State Diagram Research Articles

Exploring the Structural, Elastic, and Optoelectronic Properties of ScCuO3 via Density Functional Theory Approach

A thorough analysis of the structural, elastic, electronic, and optical properties of ScCuO3 perovskite is conducted using density functional theory. The compound's structural and mechanical stabilities are established under pressure. The values of Pugh's ratio (B/G) and the Zener anisotropy factor indicate that ScCuO3 displays ductile behavior and elastic anisotropy under varying pressures. The metallic behavior of ScCuO3 is confirmed by its electronic band structure, which shows that a few valence bands intersect the Fermi level. The Cu‐3d and O‐2p orbitals overlap near the Fermi level, which is found from the density of states diagram. It is also proclaimed that the Cu‐3d states strongly hybridized with O‐2p states are observed under applied pressure. Various optical properties (dielectric function, photoconductivity, absorption coefficient, loss function, reflectivity, and refractive index) are also analyzed. The compound has the highest reflectivity and is found in the low‐energy region, making it suitable as a coating material for reducing solar heating. The absorption spectra and optical conductivity indicate the metallic nature of ScCuO3, which is supported by the calculations of the electronic band structure. The current study explores the potential applications of ScCuO3 in various optoelectronic devices.

Thermodynamics of Liquid Alloys and Vapor–Liquid Equilibrium in the Antimony–Tellurium System

The partial and integral thermodynamic functions of formation and evaporation of antimony-tellurium melts were calculated based on the vapor pressure values of the components in the Sb–Sb2Te3 and Sb2Te3–Te systems. It is shown that integral functions of evaporation enthalpy and entropy insignificantly change in value from the alloy corresponding to the Sb2Te3 composition and slightly decrease in the direction of antimony and tellurium on the state diagram. However, they can be described by a linear dependence in the entire concentration interval of solutions existence within the experiment error. The boundaries of liquid and vapor coexistence fields at atmospheric pressure (101.3 kPa) and in vacuum (0.9 kPa) were calculated based on the partial pressure values of melt components. It is shown that the separation of antimony alloys with tellurium by distillation into elements at atmospheric pressure is difficult because of high boiling temperatures of antimony-based alloys. It would require a significant number of condensate re-evaporation cycles in a vacuum. The results aim at creating the fundamental physical and chemical foundations of the distillation technologies for processing melted chalcogenide systems. The second aim is to issue effective practical recommendations necessary for developing and improving the process of extracting rare metals from polymetallic mattes by vacuum-thermal method.Graphical

From binary PZT system to multi-component ferroactive materials

For the first time, ceramic solid solutions of the five-component system 1-x)(0.5(Na0.5K0.5)NbO3–0.5Pb(Zr0.5Ti0.5)O3)-x/2CdNb2O6 with concentrations of CdNb2O6x = 0.000; 0.025; 0.050; 0.075 were prepared. Experimental studies of crystalline and grain structure, dielectric, piezoelectric and ferroelastic properties have been carried out over a wide temperature range. X-ray diffraction data were used to construct a concentration diagram of the phase states and to establish correlations between the behaviour of the macroproperties of the solid solutions and the features of their crystal structure. A conclusion is made about the expediency of using the obtained results in the creation of similar materials and devices based on them.

Formalization and modeling of turbocode encoding/decoding processes for 5G communication systems

Improving the energy characteristics in 4G and 5G mobile communication systems is provided by the use of adaptive control technology for encoding, modulation and power parameters. The paper considers promising adaptive coding schemes in mobile communication systems. The article formalizes the process of optimizing the operation of the turbo code encoder and decoder by using adaptive selection of the size of state diagrams based on the proposed decoding uncertainty indicator. In contrast to the known methods of TC adaptation, the size of the TC encoder/decoder state diagram is adaptive depending on the signal-to-noise ratio in the channel and the values of the normalized number of changes in the sign of the a posteriori-a priori logarithmic relations of the likelihood functions about the transmitted data bits of the turbo code decoder. Analysis of the simulation results shows that the reliability of transmission is increased by choosing a rational size of the TC encoder/ decoder state diagram. The proposed formalization of the model of the TC functioning process is a further development of adaptive coding technologies while preserving the transmission system bandwidth and differs from those known in that various TC MLRS polynomials are used for adaptation, which determine the necessary structure and size of the TC encoder and decoder state diagram. The interleader parameters are selected as fixed. Simulation modeling was used to analyze the efficiency of optimizing the operation of the encoder and decoder of the turbo code by using adaptive size selection of state diagrams. For comparison, the fourth-generation LTE-Advanced Mobile Communication Standard was chosen. The simulation was carried out in Visual Studio 2019 the data transmission system with Turbo codes, modulator (demodulator) OFDM, channel with additive Gaussian white noise (ABGN) was modeled. The results of the work can be used in conjunction with other adaptation methods, such as coding rate adaptation, based on polynomials of TC component codes, in systems with multiparametric adaptation that function under conditions of complete or partial a priori uncertainty.

