Five-component System Research Articles

Liquidus temperatures in the La2O3-SrO-TiO2-ZrO2-Fe2O3 system: Calculation and experiment

Ceramics based on the La2O3-SrO-TiO2-ZrO2-Fe2O3 system is of considerable interest for the development of the materials based on high-entropy oxides when their high-temperature endurance is required. However, limited information on its high-temperature behavior greatly limits its applications. In the present work, the potential of the geometric method for liquidus temperature calculation (GMLTC) in five-component oxide systems using data on the corresponding binary systems is verified for the first time with the example of the La2O3-SrO-TiO2-ZrO2-Fe2O3 system. The liquidus temperatures in the studied system calculated accordingly were experimentally confirmed by visual polythermal analysis within the limits not exceeding 10 % of the determined melting temperature. This allows us to recommend the proposed GMLTC approach for prediction of the position of liquidus curves in multicomponent oxide systems, which is particularly important for the calculations of liquidus temperatures of high-entropy oxides with unique physicochemical properties valuable for application at high temperatures up to 3000 K.

Concentration effects in multicomponent metallic solid solutions

In the equiatomic approximation, the dependence of the lattice FCC parameter and the Debye temperature from the atomic fate x of the doping element, which is alternately represented by all elements of a multicomponent solid solution, including high-entropy alloys were obtained. The calculations were carried out on the example of a five-component (based on Cu, Ni, Co, Fe, and Al) or six-component (based on Cu, Ni, Co, Fe, and Cr, Ti) metal systems. It was found that by varying x within x = (0 - 0.3), it is possible to obtain a change in the lattice FCC parameter from 0 to 0.03 nm and the Debye temperatures from 0 to 80 K. The proposed new characteristics are integral and differential concentration coefficients, the magnitude and sign of which can predict concentration dependences for the lattice parameter and the Debye temperature.

Multi-Variable Multi-Metric Optimization of Self-Assembled Photocatalytic CO2 Reduction Performance Using Machine Learning Algorithms.

The sunlight-driven reduction of CO2 into fuels and platform chemicals is a promising approach to enable a circular economy. However, established optimization approaches are poorly suited to multivariable multimetric photocatalytic systems because they aim to optimize one performance metric while sacrificing the others and thereby limit overall system performance. Herein, we address this multimetric challenge by defining a metric for holistic system performance that takes multiple figures of merit into account, and employ a machine learning algorithm to efficiently guide our experiments through the large parameter matrix to make holistic optimization accessible for human experimentalists. As a test platform, we employ a five-component system that self-assembles into photocatalytic micelles for CO2-to-CO reduction, which we experimentally optimized to simultaneously improve yield, quantum yield, turnover number, and frequency while maintaining high selectivity. Leveraging the data set with machine learning algorithms allows quantification of each parameter's effect on overall system performance. The buffer concentration is unexpectedly revealed as the dominating parameter for optimal photocatalytic activity, and is nearly four times more important than the catalyst concentration. The expanded use and standardization of this methodology to define and optimize holistic performance will accelerate progress in different areas of catalysis by providing unprecedented insights into performance bottlenecks, enhancing comparability, and taking results beyond comparison of subjective figures of merit.

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.

Phase formation in the system Na+,Ca2+,Al3+|| SO42–,HCO3--H2O at 273 K

The article discusses the results of determining possible phase equilibria on geometric images of a five-component mutual water-salt system of sulfates, sodium bicarbonates, calcium and aluminum at 273 K, followed by the construction of its phase complex diagram. The patterns that determine the structure of the phase complex of this system are needed both to obtain scientific data used as reference material, as well as to create optimal conditions for the disposal of liquid waste from industrial aluminum production containing sulfate, bicarbonate salts of sodium, calcium and aluminum. To achieve this goal, we used the translation method, according to which the dimension of the geometric images of the diagram of the original (private) system, when adding a subsequent component to it, increases by one, i.e. the geometric images are transformed. Due to the fact that the studied five-component system consists of five particular four-component systems, the addition of a fifth component to any of them is accompanied by a transformation of the geometric images of all five four-component systems. Transformed geometric images, based on their topological properties, are translated (transferred) to the level of a five-component composition. At the level of a five-component composition, transformed and translated geometric images, observing the Gibbs phase rule, intersect and form geometric images of a given level of component. The study of the phase equilibria of a five-component water-salt mutual system of sulfates, sodium bicarbonates, calcium and aluminum and the construction of its phase complex diagram by the translation method at 273 K showed that it is characterized by the presence of twelve divariant fields, ten monovariant curves and three non-invariant points at this temperature. Based on the data obtained, a complete closed phase diagram of the studied system was constructed for the first time and, for ease of reading, fragmented along the divariant crystallization fields of equilibrium solid phases.

