Charge Components Research Articles

Структура та властивості багатошарового металу, наплавленого електродними порошковими дротами з осердям із порошків феросплавів та гранульованих твердосплавних матеріалів

Comparative studies of the possibility of using granulated hard alloy powders as a charge of flux-cored wires for electric arc surfacing have been carried out. In the studies, granulated powder of the PG-R6M5 brand with a fraction of 50...300 μm was used. As a standard, a flux-cored wire was used, in the core of which there was a composition of powders of different ferroalloys of the same fraction. The content of the charge components in the core of the standard wire was selected and calculated so as to obtain a similar chemical composition to the wire containing granulated hard alloy powder. The test samples were obtained by layer-by-layer electric arc surfacing under the flux layer with flux-cored wires on low-carbon steel plates. To obtain identical dependences, the flux-cored wires had the same diameter and filling factor and differed only in the content of the core. The test samples were deposited under the same conditions with strict adherence to the deposition regimes, which were monitored using a high-speed analog-to-digital converter. It was determined that the use of granulated hard alloy powder as a charge of flux-cored wire has a positive effect on the melting characteristics of the wire and the stability of the welding process in general in comparison with the standard reference wire, the charge of which contains ferroalloys. This effect can be explained by the greater chemical purity of the granulated powder and the uniformity of the physicochemical properties of its particles in comparison with the powders of various ferroalloys. The determined features of the melting of the wire with a charge with granulated hard alloy powder have a positive effect on the quality of the formation of the multilayer deposited metal and its structure, leading to an increase in its homogeneity, some grinding of the grain and a decrease in the number and size of microdefects, which should positively affect the operational properties of the deposited metal. Keywords: electric arc surfacing, multilayer deposited metal, tool steels, granular hard alloy powder, ferroalloy, metal structure.

Thermodynamic analysis of interactions between the components of the charge during the production of metallurgical silicon

The theoretical foundations of the recovery process and the technology of silicon smelting in electric arc furnaces are considered. The results of a study of thermodynamics, reaction kinetics, and mechanisms of the melting process are presented. Production issues are covered: charge preparation, smelting, refining, gas purification. Physicochemical models of the carbothermal process were developed, proposed and tested under industrial conditions (Tau-Ken-Temir LLP), which made it possible to assess the influence of the specified technological parameters of the smelting (chemical composition and loading coefficients of charge components, temperature) on silicon recovery and grade. To obtain the base material, metallurgical grade silicon is used, obtained by melting in ore-thermal furnaces (RTP). In this regard, the research goal is determined, which consists in studying ways to improve the quality (chemical purity) of silicon, and methods for achieving it at this stage of the study - modeling the carbothermal process for producing silicon.The article describes the main mechanism for the recovery of silica in the furnace, presents one of the designs of the furnace and the technological scheme for the production of silicon. The author suggested studying the process of producing metallurgical silicon in RTP using the HSC Chemistry software package. A model of silicon smelting in RTP was formed, which adequately describes the technological process for producing metallurgical silicon.

The visible magneto-optical response of RE1-xAxMnO3manganites: relationship with the charge component of the material.

Magnetic circular dichroism (MCD) spectroscopy for manganite films of various compositions and morphologies has been studied in the range of 1.2-3.7 eV. The primary focus was on the temperature behavior of the MCD spectra, as well as the magnetization and resistivity of the films. The data obtained were analyzed in comparison with magneto-optical spectroscopy of the Kerr rotation (KR) on both single crystal and thin film of manganites. It has been established that the MCD response at 2.3 eV is typical for manganites transitioning into a conducting state. Consequently, it reflects a change in the band structure of the material. This response is also observed in the KR spectrum of manganites in the range 2.3-2.6 eV below the metal-insulator transition temperature. These findings complement the understanding of the electronic structure of manganites in general. Moreover, they also provide a basis for the search for new functional materials.

Toward the Chemical Structure of Diborane: Electronic Force Density Fields, Effective Electronegativity, and Internuclear Turning Surface Properties.

