing system to ensure the privacy of the votes, and the calculation results are encrypted and uploaded to the blockchain, making them verifiable. Finally, a security proof and performance analysis of the scheme were conducted.

Removal of Attached Zinc Oxide and Titanium Dioxide Nanoparticles from Spinach Leaves by Rinsing in the Absence and Presence of Preexisting Surface Extracellular Polymeric Substances (EPS)

Interest in the use of nanoparticles in agriculture has grown in recent years due to their potential abilities across a range of applications that could increase agricultural production, improve the efficiency of nutrient delivery, or improve pest management. However, as with any application of nanomaterials, concern exists about potential risks to human health. Because many applications might result in the attachment of nanoparticles to produce surfaces, it is important to understand the conditions under which rinsing is likely to remove nanoparticles from surfaces and the degree to which they can be removed. This work explored the rinsing removal of two types of nanoparticles, titanium dioxide (TiO2) and zinc oxide (ZnO), from spinach leaf surfaces in the absence and presence of biofilms based on extracellular polymeric substances (EPS). A hypothesis driving the work was that the presence of biofilms might enhance the retention of nanoparticles. The work combined experiments to determine surface energy parameters for fresh and rotten spinach, for use in extended DLVO (xDLVO) calculations, as well as direct rinsing experiments to explore nanoparticle removal from spinach surfaces. Nanoparticles were quantified using backscattered scanning electron microscopy using techniques developed for the work. Results of xDLVO calculations suggest that the presence of biofilms may actually be likely to reduce the retention of nanoparticles by produce surfaces, although this effect was not apparent in rinsing experiments, which exhibited similar removal of high-concentration TiO2 from spinach leaves. Overall, nanoparticles deposited from high-concentration suspensions were found to be removed to a greater degree by rinsing, while those deposited from low-concentration suspensions exhibited no apparent release, even under conditions where release might be favored.

Enhanced Adsorption Properties of Noble Metal Modified MoS2/WS2 Heterojunctions

AbstractMoS2/WS2 in‐plane heterojunction is constructed using density functional theory (DFT), and its adsorption properties for different gas molecules (CO, CO2, NO2, H2S, SO2, and SO3) are analyzed. Results indicate that the heterojunction exhibits excellent selection toward S‐series gas molecules (H2S, SO2, and SO3), particularly SO3. The adsorption energy is determined to be −3.67 eV. Then, the adsorption properties of the heterojunction are further improved by noble metal (Ag, Au, and Pt) modification. Noble metal atoms alter the surface potential energy of the heterojunction, resulting in stronger adsorption activity. For instance, the binding energies of noble metals in the Ag‐MoS2/WS2, Au‐MoS2/WS2, and Pt‐MoS2/WS2 systems are −1.03, −1.04, and −2.76 eV, respectively. Additionally, there has been a significant alteration in their bandgaps. Notably, the bandgap of Pt‐MoS2/WS2 has decreased to 1.42 eV (24.16%), which is the most pronounced change. Then, the charge density difference and density of states of noble metal‐modified MoS2/WS2 heterojunction adsorbed SO3 are analyzed. The results demonstrate that the adsorption capacity of a noble metal‐modified system for SO3 is enhanced. Finally, raising the temperature can accelerate gas molecule desorption from the system. Combining all calculation results, Ag‐MoS2/WS2 in‐plane heterojunction can be used as a candidate gas‐sensitive material for detecting SO3 at room temperature (300 K). The Pt‐MoS2/WS2 in‐plane heterojunction is demonstrated to possess effective adsorbent properties for trapping SO3 gas molecules at room temperature. This provides a new idea and theoretical basis for gas sensor development.

