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Equilibrium phase formations below 600 K in the parts Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 of the Fe–Ag–Ge–Te system were established by the electromotive force (EMF) method. The positions of 3- and 4-phase regions relative to the composition of silver were applied to express the potential reactions involving the AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 compounds. The equilibrium synthesis of the set of phases was performed inside positive electrodes (PE) of the electrochemical cells: (−)Graphite ‖LE‖ Fast Ag+ conducting solid-electrolyte ‖R[Ag+]‖PE‖ Graphite(+), where LE is the left (negative) electrode, and R[Ag+] is the buffer region for the diffusion of Ag+ ions into the PE. From the observed results, thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 were experimentally determined for the first time. The reliability of the division of the Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 phase regions was confirmed by the calculated thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 in equilibrium with phases in the adjacent phase regions. Particularly, the calculated Gibbs energies of Ag2FeGeTe4 in two different adjacent 4-phase regions are consistent, which also indicates that it has stoichiometric composition.

The equilibrium concentration space of the Ag–In–Te system in the part AgInTe2–Te–In2Te3 was studied through the modified solid-state electromotive force (EMF) method by dividing In2Te3–In2Te5–Ag3In97Te147 (I), In2Te5–Te–Ag3In97Te147 (II), Ag3In97Te147–Te–AgIn5Te8 (III), AgIn5Te8–Te–AgIn3Te5 (IV), and AgIn3Te5–Te–AgInTe2 (V), into separate phase regions at T ≤ 500 K. The formation of a thermodynamically stable combination of the binary and ternary phases in the (I)–(V) phase regions from a metastable phase mixture of substances was carried out at T ≤ 500 K in the R(Ag+) part of the positive electrode (PE) of the galvanic cells (GCs) of the structure: (−) C |∙| Ag |∙| SE |∙| R(Ag+) |∙| PE |∙| C (+), where C is the graphite (inert electrode), SE is the solid-state electrolyte (Ag3GeS3Br glass), and Ag is the left (negative) electrode. The Ag+ ions in the R(Ag+) region functioned as small nucleation centers for the formation of the stable phases. The spatial position of the (I)–(V) phase regions in the concentration space of the Ag–In–Te system relative to the position of silver was used to express the overall potential-forming reactions with the participation of the substances Ag, Te, In2Te5, Ag3In97Te147, AgIn5Te8, AgIn3Te5, and AgInTe2. The subsequent EMF measurements were carried out by applying the same GCs. The temperature dependences of the EMF of GCs with PE of the (I)–(V) phase regions were here used to determine, for the first time, the values of standard thermodynamic functions of the binary and ternary compounds. The determined values of the Gibbs energies of the formation of compounds are equal: GIn2Te5○=(182.7±1.9) kJ·mol−1, GAgInTe2○=(115.0±3.1) kJ·mol−1, GAgIn3Te5○=(301.5±6.5) kJ·mol−1, GAgIn5Te8○=(487.6±11.3) kJ·mol−1, and GAg3In97Te147○=(8594±189) kJ·mol−1 The correctness of the division of the equilibrium phase space of the Ag–In–Te system in the part AgInTe2–Te–In2Te3 involving the AgInTe2, AgIn3Te5, AgIn5Te8, and Ag3In97Te147 compounds was confirmed by the agreement of the calculated and literature-based thermodynamic data for In2Te5 compound. Compositions of pairs of the ternary compounds for their subsequent practical application were proposed.