The chemical structure of diborane was elucidated through the superposition of the vector fields of the electron density gradient ∇ρ(r), the electrostatic force Fes(r), and the kinetic force Fk(r), together with the analysis of the cumulative charges of the atoms and pseudoatoms delimited in the aforementioned fields. It was proposed that the Fk-pseudoatomic charge could be employed as a metric for quantifying the ionic component of a related atomic charge. The electron permeability across an internuclear turning surface─specifically, the zero-flux surface in Fk(r)─was characterized by probing it through mapping the total static potential φem(r). The conceptualization of post hoc electronegativity was presented for consideration. Our analysis revealed that the ordinary B-H and bent B-μ-H bonds in diborane demonstrate the polar covalent character with minor contributions of the ionic component. The former bond exhibits a greater electron permeability through the internuclear turning surface, indicating a stronger tendency for electron sharing between the corresponding nucleus-dominated regions. The electron density accumulation along the bent B-μ-H bond path diverges from the minimum action trajectories of the forces Fes(r) and Fk(r). This phenomenon can be associated with the structural strain within the angled, three-center two-electron bonding B-μ-H-B. The internuclear B···B paths were identified in Fes(r) and Fk(r), in contrast to ∇ρ(r). This fact, in conjunction with a pronounced electron permeability through the mutual turning surface between the two boron nuclei, implies a certain degree of electron exchange between the boron-dominated pseudoatomic regions. Furthermore, the anomalous [B-]H···μ-H intermolecular polar interactions were described between the strongly negatively charged hydrogen atoms in the monoclinic crystalline β-phase of diborane. In fact, the ionic contributions to the charges of the hydrogen atoms are shown to be relatively small.

Mass transfer and formation of micro-inclusions in Ti-sapphire grown by the HDC method

The formation mechanism of micro-inclusions in titanium-sapphire crystals grown with the method of horizontal directional crystallization in a gas atmosphere was studied. It has been shown that the micro-inclusions of metallic tungsten and/or molybdenum are mainly formed at the surface of the unmelted charge. The thermodynamic analysis of the possible reactions of Mo and W among the charge components, the products of charge dissociation, and the components of the technological atmosphere was carried out. It is shown that CO2, CO, H2O, as well as suboxides of Al and Ti, can serve both as oxidizers of Mo and W and as reducing agents of their condensed oxides. The mechanism of mass transfer within which gaseous Mo and W oxides are reduced on the charge surface to form metal micro-particles was proposed. These particles further fall into the melt and then are transported with convective flows to the crystallization front and embedded into the crystal as micro-inclusions.

Revealing the three-dimensional structure of microbunched plasma-wakefield-accelerated electron beams

Plasma wakefield accelerators use tabletop equipment to produce relativistic femtosecond electron bunches. Optical and X-ray diagnostics have established that their charge concentrates within a micrometre-sized volume, but its sub-micrometre internal distribution, which critically influences gain in free-electron lasers or particle yield in colliders, has proven elusive to characterize. Here, by simultaneously imaging different wavelengths of coherent optical transition radiation that a laser-wakefield-accelerated electron bunch generates when exiting a metal foil, we reveal the structure of the coherently radiating component of bunch charge. The key features of the images are shown to uniquely correlate with how plasma electrons injected into the wake: by a plasma-density discontinuity, by ionizing high-Z gas-target dopants or by uncontrolled laser–plasma dynamics. With additional input from the electron spectra, spatially averaged coherent optical transition radiation spectra and particle-in-cell simulations, we reconstruct coherent three-dimensional charge structures. The results demonstrate an essential metrology for next-generation compact X-ray free-electron lasers driven by plasma-based accelerators.

