Search Results (221)

This study investigates the influence of RE elements on the room- and high-temperature properties of magnesium alloys. The effects of RE type, addition level, and multi-element alloying strategies were systematically analyzed to clarify the underlying strengthening mechanisms and processing pathways for optimizing Mg–RE alloys. RE elements enhance the mechanical and thermal properties of Mg alloys through crystal structure modification, formation of thermally stable dispersed phases, precipitation strengthening, and solid-solution strengthening. Compared with conventional alloying elements, RE additions offer distinct advantages in strengthening efficiency and overall performance. To fully exploit these benefits, new research paradigms that integrate machine learning and other advanced techniques are required, enabling the intelligent design of multicomponent alloy systems tailored to specific application requirements. Full article

In the light of increasing research into amorphous composites and their applications, as-cast specimens of multicomponent Ti₄₈Zr₁₈V₁₂Cu₅Be₁₇ amorphous composites were prepared via water-cooled copper mold suction casting. Subsequently, the as-cast specimens were subjected to semi-solid isothermal treatment to obtain semi-solid specimens. Taking the semi-solid specimens as the research object, room temperature compressive deformation behavior was investigated by analyzing the shear band characteristics on the side surfaces of the compressed specimens. The evolution of shear bands at various stages of plastic deformation was investigated via scanning electron microscopy (SEM). Additionally, significant work hardening was observed after yielding. Surface deformation morphologies indicate that the work-hardening behavior is associated with plastic deformation, interactions between shear bands, and interactions between shear bands and β-Ti crystals. Experiments have demonstrated that at a specific deformation extent, shear bands preferentially initiate at the crystal–amorphous matrix interface. In the final stage of plastic deformation, shear bands propagate through work-hardened β-Ti crystals into the amorphous matrix, with their propagation retarded by the β-Ti crystals. When shear bands in the amorphous matrix are obstructed by β-Ti crystals and can no longer propagate, some evolve into cracks. These cracks then propagate exponentially, leading to eventual fracturing of the specimens and termination of plastic deformation. The research findings provide a theoretical basis for analyzing the deformation capacities of various amorphous composites. Full article

The interest in synthesizing new dielectric materials is caused by their potential application in various electronic and sensor devices as well as in a large variety of electronic components. The present work reports the synthesis of glasses in the Na₂O/Al₂O₃/BaO/ZrO₂/TiO₂/B₂O₃/SiO₂ system prepared by melt-quenching. These glasses were then crystallized to glass–ceramics by a controlled thermal treatment. X-ray diffraction experiments reveal the precipitation of Ba₂TiSi₂O₈ (fresnoite) and BaTiO₃, which probably forms a BaZr_xTi_1−xO₃ solid solution. The microstructure is studied by scanning electron microscopy and shows the presence of mulberry-shaped, crystallized structures with a densely-branching morphology. Microcomputed X-ray tomography is used to gather information on the volume fraction and average size of the crystallized volume as an effect of the applied temperature–time schedule. Longer annealing times lead to a higher volume fraction and increasing average size of the crystallization structures obtained. The dielectric properties analyzed by impedance spectroscopy are insulating and show relatively high dielectric constants ≥ 100 and moderate loss tangent values at 10 kHz. Full article

