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Gd-doped Ba1-xGdxCo2Fe16O27 (BGxCF) x = (0.00, 0.05, 0.10, 0.15, 0.20, and 0.25) wt.% W-type hexaferrite ceramic pellets were synthesized by ball milling solid-state reaction technique. XRD patterns of the prepared samples verify the single-phase polycrystalline nature without any impurity phase. The doping of Gd ions in the samples impacted the lattice parameters, unit cell volume and bulk density increases. Morphological results analysis using SEM shows the hexagonal plate-like structure of the BGxCF particles. The increase of Gd contents in the samples created multi-domain structure and grain growth occurred. FT-IR analysis confirmed the existence of the octahedral and tetrahedral vibration of Fe–O, with Gd substitution bond strength between the atom decreases. Raman analysis verifies the existence of A1g, E1g and E2g Raman modes, with Gd wt.% increases there is a red shift of the vibration modes. Magnetic results reveal that with Gd substitution in the BGxCF samples, the magnetization saturation (Ms) increased for x = 0.05, and 0.10 samples due to strain magnetization, while, for x = 0.15 and 0.20 samples, Ms decreased due to the spinning by Gd ions, and but it is increased for x = 0.25 samples. Moreover, with increases of Gd wt.% in the samples, there is a decrease in the coercive field due to the increase of particle size and a decrease of magnetocrystalline anisotropy. In addition, the dielectric properties revealed increases in both permittivity and dielectric loss with the Gd contents in BGxCF samples. Permeability studies show the existence of spin resonance phenomena in the samples. The magnetic losses in the Gd-doped samples are higher than the undoped sample due to the decreases of magnetocrystalline anisotropy. The highest values of both dielectric and magnetic losses of the Gd-doped BGxCF samples make these materials enhance its performance in microwave potential devices applications. [ABSTRACT FROM AUTHOR]

Infections originating from pathogenic microorganisms can significantly impede the natural wound-healing process. To address this obstacle, innovative bio-active nanomaterials have been developed to enhance antibacterial capabilities. This study focuses on the preparation of nanocomposites from thermally reduced graphene oxide and zinc oxide (TRGO/ZnO). The hydrothermal method was employed to synthesize these nanocomposites, and their physicochemical properties were comprehensively characterized using X-ray diffraction analysis (XRD), High-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR), Raman spectroscopy, UV-vis, and field-emission scanning electron microscopy (FE-SEM) techniques. Subsequently, the potential of TRGO/ZnO nanocomposites as bio-active materials against wound infection-causing bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, was evaluated. Furthermore, the investigated samples show disrupted bacterial biofilm formation. A reactive oxygen species (ROS) assay was conducted to investigate the mechanism of nanocomposite inhibition against bacteria and for further in-vivo determination of antimicrobial activity. The MTT assay was performed to ensure the safety and biocompatibility of nanocomposite. The results suggest that TRGO/ZnO nanocomposites have the potential to serve as effective bio-active nanomaterials for combating pathogenic microorganisms present in wounds. [ABSTRACT FROM AUTHOR]

Designing and synthesis of cost-effective and improved methanol permeable and proton conductive membranes are the main challenges for preparation of polymeric electrolyte membrane (PEM). Herein, a cost-effective PEM membrane based on phosphorylated polyvinyl alcohol (PVA)-grafted-cellulose acetate (CA) was prepared by a solution-casting technique. Water and methanol uptakes of phosphorylated PVA/CA membranes were characterized as function with the molar ratio of CA. Additionally, structure and morphology of phosphorylated PVA/CA (Ph-PVA/CA) membranes were verified by FT-IR analysis, SEM investigation. Furthermore, ion exchange capacity (IEC), proton conductivity and methanol permeation of Ph-PVA/CA membranes were examined based on the concentration of OPA basically. The results manifested a perceptible improvement in proton conductivity from 0.035 to 0.05 S/cm at 25 and 70 °C, respectively using 600 μL of OPA, and IEC of 2.1 meq/g using 400 μL of OPA at ambient temperature. On the other hand, methanol permeability (P = 1.08 × 10–10 cm2/s) was lower than Nafion 117 admirably. The optimum OPA concentration was 200 μL according to conductivity measurements (at 10% PVA, 150 μL GA, and CA 7%). Finally, prepared Ph-PVA/CA membranes exhibited enhancement in critical natures such as proton conductivity and IEC combined with its low-cost materials, which make them excellent candidate as PEM for DMFCs application. [ABSTRACT FROM AUTHOR]