Entanglement in Quantum Dots: Insights from Dynamic Susceptibility and Quantum Fisher Information

AbstractThis study investigates the entanglement properties of quantum dots (QDs) under a universal Hamiltonian where the Coulomb interaction between particles (electrons or holes) decouples into charging energy and exchange coupling terms. Although this formalism typically decouples the charge and spin components, confinement‐induced energy splitting can induce unexpected entanglement within the system. By analyzing the dynamic susceptibility and quantum Fisher information (QFI), significant behaviors are uncovered influenced by exchange constants, temperature variations, and confinement effects. In QDs with Ising exchange interactions, far below the Stoner instability (SI) point, where the QD is in a disordered paramagnetic phase, temperature reductions lead to decreased entanglement, challenging conventional expectations. These findings demonstrate that for QDs with small exchange interactions, the responses of easy‐plane () and easy‐axis () configurations are similar, with increased anisotropy broadening susceptibility and shifting its maximum to higher frequencies. For large exchange interactions, the susceptibility differences between easy‐plane and easy‐axis QDs become significant, with easy‐plane QDs exhibiting a higher susceptibility magnitude. Additionally, the study reveals that temperature variations affect the dynamic response functions differently in easy‐axis and easy‐plane QDs. In easy‐plane QDs, QFI consistently decreases with increasing temperature, whereas in easy‐axis QDs, QFI behavior is highly dependent on the strengths of and , showing either an increase or decrease with temperature based on specific coupling conditions. Conversely, at low temperatures, anisotropic Heisenberg models exhibit enhanced entanglement near isotropic points. Overall, this work contributes to advancing the understanding of entanglement in QDs and its potential applications in quantum technologies.

ВАРИАНТ КОМПАКТИРОВАНИЯ МЕЛКОДИСПЕРСНЫХ ЖЕЛЕЗОСОДЕРЖАЩИХ МАТЕРИАЛОВ ДЛЯ МЕТАЛЛУРГИЧЕСКОГО ПЕРЕДЕЛА

The paper presents the results of a study of options for compacting fine iron-containing materials for metallurgical processing. The authors have proposed a method that involves the use of, in addition to an iron-containing material, a thermoplastic binder material. In this case, aggregation of the mixture and strengthening of the resulting aggregates is carried out simultaneously in a closed mold under the influence of pressure and temperature not lower than the softening temperature of the thermoplastic material. It is possible to obtain a compact unit, convenient for storage and transportation, that successfully performs the functions of a charge component during cupola and blast furnace melting of cast iron.

Niobium’s Effect on the Properties of a Quasi-High-Entropy Alloy of the CoCrFeMnNi System

Niobium’s Effect on the Properties of a Quasi-High-Entropy Alloy of the CoCrFeMnNi System

A Comparative Study about Production of Va nadium Carbide via Self Propagating High Temperature Synthesis and Reduction

Vanadium carbide is important for industrial applications because of its high hardness, high temperature resistance, high chemical, and thermal stability. It is generally obtained from the reaction between V and C powders at a high temperature ranging from 1100 to 1500°C. Investigations on these high strength, high abrasion resistant, hard materials have been intensified in recent years and consequently, significant improvements have been achieved. In this study, VC alloys are produced with low cost processes, by reducing the oxides of their components by SHS methods and ball mill-assisted carbothermal reduction. In the experimental stage, V2O5 was used as oxidized Vanadium source, Cblack as carbon source, magnesium and Cblack as reductant. In the study, VC powders were synthesized by two different methods and optimum production conditions were determined. Furthermore, the effect of different stoichiometric charge components and the effect of experiment durations were realized by X-ray diffraction, HSC Chemistry, and SEM analyses for different reductants.

A SET OF TECHNICAL AND TECHNOLOGICAL PROPERTIES OF COAL FOR EVALUATING THE EFFECTIVENESS OF ITS USE

Purpose: assessment of the use of coal as a component of coal charge based on the definition of a set of technical and technological properties. The main consumption of hard coal is concentrated in the power industry, where coal is used by burning to obtain a certain amount of energy. However, the use of fossil fuels only for obtaining heat and energy is not rational, since this type of raw material belongs to non-renewable energy sources. The study of the structure and properties of individual brands of coal will allow to develop fundamentally new technological techniques for preparing coal for coking by means of targeted regulation of cohesive properties for rational use.