The goal of this study is to develop an efficient machine learning framework for designing high-hardness multi-metal nitride coatings, overcoming the limitations of traditional trial-and-error methods. The development of multicomponent metal nitride hard coatings via multi-arc ion plating remains a significant challenge due to the vast compositional search space. Although theoretical studies in macroscopic, mesoscopic, and microscopic domains exist, these often focus on idealized models and lack effective coupling across scales, leading to time-consuming and labor-intensive traditional methods. With advancements in materials genomics and data mining, machine learning has become a powerful tool in material discovery. In this work, we construct a compositional search space for multicomponent nitrides based on electronic configuration, valence electron count, electronegativity, and oxidation states of metal elements in unary nitrides. The search space is further constrained by FCC crystal structure and hardness theory. By incorporating a feature library with micro-, meso-, and macro-structural characteristics and using clustering analysis with theoretical intermediate variables, the model enriches dataset information and enhances predictive accuracy by reducing experimental errors. This model is successfully applied to design multicomponent metal nitride coatings using a literature-derived database of 233 entries. Experimental validation confirms the model’s predictions, and clustering is used to minimize experimental and data errors, yielding a strong agreement between predicted optimal molar ratios of metal elements and nitrogen and measured hardness performance. Of the 100 Vickers hardness (HV) predictions made by the model using input features like molar ratios of metal elements (e.g., Ti, Al, Cr, Zr) and atomic size mismatch, 82 exceeded the dataset’s maximum hardness, with the best sample achieving a prediction accuracy of 91.6% validated against experimental measurements. This approach offers a robust strategy for designing high-performance coatings with optimized hardness. Full article

Background/Objectives: Increasing the solid-state landscape of an active pharmaceutical ingredient (API) by generating new crystalline forms (e.g., polymorphs, cyclodextrin (CD) inclusion complexes, co-crystals, and salts) can yield products with significantly enhanced biopharmaceutical properties (especially increased water solubility), thereby improving API delivery and extending its lifetime. The aim of this study was the isolation of new solid forms of the poorly water-soluble non-steroidal anti-inflammatory drug fenbufen (FBF), for which relatively few solid phases have been reported to date. Further motivation for the study is the recent finding that it has potential for repurposing to treat acute pancreatitis. Methods: Interventions for generating new solid forms of FBF included (a) polymorph screening with a variety of solvent media, (b) attempts to form solid inclusion complexes with the native cyclodextrins α-, β-, and γ-CD using various preparative methods, and (c) co-crystallization with a series of coformers to produce co-crystals and/or molecular salts. Results: No new polymorphic forms of FBF were identified, but screening with CDs resulted in isolation and characterization of a new solid inclusion complex with γ-CD. However, co-crystallization of FBF with the water-soluble coformer isonicotinamide yielded two new products, namely a 1:1 co-crystal and an unusual multi-component ionic co-crystal, whose aqueous solubility indicated significant enhancement of FBF solubility. Conclusions: Due to its extremely low water solubility, FBF presented challenges during the study aimed at modifying its crystalline form. However, two new supramolecular forms, a co-crystal and an ionic co-crystal, were isolated, the latter phase having potential for further formulation owing to its significantly enhanced solubility. Full article

The content of modified materials in multicomponent gel phase change materials directly affects their performance characteristics. To investigate the influence of different contents of modified materials on the performance features of Na₂HPO₄·12H₂O-based multicomponent Gel Phase Change Materials, four single factors (Na₂SiO₃·9H₂O, C₃₅H₄₉O₂₉, KCl, and nano-α-Fe₂O₃) and their interactions were selected as influencing factors. Using the Taguchi method with an L₂₇(3¹³) orthogonal array, multi-step melt–blending experiments were conducted to prepare a novel multi-component phase change material. The characteristics of the new multi-component phase change material, including supercooling degree (ΔT), phase change temperature (T_m), latent heat of phase change (ΔH_m), and cooling time (CT), were obtained. In addition, characterization techniques such as DSC, SEM, FT-IR, and XRD were employed to analyze its thermal properties, microscopic morphology, chemical stability, and crystal structure. Based on the experimental results, the signal-to-noise ratio (S/N) was used to rank the influence of each factor on the quality characteristics, and the p-value from analysis of variance (ANOVA) was employed to evaluate the significance of each factor on the performance characteristics. Then, the effects of each significant factor on the characteristics of the multiple gel phase change materials were analyzed in detail, and the optimal mixing ratio of the new multiple gel phase change materials was selected. The results showed that Na₂SiO₃·9H₂O, KCl, and α-Fe₂O₃ were the most critical process parameters. This research work enriches the selection of composite gel phase change materials for solar greenhouses and provides guidance for the selection of different modified material contents using Na₂HPO₄·12H₂O as the starting material. Full article