The development of eco-friendly materials for advanced applications is highly demanded. The current study focuses on the preparation of conductive membranes based on tricarboxylic cellulose (TCC) loaded with cubic bismuth sodium titanate (BNKT) nanoceramics. FTIR, SEM, and EDX analyses confirm the presence of loaded BNKT on the membranes. The electrical response of the cellulose/xBNKT (x = 5, 10, 15, and 20% wt/wt) membrane is investigated using impedance spectroscopy. The real part (Z′) and the imaginary part (Z″) of the complex impedance are studied as a function of frequency (4Hz ~ 8MHz) and temperature (20 ~ 160 °C) for the different compositions. Impedance and modulus studies reveal a Debye-type relaxation phenomenon. The dielectric studies manifest promising dielectric properties. The bactericidal performance of all nanomembranes is evaluated. The nanomembrane with 20% BNKT (C20) exhibits bactericidal activity against Gram-negative and Gram-positive bacteria, with 6 log CFU reductions observed after an exposure time of 180 min. Treatment with the C20 nanomembrane shows the highest amounts of protein efflux. The results indicate that the C20 nanomembrane layer eradicated all bacterial cells. The findings suggest that the C20 nanomembrane is recommended as an intelligent and innovative antibacterial nano-system for bio-applications. [ABSTRACT FROM AUTHOR]

In this study, copper matrix composites were prepared using the cold and hot pressing technique and then investigated to select the suitable one for the self-lubricating applications. A hybrid of alumina and molybdenum disulfide with a 1:1 ratio by the mechanical milling for 40 h was proceeded to peel the molybdenum disulfide and cover the alumina particles with their layers. Three different samples like Cu, Cu/10 Al2O3, and Cu/hybrid 20(Al2O3–MoS2) were mixed for 15 h. The ball-to-powder ratio in the two mentioned steps was 10:1. The X-ray analysis, HRTEM, Raman spectra, and scanning electron miscopy were used to study the crystal structure, chemical composition, and morphology of the new hybrid and prepared samples. The density was evaluated by the Archimedes method. Mechanical properties, including hardness, wear rate, and coefficient of friction, were investigated. The mixing for 15 h improves the exfoliation of MoS2 flakes inside the copper matrix. A clear hardness improvement was achieved by adding alumina and the mixture of (Al2O3–MoS2). The copper sample reinforced with the hybrid of alumina/MoS2 gave the lowest mechanical wear rate and the lowest average friction coefficient of 0.17. [ABSTRACT FROM AUTHOR]

This paper presents a new phase-shift modulation for isolated dual active bridge (DAB) direct current–direct current (DC–DC) converter. The proposed technique aims to minimize the maximum current stress of the converter, which could directly increase the efficiency and reduce the device losses. This modulation technique controls the converter power through only two phase-shift angles or two degrees of freedom; one phase shift is used between the legs of its first bridge and the other one between the legs of the second bridge. Although the traditional single-phase shift (SPS) technique has only one degree of freedom, it suffers from many drawbacks in terms of high current stress and reverse circulating power flow, which decrease the converter efficiency. On the other hand, increasing the number of phase-shift angles can enhance the system performance but also increase the control complexity. Thus, a comparative analysis between the proposed modulation technique and the traditional SPS was conducted; the new method showed better performance in terms of current stress reduction, along with implementation simplicity. [ABSTRACT FROM AUTHOR]

Objectives: To compare the clinical performance and surgical outcomes of the new digital single use flexible ureteroscope (WiScope®) with a reusable digital flexible ureteroscope. Patient and methods: Our prospective study includes patients with renal stones less than 2 cm who underwent retrograde flexible ureteroscopy and laser lithotripsy. Patients were randomized into two groups: group A included patients who underwent laser lithotripsy using WiScope® Single use digital flexible ureteroscope and group B included patients who underwent laser lithotripsy using reusable flexible ureteroscope. Image quality, deflection, ease of insertion, maneuverability, and overall performance were assessed using either a visual analog or Likert scale. Operative outcomes and complications were collected and analyzed in both groups. Results: A total of 242 patients were included in our study. There were 121 patients in the WiScope® group and 121 patients in reusable ureteroscope group. The WiScope® had higher maneuverability (9.3 ± 0.7 vs. 7.2 ± 0.8, P < 0.001) and less limb fatigue but had lower image quality when compared to reusable digital flexible ureteroscope (7.6 ± 0.9 vs. 9.2 ± 0.6, P < 0.001). There were no differences in operative time, complication rates and rates of relook ureteroscopy. Conclusions: The WiScope® single use flexible ureteroscope has comparable outcomes to the reusable flexible ureteroscope with regard to maneuverability, limb fatigue, and deflection. However, it has a lower image quality. [ABSTRACT FROM AUTHOR]

