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The effects of nano-sized Ni_0.5Zn_0.5Fe₂O₄ (NZFO) addition on the superconducting properties of Bi_1.6Pb_0.4Sr₂CaCu₂O₈ (Bi-2212) were investigated. Samples were prepared using the solid-state reaction method with NZFO addition of 0 to 0.5 wt%. The structural, electrical, and magnetic properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical resistance measurements, and AC susceptibility analysis. All samples exhibited normal metallic characteristics above onset transition temperature, T_c−onset. The resistance versus temperature measurements showed T_c−onset and zero transition temperature, T_c−zero for all samples ranging between 72 and 82 K, and 55 and 70 K, respectively. Scanning electron microscopy (SEM) revealed noticeable microstructural changes with higher additions of nano-sized NZFO. Despite these changes, the addition of nano-sized NZFO did not significantly suppress the intra- and intergrain characteristics of the Bi-2212 phase. The x = 0.06–0.08 wt% samples showed the highest intergrain peak temperatures, Josephson current and Josephson coupling energy even though the transition temperatures and Bi-2212 phase volume fraction were suppressed. This work showed that the appropriate addition of nano-sized NZFO could significantly enhance grain connectivity and critical current density, highlighting its potential as an effective flux pinning center for Bi-based superconductors.

This study explores the reconstruction method within the framework of (f(Q, {mathbb {T}})) gravity by utilising the new agegraphic dark energy (A(mathbb {DE)}) model, where Q represents non-metricity and ({mathbb {T}}) is the trace of the energy–momentum tensor. The (f(Q, {mathbb {T}})) new A({{mathbb {D}}}{{mathbb {E}}}) model is developed through a non-interacting correspondence approach. This theoretical model is then examined in the context of a flat Friedmann–Robertson–Walker (FRW) cosmological framework, which is defined by a power-law scale factor and a pressureless perfect fluid. This modified gravity framework effectively captures different stages of the evolution of the Universe. The reconstructed model is employed to calculate the equation of state parameter, phase planes and the squared speed of sound. The equation of state parameter indicates a quintessence phase, the (omega _{mathbb{D}mathbb{E}})–(omega '_{mathbb{D}mathbb{E}}) plane reveals the freezing region and the (textbf{r})–(textbf{s}) phase plane corresponds to the Chaplygin gas model. Additionally, the squared sound speed parameter suggests instability in the current cosmic evolution. Our study demonstrates that (f(Q, {mathbb {T}})) gravity provides an accurate and comprehensive framework for explaining cosmic expansion, effectively encompassing the dynamics across all stages of the Universe’s evolution.

The temporal and spatial scales associated with linear and nonlinear ion acoustic waves (IAWs) in Titan’s ionosphere have been estimated in the presence of an extremely small ambient magnetic field of the order of (B_0 simeq 2 times 10^{-4}) G. Titan’s ionosphere has many kinds of positive and negative ions but for analytical calculations, the dominant ions HCNH⁺ and CN⁻ are taken into account along with free electrons keeping in view the observations of the Cassini spacecraft. The frequencies of IAW turn out to be of the order of (0.001) rad/s, and parallel wavelengths of the order of several kilometers, which are very different from Earth’s ionosphere. Shear flow-driven purely growing instability is also investigated. It is found that the IAWs become unstable in the presence of field-aligned shear flow of positive and negative ions. It is pointed out that the nonlinear IAWs can give rise to large solitary electrostatic structures with widths of the order of several hundred kilometers. The values of plasma beta corresponding to positive and negative ions are (beta _{a}simeq (0.046)ll 1) and (beta _{b}simeq (0.006)ll 1), which are suitable for the propagation of electrostatic waves.

The enrichment of metal ions on the surface of clay particles significantly leads to the loosening of the particle surface structure, thereby weakening the macroscopic engineering properties of the clay. In this study, sodium ions (Na⁺) and potassium ions (K⁺) as monovalent metal ions, along with lead ions (Pb²⁺) and zinc ions (Zn²⁺) as divalent metal ions, were selected as metal ion contaminants. The focus was to investigate their effects on the microstructural morphology, macroscopic engineering properties, and electrical properties of the clays. The aim of the study is to clarify the relationship between the valence state and concentration of these four types of metal ions and the engineering properties of clay, and to predict the engineering properties of metal-ion-contaminated clay using resistivity parameters. The results indicate that the incorporation of metal ions reduces the average particle size, transforming the soil structure from flaky to a honeycomb form. Under the same loading conditions, metal-ion-contaminated clay exhibits a lower void ratio. As the concentration of metal ions increases, pore volume decreases, thereby enhancing soil compressibility. Alkali metal ions primarily influence the soil structure through a dispersive effect, while heavy metal ions exert a cohesive effect. Monovalent alkali metal-ion-contaminated clay demonstrates larger compression coefficients across all load levels, whereas heavy metal-contaminated soils exhibit higher compression coefficients under low loads. Furthermore, the shear strength and cohesion of metal-ion-contaminated clay are lower than those of field-state clay. At lower concentrations, the internal friction angle may exceed that of field-state clay; however, as the concentration of metal ions increases, the shear strength, internal friction angle, and cohesion significantly decrease. The presence of metal ions also reduces soil resistivity, which declines at a diminishing rate with increasing concentration. At lower ion concentrations, monovalent alkali metal ions have a slightly stronger effect on reducing resistivity compared to divalent heavy metal ions. Resistivity parameters effectively reflect the compressibility and shear characteristics of metal-ion-contaminated clay, revealing a negative linear correlation between resistivity and compression ratio under uniaxial loading, while a positive linear correlation exists with shear strength, internal friction angle, and cohesion. These insights provide a basis for the rapid evaluation of engineering characteristics in metal-ion-contaminated clay.