The polymorphism of ammonium nitrate has significantly limited its application. Incorporating potassium nitrate into crystals of ammonium nitrate is one of the most commonly used methods to inhibit its polymorphic transition. To accurately prepare crystals of ammonium nitrate with varying contents of potassium nitrate, the solid–liquid phase equilibrium relationship of the quaternary system (NH₄NO₃-KNO₃-H₂O-C₂H₅OH) was studied at 298.15 and 303.15 K. The solubility of components in the equilibrium liquid phase and the composition of the wet-solid phase were determined through formaldehyde titration and gravimetric methods. Based on the solubility data, the phase diagram of the multicomponent system was subsequently constructed. Experimental data demonstrate that the concentration of ammonium nitrate in solution decreases as the potassium nitrate concentration increases. Furthermore, as the ethanol content in the solvent system increases, the equilibrium solubility of ammonium nitrate and potassium nitrate exhibits a concomitant reduction. Correlation analysis of the solubility data for the multicomponent system was performed using the nonrandom two-liquid model. Error analysis demonstrates that the calculated values exhibit satisfactory agreement with the experimental data. Full article

Objectives: Drug–drug cocrystallization represents a promising approach for the development of novel combination drugs with improved physicochemical and biopharmaceutical properties. The aim of the present research is to prepare novel drug-drug cocrystalline forms of antiepileptic drug carbamazepine (CBZ) with sulfacetamide (SCTM). Methods: The novel CBZ cocrystal methanol solvate and cocrystal hydrate were prepared via solvent evaporation technique and characterized by single crystal X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis. Results: Single-crystal X-ray diffraction and thermal analysis revealed that the multicomponent solids are isostructural, wherein the solvent molecule does not play a structure-forming role. To optimize the synthesis of [CBZ+SCTM+H₂O] (1:1:0.7), the binary and ternary phase diagrams were constructed in acetonitrile at 25 °C. A thorough investigation of the cocrystal hydrate behavior in aqueous solution showed that the pH of the dissolution medium exerted a significant effect on the stability and solubility of [CBZ+SCTM+H₂O] (1:1:0.7). According to the dissolution and diffusion experiments in a buffer solution pH 6.5, the cocrystal hydrate characterized an enhanced dissolution rate and flux of CBZ. Pharmacokinetic studies in rabbits showed that the novel cocrystal hydrate exhibited a comparable bioavailability to the parent CBZ. Conclusions: Overall, this work reports the preparation of a novel CBZ drug-drug cocrystal hydrate, which can be considered as an alternative CBZ solid form for oral usage, possessing additive pharmacological effect. Full article

Melt crystallization is a promising separation technique that produces ultra-high-purity products while consuming less energy and generating lower CO₂ emissions than conventional methods. However, accurately modeling melt crystallization is challenging due to significant non-idealities and complex phase equilibria in multicomponent systems. This study develops and evaluates two neural network-based surrogate models for acrylic acid melt crystallization: a stand-alone (black-box) model and a thermodynamically guided (hybrid) model. The hybrid model incorporates UNIQUAC-based solid–liquid equilibrium constraints into the learning process. This framework combines first-principles thermodynamic knowledge—particularly activity coefficient calculations and mass balance equations—with multi-output regression to predict key process variables. Both models are rigorously tested for interpolation and extrapolation, with the hybrid approach demonstrating superior accuracy even under operating conditions significantly outside the training domain. Further analysis reveals the critical importance of accurate solid–liquid equilibrium (SLE) data for thermodynamic parameterization. A final case study illustrates how the hybrid approach can quickly explore feasible operating regions while adhering to strict product purity targets. These findings confirm that integrating mechanistic constraints into neural networks significantly enhances predictive accuracy, especially when processes deviate from nominal conditions, providing a practical framework for designing and optimizing industrial-scale melt crystallization processes. Full article