Designing a UML automated drip irrigation system to improve the efficiency of greenhouse agriculture

This article discusses the process of designing an automated drip irrigation system for a greenhouse using the UML (Unified Modelling Language) language. The main purpose of the study is to create a detailed and visual model of the system that describes all aspects of its operation, from collecting data from sensors to controlling the irrigation process. In the course of the work, various UML diagrams were developed, including a use case diagram, a class diagram, a sequence diagram, and a state diagram. These diagrams provided a comprehensive view of the system, its components and their interactions, which greatly simplified the design process and allowed to identify possible problems in the early stages of development. The practical application of the automated drip irrigation system has a number of advantages for greenhouse agriculture. The system optimizes the use of water resources, reduces labour costs and minimizes the influence of the human factor, increasing the accuracy and reliability of irrigation. In addition, it provides the ability to monitor and manage irrigation in real time, which allows you to quickly respond to changes in conditions and prevent possible problems.

Simulation model for predicting ecological condition of urban areas at traffic intersections

This article substantiates the relevance of the development and use of digital tools that allow modeling objects and processes of transport systems to determine the environmental consequences of changes in their quantities and states. The use of methods of structural analysis, systematization, observation, statistical analysis of data allowed to establish all key objects of the system and their qualitative and quantitative indicators necessary to create a digital twin. The use of simulation modeling methods allowed to formalize the obtained results into models involved in the digital twin of the transport system. Using the graphical method, state diagrams were developed to demonstrate the transition of states of each object of the process depending on changes in environmental conditions. On the basis of the statistical analysis of pollutant emissions in the study area, a parametric model was developed for each pollutant factor.

Lattice QCD Overview

I review recent progress in lattice QCD calculations of the QCD phase diagram and equation of state at non-zero temperature and baryochemical potential. I also discuss some connections with heavy ion collisions.

Introductory Visual Lecture on QCD at Large \(N_{c}\): Bound States, Chiral Models, and Phase Diagram

Introductory Visual Lecture on QCD at Large \(N_{c}\): Bound States, Chiral Models, and Phase Diagram

Control of liquid crystals combining surface acoustic waves, nematic flows, and microfluidic confinement.

The optical properties of liquid crystals serve as the basis for display, diagnostic, and sensing technologies. Such properties are generally controlled by relying on electric fields. In this work, we investigate the effects of microfluidic flows and acoustic fields on the molecular orientation and the corresponding optical response of nematic liquid crystals. Several previously unknown structures are identified, which are rationalized in terms of a state diagram as a function of the strengths of the flow and the acoustic field. The new structures are interpreted by relying on calculations with a free energy functional expressed in terms of the tensorial order parameter, using continuum theory simulations in the Landau-de Gennes framework. Taken together, the findings presented here offer promise for the development of new systems based on combinations of sound, flow, and confinement.

Aluminosilicate colloidal gels: from the early age to the precipitation of zeolites.

Aluminosilicate hydrogels are often considered to be precursors for the crystallisation of zeolites carried out under hydrothermal conditions. The preparation of mechanically homogeneous aluminosilicate gels enables the study of these materials through bulk rheology and observation of the aging dynamics until the precipitation of crystalline zeolites. The first part of this study deals with the establishment of ternary state diagrams, in order to identify the range of chemical formulations that enable preparation of single-phase homogeneous gels. Then, by studying the viscoelastic moduli during the gelation reaction, and by yielding the gel under large deformation, we propose an empirical law considering the partial order of reaction on each chemical element, to predict the gelation time according to the chemical formulation. The scaling behavior of the elastic properties of this colloidal gel shows a transition from a strong link behavior to a weak link regime. Long term aging results in the shrinkage of the gel, accompanied by syneresis of interstitial liquid at the surface. Zeolites precipitate through crystallisation by a particle attachment mechanism, when thermodynamic equilibrium is reached. The stoichiometry of the precipitated zeolites is not only consistent with the concentration of the remaining species in the supernatant but, surprisingly, it is also very close to the partial order of the reaction of the chemical elements involved in the determination of the critical gel point. This indicates a strong correlation between the morphology of the soft amorphous gel network that is formed at an early age and those of the final solid precipitated crystals.