A review of research on transverse forces, developed by a ship's propulsion and steering system

In this article, the transverse component of forces developed by the ships propulsion and steering system and its dimensionless hydrodynamic coefficients have been investigated, as well as various methods of their estimation. System of the open propeller with rudder and system of propeller with swiveling nozzles were selected for this study since they are the most frequently used systems on river vessels. Formulas for finding transverse forces of different types of propulsion and steering complexes are unified. Calculations of the coefficients characterizing the transverse force according to the existing methods are carried out. The results of calculations are compared with the results obtained when identifying these coefficients according to the data of full-scale trials of ships. The significant discrepancy between the mentioned values allowed to conclude that modern calculation methods of ships propulsion and steering system transverse forces are not perfect enough for adequate modelling of controlled curvilinear motion of river vessels and require further improvement.

A Study of the Response Surface Methodology and Finite Element Method to Model Aircraft Engine Body Deformations During Hole Drilling.

The aviation industry is still looking for effective manufacturing methods. Currently, the challenge is still the machining of shapes in thin-walled materials. This work focuses on the analysis of the influence of these parameters on deformations during the drilling process of holes in the adapters of aircraft engine body accessories. The drilling process was carried out in the thin-walled superalloy Inconel 718, which is classified as a difficult-to-machine material. During the analyses, experimental studies based on the Response Surface Method (RSM) and finite element method (FEM) calculations were carried out simultaneously. The aim of this work was to analyze the developed mathematical models describing nonlinear relationships between cutting parameters, cutting forces, and deformations of the aircraft engine body characterized by a complex, thin-walled geometric structure. By using the proposed solutions, it is possible to achieve integration between the techniques of conducting research, performing calculations using FEM, and designing the machining. The advantage of this comprehensive approach used in our work is the development of mathematical models that strongly fit the results of the research. The results of analyses and calculations presented in the article and the research methodology used can be applied to industrial conditions.

Investigation of the conditions for the development of quarries of non-metallic building materials on the Upper Belaya, taking into account their impact on the level regime

Currently, the Belaya River is in rather difficult hydrological and navigable conditions, which is generally due to the low water content in the region and the many years of mining of non-metallic building materials actively carried out here. Under existing conditions, it is not enough to ensure guaranteed dimensions of the ship's course only by carrying out track work and strict regulation of production volumes is necessary. As part of the research carried out, the main tasks of conducting hydraulic calculations and methods of their solution are considered, the results of hydraulic calculations of the landing of water levels from quarrying are presented, which showed that in a significant part of the site (33 km of the 76 km studied) further quarrying should be completely prohibited until the restoration of the riverbed and the introduction of building materials quarries on the site; the possibility of quarrying at three sites in limited volumes was allowed; recommendations were given on the parameters of building materials production at a promising field for development. The paper also assesses the impact of dredging for navigation purposes on the amount of water level landing, which showed that they play a secondary role in the general anthropogenic impact on the Upper Belaya riverbed, but at the same time intensive channel mining of building materials and dredging is impossible due to their significant combined effect on the level regime. The implementation of the conclusions and recommendations obtained from the research results will minimize the adverse impact of mining operations.

Identification of the angles of attack of a hydrodynamic anchor in comparison of numerical and physical experiments

The article is devoted to the urgent task of increasing the effectiveness of rescue operations for the protection of human life at sea by maximizing the drift of rescue vehicles using a hydrodynamic anchor. The paper defines the hydrodynamic characteristics of a hydrodynamic anchor by two different methods: numerical hydrodynamic modeling and physical experiment in a direct experimental pool by pulling a full-scale hydrodynamic anchor with fixed speeds. The identification of the angles of attack of the hydrodynamic armature was carried out in comparison of numerical and physical experiments and the results of calculations of the angles of the working stroke were shown. The angles of installation of the hydrodynamic armature for the angles of attack of the wing, as well as the angles of attack for idling were determined.

