Predominant Phase Research Articles

The THE EFFECT OF ZIRCONIUM ADDITIVES ON PROPERTIES OF (Cu22%Zn4%Al) SHAPE MEMORY ALLOY

Shape memory alloys (SMAs) are one of the most important types of smart materials. It define as the materials that can undergo large pseudo elastic deformations while having the ability to recover to their original shape once subjected to a memory stimuli such as a specific temperature ,stress ,or strain. This study examines the effects of varying Zirconium (Zr) additive amounts on the microstructure, mechanical, and shape memory effect for all specimens of Cu-Zn-Al SMAs. Powder metallurgy was used to create Cu–22%Zn–4%Al SMAs, both base and with the inclusion of 0.2 and 0.4 weight percent Zr. 650MPa compact pressure was used to create the alloys after the particles had been mixed for five hours. The alloys underwent a three-step sintering procedure in a vacuum tube furnace for one hour at 350 ˚C, then for one hour at 550 ˚C, and for two hours at 850 ˚C. To characterise the microstructural and phase characteristics of alloys, both with and without Zr additions, XRD diffraction analyses, optical microscopy (OM), and scanning electron microscopy (SEM) were performed. With differential scanning calorimetry, the transition temperatures of all alloys were determined (DSC).As well as the shape memory effect test (SME) was measured. Results confirmed that all alloys compositions were found to include the predominant (Cu5Zn8) phase, as proven by XRD and microstructural investigation. The Zr addition dramatically lowered the transition temperatures, according to the transformation temperature data. Hardness experiments reveal that alloys' hardness and volume losses were enhanced by adding up to 0.4% weight percent of Zr reached to (64.8%) and (0.3909)mm3 respectively compared to base alloy.

Dry Magnetic Separation and the Leaching Behaviour of Aluminium, Iron, Titanium, and Selected Rare Earth Elements (REEs) from Coal Fly Ash

Coal fly ash (CFA) is a commercially viable source of alumina comparable to traditional bauxite deposits. Due to its high silica content and alumina in the refractory mullite phase, the most suitable processing technique is the sinter-H2SO4 leach process. However, this process is energy-intensive, has low selectivity for Al, and generates a secondary solid waste residue. To develop a sustainable process that is economically attractive, Al can be extracted with REEs, Ti, and Fe as saleable products, while secondary solid waste is regenerated for further applications to achieve high-value and high-volume utilisation of CFA. This study focused on the potential extraction of selected REEs (Ce, La, Nd, Y, and Sc), Al, Ti, and Fe, using dry magnetic separation and the sinter-H2SO4 leach process. XRD analysis showed that CFA is predominantly amorphous with crystalline mullite, quartz, and magnetite/hematite. Further analysis using SEM-EDS and TIMA showed Al-Si-rich grains as the predominant phase, with discrete REE-bearing grains (phosphates and silicates) and Fe-oxide (magnetite/hematite) grains. Traces of REEs, Ti, Ca, Si, and Fe were also found in the Al-Si-rich grains. Discrete Fe-oxide was recovered using dry magnetic separation, and up to 65.9% Fe was recovered at 1.05 T as the magnetic fraction (MF). The non-magnetic fraction (non-MF) containing quartz, mullite, and amorphous phase was further processed for preliminary leaching studies. The leaching behaviour of Al, Ti, Fe, and the selected REEs was investigated using the direct H2SO4 and sinter-H2SO4 leaching processes. The maximum extraction efficiency was observed using the sinter-H2SO4 leach process at 6 M H2SO4, a 1:5 solid-to-liquid ratio, 70 °C, and a residence time of 10 h, yielding 77.9% Al, 62.1% Fe, 52.3% Ti, and 56.7% Sc extractions. The extraction efficiencies for Ce, La, Nd, and Y were relatively lower at 23.2%, 27.6%, 11.3%, and 11.2%, respectively. Overall, the results demonstrate that the extraction of REEs using the sinter-H2SO4 leach process is strongly influenced by the complex CFA phase composition and the possible formation of insoluble calcium sulphates. Appreciable extraction of Al, Fe, Ti, and Sc was also observed, suggesting a potential two-step leaching process for the extraction of REEs as a feasible option for the industrial recovery of multiple saleable products.