Understanding the interaction between submerged water jets and cohesive deep-sea sediment is critical for optimizing deep-sea polymetallic nodule hydraulic mining techniques. This research investigated the distinct erosion behavior of cohesive sediments through laboratory experiments and numerical simulations. Cohesive deep-sea sediments were simulated using bentonite–kaolinite mixtures. A series of laboratory experiments, including vane shear tests and viscosity tests under varying moisture content, were conducted to assess the sediments’ mechanical properties. Experimental submerged water jet erosion tests provided basic data for validating the numerical simulations. A Eulerian multi-fluid (EMF) model was implemented to capture sediment–water jet interactions under varying operational parameters, including jet velocities and nozzle heights. The erosion process was found to comprise three distinct stages, including rapid erosion, steady erosion, and stabilization. Two distinct erosion mechanisms were identified, depending on the jet intensity, which affected the depth and shape of the erosion pits. Quantitative analysis revealed that erosion depth exhibits an approximately linear relationship with jet velocity and nozzle height, whereas the erosion diameter shows nonlinear characteristics. These findings enhance the fundamental understanding of cohesive sediment responses under hydraulic disturbances, providing crucial insights for the design and optimization of efficient deep-sea mining systems.

In many industrial applications, the varying speed of the motor drives has become essential for the fast dynamic load conditions. Therefore, the detailed analysis of Field Oriented Control (FOC) with the sensor-less technique of BLDC is proposed where the reference speed is obtained from the MPPT based ANFIS controllers for control the speed. The FOC not only control the magnitude but also provides the phasor control. With Back-EMF estimation process, the motor is applied to obtain the torque ripple minimization and correct speed control using simpler IFOC. It is used to estimate speed in a sensorless and to map the continuous velocity variation. This approximate velocity is used to activate and to predict hall switching output less BLDC motor signals with low tension MATLAB / Simulink tool is using for results verification.

This study compiles original experimental and literature data on the thermodynamic properties (Δ f G°, S°, Δ f H°) of silver tellurides (α-Ag 2 Te, β-Ag 2 Te, Ag 1.9 Te, Ag 5 Te 3 , AgTe) obtained by the method of solid-state galvanic cell with the RbAg 4 I 5 and AgI solid electrolytes. The thermodynamic data for empressite (AgTe, pure fraction from Empress Josephine Mine, Colorado USA) have been obtained for the first time by the electrochemical experiment with the virtual reaction Ag + Te = AgTe. The Ag–Te phase diagrams in the T  −  x and log f Te 2 (gas) − 1/ T coordinates have been refined, and the ternary Ag–Te–O diagrams with Ag–Te–TeO 2 (paratellurite) composition range have been calculated.

The equilibrium T  −  x space of the Ag-Ga-Te-AgBr system in the part Ag 2 Te-GaTe-Te-AgBr-Ag 2 Te below 600 K has been divided into separate phase regions using the electromotive force (EMF) method. Accurate experimental data were obtained using the following electrochemical cells (ECs): (−) IE | NE | SSE | R{Ag + } | PE | IE (+), where IE is the inert electrode (graphite powder), NE is the negative electrode (silver powder), SSE is the solid-state electrolyte (glassy Ag 3 GeS 3 Br), PE is the positive electrode, R{Ag + } is the region of PE that is contact in with SSE. At the stage of cell preparation, PE is a non-equilibrium phase mixture of the well-mixed powdered compounds Ag 2 Te, GaTe, Ga 2 Te 3 , AgBr, and tellurium, taken in ratios corresponding to two or three different points of interest for each of the phase regions. The equilibrium set of phases was formed in the R{Ag + } region at 600 K for 48 h with the participation of the Ag + ions. Silver cations, displaced for thermodynamic reasons from the NE to the PE of ECs, acted as catalysts, i.e., small nucleation centers of equilibrium phases. The spatial position of the established phase regions relative to the position of silver was used to express the overall reactions of synthesis of the binary Ga 2 Te 5 , Ga 7 Te 10 , Ga 3 Te 4 , ternary AgGa 5 Te 8 , and quaternary Ag 3 Ga 10 Te 16 Br, Ag 3 Ga 2 Te 4 Br, Ag 27 Ga 2 Te 12 Br 9 compounds in the PE of ECs. The values of the standard thermodynamic functions (Gibbs energies, enthalpies, and entropies) of these compounds were determined based on the temperature dependencies of the EMF of the ECs.