USE of Thermal Power Engineering Waste to Reduce the Average Density of Ceramic Wall Materials with a Matrix Structure

It has been presented the results of studies on reducing the average density of ceramic wall materials through the use of ash granules. The chemical, granulometric, and mineral compositions of clay raw materials and fly ash are given. It has been considered the compositions of ceramic charges with different contents of thermal power waste and sample preparation techniques. In the first case, mechanical mixing of the charge components was used, in the second case, granulation of the components and creation of a shell on the surface of the granules was used. The physical and mechanical properties of ceramic samples produced by both methods are presented. It has been established that an increase in the fly ash content in the charge leads to a decrease in the average density and compressive strength of ceramic samples. The use of the developed method for producing ceramic materials increases the strength characteristics of the samples, which makes it possible to increase the content of the ash component to 70–80 wt. % in the composition of the charge. It has been shown that the content of fly ash in the charge is more than 60 wt. % leads to an increase in water absorption of more than 20%, which practically indicates the absence of sintering processes in ash granules. Prospects and main directions for further research are formulated.

Understanding of polarization reversal and charge trapping under imprint in HfO2-FeFET by charge component analysis

Polarization reversal and charge trapping under imprint in HfO2-based ferroelectric FET (FeFET) are studied by charge component analysis. By decomposing the effects of spontaneous polarization and charge trapping using the transient current measurement with triangle waves in both metal–ferroelectric–metal (MFM) and metal–ferroelectric–insulator-Si (MFIS) capacitors, we found that V th under imprint in MFIS is determined by both coercive voltage (V c) shift due to imprint and the subsequent modulation of charge trapping at the same polarization. In addition, a comparison of V c shift due to imprint of MFM and MFIS was performed. V c shift of MFIS was found to be in good agreement with that of MFM. This implies that the imprint in FeFET can be predicted from MFM even though FeFET has a complex structure with an interfacial layer.

Influence of Concentration, Surface Charge, and Natural Water Components on the Transport and Adsorption of Polystyrene Nanoplastics in Sand Columns.

Information about the influence of surface charges on nanoplastics (NPLs) transport in porous media, the influence of NPL concentrations on porous media retention capacities, and changes in porous media adsorption capacities in the presence of natural water components are still scarce. In this study, laboratory column experiments are conducted to investigate the transport behavior of positively charged amidine polystyrene (PS) latex NPLs and negatively charged sulfate PS latex NPLs in quartz sand columns saturated with ultrapure water and Geneva Lake water, respectively. Results obtained for ultrapure water show that amidine PS latex NPLs have more affinity for negatively charged sand surfaces than sulfate PS latex NPLs because of the presence of attractive electrical forces. As for the Geneva Lake water, under natural conditions, both NPL types and sand are negatively charged. Therefore, the presence of repulsion forces reduces NPL's affinity for sand surfaces. The calculated adsorption capacities of sand grains for the removal of both types of NPLs from both types of water are oscillating around 0.008 and 0.004 mg g-1 for NPL concentrations of 100 and 500 mg L-1, respectively. SEM micrography shows individual NPLs or aggregates attached to the sand and confirms the limited role of the adsorption process in NPL retention. The important NPL retention, especially in the case of negatively charged NPLs, in Geneva Lake water-saturated columns is related to heteroaggregate formation and their further straining inside narrow pores. The presence of DOM and metal cations is then crucial to trigger the aggregation process and NPL retention.

Comprehensive analysis of read-after-write latency in HfZrOX-based ferroelectric field-effect-transistors with SiO2 interfacial layer

In this paper, a quantitative analysis is performed focusing on the read-after-write latency (RWL) phenomenon in HfOX-based ferroelectric field-effect transistors with a metal-ferroelectric-insulator-semiconductor structure. RWL is scrutinized by modifying two variables: the pulse width (tp) for the “write 1” operation and the operating temperature (T); the response of the charge component is found to follow an emission mechanism. Additionally, we identified a notable change in charge behavior at a specific temperature (Tb), where capture and emission are in balance. Experimental investigations have demonstrated that the activation energy (EA) for these charge components is situated between 0.2 and 0.5 eV, and the Tb is ∼50 °C. By elucidating the relationship between T, tp, remnant polarization (Pr), and Tb, we offer insights into the importance of optimizing tp and Pr on the transient response of the balanced charge and the related RWL phenomenon.