Geometric acceleration of complex chemical equilibrium calculations — Performance in two- to five-component systems

Incorporating multicomponent, multiphase, complex chemical equilibrium calculations into process and multiphysics models can provide significant insights into industrial processes that current modelling or measurements cannot. Equilibrium calculations are however, in general, omitted or incorporated in a simplified manner due to their computational expense. Several methods have been developed to accelerate these calculations.A new accelerator algorithm was developed (Roos and Zietsman, 2021) based on phase diagram geometry, the Gibbs phase rule, and the lever rule to include equilibrium calculations into models more efficiently. This framework of established thermochemical theory provides a sound basis for discretisation and interpolation, and allows the accelerator algorithm to work in systems with any number of components. The work presented here aimed to test accelerator performance and demonstrate that it has the capability of achieving noteworthy levels of acceleration while maintaining acceptable accuracy.The accelerator was tested on ten 2-component systems, four 3-component systems, a simplified 4-component ilmenite smelting system, and a simplified 5-component iron- and steelmaking system. As the number of system components increased, so did the computational expense of direct equilibrium calculations. This translated to larger acceleration factors for higher-order systems — from 20 in 2-component systems to 1000 in the 5-component system. In a small number of cases it was observed that the acceleration factor was smaller than one during interpolation. This was attributed to slow searching times for suitable interpolation cells from the database.Phase composition interpolation errors are less than 1 × 10-2molmol−1. This translates to an interpolated phase composition being accurate to within 99% of the calculated composition and results in phase fraction errors of 1 × 10-2 and less. In a very small number of cases the interpolation errors made on physical and thermochemical properties are as high 10%. This is because system properties are calculated as a phase fraction weighted sum of phase properties and errors made on system properties can therefore become large due to interpolation errors being made twice. However, the majority of errors made on physical and thermochemical properties are in the order of 1% and less. The level of accuracy achieved by the accelerator algorithm was acceptable for the chosen discretisation tolerances.

Phase Assemblage of the Li+,Na+,K+||F–,Cl–,Br– Five-Component Reciprocal System and Its LiF–KCl–KBr–NaBr–NaCl Stable Pentatope

The phase assemblage of the Li+,Na+,K+||F–,Cl–,Br– five-component reciprocal system was studied for the first time. The phase tree obtained by partition of the phase assemblage into stable elements is linear. It consists of the following stable elements: the LiF–NaF–KF–KBr–KCl pentatope, LiF–NaBr–NaCl–KCl–KBr–NaF hexatope, and NaCl–KCl–KBr–LiBr–LiCl–LiF–NaBr heptatope, linked by the LiF–NaF–KCl–KBr stable tetrahedron and the LiF–KBr–NaBr–NaCl–KCl square pyramid (pentatope). Phase equilibria in the LiF–KCl–KBr–NaBr–NaCl stable pentatope were studied by differential thermal analysis (DTA). Monovariant phase equilibrium L ⇄ LiF + NaClxBr1 – x + KClyBr1 – y occurs in the pentatope, where NaClxBr1 – x and KClyBr1 – y are continuous solid solutions (css) between NaCl and NaBr, KCl and KBr salt pairs, respectively. The composition of the mixture at point Min◻ 591 and the lowest monovariant equilibrium temperature were determined. A 3D computer model was designed as a projection of the phase assemblage on the LiF–KCl–KBr–NaBr–NaCl pentatope in KOMPAS-3D software. The volumes of crystallizing equilibrium phases were outlined.

Phototransduction in a supramolecular cascade: a mimic for essential features of the vision process.