Polythermal sections in the vicinity of the quaternary compounds Ag2FeSnS4 and Ag2FeSn3S8 have been modeled. The mechanism of formation of these quaternary compounds and their thermal stability have been investigated. Measurements of electromotive force allowed calculations of the standard thermodynamic functions ΔG°, ΔH°, and S° of the Ag2FeSnS4 and Ag2FeSn3S8 compounds. Based on calorimetric measurements, the enthalpies of phase transitions of the selected compounds were determined. Furthermore, the heat capacities of both quaternary compounds were estimated by applying different calculation methods. Thermodynamic properties of the quaternary compounds, which are regarded as functional magnetic materials, were analyzed and are discussed in detail.

Zinc arsenides are promising semiconductors due to their natural abundance, unique electronic properties such as high carrier mobility and structural anisotropy and significant potential for advancing sustainable technologies. In light of discrepancies in existing literature and the growing relevance of these compounds, this study presents a thermodynamic investigation of ZnAs2 and Zn3As2 within the temperature range of 300-440 K using the low-temperature electromotive force (EMF) method. Equilibrium samples from the ZnAs2 + As and Zn3As2 + ZnAs2 two-phase regions of the Zn-As system were utilized, with phase compositions confirmed by powder X-ray diffraction analysis. The experimental data enabled the calculation of partial molar functions of zinc in the alloys, as well as the standard thermodynamic functions of formation and standard entropies for ZnAs2 and Zn3As2 compounds. A comparative analysis with previously reported data was conducted, providing insights into the thermodynamic behavior of zinc arsenides and improving the accuracy of existing knowledge.

Interaction of Pr/Dy with oxygen in nickel melts at PAr = 0.1 MPa and constant temperature was studied using the EMF instantaneous fixing method using a Mo[Cr/Cr2O3//ZrO2(MgO)//O(Nil)]Mo cell and certified sensors. Dependences a[O] = f[Pr/Dy, %] expressed in the form of logarithmic equations made it possible to compare them with each other in the concentration range of 0.001–0.2 wt % of each deoxidizer and determine that the deoxidizing ability of Pr is 1.7 times higher compared to Dy. The activity of oxygen a[O] in Ni–O–Al–(Pr/Dy) melts was calculated in comparison with Al at a concentration of 0.05 wt % of elements and its sevenfold decrease was shown for the first deoxidizer and elevenfold for the second. The morphology of nonmetallic inclusions in metallographic sections of Ni–O–Pr/Dy alloys has been studied, indicating that the inclusions are located along grain boundaries and have different configurations and a complex heterophase composition. Analysis of nonmetallic inclusions with the maximum content of deoxidizing element proved the existence of Pr/Dy oxygen compounds, which confirmed the data of thermodynamic and mass spectrometric studies. The average content of Zr in nonmetallic inclusions during the deoxidation of Pr is two times higher than in experiments during the deoxidation of Dy, which indicates the interaction of Pr/Dy with the EMF ZrO2 sensor and the preferential interaction of Pr compared to Dy and correlates with the data on the determination of a[O].

In the present paper, we report the standard molar Gibbs energy of formation for CaThF 6 measured by gas equilibration and e.m.f. methods. The HF(g) vapour pressure over the equilibrium reaction: CaThF 6 cr + 2 H 2 O g = CaF 2 cr + ThO 2 cr + 4 HF g has been measured using transpiration technique. The above reaction mechanism has been established employing TG and XRD techniques. A fluoride e.m.f. cell: (−)Pt, CaF 2 (cr) + ThOF 2 (cr) + CaThF 6 (cr) |CaF 2 (cr)| NiO(cr) + NiF 2 (cr), Pt(+) has been constructed to measure Gibbs energy of formation of CaThF 6 (cr) using CaF 2 (cr) as a solid electrolyte. The isobaric heat capacity Cp m ∘ T of the compound has been measured using differential scanning calorimetric technique. Based on the experimental results, thermodynamic functions for CaThF 6 have been generated.