Water flow in a cylindrical nanopore with an object

Understanding the physics of water movement through a nanopore with an object is critical for better control of water flow and object translocation. It should help in the design of nanopores as molecular and viral sensors. We evaluated how the external electric field and ion concentrations, pore wall charge density, disk radius and charge density, and ion mobility influence the water flow in a charged cylindrical nanopore using Poisson–Nernst–Planck–Navier–Stokes simulations. We dissected water flow induced by the external electric field (“external” component) from that generated by the field induced by the fixed and mobile charges (“charge” component). The velocity and direction of the axial flow “external” component were controlled directly by the external electric field. The pore wall charges also influenced them indirectly by altering the density and distribution of mobile charges. Higher external concentrations enhanced the axial water flow by lowering its charge component. The ion mobility and disk charge slightly influenced the axial water flow. The axial body forces near the wall drive the axial water flow near the pore wall. If the disk is large, water also flows axially in the opposite direction near the pore center. Local forces near the disk do not control the radial water flow near the disk. The axial body force and water flow near the pore wall do. If an annulus replaces a disk, the axial forces near the pore wall control the radial flow near the annulus and the axial flow within its hole.

The nature of some Late Bronze Age iron-bearing artefacts of the Ural-Kazakhstan region

The problem of the beginning of iron production in the Late Bronze Age of the Ural-Kazakhstan region is dis-cussed. For this, 13 iron-bearing artefacts from nine settlements that functioned in the 2nd mil. BC were studied using the SEM-EDS and LA-ICP-MS methods: metal objects, metallurgical slags, and a bimetallic droplet. Most of the studied artefacts are not related to the iron metallurgy. High ferric impurities in copper metal products of the Late Bronze Age on the territory of the Southern Trans-Urals are caused by the use of iron-rich ore concentrates. The raw materials for these products were represented by mixed oxidized-sulphide ores from the cementation subzone of the volcanogenic massive sulphide and skarn copper deposits. Iron droplets, frequently found in the Late Bronze Age copper slag in the Ural-Kazakhstan region, are not directly related to iron metallurgy. They are by-products of the copper metallurgy formed in the process of copper extraction from the iron-rich components of the furnace charge or fluxes (brown iron ore, iron sulphides). The only artefacts that indicate direct smelting of metal from iron ore are the slag fragments from the Kent settlement. Presumably, oxidized martitized ore of the Kentobe skarn deposit or its nearby analogues was used to extract iron at the Kent settlement. Rare finds of iron slags from the Late Bronze Age, known only in the territory of Central Kazakhstan, confirm an extremely small scale of iron production. Iron ore had been already deliberately used for these experiments. However, iron metal-lurgy in the Ural-Kazakhstan region developed into a mature industry much later. The discovery of iron metallurgy based on the smelting of copper-sulphide ores in the Ural-Kazakhstan steppes is doubtful. The use of sulphide ores here is known from the 20th c. BC, and it was widespread. In the meantime, the first iron slags and products appear much later, and their finds are sporadic. The development of iron metallurgy on the basis of experiments with iron ores seems more likely.

Point of Zero Charge of Soils - It’s Dynamics under Fertilizer Management Practices and Nutrient Availability