The tailored design of a light-triggered supramolecular cascade results in an artificial machinery that assimilates the transduction of photons into chemical communication and the final release of a neurotransmitter. This is reminiscent of key steps in the natural vision process.

Selective maintenance and inspection optimization for partially observable systems: An interactively sequential decision framework

Selective maintenance is an important condition-based maintenance strategy for multi-component systems, where optimal maintenance actions are identified to maximize the success likelihood of subsequent missions. Most of the existing works on selective maintenance assumed that after each mission, the components’ states can be precisely known without additional efforts. In engineering scenarios, the states of the components in a system need to be revealed by inspections that are usually inaccurate. Inspection activities also consume the limited resources shared with maintenance activities. We, thus, put forth a novel decision framework for selective maintenance of partially observable systems with which maintenance and inspection activities will be scheduled in a holistic and interactively sequential manner. As the components’ states are partially observable and the remaining resources are fully observable, we formulate a finite-horizon Mixed Observability Markov Decision Process (MOMDP) model to support the optimization. In the MOMDP model, both maintenance and inspection actions can be interactively and sequentially planned based on the distributions of components’ states and the remaining resources. To improve the solution efficiency of the MOMDP model, we customize a Deep Value Network (DVN) algorithm in which the maximum mission success probability is approximated. A five-component system and a real-world multi-state coal transportation system are used to demonstrate the effectiveness of the proposed method. It is shown that the probability of the system successfully completing the next mission can be significantly increased by taking inspections into account. The results also demonstrate the computational efficiency of the customized DVN algorithm.

Front Cover: A convenient separation strategy for fungal anthraquinones by centrifugal partition chromatography

DOI: 10.1002/jssc.202100869 The cover picture shows a visual representation of the vivid colors found in basidiomycetes. Starting from fruiting bodies of Cortinarius sanguineus, a separation strategy for anthraquinones was developed based on centrifugal partition chromatography (scheme in the middle). The methanolic crude extract (top right) was fractionated (bottom right) using a five-component solvent system, allowing the isolation of fungal anthraquinone pigments (bottom left).

A combined forecasting system based on multi-objective optimization and feature extraction strategy for hourly PM2.5 concentration

Accurate hourly PM2.5 concentration prediction plays a key role in air quality monitoring and controlling system, especially when severe haze occurs frequently. A PM2.5 hourly prediction system is developed in this paper, based on an advanced data processing strategy, an effective feature selection technology and a novel optimization algorithm. First, the collected original sequence is decomposed into a group of filters with different wave frequencies and each filter is weighted and reconstructed to mitigate the negative impact of noisy fluctuations. Then mRMR is introduced for extracting interaction information between pollutants, further determining the input of artificial intelligence models. Whereafter, a five-component combined system is taken shape, in which BPNN, ELM, GRNN and BiLSTM are employed as foundation models while Multi-objective Water Cycle Algorithm (MOWCA) is the weight optimization model. The results of hourly PM2.5 concentration prediction simulation experiment in the Bei–Shang–Guang–Shen area make clear that the developed system with minimum forecasting error, excellent generalization capability and robust prediction performance shows a definite latent capacity and future to deal with early warning problems and to design suitable abatement strategies.

Composition of the lunar mantle for lower mantle high-velocity seismic model

We investigated models of the internal structure of initially homogeneous Moon differentiated as a result of partial melting, using data on seismic velocities according to the seismic models assume the zonal structure of the lunar mantle is a model of the Moon which was obtained with using the array processing methods of high velocities in the lower mantle. As a result of inversion of gravity (mass, moment of inertia), seismic (P- and S-waves velocities) and petrological (balance ratios) data, the Monte Carlo method was used to reconstruct the chemical composition and internal structure of the Moon. The phase composition and physical properties of the mantle were obtained with Gibbs free energy minimization method and equations of state in the five-component system CaO-FeO-MgO-Al2O3-SiO2. For all models, possible values of seismic velocities and concentrations of the main oxides in three zones of the mantle were obtained, satisfying the geochemical and geophysical constraints and the possible sizes of the Fe-10%S core were determined. It was found that the lunar mantle chemical composition (concentration of FeO, Al2O3 and CaO) differs depending on the mantle zone. Constraints on the values of seismic velocities in the lower mantle and the most probable size of the lunar core were determined: VP ≤ 8.45 km/s; Fe-10%S core radius is ∼360 km.