The present study focuses on investigating the evolution of phase transformations in the Mg-Ni-Ce system under the influence of mechanical synthesis (MS) and spark plasma sintering (SPS). Magnesium powder mixtures with different nickel and cerium contents (Mg-3%Ni-2%Ce, Mg-7%Ni-3%Ce, and Mg-10%Ni-5%Ce) were mechanically activated along with various grinding parameters. The X-ray phase analysis (XRD) has shown the successive stages of the phase formation in the MS process: from the initial components to the formation of intermetallic compounds of Mg₂Ni, Mg₁₂Ni₆, and CeMg₃. An increase in the intensity of mechanical treatment facilitated the accelerated destruction of the crystal lattice, the generation of defects, and the formation of new phases, as evidenced by the broadening and reduction in the intensity of Mg diffraction peaks. The subsequent SPS stage promoted the completion of phase transformations, structural stabilization, and the formation of a dense, multicomponent microstructure with a uniform distribution of intermetallic compounds. The observed average crystallite sizes ranged from 20 to 70 nm, depending on the processing conditions. The research results demonstrate the possibility of targeted control over the phase composition, opening new opportunities for the development of highly efficient hydrogen-absorbing alloys. Full article

In this work, a multicomponent PZT-type material doped with manganese Mn, antimony Sb, samarium Sm, and tungsten W was fabricated using classical powder technology. Sintering of the ceramic samples was performed by the free sintering method (pressureless sintering). The influence of samarium on the properties of PZT was analyzed using a variable amount of samarium Sm³⁺ (from 0.8 to 1.2 wt.%) and tungsten W⁶⁺ (from 1.4 to 1.2 wt.%) admixture compared to the Pb(Zr_0.49Ti_0.51)_0.963Mn_0.021Sb_0.016O₃ + W⁶⁺1.8 wt.% reference composition. XRD studies have shown that PZT-type ceramic samples have a tetragonal structure with a point group of P4mm. Field emission scanning electron micrographs (FE-SEMs) showed fine and properly crystallized grains with an average grain size of 5.65–7.70 μm and clearly visible grain boundaries. The polarization–electric field (P-E) hysteresis measurement confirmed the ferroelectric nature of the ceramic materials with high P_m maximum polarization values (from 12.38 to 16.46 μC/cm²). Dielectric studies of PZT-type materials have revealed high permittivity values (from 1025 to 1365 at room temperature (RT) and from 18,468 to 25,390 at phase transition temperature T_m) with simultaneously low tanδ dielectric loss factor values (from 0.004 to 0.011 at RT) and low DC electrical conductivity, which are important parameters for microelectronic applications. The most homogeneous structure and the most favorable set of utility parameters are represented by the composition with an equal content of Sm and W admixtures, i.e., for 1.2 wt.%. Full article

This study examines the thermal conduction resistance in anisotropic bodies using linear extended irreversible thermodynamics. The fulfilment of the Onsager Reciprocal Relations in anisotropic bodies, such as crystals, has been demonstrated. This fulfilment is achieved by incorporating Newton’s heat transfer coefficients into the calculation of the entropy production rate. Furthermore, a basic principle for the transport of heat, similar to the Onsager–Fuoss formalism for the multicomponent diffusion at a constant temperature, was established. This work has the potential to be applied not just in the field of material science, but also to enhance our understanding of heat conduction in crystals. A novel formalism for heat transfer analogous to Onsager–Fuoss model for multicomponent diffusion was developed. It is believed that this work could be applied for educational purposes. Full article