First-principles study of VS<sub>2</sub> as anode material for Li-ion batteries

With the increase of performance requirements for lithium-ion batteries (LIBs), it is particularly important to study and develop new electrodes for lithium-ion batteries. In this work, a 3×3×1 supercell of VS<sub>2</sub> is constructed, and the possibility of using it as an anode material for lithium-ion batteries is study by the first-principles method based on density functional theory. Through the analysis of the energy band diagram, it is found that VS<sub>2</sub> has metallic properties. Combining the density of states diagram, the analysis shows that the energy band near the Fermi level of VS<sub>2</sub> is contributed by the 3d state of V and the 3p state electrons of S, which means that the conductive properties of VS<sub>2</sub> are largely affected by the 3d state of V and the 3p state electrons of S. Of the vacancies, bridge sites, and top sites of lithium adsorbing vanadium (V), the top site has the lowest adsorption energy, indicating that lithium will preferentially adsorb the top site of vanadium (V). Through first-principles molecular dynamics simulations of the top position of adsorbed vanadium (V), it is found that at a temperature of 300 K, the total energy of the system and the magnitude of the total temperature fluctuation can reach a steady state, indicating that lithium can exist at the top position of stably adsorbed vanadium (V). Moreover, the interlayer spacing of the double-layer VS<sub>2</sub> reaches 3.67 Å, which is larger than the interlayer spacing of graphene. From the top position to the vacancy, its diffusion barrier is only 0.20 eV. Its interlayer spacing is larger than the double-layer graphene’s, and its diffusion barrier is lower than graphene’s, indicating that lithium has very good diffusivity on the VS<sub>2</sub> surface, and lithium can migrate quickly on the VS<sub>2</sub> surface, which is conducive to the rapid charge-discharge process of LIB. In addition to excellent electrical conductivity, VS<sub>2</sub> has good mechanical properties. The calculated Young's modulus is 96.82 N/m, and the Young's modulus and Poisson’s ratio do not decrease after adsorbing lithium, indicating that the rigidity of VS<sub>2</sub> will not be reduced in the diffusion and migration process of lithium. On the other hand, it has excellent deformation resistance. In order to be more accurate and closer to the actual situation, a double-layer VS<sub>2</sub> model is constructed, with a maximum number of lithium atoms adsorbed between layers being 18. The calculated theoretical capacity of VS<sub>2</sub> (466 mAh/g) is higher than the theoretical capacity of graphene (372 mAh/g). Our results indicate that VS<sub>2</sub> has excellent electrical conductivity and mechanical stiffness, making it a promising cathode material for lithium-ion batteries.

Rheological effects on purely-elastic flow asymmetries in the cross-slot geometry.

Viscoelastic flows in the cross-slot geometry can undergo a transition from a steady symmetric to a steady asymmetric flow state, ostensibly due to purely-elastic effects arising beyond a critical flow rate, or Weissenberg number Wi. However, some reports suggest that shear thinning of the fluid's viscosity may also play an important role in this transition. We employ a series of polymer solutions of varying rheological properties to investigate in detail how the interplay between fluid elasticity and shear thinning affects the onset and development of asymmetric flows in the cross-slot. Flow velocimetry is performed on each of the polymer solutions, and is used to assess the degree of flow asymmetry I in the cross-slot as a function of both Wi and a dimensionless parameter S quantifying the flow-rate-dependent extent of shear thinning. Typically, the flow field breaks symmetry as Wi is increased beyond a critical value, but the magnitude of I is found to also be dependent on S. For a few specific polymer solutions, the flow field recovers symmetry above a second, higher critical Wi as S becomes small. The experimental results are summarized in a flow state diagram in Wi-S space, showing the relationship between flow asymmetry and fluid rheology. Finally, to gain a deeper understanding of the effects of shear thinning, numerical simulations are performed using the linear simplified Phan-Thien-Tanner model. We demonstrate that the degree of both shear thinning and elasticity of the fluid, and their interplay, are important factors controlling elastic instabilities in the cross-slot geometry.

Simulation modeling in infrastructure modernization projects of the Russian part of the Central Eurasian Corridor

The article presents a brief characteristic of international transport corridors running through Russia. Their key nodes and the need for their sustainable development are identified. The use of structurization, analysis and synthesis methods allowed the study to obtain quantitative and qualitative characteristics of transport infrastructure facilities of Russian cities, through which the railway branches of the Central Eurasian Corridor pass. The rules of interaction between the key elements that make up the structure of each of the research objects have been established. A set of such rules and object characteristics became the input parameters for the simulation model of the problem domain. The problem area includes all bottlenecks in the transportation network formed by the intersection and merging of traffic flows. State diagrams illustrating the peculiarities of the behavior of object groups of the simulation model on the example of the city of Orenburg are developed.