Classification and Enumeration of Subsolidus Sections in Five-Component Systems with Stoichiometric Compounds

Classification and Enumeration of Subsolidus Sections in Five-Component Systems with Stoichiometric Compounds

Semi-rational vector rogon–soliton solutions of the five-component Manakov/NLS system with mixed backgrounds

The five-component Manakov system (alias 5-Manakov system) appears in many fields such as nonlinear optics, Bose–Einstein condensates (alias the spin-2 Gross–Pitaevskii equation), and ocean. In this Letter, we investigate the semi-rational vector rogon–soliton and soliton of the 5-Manakov system with mixed zero and non-zero backgrounds by using the modified Darboux transform. The key point is to explicitly solve the multiple roots of a sixth degree characteristic polynomial equation. In particular, we exhibit the wave structures of the fundamental semi-rational vector rogon with grey solitons and soliton solutions, and their higher-degree forms. Moreover, the semi-rational vector rogon with grey solitons corresponding to the components with non-zero backgrounds are PT-symmetric. These semi-rational wave structures will be useful to further understand some related physical phenomena and to design the relative experiments.

Multi-transonic spherical-type flows around massive black holes: galactic potential induced standing isothermal shocks

Accretion on length-scales of interstellar or even intergalactic is particularly relevant, in the context of spherical or quasi-spherical hot mode accretion, supposedly powering low excitation radio galaxies in the maintenance-mode feedback paradigm. In the present study, we aim to analyze such a spherical-type flow around the host active nucleus in the backdrop of a five-component galactic system (SMBH, stellar, dark matter, diffuse hot gas, Λ), with the principal intent to address the issue of galactic potential induced shock formation in the flow, that may contain (dissipative) isothermal standing shocks. The present paper is an extension of Raychaudhuri et al. (2018) [83], who conducted a preliminary investigation of such a problem. The galactic potential, not only renders the flow to be multi-transonic in nature, the flow topology resembles `Xα' and `α X' type trajectories of advective flows in the vicinity of the BHs/compact objects. Owing to the influence of the galactic potential, the entire range of galactic mass-to-light ratio (ΥB) allows shock formation in central to the outer radial regions of our wind-type flows, with the strength of those galactic induced shocks found to be comparable to that of the shocks one would expect in the advective flows in the vicinity of a BH. We also observe that the shock parameters remain sensitive to ΥB. We discussed the possible implication of these shocks in the context of radio source dynamics as well as their potential association with flaring in radio jets. Our study also reveals that galactic potential could substantially augment the mass inflow rate.

Experimental determination of hydrate dissociation conditions in CO2 + hexane + dodecane system, + 1-propanol or + tetra-n-butyl ammonium bromide

Hydrate dissociation conditions for one four-component system and two five-component systems, the CO2 + hexane + dodecane + water system, the CO2 + hexane + dodecane + 1-propanol + water system, and the CO2 + hexane + dodecane + tetra-n-butyl ammonium bromide (TBAB) + water system, were measured in the pressure range of (1.5 to 4) MPa and temperature range of (283 to 290) K at (0.1, 0.2 and 0.3) mass fraction of 1-propanol or TBAB. The experimental measurements were performed using the isochoric pressure-search method in a high pressure blind cell. The hydrate dissociation conditions (temperature and pressure) for the CO2 + hexane + dodecane + water system were compared with experimental data available in international literature were good agreement between the data was founded which indicates the viability of the experimental technique reported in this study. The experimental uncertainties were determined for temperature and pressure as combined standard uncertainties and are 0.16 K and 0.04 MPa, respectively. The relative standard uncertainty in composition was estimated to be 0.0014. In order to verify the reliability of the experimental data containing 1-propanol, a thermodynamic consistency test was performed.