POSSIBILITIES OF NEURAL NETWORKS FOR LEARNING FOREIGN LANGUAGES IN HIGHER EDUCATIONAL INSTITUTIONS

The article analyses the possibilities of using neural networks in teaching foreign languages in higher education institutions. It is determined that a neural network is a computer program that works in accordance with the human brain, i.e., it passes input data through a system of "neurons" - simpler programs that interact with each other, and then produces a certain calculation result based on this interaction, taking into account the experience and errors from previous runs of the programme. Neural networks are based on a mathematical model that can mimic the functioning of biological neurons, i.e. the principles by which the human brain works and is able to learn and absorb new information. Accordingly, the educational process was not ignored. Today, this new tool in the educational process is rapidly being used in the study of foreign languages in higher education institutions. At the moment, there are such neural networks as Chat GPT, Twee, MagicSchool.ai, ReadyTo, Curipod. The article notes that neural networks open up new opportunities for learning and teaching foreign languages in higher education. Besides, chatbots are one of the examples of neural networks. The author notes that a chatbot is a specially adapted network that has the ability to simulate dialogues with real people, answer questions, search, analyse and modify information according to the user's request or communicate in a user-specified manner. In this article, the author discusses the advantages and disadvantages of chatbots. The main disadvantage is that chatbots make mistakes and cannot replace natural communication through non-verbal means. Nevertheless, neural networks are very lightweight, simple and easy-to-use tools that do not require special skills to work with. In addition, they are great helpers for teachers in creating and preparing materials for classes that are original, interesting and motivating for students in learning a foreign language.

Optimization Algorithms for Sustainable Operation of Multi-Unit Hydropower Plants

The work presented in this article concerns numerical studies on optimization methods used for the sustainable utilization of the energy potential of water, converting it into electricity in a hydropower plant equipped with more than one unit. These methods allow for maximization of production in given hydrological conditions, leading to the balanced, lossless, and environmentally friendly use of the renewable energy source that is water. Methods are selected from three groups, i.e., analytical, enumeration, and randomized. The results of calculations of optimal points of selected test functions carried out using the Broyden–Fletcher–Goldfarb–Shanno Limited-Memory Version (L-BFGS-B), Explicit Complete Enumeration (ECE), and Genetic Algorithm (GA) methods provided basic information on the features of these methods. Based on these tests, the GA method was selected to solve the problem of the optimal load distribution in a hydropower plant equipped with three identical hydro units. The defined optimization problem consisted of finding a configuration of hydro units in operation that would guarantee the maximum efficiency of the power plant under the imposed hydrological conditions. During the numerical studies, a number of calculations were performed to identify the impact of procedures and parameters characteristic of the optimization methods on the obtained results. Particular attention was paid to the GA method and penalty functions, enabling the elimination of results from the area of prohibited solutions.

Multi-Stage Design Method for Complex Gas Supply and Exhaust System of Space Station

The supply and exhaust system of the experimental rack on the Chinese space station is a complex integrated system. In this paper, a multi-stage simulation, testing, and verification method is designed for a multi-team, multi-location, and multi-stage integrated gas system. This method is designed to solve the problem of missing input parameters between the gas supply system and the exhaust system. Preliminary tests and strategy verifications were carried out through theoretical simulation and semi-physical simulation, and good calculation results were obtained for the single-rack product. The external systems were tested using a simulation system, and a calculation method was designed to obtain relatively accurate parameters. In the early stage, the performance of the product was predicted using the parameter library of Flomaster and semi-physical simulation methods, but the error was large. In the middle and late stages of development, as some products became realistic, multi-stage testing was carried out using a vacuum simulator, simulated flow resistance, and other methods, achieving a performance prediction with an error of 12% before ground testing. The final ground test and on-orbit test showed that the design and calculation method of this paper is effective. The multi-stage design method proposed in this paper was successfully applied to the integrated gas system of the Chinese space station, which can provide a reference for the design of fluid components in long-term system engineering.