Morphology-Tailored Dynamic State Transition in Active-Passive Colloidal Assemblies.

Mixtures of active self-propelled and passive colloidal particles promise rich assembly and dynamic states that are beyond reach via equilibrium routes. Yet, controllable transition between different dynamic states remains rare. Here, we reveal a plethora of dynamic behaviors emerging in assemblies of chemically propelled snowman-like active colloids and passive spherical particles as the particle shape, size, and composition are tuned. For example, assembles of one or more active colloids with one passive particle exhibit distinct translating or orbiting states while those composed of one active colloid with 2 passive particles display persistent "8"-like cyclic motion or hopping between circling states around one passive particle in the plane and around the waist of 2 passive ones out of the plane, controlled by the shape of the active colloid and the size of the passive particles, respectively. These morphology-tailored dynamic transitions are in excellent agreement with state diagrams predicted by mesoscale dynamics simulations. Our work discloses new dynamic states and corresponding transition strategies, which promise new applications of active systems such as micromachines with functions that are otherwise impossible.

Single‐Step Kinetic Predictions Based on a Constructed Isoconversional State Diagram

AbstractA new concept called isoconversional state diagram, which can be used to predict the kinetics of single‐step condensed phase reactions, is introduced. A state represents a certain extent of conversion degree α in a reaction. The construction of the isoconversional state diagram is based on the isoconversional state equation, which is a piecewise linear equation about 1/T and lnβ, where T is the temperature and β is the heating rate. The slope of the linear equation is controlled by the activation energy Eα and its intercept contains the inherent information of the kinetic triplet, i.e., the pre‐exponential factor Aα, the activation energy Eα and the reaction model f(α). Consequently, the geometric methods for nonisothermal and isothermal kinetic predictions are derived. The latter reflects the physical meaning of the relationship between reactions under isothermal and nonisothermal conditions, i.e., the time to advance from αi to αi+1 at isothermal temperature Tiso is equal to the time to heat from Tiso to under heating rate , where Tiso, and must be determined from the isoconversional state diagram.

In Ukrainian

The review material reveals the question of the influence of impurities on the physical properties of alloys, as well as the influence of gases on processes in alloys. It has been established that the presence of hydrogen affects diffusion in alloys, and gases have a significant effect on the thermoelectromotive force of metals. The paper describes the addition of a third element to binary systems, which can expand or narrow the domain of existence of an ordered phase. The above examples of adding an impurity of vanadium or molybdenum to an alloy of iron and chromium increase the ordering temperature. It has been established that gases can have a significant effect on the thermoelectromotive force of metals and increase the hardness and reduce the ductility of metals, as well as cause their brittleness and delamination. It has been established that hydrogen (H2) in alloys (for example, Fe-Ni and Au-Cu) affects diffusion and atomic ordering processes. Also, a small concentration of hydrogen, as an impurity, can change the electrical resistance of alloys (for example, in a Pd-Au alloy). It has been established that the addition of a third element to binary systems can change the state diagram, which must be taken into account when solving problems for the production of heat treatment modes for alloys, determining the conditions for phase equilibrium, etc. The paper considers the dependence of hydrogen solubility on temperature in metals (Cu, Fe and Al) and establishes the dependence of hydrogen solubility in a metal on the concentration of impurity metals. The temperature dependence of hydrogen solubility in Fe-V alloys is also shown. The shift of the density of state is studied for different distributions of impurity atoms in the alloy in the order-disorder system, and the dependence of the density of states of disordered and ordered solid solutions is studied. The dependence of the relative solubility of atoms introduced into the pores of alloys with an fcc structure (of the Cu3Au type) is indicated, taking into account the solubility, on the parameter χ, which is proportional to the degree of long-range order in the octahedral and tetrahedral pores of the alloys. The dependence of the relative solubility of intercalated atoms in octahedral pores of alloys with a bcc structure (such as CuZn and Fe3Al) is considered. A plot of the dependence of the concentration of dissolved impurity atoms on the degree of order is shown for substitutional alloys with a bcc lattice, where the M2 coefficient is introduced, which does not depend on the degree of order. The effect of pressure as a measure of long-range order is also studied, where its step decreases or increases, or decreases and then increases and vice versa (order-disorder phase transition). An equally important result is the graphic dependence of solubility (c) on pressure (P) in disordered and ordered alloys.