Impurity Behavior in Cast Copper Anodes: Implications for Electrorefining in a Circular Economy

The behavior of impurities in cast copper was investigated to simulate production with increased utilization of secondary sources within the framework of a circular economy. The incorporation of impurities, particularly Ni, Sn, and Sb, from recycled Cu may significantly impact the electrorefining process. In this study, commercial anodes were doped with Ni, Sn, and Sb concentrations of 2500–6500 g/t, 300–900 g/t, and 450–950 g/t, respectively. Anode concentrations of Pb and Bi were maintained at 1000 g/t and 350 g/t, respectively. As concentrations were examined at two levels, 860 or 1700 g/t, depending on the commercial anode used to create the doped samples. Electron microscopy with microprobe analysis revealed that the commercial anodes contained three predominant phases: Cu2O, (Cu,Ag)2(Se,Te), and a complex oxide phase of Cu, Pb, As, Sb, and/or Bi. Ni, the main impurity, primarily accumulated within the Cu grains, while Sn and Sb tended to form oxidized inclusions. The distribution of Ni in Cu grains was ca. 20% lower in the anodes doped at higher Ni concentrations due to the formation of nickel-bearing inclusions, such as Kupferglimmer and NiO. The doped anodes showed lower quantities of Cu2O inclusions than the commercial anodes due to the preferential formation of oxides with other impurities, including SnO2. These findings highlight potential challenges for Cu electrorefining in a circular economy, as Ni, Sb, and Sn may impact the deportment of these impurities to slimes or electrolyte and may cause copper depletion in the refining electrolyte.

Unlocking Low‐Temperature Ammonia Decomposition via an Iron Metal–Organic Framework‐Derived Catalyst Under Photo‐Thermal Conditions

AbstractPhoto‐thermal catalysis, leveraging both thermal and non‐thermal solar contributions, emerges as a sustainable approach for fuel and chemical synthesis. In this study, an Fe‐based catalyst derived from a metal–organic framework is presented for efficient photo‐thermal ammonia (NH3) decomposition. Optimal conditions, under light irradiation without external heating, result in a notable 55% NH3 conversion. Mechanistic investigations reveal that the enhanced catalytic activity arises from the synergistic interplay between light‐induced hot carriers and elevated temperatures during irradiation. Supported by density functional theory calculations, the findings elucidate the dual role of the catalyst. At lower temperatures, photo‐generated electrons in the Fe3O4 phase serve to raise the energies of reaction intermediates, preventing the formation of a thermodynamic sink. Conversely, at higher temperatures, metallic Fe emerges as the predominant active phase, with thermal contributions prevailing. Overall, this work advances the understanding of the cooperative effects between light and heat in photo‐thermal systems, paving the way for innovative applications in sustainable energy conversion.

The Effect of the MgO/Al2O3 Ratio on the Thermal and Refractory Behaviors of Cordierite Ceramics

In this study, cordierite-based ceramics (2MgO·2Al2O3·5SiO2) were synthesized using high-purity MgO, Al2O3, and SiO2 as starting materials. The influence of the MgO/Al2O3 ratio on various properties, including the thermal behavior, pyrometric cone refractory behavior, phase formation, physical properties, and microstructure of the synthesized ceramics, was systematically analyzed. Increasing the MgO/Al2O3 ratio progressively weakened the cordierite network, leading to lower temperatures for liquid formation and melting. This resulted in reduced viscosity and increased fluidity. Subsequently, the thermal and refractory behaviors were observed at lower temperatures with higher deformation rates under higher MgO/Al2O3 ratios. The lower viscosity of the liquid formed at reduced temperatures contributed to an increase in the density of sintered bodies, reduced porosity, and enhanced shrinkage. X-ray diffraction analysis confirmed that cordierite was the predominant phase in samples sintered at 1300, 1350, and 1400 °C, with higher cordierite formation at higher temperatures. Conversely, the formation of secondary phases, such as spinel, cristobalite, and enstatite, decreased with increasing sintering temperature. Pyrometric cones were then constructed for a range of temperature settings, and their deformation characteristics at specific temperatures were used to evaluate the refractoriness under diverse conditions.