Competition and Precipitation Mechanism of Inclusions in the Al–Ti–Mg Complex Deoxidized Steel

In this work, the competitive precipitation mechanism of inclusions in Al–Ti–Mg complex deoxidized steel is investigated by experimental observation and thermodynamic analysis. Many types of inclusions are observed in steel, and the two and multi‐layer structural inclusions are composed of the single‐particle inclusions of TiS, TiN, TixOy, MnS, Al2O3, and MgAl2O4. Thermodynamic calculation results suggest that the transformation order of Al2O3 contains two pathways: one is Al2O3 → MgAl2O4 → MgTi2O4 → MgO and the second is Al2O3 → Ti2O3 → MgTi2O4. However, the transformation reaction of Al2O3 into MgAl2O4 or Ti2O3 has not completely ended, and no MgTi2O4 and MgO inclusions are found in the steel sample. The precipitation order of Ti2O3, TiN, TiS, and MnS in present steel is Ti2O3 → TiS → TiN → MnS. MnS only precipitated in solid steel, TiS, and TiN precipitated in the solid–liquid interface at T < 1794 K and T < 1796.5 K, respectively. The actual transformation and precipitation order of inclusion in the present Al followed by Ti–Mg deoxidized steel is Al2O3 → MgAl2O4 → Ti2O3 → TiN → TiS → MnS or Al2O3 → Ti2O3 → TiN → TiS → MnS.

Расчет удельной электропроводности расплавов смесей LiF+NaF

The calculation of the specific electrical conductivity of lithium and sodium fluorides mixtures melts is presented. The Iinterest in the LiF–NaF system melts is determined by their practical significance. Melts of LiF+NaF mixtures are used in heat-storing compositions and in metallurgy. They are part of various multicomponent systems. The specific electrical conductivity calculation by isoconcentration, isothermal and interpolation methods is given for LiF+NaF mixtures melts of various compositions using known reference data for the temperature range 1020...1340 K. A calculation has been performed for the eutectic composition. The resulting analytical equations have been used to describe and calculate the specific electrical conductivity of the eutectic mixture for temperatures 5°, 10°, 50°, 75°, 100° above the liquidus. The specific electrical conductivity of the eutectic mixture melt is calculated on isotherms by interpolation for the isoconcentration dependences of hypoeutectic and hypereutectic mixtures. Isotherms of electrical conductivity (1020...1340 K) of melts depending on the content of LiF and NaF components are described by a third-degree polynomial. Depending on the temperature, the coefficients in the resulting equation change linearly. A comparison has been made of the values of specific electrical conductivity ϰ(LiF+NaF), calculated from the obtained equations. The description of ϰ(LiF+NaF) by isoconcentration and isothermal methods has showed satisfactory convergence of calculation results and makes it possible to calculate the specific electrical conductivity of LiF+NaF mixtures melts of any given composition, including eutectic.

Novel Tripeptides as Tyrosinase Inhibitors: In Silico and In Vitro Approaches.

Tyrosinase is a key enzyme responsible for the formation of melanin (a natural skin pigment with ultraviolet-protection properties). However, some people experience melanin overproduction, so new, safe, and biocompatible enzyme inhibitors are sought. New tripeptide tyrosinase inhibitors were developed using molecular modeling. A combinatorial library of tripeptides was prepared and docked to the mushroom tyrosinase crystal structure and investigated with molecular dynamics. Based on the results of calculations and expert knowledge, the three potentially most active peptides (CSF, CSN, CVL) were selected. Their in vitro properties were examined, and they achieved half-maximal inhibitory concentration (IC50) values of 136.04, 177.74, and 261.79 µM, respectively. These compounds attach to the binding pocket of tyrosinase mainly through hydrogen bonds and salt bridges. Molecular dynamics simulations demonstrated the stability of the peptid-tyrosinase complexes and highlighted the persistence of key interactions throughout the simulation period. The ability of these peptides to complex copper ions was also confirmed. The CSF peptide showed the highest chelating activity with copper. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay confirmed that none of the test tripeptides showed cytotoxicity toward the reconstructed human epidermis. Our results indicated that the developed tripeptides were non-toxic and effective tyrosinase inhibitors. They could be applied as raw materials in skin-brightening or anti-aging cosmetic products.