Surfactant-Polymer Interactions in a Combined Enhanced Oil Recovery Flooding

The traditional Enhanced Oil Recovery (EOR) processes allow improving the performance of mature oilfields after waterflooding projects. Chemical EOR processes modify different physical properties of the fluids and/or the rock in order to mobilize the oil that remains trapped. Furthermore, combined processes have been proposed to improve the performance, using the properties and synergy of the chemical agents. This paper presents a novel simulator developed for a combined surfactant/polymer flooding in EOR processes. It studies the flow of a two-phase, five-component system (aqueous and organic phases with water, petroleum, surfactant, polymer and salt) in porous media. Polymer and surfactant together affect each other’s interfacial and rheological properties as well as the adsorption rates. This is known in the industry as Surfactant-Polymer Interaction (SPI). The simulations showed that optimum results occur when both chemical agents are injected overlapped, with the polymer in the first place. This procedure decreases the surfactant’s adsorption rates, rendering higher recovery factors. The presence of the salt as fifth component slightly modifies the adsorption rates of both polymer and surfactant, but its influence on the phase behavior allows increasing the surfactant’s sweep efficiency.

Two synthetical five-component nonlinear integrable systems: Darboux transformations and applications

A generalized [Formula: see text] matrix spectral problem is investigated to generate two five-component nonlinear integrable systems, which involve an arbitrary smooth function. These systems are proven integrable in the sense of Lax pair. As the reduction cases, a four-component reaction diffusion equation and a four-component modified Korteweg-de Vries (mKdV) equation are solved by Darboux transformation approach.

Phase complex of the system Na,Ca||SO4,CO3,HCO3-H2O at 100 ºC

The article discusses the results of determining the possible phase equilibria in geometric images of a five-component reciprocal water-salt system of sulfates, carbonates, sodium bicarbonates and calcium at 100 ºC with subsequent construction of its phase complex diagram. The laws that determine the structure of the phase complex diagram of this system are needed to be obtained for the production of scientific data used both as a reference material and also to create the optimal conditions for the recycling of liquid waste industrial production of aluminum-containing sulfate carbonate and bicarbonate salts of sodium and calcium. It was established that the system under study at 100ºC is characterized by the presence of 31 divariant double saturation fields, 25 monovariant trisaturation curves and 14 invariant points.

Time-dependent synergism of five-component mixture systems of aminoglycoside antibiotics to Vibrio qinghaiensis sp.-Q67 induced by a key component.

A large number of antibiotics are entering the aquatic environment accompanying human and animal excreta, which will threaten the survival of aquatic organisms and even human health. It has been found that binary mixtures of aminoglycoside (AG) exhibit additive action and can be evaluated well by a classical model, concentration addition (CA) in our past study. Therefore, to investigate the toxicity interaction within multi-component mixtures of AG antibiotics, five antibiotics, kanamycin sulfate (KAN), neomycin sulfate (NEO), tobramycin (TOB), streptomycin sulfate (STS), and gentamicin sulfate (GEN), were selected to construct five-component mixture systems by a uniform design ray method. The toxic effects (luminescence inhibition) of single antibiotic and five-antibiotic mixture systems towards a photobacterium Vibrio qinghaiensis sp.-Q67 (V. qinghaiensis) in different exposure time (0.25, 2, 4, 8, and 12 h) were determined by the time-dependent microplate toxicity analysis method. The concentration-effect data were fitted by a nonlinear least square method, toxicity interaction within mixture systems was analyzed by a CA model, and the interaction intensity was characterized by deviation from the CA model (dCA). Besides, the toxicity mechanism of five antibiotics and their five-component mixtures to V. qinghaiensis was analyzed by electron microscopy. The results show that toxicity of five antibiotics and their five-component mixture systems to V. qinghaiensis is time-dependent and has strong long-term toxicity. Different from binary AG antibiotic mixture systems, five-antibiotic mixture systems exhibit obviously time-dependent synergism. In addition, toxicity of the five-antibiotic mixtures can be 1.4 times higher than that of the mixtures without synergisms at the same concentration level. According to dCA, synergism intensity (dCA) curves of rays move slowly from the high concentration region to the medium or lower one and the maximum dCA values also increase, decrease, or first increase, then decrease with the lengthening of exposure time. The inhibition activity and synergism intensity of mixture rays have good correlation with the concentration ratios of STS, the key component for synergism. The cell morphology of V. qinghaiensis indicates the strong toxicity of five antibiotics and their mixture rays is not due to the destruction of cell structure, but the inhibition of the light-emitting activity of the photobacterium.