Metal oxides e.g., Al2O3 and SiO2 loaded-hydrogel blended membranes composed of poly(vinyl alcohol)/poly(vinyl pyrrolidone) (PVA/PVP, PVA/PVP/Al2O3, PVA/PVP/SiO2, PVA/PVP/Al2O3/SiO2) were successfully prepared on precleared glass plates by dip coating method. Meanwhile, series of obtained crosslinked hydride composite hydrogel membranes were successfully prepared using solution-casting method. Samples have been characterized for use in microelectronic devices. Results of X-ray diffraction revealed that the structure of doped sample with nanoparticle has a polycrystalline structure (hexagonal and Orthorhombic), while FE-SEM micrographs show grains in nanoscale and homogenous in nature of membranes. Interestingly, optical measurements of composites blended membranes were recorded using UV/Vis spectrometer. The optical parameters such as refractive index and optical energy gap were estimated. Moreover, complex dielectric constants were calculated optically for all composites, the experimental data shows the additive of nanoparticles composites has a direct energy band gap. Where, Eg for PVA/PVP/SiO2, PVA/PVP/Al2O3 and PVA/PVP/Al2O3/SiO2 at 1.82, 2.55, and 1.95 eV), respectively. While the sample PVA/PVP has an indirect band gap Eg of value 2.24 eV. Finally, the frequency dependence of the transport properties was measured, where results showed improvement of dielectric behavior with metal oxides loading. The experimental data of composite blended membranes can be used in optoelectronics devices. [ABSTRACT FROM AUTHOR]

Di-indium tri-sulfuric (In2S3) thin films are fabricated with annealing indium thin films in a sulfur environment. The effect of both annealing temperature and pressure on the structure, morphology, Raman, and photoluminescence (PL) spectroscopy has been studied. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) of the prepared thin films showed different structural phases and morphology with varying annealing temperature and pressure. Energy dispersive X-ray (EDX) analysis confirmed the chemical composition and the atomic ratio of In/S for the In2S3 thin films. The optimum annealing conditions of In2S3 thin films are 550 °C and 100 Torr. The outcome results revealed a new good growth method for In2S3 thin films to be used for different applications. [ABSTRACT FROM AUTHOR]

Multiferroic (x)BaTiO3/(1 − x)Li0.5Fe2.5O4 (0.0 ≤ x ≤ 1) perovskite/spinel nanocomposite was synthesized using a modified citrate auto-combustion method. Both BaTiO3 (BTO) and Li0.5Fe2.5O4 (LFO) phases along with their composites were successfully characterized using X-ray diffraction, Fourier transformation infrared spectroscopy, and X-ray absorption fine structure spectroscopy. The nanoscale, morphology, and magnetic properties were imaged and acquired using high resolution transmission electron microscopy, atomic force microscopy, and vibrating sample magnetometer. Synchrotron radiation-based elemental selective XAFS technique was performed around Fe K-edge to obtain the selective and the detailed local structural information of Li0.5Fe2.5O4 nanoparticles (NPs). The main remarkable result in this work is the enhancement in the coercivity (HC) of LFO NPs after compositing with BTO particularly at x = 0.6, and at x = 0.8. Based on the collected results, BTO/LFO nanocomposite can be seen as a good candidate for different technological applications including magnetically modulated piezoelectric, safety rechargeable batteries, and multilayer ceramic capacitor. [ABSTRACT FROM AUTHOR]