Studying the Recurrent Sequence Generated by Power Function using QUATTRO-20

We presented the bifurcational diagram of power function Fi(x) = r·x·(1 – x^2) which could be treated as first approximation of trigonometric function F(x) = r·x·cos x. Using second composite Fi^2(x) in analytical form and solving 8-th degree polynomial equation bifurcational diagram with period doubling 1, 2, 4 was obtained and attractors were established. Analytical solutions of expressions x = Fi^2(x) allows us to establish the fixed point attractors and periodic attractors in interval (-V5,V5). Bifurcation diagram obtained analytically was compared with its aproximate analogue Finite State diagram. ‍

DETERMINATION OF THE THERMODYNAMIC PARAMETERS OF α-IRON IN BINARY SYSTEMS Fe-Cr AND Fe-Ti

This article presents the results of calculations of the thermodynamic parameters of binary Fe-Cr and Fe-Ti systems based on their state diagrams using the Bjerrum-Guggenheim osmotic coefficient, for the region of iron crystallization from the iron activity of an ideal α-γ solution for the above systems. When calculating the lines of phase equilibrium in the Fe-Cr and Fe-Ti systems, it was established that the Bjerrum-Guggenheim coefficient can serve as an assessment parameter characterizing the role of exchange forces between atoms, and by its dimension (Фi><1) one can qualitatively judge the nature of the intermolecular interactions in the system. The results of this work made it possible to correctly solve the direct Gibbs problem, namely, to obtain an analytical dependence of phase compositions on temperature at phase equilibria based on the laws of phase formation. It is shown that with the help of the Bjerrumm-Guggenheim osmotic coefficient (Fi), the real equilibrium in the system under study can be determined in detail and their correct analytical expression can be obtained. When calculating phase equilibrium lines in systems with different types of interaction between components, it was established that the Bjerrum-Guggenheim coefficient can serve as an assessment parameter characterizing the role of exchange forces between atoms. Keywords: thermodynamics; Bjerrum-Guggenheim coefficient; state diagram; osmotic coefficient; binary systems.

Design of a Vending Machine Using Verilog HDL and Implementation in Genus & Encounter

This paper proposes the design, implementation, and verification of a vending machine using the Finite State Machine (FSM) methodology in Verilog HDL. The FSM is used to manage the multiple states of the vending machine, including “idle,” “accepting coins,” “dispensing item,” and “returning change.” The implementation of the vending machine is done in Verilog HDL, and the FSM is implemented as a state diagram. The design is then synthesized using the Genus synthesis tool and implemented using the Encounter implementation tool. The Genus tool uses advanced optimization techniques, such as timing-driven placement and clock tree synthesis, to improve the design’s performance and area. The Encounter tool performs physical design, including placement and routing, to meet the design’s timing, power, and area constraints. To validate the design’s correctness and functionality, a test bench is created to simulate the behavior of the vending machine. The simulation results are then used to verify that the design meets the required specifications and that the FSM behaves as expected. The proposed design is then can be implemented on a Field Programmable Gate Array (FPGA) to demonstrate its effectiveness in a real-world scenario. The results of the implementation are presented and analyzed to validate the design’s performance, power consumption, and area. Overall, the vending machine using FSM in Verilog HDL, implemented in Genus and Encounter, provides a reliable and efficient solution for users to purchase items from the machine. The proposed design and implementation demonstrate the feasibility and effectiveness of this approach, and the results show that the design meets the required specifications and performs well in a real-world scenario.

Thermodynamics of Formation and Liquid-Vapor Phase Transitions of Antimony Alloys with Selenium and Sulfur.

The authors conducted liquid solution studies of antimony with selenium and sulfur in order to provide information on the thermodynamic functions of the formation of these alloys. The studies are based on the vapor pressure values of the components, comprising the double partial systems of antimony with antimony chalcogenides (Sb2Se3 and Sb2S3) and antimony chalcogenides with chalcogens (Se and S). We calculated the thermodynamic functions of mixing (graphical dependencies) and evaporation (tabular data) based on the partial vapor pressure values of components, which are represented by temperature-concentration dependencies. Based on the partial pressure values of melt components, we calculated the boundaries of liquid and vapor coexistence fields at atmospheric pressure (101.3 kPa) and in a vacuum (0.9 kPa). We established the absence of the stratification region on the Sb2S3-S diagram due to the fact that, on state diagrams, the stratification region is indicated at temperatures above 530 °C, while the boiling point of liquid sulfur at an atmospheric pressure corresponds to 429 °C. Based on the position of the field boundaries (L + V) on the state diagrams, the separation of antimony alloys with selenium and sulfur via distillation into elements at atmospheric pressure is difficult due to the high boiling points of antimony-based alloys in a vacuum: Sb2Se3-Se melts require some number of condensate re-evaporation cycles.