SYNTHESIS AND CHARACTERIZATION OF NiFe2O4 SPINEL NANOPARTICLES

Introduction. Nickel ferrite (NiFe2O4) spinel nanoparticles have attracted great interest in recent years due to their unique physicochemical properties and wide range of applications in various fields. Methodology. In this work, the synthesis of NiFe2O4 nanoparticles by the sol-gel method was studied. The synthesized NiFe2O4 nanoparticles were characterized using methods such as X-ray diffraction analysis and energy-dispersive X-ray microanalysis. Results and discussion. The results of Xray diffraction analysis showed that the main phase in the analyzed samples is iron-containing oxide of cubic structure NiFe2O4, and the position and relative intensity of the peaks correspond to the standard JCPDS No. 54–0964. Also, EDS analysis of the studied samples showed that the nanopowders consist of the elements Ni, Fe and O, which indicates the purity of the synthesized sample and the absence of any impurities. FTIR spectrum of NiFe2O4 nanoparticles showed two main peaks at 458 cm−1 and 548 cm−1 corresponding to the metal-oxygen band. Conclusion. The results of the study of the magnetic properties of the obtained NiFe2O4 nanoparticles show that the magnetic properties change depending on the alloy components and phase composition, i.e. FeNiO (77% Fe3O4 - magnetite 23% Fe0.64Ni0.36) is a particle of about 25 nm size, a multicomponent ferromagnetic powder with a predominant magnetite phase, low coercivity and relatively large saturation magnetization values. This means that they are a soft magnetic material with high magnetic properties.

Optimization of Structural, Dielectric, and Electrical Properties in Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 through site engineering for Biocompatible Energy Harvesting

Optimization of Structural, Dielectric, and Electrical Properties in Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 through site engineering for Biocompatible Energy Harvesting

Unveiling the Corrosion Mechanism of the NixSey Intermetallic Compound in Water-Based Solution.

In this study, Ni-Se intermetallic compound coatings were fabricated using electrodeposition at various process temperatures (40-70 °C). The results show that increasing the process temperature promotes the deposition of Se, which leads to a transition in the crystal phase of the samples from the Ni0.85Se phase, prepared under low-temperature conditions, to a NiSe2 phase. The dissolution rate of Se in pure water from Ni-Se coatings is inversely related to the incorporated Se content, which indicates that the Ni0.85Se phase has a higher natural corrosion rate compared to the NiSe2 phase. Under the influence of an electric field, the corrosion behavior of Ni-Se coatings is dominated by a two-stage reaction involving Se transformation and dissolution. Coatings with a predominant Ni0.85Se phase exhibit more severe corrosion behavior compared to those with a predominant NiSe2 phase, which suggests that the corrosion reaction is enhanced by the electric field. However, because coatings with a predominant NiSe2 phase contain a higher proportion of Se22- ions, the dissolution reaction of SeOx, generated during the electrochemical reaction, is retarded, thereby inhibiting the progression of the corrosion reaction. Consequently, coatings with a predominant NiSe2 phase exhibit relatively better corrosion resistance in a water-based electrolyte.

Promotional effect of external magnetic field in FexOy/ZSM-5 for selective CO2 hydrogenation to C2–C4 and aromatic hydrocarbons

Promotional effect of external magnetic field in FexOy/ZSM-5 for selective CO2 hydrogenation to C2–C4 and aromatic hydrocarbons

Comprehensive Evaluation and Management of Liver Hydatid Cyst.

Hydatid cyst infection is a severe disorder caused by exposure to the infectious form of the Echinococcus granulosus parasite, which is widespread worldwide. This study examined a total of 125 patients who were diagnosed with hepatic hydatid cysts based on clinical and surgical evaluations. Patients with cysts larger than 5 cm displayed markedly elevated levels of ALT, AST, and ALP in comparison to those with smaller cysts. The heightened levels suggest a disturbance in liver functionality resulting from the infection. Furthermore, the patients exhibited elevated serum bilirubin levels. An evident differentiation was observed between patients with cysts over 5 cm in size and those with smaller cysts, indicating have a higher effect on liver function in individuals with bigger cysts. A total of 225 hepatic hydatid cysts were diagnosed using CT scans. The predominant cyst phases seen were Stage I and II, accounting for 58% and 45% of cases, respectively. Upon diagnosis, 79% The cysts range in size from 5 to 10 cm. CT imaging provides additional features that aid in the identification of type I unilocular echinococcosis. However, it is important to note that no single imaging feature is clearly diagnostic of this type of cyst.. Nevertheless, imaging techniques can assist in differentiating these cysts from non-parasitic liver cysts. On the other hand, Type II, III, and V hydatid cysts can be accurately identified by their distinct imaging characteristics.