Aims: To study the dynamics of point of zero charge of different soil types and determine the availability of nutrients under the influence of specific fertilizer management practices.
 Study Design: Completely Randomized Design.
 Place and Duration of Study: Department of Soil Science, Assam Agricultural University, Jorhat, Assam; between March 2020 and December 2021.
 Methodology: We estimated the point of zero charge (PZC) components, i.e., the point of zero salt effect (PZSE) and point of zero net charge (PZNC) in six surface soil samples [black soil (Vertisol), laterite soil (Alfisol), red soil (Alfisol) of Odisha, and alluvial soils belonging to Entisol, Inceptisol, and Alfisol of Assam, India] through potentiometric titration and ion retention methods respectively. The soils were subjected to four specific fertilizer management practices under laboratory incubation, viz., FYM @ 5 t ha-1 (T1), NPK @ 80:40:40 for Odisha soils and 60:20:40 for Assam soils (T2), T1 + T2 (T3) and T3 + Lime requirement/ Gypsum requirement (T4). The PZC components and availability of nutrients were determined at 15 and 30 days after incubation.
 Results: The PZSE values of the soils ranged from 2.18 to 4.70, while PZNC values were achieved at relatively lower pH ranging from 2.03 to 4.10. Highest values of PZSE and PZNC were recorded under treatment T2 followed by T3, T4 and T1 for all the incubated soil samples, however there was a decrease in the PZC values with increase in days of incubation. Comparatively, the treatment T4 resulted as the most ideal fertilizer management practice. Besides providing optimum amount of primary and maximum amount of secondary nutrients, T4 regulated the PZC values favouring minimal loss of nutrients and enhanced nutrient use efficiency. The availability of nutrient ions is influenced by the difference between soil solution pH and PZC values of the soil, which recorded to be highest for Vertisol (OS1), followed by Entisol (AS1), Inceptisol (AS2), and Alfisol (AS3, OS2, OS3) soil orders.
 Conclusion: The exchange and availability of cationic nutrients get enhanced due to higher CEC in soils with high clay and organic matter percentage. The pH of these soils must therefore be regulated for better availability of anionic nutrients. Highly weathered soil of Alfisol order exhibit optimal CEC over a narrow pH range, favouring better availability of anionic nutrients and hence simultaneously require frequent fertilizer application along with organic manures for the enhanced retention, mobility and availability of nutrients in soil.

A universal optimization framework for commercial building loads using DERs from utility tariff perspective with tariff change impacts analysis

To accommodate the changes in the nature and the pattern of electricity consumption with the available resources, utilities have introduced variety of tariffs over the years. This paper develops a comprehensive optimization framework that addresses the challenges associated with the diversity of utility tariffs for commercial loads. Optimization of commercial building net load through Battery Energy Storage System (BESS) and renewable energy resources is modeled and explored for minimizing billing cost for different tariffs. Cost functions are formulated for each possible commercial utility tariff type, engendering the universal cost function format. An algorithm is developed to apply the optimization model and generate the desired optimal outputs (e.g., optimal net load and BESS power, costs and savings, etc.). The results for several building loads and all tariff types are compared and analyzed to present the findings. An impacts analysis is performed to observe how different changes in tariffs affect the optimizations results. Results exhibit that for same building load and renewable generation, the tariff type can have an overwhelming impact on costs and savings. Tariffs without Time of Use (TOU) charges or peak demand charge components offer lower savings opportunity from BESS optimization. Price change sensitivities showed the complicated dynamics among TOU price components on savings and historical trend analysis as an effective tool to predict future savings. Tradeoff between energy and demand charge heavy tariff options are also discussed for user benefit. The recent change in TOU time periods presents limited desired benefits while the modified tariff proposed in this paper exhibit significant improvement in terms of utility operation.

Pyrometallurgical Technology for Extracting Iron and Zinc from Electric Arc Furnace Dust

This study is aimed at developing a technology for processing electric arc furnace dust (EAFD) into granulated cast iron and a zinc-containing product. The study object was the dust from the EAF of PJSC Magnitogorsk Iron and Steel Works (Magnitogorsk, Chelyabinsk region). It has been established that the dust contains valuable components in the form of ZnFe2O4 and ZnO. The processing of EAFD involves the reduction of Fe and Zn in a charge from their oxygen-containing forms with C and CO. The content of the charge components was calculated in % as follows: EAFD—17.44; scale—51.33; hard coal—20.61; quartz sand—4.71; lime—5.91. The experiments in the high-temperature LHT 08/17 furnace (Germany) allowed for defining the optimal temperature regime for reduction melting. As a result of laboratory tests, granulated pig iron samples were obtained, containing in wt%: Fe—95.27; C—4.4; S—0.07, and others. Captured zinc-containing product after calcination (to remove halogens) contained 90.21 wt% ZnO. The resulting granulated pig iron is recommended as one of the charge components in electrometallurgical steel production. The zinc-containing product is recommended as a raw material for Zn production and others.