SPECTRAL and FOCAL PARAMETERS of CRIMEAN-BLACK SEA REGION EARTHQUAKES in 2020

The results of calculation and analysis of spectral and focal parameters of 11 earthquakes in the Crimean-Black Sea region in 2020 within the range of energy classes Кп=5.2–11.3 are presented. The dynamic parameters of the sources were reconstructed from 70 amplitude spectra of P- and S- seismic wave records rec orded by eight digital regional seismic stations. For the two strongest earthquakes of 2020: March 15 and April 12, the focal mechanism solutions were obtained. The type of slip in the sources of both earthquakes is a reverse fault. In addition, the spectral properties of the sources of 10 weak earthquakes that occurred near the southern coast of Crimea were considered from the energy spectra of records at the Alushta station. An analysis of the results obtained is given.

STUDY OF THE DYNAMICS OF A VIBRATION MACHINE CONSIDERING THE INFLUENCE OF THE PROCESSING MEDIUM

This paper presents the results of studying the dynamics of a vibration machine, takinginto account its interaction with the processing medium based on representing the medium as a continuoussystem. The application of the complex number method significantly simplifies the formation of equations ofmotion for the discrete-continuous system, which is a computational model of the vibration system "machinemedium."The study substantiates and develops a method for considering the mutual influence of the machineand the processing medium, based on representing the medium as a continuous system. The dynamicsof the vibration system "machine-medium" is studied, and oscillation parameters are determined withoutconsidering resistance forces. It is found that the overall motion of the vibration system is described by fourcomponents. The first three describe the natural oscillations of the system, of which the first two are determinedonly by initial conditions, and the third reflects the accompanying oscillations caused by the externalforce applied to the system. The last component defines the forced oscillations following the external force'schange law. This result shows that the oscillations of the vibration system are not strictly harmonic, which isconfirmed by the provided graphs. The dynamics of the "machine-medium" vibration system, consideringresistance forces, are studied, and analytical dependencies for determining oscillation amplitudes and natural and resonant frequencies are obtained. The results of the amplitude calculations of the vibration platform forvarious heights of compacted concrete mixtures reveal the influence of the resistance coefficient and theratio of oscillation frequency to the wave propagation speed in the mixture. Analysis of the obtained graphsshows that the resistance coefficient has a different effect on the amplitude of oscillations for different heightsof the compacting mixture. Certain mixture height zones of the vibration system "machine-medium" operatein a near-resonant mode. A significant influence on the amplitude is exerted by the wave propagation speed,which is included in the analytical formulas for determining the numerical values of the coefficients accountingfor reactive and active components of resistance.

VERIFICATION OF ENERGY CHARACTERISTICS OF A THREE-PHASE BRIDGE COMPENSATION CONVERTER WITH ONE COMMUTATING LINK

The article considers the issue of reliability of the results of analytical calculation of the feedforward control angle of power electric valves and the commutate angle of a three-phase bridge compensating converter of electric energy with one commutating link. It is noted that the value of these angles determines the capabilities of the converter regarding the generation of reactive energy together with the power supply of the consumer of direct current electric energy. Based on the complexity of the analytical calculation of these characteristics, the issue of verification of the obtained results is relevant, which also confirms the adequacy of the applied research methodology. As a tool for achieving the goal of the work, the authors use circuit simulation in the Micro Cap package. The modeling technique is described in detail, the results of modeling several modes of converter operation are presented, and these results are analyzed. A comparative analysis of the numerical values ​​of the control and commutating angles obtained as a result of analytical calculation and circuit modeling of the same modes of converter operation showed that the discrepancy does not exceed 5%. This indicates the adequacy of the applied modeling technique and the acceptable accuracy of the results of analytical calculations. Refer. 3, fig. 3, table 3.

In-Situ Grafting Strategy Enables Functional Separator for Advanced Lithium-Sulfur Batteries.