Mitigating Mechanical Stress by the Hierarchical Crystalline Domain for High-Energy P2/O3 Biphasic Cathode Materials.

Sodium-ion batteries (SIBs) have captured widespread attention for grid-scale energy storage owing to the wide distribution and low cost of sodium resources. Delivery of high energy density with stable retention remains a challenge in developing cathode candidates for rechargeable SIBs. Inspired by the concept of "cationic potential", here, we present a hierarchical crystalline domain in hexagonal particles with target chemical composition (Na0.8Li0.03Mg0.05Ni0.28Fe0.05Mn0.54Ti0.05O2) from the inner bulk O3 phase (71.1 wt %) to the outer P2-type shell (28.9 wt %) of the structure. Benefiting from the mitigated mechanical stress of the predominant bulk O3 phase under the protection of the surficial P2 crystalline domain at the microscale during Na+ (de)intercalation, the brittle fracture, plastic yielding, and structural damage of the bulk O3 phase are effectively prohibited during battery cycling, thereby achieving good structural integrity. As a consequence, the biphasic P2/O3-Na0.8Li0.03Mg0.05Ni0.28Fe0.05Mn0.54Ti0.05O2 material exhibits satisfactory electrochemical properties, with a high energy density of 506 Wh kg-1 and good capacity retention of 85.5% over 200 cycles. This work highlights the importance of tailoring the crystalline domain to mitigate the reaction-induced stress and particle fracture of layered biphasic cathode materials for high-energy SIBs.

Hydrothermal Approach of Spinel Copper Cobaltite (CuCo2O4) Nanostructures and Their Structural and Functional Properties

CuCo2O4 nanoparticles were synthesized via facile hydrothermal route using oxalic as a precipitant, thermal decomposition of CuCo2O4 precursor at 400[Formula: see text]C. The structural studies from X-ray diffraction (XRD), Fourier transform infrared spectrometer, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) disclose the predominant spinel crystal phase for copper cobaltite. The optical absorption spectra reveal two band gaps of 3.8[Formula: see text]eV and 4.4[Formula: see text]eV in the CuCo2O4 nanoparticles. The cyclic voltammetry (CV) was used to assess the electrochemical characteristics of the resulting product in an organic electrolyte at −1.5–1.5[Formula: see text]V under ambient conditions. On 22.4[Formula: see text]nm CuCo2O4 nanoparticles, a greater capacitance of 920[Formula: see text]F/g at a scan rate of 5[Formula: see text]mV/s was achieved.

Effects of anode geometry on DC magnetron sputtering of copper oxide films deposition

Abstract Effects of anode shape are examined in a custom-made DC magnetron sputtering system. Polycrystalline copper-oxide (CuO) films are deposited using wedge, ring and disc shaped anodes. Current–voltage (I-V) characteristics of the discharge were fitted with models of plasma discharge. Above 700 V a notable rise in average plasma impedance, from approximately 2kΩ to 7kΩ was observed. Scanning electron microscope (SEM) images reveal uniform and porous film growth. The deposition increased significantly with increasing the anode surface area due to decrease in gas density in cathode sheath. For all the anode shapes tested, the deposition rates were higher in magnetron sputtering compared to DC sputtering mode. X-ray diffraction (XRD) of the films deposited with the disk anode revealed polycrystalline films with predominant CuO phase. With increasing sputtering power, average crystallite size vary from 11 nm to 21 nm, dislocation density vary from approximately 8.4×〖10〗^(-3) nm-2 to 2.3×〖10〗^(-3) nm-2 and micro strain from approximately 3.3×〖10〗^(-3) to 1.7×〖10〗^(-3). This indicate that higher sputtering at higher powers produce higher quality films. Atomic force microscopy revealed that the rms roughness of the samples is about 4 nm.