In this report, Yb0.8Ca0.2MnO3, Dy0.8Ca0.2MnO3, and Nd0.8Ca0.2MnO3 perovskite compounds have been felicitously elaborated based on a fertile cost-effective solid-state reaction strategy. Dy0.8Ca0.2MnO3 and Nd0.8Ca0.2MnO3 powders were found to manifest orthorhombic structure, whereas the Yb0.8Ca0.2MnO3 sample was found to demonstrate hexagonal structure. However, the YbO2 secondary impurity phase was evinced with the perovskite Yb0.8Ca0.2MnO3 phase. The samples' SEM images emerged with the uniform pseudo-cubic-like structure, and the grain sizes of the perovskite materials were in the range between 250 and 600 nm. FT-IR spectrums emphasized the band peaks linked with the functional group of the perovskite manganite compounds. Magnetic moment–magnetic field dependence features asserted antiferromagnetic characteristics for Yb0.8Ca0.2MnO3 and Dy0.8Ca0.2MnO3 samples, while the Nd0.8Ca0.2MnO3 sample disclosed paramagnetic phase at room temperature. Dielectric properties elucidated the normal behavior of perovskite at room temperature. This study explores the rule of the rear earth elements on tune the properties of perovskite compounds. [ABSTRACT FROM AUTHOR]

The optical properties of these films were measured using UV/Vis spectrophotometer. The optical parameters; energy gap (Eg), refractive index (n), extinction coefficient (k), the optical energy gap affected strongly by changing the substrate type. Moreover both of oscillating energy (Eo), dispersion energy (Ed), the effective mass of these films with different substrate had been calculated optically, another important parameters, such as the dielectric constant (ε\) and dielectric loss (ε\\) and both of the real part (σ1) and imaginary part (σ2) of optical conductivity were determined. The ratio of VEL to SEL as functions of photon energy for Y0.225Sr0.775CoO3 films was calculated optically. Finally, the density of both valence band (NV) and conduction band (NC) for these films has been calculated. The dielectric constants for these films were determined. [ABSTRACT FROM AUTHOR]

We comparatively fabricated thin films of La0.01Ba0.99TiO3(LBTO), Sm0.5Sr0.5CoO3(SCO) and Sm0.5Sr0.5CoO3/La0.01Ba0.99TiO3 (SCO/LBTO) thin films grown on quartz substrates using pulsed laser deposition technique. The structure of these samples was carried out using X-ray diffraction, and these samples had a polycrystalline structure. The surface topography for these films was studied using scanning electron microscopy (FE-SEM) and shows grains with nano-sized and uniform nature of the thin films. The optical properties such as transmittance, absorbance and reflectance of these thin films were studied. The optical results such as absorption coefficient, optical energy gap and refractive index were determined. The oscillation energy and dispersion energy, on the other hand the dielectric results such as dielectric loss and dielectric tangent loss, were determined, while nonlinear optical results such as the third-order nonlinear optical susceptibility χ(3) were calculated for all these samples. Finally, the electronic results such as the density of state for both the valence and conduction band were determined. [ABSTRACT FROM AUTHOR]

Glass–ceramics of the SiO2–Al2O3–TiO2-GO quaternary system was successfully prepared by sol–gel technique. The effects of TiO2/GO weight ratios on the structure and physical properties of glass–ceramics have been extensively examined. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) have been used to characterize and identify the structural phase as well as the surface morphology of all samples. The crystalline phases of all prepared samples exhibited anatase phase of titania (Tetragonal: TiO2). But with increasing the amount of Graphite the phase of GO appeared. The thermal properties of the samples have been studied using thermal analysis, differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA) technique. The electrical properties have been enhanced with increased TiO2/GO weight ratios up to 1.25, and its electrical conductivity and dielectric constant were 6 × 10–10 S/cm and 9.95, respectively, at frequency 1 MHz. In addition, mechanical properties including density, hardness, and wear rates were measured. The experimental data depicted that, the micro-hardness reached a maximum value of approximately 14 GPa at 2.50 GO wt. %. While the wear rate has a value of nearly 53 × 10–5 mm3/Nm, this is very small paralleled to other glass–ceramics. Besides, good machinability index (m = 0.23) can be a good candidate for machinability applications. [ABSTRACT FROM AUTHOR]