Background

Most acute abdominal pain raises the suspension of infectious or inflammatory processes. The most obvious sign of acute intra-abdominal inflammation is frequently the identification of inflamed fat on the ultrasound. The study aimed to determine the specificity and sensitivity of focal hyperechogenic fat sign as a localizer of abdominal pathologies and to correlate findings with other imaging modalities as well as operative and pathological data.

Results

Seventy-six patients with abdominal pain have been examined by ultrasound. In 32 patients (42.1%), focal hyperechogenic fat sign was the only detected sign by ultrasound; however, it was associated with other findings in 44 patients (57.9%). In 16 patients (21.1%), echogenic fat represents the primary source of pathology, while in 59 patients (77.6%), underlying pathologies were detected, & the echogenic fat was a secondary finding. The diagnostic performance of hyperechogenic fat signs shown in the US in detecting the cause of abdominal pain was true-positive sign in 75 cases & false positive in one case. Its sensitivity is high. It was about 98.7%.

Conclusion

Our investigation demonstrated that focal hyperechoic mesenteric fat sign on abdominal ultrasound exhibited exceptionally high diagnostic performance, with a sensitivity of 100% and accuracy of 98.7% in detecting potential intra-abdominal pathologies. However, these findings necessitate validation through larger, multi-center prospective studies to establish broader clinical applicability.

This paper discusses the synthesis of W-type hexaferrite and lanthanum perovskite nanoparticles using the auto-combustion method. Structural analysis conducted through X-ray powder diffraction (XRD) confirms the formation of polycrystalline nanoparticles exhibiting W-type hexaferrite (HF) and orthorhombic perovskite structures. Optical characterization via UV-visible spectroscopy reveals band gaps of 3.2 eV for direct transitions and 2.2 eV for indirect transitions. Scanning electron microscopy (SEM) images illustrate the microstructure, showing grains with prominent hexagonal faces and a spongy morphology, with sizes ranging from 40 to 70 nm. Additionally, antiferromagnetic properties are demonstrated by the hysteresis loop obtained from vibrating sample magnetometer (VSM) measurements. The antibacterial and antifungal activities of the nanosized composite BaCo₂Fe₁₆O₂₇ and LaFeO₃ have been evaluated against various gram-positive and gram-negative bacterial strains.

Clays are layered structure and the layers can be separated by mechanical or chemical processes. In the present study, bentonite clay (BC) has been exfoliated by ultrasonication with distilled water as a medium. Sonication has been carried out for 30, 60 and 120 min. The clay samples have been characterized by X-ray diffraction, scanning electron microscopy and thermal analysis for phase, morphology and thermal stability, respectively. Sonication for 60 min leads to a better exfoliation and reduction in particle size of the clay. The clay powders have been utilized to prepare composites with polypropylene (PP). Compounding has been performed using a twin screw extruder by melt mixing technique and composite specimens have been prepared by the injection moulding technique. Tensile strength, Izod impact strength, hardness along with density have been evaluated for composites. It has been observed that the sample prepared with BC sonicated for 60 min shows the optimum properties due to better exfoliation of clay. Enhancement in tensile and impact strength has been 10.2% and 11.9% for the aforementioned composite as compared to untreated bentonite clay-based composite.

We describe an algorithm to be used for the numerical integration of plasticity models in finite element or finite difference codes. The algorithm is simple to code and implement. It is presented here for a generic form of plasticity model encompassing both single and multiple yield surfaces, and it is readily adaptable to more complex models. Three examples are given to demonstrate the efficacy of the algorithm in controlling integration errors.

In response to the urgent need for new hydrogen storage materials, this study explores the potential of BaMH₃ perovskite hydrides (M=Co and Ni) using first-principles calculations. The structural, electronic, mechanical, optical, and hydrogen storage properties of these compounds are examined in detail. The results reveal negative formation enthalpies, suggesting their thermodynamic stability and compliance with Born’s mechanical stability criteria. Band structure and electronic density of states analysis show metallic behavior with metal-hydrogen ionic bonding. Furthermore, BaCoH₃ and BaNiH₃ exhibit notable ductility and display optical conductivity in the infrared and visible regions, while offering impressive hydrogen storage capacities of 1.48 wt% and 1.49 wt%, respectively. Additionally, the gravimetric ratios indicate that the two compounds are well-suited for long-term hydrogen storage as fuel sources and could make significant contributions to various energy and transportation applications.

The novel adsorbent of KMnO₄-modified spent coffee grounds (KMnO₄-SCGS) was successfully synthesized for the adsorption of Pb(II). Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and other characterization measurements were employed to evaluate the physical and chemical properties of KMnO₄-SCGS. The results demonstrated that the adsorption behavior of Pb(II) was best fitted by the pseudo-second-order, Ritchie, and Langmuir isothermal models, indicating that the surface of KMnO₄-SCGS was composed of homogeneous adsorption. The surface complexes with manganese oxide (MnO_x) and oxygen-containing functional groups, along with electrostatic interaction, physical adsorption, and ion exchange, played significant roles in the adsorption of Pb(II). The Langmuir maximum adsorption capacity for Pb(II) was 203.8 mg/g for KMnO₄-SCGS, which was approximately 11.73 times higher than that of SCGS, and it remained over 80% after five cycles. Finally, the Box-Behnken design was utilized to optimize the results. Therefore, the modification of spent coffee grounds by KMnO₄ is a feasible approach for the adsorption of Pb(II).

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