Synthesis and characterization of p-CuO/n-ZnO heterostructured composite thin films for the detection of formaldehyde gas.

We report the synthesis and characterization of pure CuO and CuO-ZnO nanostructured composite thin films sprayed on particle-free glass substrates using chemical spray pyrolysis method. The films were systematically analyzed through microstructural, morphological, chemical, and gas-sensing studies. X-ray diffraction (XRD) studies confirmed the polycrystalline nature of the films, with a predominant monoclinic phase along the (002) direction. Key structural parameters, such as crystallite size, dislocation density, strain, and the number of crystallites per unit area, were reported from XRD analysis. Field emission scanning electron microscopy (FESEM) revealed a bundled-like morphology with uniform particle distribution, enhancing the surface area for effective gas interaction. X-ray photoelectron spectroscopy (XPS) results indicated that Cu and Zn ions existed predominantly in the 2+ oxidation state, contributing to the films' reactivity. Significantly, the gas sensing studies were investigated with static liquid distribution method, highlighting the remarkable performance of the 30 wt.% CuO-ZnO composite thin film. This composite exhibited a substantial response to 5 ppm formaldehyde at ambient conditions, showing a recovery time of 22 seconds and a response time of 15 seconds. These findings underscore the potential of CuO-ZnO composites for efficient formaldehyde gas sensing applications, marking a notable advancement in the field of environmental monitoring.

Performance optimization and environmental assessment of novel alkali-activated binders containing carbonated recycled concrete powder

Performance optimization and environmental assessment of novel alkali-activated binders containing carbonated recycled concrete powder

Optimization of Crystal Structures in Polylithionite Concentrate: A Molecular Dynamics Approach to Lithium Extraction Efficiency.

Molecular dynamics (MD) techniques offer significant potential for optimizing mineral extraction processes by simulating economically or physically restrictive conditions at the laboratory level. Lithium, a crucial metal in the electromobility era, exemplifies the need for ongoing re-evaluation of extraction techniques. This research aims to simulate the crystal structures of mineral species present in a polylithionite mineral concentrate [KLi2Al(Si4O10)(F,OH)2] using crystallographic data obtained from X-ray diffraction analysis. This study focuses on optimizing these structures, validating them through density comparisons, and determining the interaction parameter between the identified phases and lithium oxide (Li2O). The X-ray diffraction analysis revealed five predominant mineral phases: quartz (SiO2), calcite [Ca(CO3)], pyrite (FeS2), cassiterite (SiO2), and a compound Pb6O2(BO3)2SO4. Structural data, including lattice parameters, space groups, and atomic coordinates, were used to construct the crystal structures with Materials Studio 8.0, employing the Crystal Builder module. Optimization was performed using the Forcite module with the Smart optimization algorithm and the Universal force field. The interaction parameter (χ) indicated an affinity between lithium oxide and pyrite, as well as between calcite and quartz.

Microstructural characteristics of aluminosilicate minerals in cement clinker prepared from coal gangue, carbide slag, and desulfurization gypsum

Microstructural characteristics of aluminosilicate minerals in cement clinker prepared from coal gangue, carbide slag, and desulfurization gypsum

Elucidating the diffusion and interaction mechanisms of Zn2+ and H+ in MnO2 for aqueous zinc-ion batteries: A DFT study

Elucidating the diffusion and interaction mechanisms of Zn2+ and H+ in MnO2 for aqueous zinc-ion batteries: A DFT study

Improved flux pinning properties of Mg exceed MgB2 ceramics with B4C and Dy2O3 additions

Improved flux pinning properties of Mg exceed MgB2 ceramics with B4C and Dy2O3 additions

Effect of ZnO/Li2O ratio on the structure and properties of Li2O-ZnO-SiO2-P2O5 glass-ceramics sealants

Effect of ZnO/Li2O ratio on the structure and properties of Li2O-ZnO-SiO2-P2O5 glass-ceramics sealants