Single-phase ceramic samples of (1 − x)BaTiO3−x(BaNi0.5Nb0.5O3), where 0 ≤ x ≤ 0.05, were prepared. The Rietveld analyses of the X-ray diffractions indicated that the crystal structure of the samples of x = 0, 0.01, 0.02, and 0.04 are tetragonal with p4mm space symmetry group, while those of x = 0.03 and 0.05 are cubic with pm-3m space group of symmetry. The average grain size of all investigated samples was calculated based on field-emission scan electron microscopy (FE-SEM). Both Raman and photoluminescence spectra were recorded at room temperature. The polarization–electric field (P–E), hysteresis loops indicated that the coercive field, remanent polarization, and energy losses are dependent on x value. The bipolar and unipolar strain–electric field (S–E) were studied for all synthesized ceramics. The piezoelectric properties of the parent sample (x = 0) are enhanced with increasing x. The outcome results of this work are promising for applications. [ABSTRACT FROM AUTHOR]

Sb2Se3 thin films which prepared using thermal evaporation were irradiated using LASER beam with different times of exposure (texpos). X-ray diffraction (XRD) results showed that the structure of these samples had changed from amorphous structure to polycrystalline structure with (texpos). The surface topography of these samples were studied using scanning electron microscopy (SEM). The measured optical parameters such as transmission (T) and reflection (R) were effected by these radiations. The determined optical energy gap (Eg) increases with (texpos). The values of oscillating energy (Eo) and dispersion energy (Ed) increased with (texpos). The dielectrical results such as dielectric loss (ε\) and dielectric tangent loss (ε\\) were affected and increase with (texpos). The determined values for both real part of optical conductivity (σ1) and imaginary part of optical conductivity (σ2) increase also with (texpos). The nonlinear optical parameters such as, nonlinear refractive index (n2) and third-order nonlinear optical susceptibility (χ(3)). The nonlinear results affected with (texpos). Finally, the density of states and Fermi level position for these samples were determined optically. [ABSTRACT FROM AUTHOR]

In this work, we reported a detailed study on the synthesis, structural and magnetic properties of nanocrystalline La0.8Sr0.2MnO3. The synthesized nanoparticles were prepared using a sol–gel method and characterized using X-ray diffraction and high-resolution transmission electron microscope. The average particle size was found in the range from 40 to 45 nm. The magnetization versus temperature M(T) measurements as well as magnetization field dependence M(H) have been investigated using vibrating-sample magnetometer. The magnetization as a function of temperature M(T) indicated a broad second-order magnetic phase transition from ferromagnetic state to paramagnetic state in the Curie temperature region (320–340 K). The magnetocaloric effect of the sample has been estimated and presented a maximum magnetic entropy change |ΔSM|max = 0.86 J kg−1 K−1 with relative cooling power = 62.12 J kg−1 at magnetic field (H) = 2T. Based on the result of magnetocaloric properties, the investigated sample could be considered as a good refrigerant material for near room temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

The effects of reduced graphene oxide (rGO) and aluminum oxide (Al₂O₃) nanoparticles as additives on poly-aniline (PANI)/poly-acrylonitrile (PAN) nanofibers were studied through synthesis using an electrospinner. The AC conductivity and dielectric constants were measured as functions of frequency (1 –200 kHz) and temperature (30 –100 °C) for PANI/PAN/rGO/xAl₂O₃ (x = 0, 0.001, 0.002, 0.004, 0.005) nanofibers. The dielectric characteristics showed that the addition of Al₂O₃ nanoparticles enhanced both the dielectric constant and conductivity, while also reducing dielectric loss. Using cyclic voltammetry (CV), the electrochemical properties of PANI/PAN/rGO/Al₂O₃ nanofibers with varying concentrations of Al₂O₃ were investigated as a potential electrode material for supercapacitors. The electrochemical performance of PAN/PANI/rGO/Al2O₃ nanofibers with different Al2O₃ concentrations (ranging from S1 to S5) was tested in 1 M KOH solution. Sample S5 exhibited outstanding supercapacitive performance, with a high areal capacitance of 401 mF cm⁻² at a scan rate of 5 mV s⁻¹. Furthermore, at a scan rate of 50 mV s⁻¹, the PAN/PANI/rGO/Al2O₃ (S5) nanofibers demonstrated remarkable cyclic stability, retaining 92.3% of their capacitance after 10,000 cycles. The enhanced electrochemical performance of the supercapacitors was attributed to the improved conductivity of the rGO nanosheets (NSs), which facilitated charge transfer and improved the diffusion of KOH electrolyte. These experimental results suggest that rGO NSs hold significant potential as materials for supercapacitor electrodes. [ABSTRACT FROM AUTHOR]