Supported lipid bilayers (SLBs) that model neuronal membranes are needed to explore the role of membrane lipids in the misfolding and aggregation of amyloid proteins associated with neurodegenerative diseases, including Parkinson’s and Alzheimer’s disease. The neuronal membranes include not only phospholipids, but also significant amounts of cholesterol, sphingomyelin, and gangliosides, which are critical to its biological function. In this study, we explored the conditions for the formation of an SLB, for the five-component lipid mixture composed of zwitterionic 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC), anionic 1,2-dioleoyl- sn-glycero-3-phospho-L-serine (DOPS), nonionic cholesterol (Chol), zwitterionic sphingomyelin (SM), and anionic ganglioside (GM), using the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, by varying experimental parameters such as pH, buffer type, temperature, vesicle size, and osmotic stress. SLB formation from this multicomponent lipid system was found challenging because the vesicles adsorbed intact on the quartz crystal and failed to rupture. For most of the variables tested, other than osmotic stress, we found no or only partial vesicle rupture leading to either a supported layer of vesicles or a partial SLB that included unruptured vesicles. When osmotic stress was applied to the vesicles already adsorbed on the surface, by having a different salt concentration in the rinse buffer that follows vesicle flow compared to that of the dilution buffer during vesicle flow and adsorption, vesicle rupture increased, but it remained incomplete. In contrast, when osmotic stress was applied during vesicle flow and adsorption on the surface, by having different salt concentrations in the dilution buffer in which vesicles flowed compared to the hydration buffer in which vesicles were prepared, complete vesicle rupture and successful formation of a rigid SLB was demonstrated. The robustness of this approach to form SLBs by applying osmotic stress during vesicle adsorption was found to be independent of the number of lipid components, as shown by SLB formation from the 1-, 2-, 3-, 4-, and 5-component lipid systems. Full article

C-S-H/PCE suspension can boost the hydration degree and strength of cement composite binding. However, the suspension will inevitably precipitate after a period of time, which is not conducive to its preservation, and its low solid content increases transportation costs in practical applications. In this study, utilizing synthetic PCE as a template, C-S-H/PCE suspension was synthesized using a co-precipitation method. Subsequently, powder seeds were produced via the spray-drying technique, and these prepared powder seeds were analyzed via microscopic characterization. The impact of these powder nucleating agents on cement hydration kinetics was evaluated through hydration heat measurements and hydration degree, fluidity, and compressive strength testing. The results indicated that these powder seeds exhibited a nano-film morphology. Their nucleation effect significantly enhanced the cement hydration rate, increased the degree of hydration, and improved strength. The hydration kinetics showed that the hydration of cement mixed with nucleating agents was not governed by a single reaction mechanism, but rather constitutes a complex, multi-component reaction process. As the content of nucleating agents increased, higher dosages of nucleating agents accelerated the production of more products within a short period, causing the system to rapidly transition to phase boundary reaction control. When the dosage of nucleating agents reached 2%, the cement hydration process bypassed the phase boundary reaction control stage and transitioned directly from the crystallization nucleation and crystal growth control process to the diffusion-controlled phase. Although the influence of powder seeds on the enhancement of the early-stage strength of mortar was slightly lower than that of the suspension, the powder was beneficial to its storage and transportation. Therefore, it has the potential to replace the suspension. Full article

Raman imaging and K-means cluster analysis of individual mineral grains supplemented by scanning electron microscopy, electron probe microanalysis, and X-ray powder diffraction were applied to study fine-grained, multi-component products of the pyrrhotite three-stage oxidative alteration in migmatitic gneiss. During the first stage, related to the kaolinization of feldspars in gneisses, pyrrhotite was replaced by marcasite via intermediate amorphous iron sulfide. Increased oxygen fugacity caused the localized crystallization of either maghemite or ferric (oxyhydr)oxides. Even higher oxygen fugacity and an increase in solution pH during the second stage of alteration resulted in the partial replacement of marcasite by pyrite, followed by the replacement of both sulfides by Fe oxides (hematite, maghemite, magnetite) and ferric (oxyhydr)oxides (goethite, feroxyhyte). The final stage of sulfide oxidative alteration resulted in the predominance of sulfates of the alunite–jarosite series over ferric oxyhydroxides and relicts of Fe sulfides. Quartz–calcite–pyrite hydrothermal veins were affected by the most recent weathering, which resulted in the crystallization of the dominant alunite–jarosite-series minerals (alunite, jarosite, Al-jarosite) and ferric (oxyhydr)oxides (goethite, lepidocrocite). Full article