A functional separator is developed by in-situ grafting nickel tetraaminophthalocyanine (NiTAPc) onto the surface of polypropylene (PP). It is applied to inhibit the shuttle effect of polysulfides (PSs) in lithium-sulfur(Li-S) batteries. The characterization results showed that NiTAPc is highly dispersed and uniformly grafted onto PP separator. In-situ grafting strategy effectively mitigates the self-agglomeration issue associated with NiTAPc and enhances the exposure of catalytically active Ni-N4 sites. These sites exhibit excellent adsorption and conversion capabilities for PSs. This is consistent with the results of theory calculations, which indicate that the presence of NiTAPc can reduce the delithiation energy barrier associated with Li2S conversion. Owingto the excellent inhibition ability of NiTAPc on the shuttle effect of PSs, the Li-S battery employing a PP-NiTAPc separator demonstrates excellent cycle stability. It showsan initial specific capacity of 1256.5mAhg-1 at 0.1 C, and a capacity retention of 582.4mAhg-1 after 500 cycles at 1 C, showcasing a minimal decay rate of 0.0547% per cycle. The strategy adopted in this study offers valuable insights for the development of modified separators for rechargeable batteries and other energy storage fields.

Renormalization-group running of dimension-8 four-fermion operators in the SMEFT

We compute the renormalization-group equations governing the evolution of dimension-8 four-fermion operators in the Standard Model effective field theory (SMEFT). We describe the calculation and present analytic results for both the full flavor structure of the SMEFT and with the assumption of minimal flavor violation. We present numerical results for the renormalization-group evolution of the coefficients, and study their impact on fits of the Large Hadron Collider (LHC) Drell-Yan data. The effects of running on the dimension-8 coefficients can reach 50% or more when evolving from 10 TeV scale down to few-GeV energies relevant for the analysis of fixed-target data. However, the impact of the dimension-8 running on the analysis of Drell-Yan data from the LHC is minimal. Published by the American Physical Society 2024

Structural Transformations in Duplex Stainless Steel CF8 Under Intensive Cold Plastic Deformation

The austenitic–martensitic transformation in austenitic–ferritic duplex stainless steel CF8 subjected to cold plastic deformation with a deformation degree ε = 10–95% is studied here using transmission Mössbauer spectroscopy (MS), conversion electron Mössbauer spectroscopy (CEMS), and X-ray diffraction (XRD) methods. It is assumed that the α′-martensite phase appeared at ε > 10%. The CEMS results showed that the formation of α′-martensite occurred most intensively in the near-surface layers of the steel, distributing in depth with the growth of the deformation degree. The volume fraction of the α′-martensite was determined based on the results of calculations carried out via the MS and XRD methods, and a good correlation was observed. A modified Olson–Cohen model was proposed to determine the dependence of the amount of α′-martensite on the deformation degree ε. The coefficients included in the Olson–Cohen expression were found.

Simulation of the processes of spraying and combustion of kerosene and liquid oxygen in the chamber of a liquid-propellant rocket engine

The paper presents the results of simulation of spray and combustion processes in the liquid-propellant rocket engine chamber using the z77 reduced kinetic mechanism of chemical reactions and a hybrid method for determining spray parameters of a swirl atomizer. Simulation was carried out for the nominal operational conditions in a three-dimensional domain using the ANSYS Fluent software. The process of spraing liquid fuel components (T-1 kerosene and oxygen) by monopropellant injectors was simulated using a model of discontinuous phases. The simulation results (pressure, temperature and velocity) were compared with the data of analytical thermogasdynamic calculation results and experimental results for pressure in chamber and gas temperature near the wall. The difference between the simulation results and the experimental results does not exceed 8%. Thus, it was shown that it is possible to use the mechanism z77 and hybrid method for determining spray parameters of a swirl atomizer presented in this paper to obtain accurate simulation results of the kerosene T-1 and oxygen spray and combustion processes of the investigated liquid-propellant rocket engine.