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Magnesium oxychloride cement (MOC) is an environment-friendly cement often used for stabilizing soft soils because of its exceptional mechanical properties. In this study, the influence of curing temperature on the strength development of MOC-solidified clay is explored, considering different MgO/MgCl2 molar ratios. Different tests were carried out to study the corresponding effects. The results show that the effect of curing temperature on the strength of MOC-solidified clay differs greatly from that of cement-solidified soil. Increasing the curing temperature leads to strength reduction, whereas decreasing the curing temperature increases the corresponding strength. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses indicate that the variation in type and amount of hydration products of the solidified soil account for the strength development difference between MOC-solidified and cement-solidified soils. A model based on the experimental results is proposed to characterize the relationship between strength development and curing time. The strength influence factor (ηT) and the strength expedite factor (K) were introduced to demonstrate the relationship between strength development at a specific curing temperature as well as at room temperature. [ABSTRACT FROM AUTHOR]

The existence of lead-zinc tailings threatens the social and ecological environment. The recycling of lead–zinc tailings is important for the all-round green transformation of economic society. In this study, the possibility of fabricating sintered ordinary bricks with lead–zinc tailings was studied based on orthogonal experimentation, and the phase composition and micromorphology of sintered products were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). With lead–zinc tailings as the main material, and clay and fly ash as additives, the effect of clay content, forming pressure, sintering temperature, and holding time on physical properties of sintered bricks was analyzed. The results show that clay content and sintering temperature have a major effect on compressive strength, while sintering temperature and holding time play an important role in water absorption. During sintering, mica, chlorite, and other components in lead–zinc tailings are decomposed to form albite, hematite, maghemite, and anhydrite, which play a role in the strength of bricks. The optimal process parameters were found to be a ratio of lead–zinc tailings:clay:fly ash = 6:3:1, forming pressure of 20 MPa, firing temperature of 1080 °C, and holding time of 60 min. The corresponding compressive strength and water absorption were 34.94 MPa and 16.02%, which meets the Chinese sintered ordinary bricks standard (GB/T 5101-2017). [ABSTRACT FROM AUTHOR]

A nanostructure of lithium-zinc copper ferrite (LiZnCu-Ferrite) prepared experimentally by the auto-combustion method depends on different parameters. The auto-combustion method operates at a temperature (160 °C) suitable for preparing the required nanostructure ferrite phase. The dependent composition was [Li 0.5-x Zn x Cu x Fe 2.5-x O 4 at (x = 0, 0.05, 0.15, 0.25, 0.35, and 0.45)]. A pre-firing at temperature (650 °C) was applied during the calcination process that was suitable to remove unwanted products. The sintering at temperature (800 °C) was suitable for a pelletized shape of ferrite samples. The X-ray diffraction (XRD) pattern showed a spinel structure of ferrite phase produced for all samples under study with the lattice constant in the range (8.345–8.368 Å) as a function of (x). The crystallite size was in the range (18.41–30.27 nm) calculated by the Scherrer method. The transmission electron microscope (TEM) showed a production of nanorods in the size range (10–45 nm) and nanoparticles in the size range (10–40 nm). There was a coincidence between the results of the XRD and TEM analyses. On the other hand, the scanning electron microscope (SEM) showed the surface morphology and the nature of grain size, which was a sign of the presence of nanostructure; it agreed with the XRD analysis. FTIR spectra showed evidence that the system Li0.5-xZnxCuxFe2.5-xO4 had spinal ferrite nanoparticles successfully prepared by sol-gel auto-combustion. A vibrating sample magnetometer (VSM) showed a change in magnetic parameters as compensation factor (x) increased for all composites of LiZnCu-ferrite such as saturation magnetization (Ms), initial magnetic permeability (μi), remanence (Mr), and coercive force (Hc) that measured from M − H loops. A saturation magnetization increased as a function of (x) and recorded a maximum value at (x = 0.15). While the coercivity, initial magnetic permeability (μi), and remanence magnetization enhanced as a function of (x) and recorded a maximum value at (x = 0.45). [ABSTRACT FROM AUTHOR]

Unburned carbon from fly ash and its graphitization products (at temperatures of 2400 and 3000°C) were tested using scanning electron microscope (SEM), X-ray diffraction (×RD) and micro-Raman spectroscopy. The same tests were also carried out for synthetic and natural graphite. Various morphological forms of products with a high degree of graphitization, such as spheroidal graphite, hexagonal plates, column plates, and jagged-edge films were identified in the sample of unburned carbon annealed at 3000°C. The product of thermal treatment at the temperature of 3000°C has the interlayer spacing d002 value characteristic for semigraphite. With increasing temperature the number of crystallites in stack N, their height Lc002 and aromaticity fa increases. The degree of G graphitization of annealed samples increases more than twice with increasing temperature. With the increase of the temperature the aliphatic chains are decomposed and the aromatic systems are reconstructed, so the degree of internal structure order increases. The Raman examinations showed that the structural parameters determined for the graphite and carbonizate samples after thermal treatment at the temperature of 3000°C are equal in the standard deviation range. [ABSTRACT FROM AUTHOR]

The synthesis, physicochemical characterizations, and biological investigations on the chelation of the antibiotic medication enoxacin (EXN) with certain vital metal ions, such as platinum(IV), ruthenium(III), and iridium(III) are discussed in this study. These compounds structures were interpreted based on elemental analysis and spectral measurements (FTIR, 1H-NMR, UV-Vis electronic, and XRD). The findings show that there is same coordination pathway for the chelation behavior of enoxacin complexes: a monodentate manner. The Pt(IV), Ru(III), and Ir(III) complexes are coordinated through the N atom of the piperazine ring, which is an unusual mode of coordination for this class of compounds. The dissolved complexes in DMSO were found to have non-electrolyte nature based on their molar conductance measurements. The formula for these complexes is [Pt(EXN)3(H2O)2Cl] (1), [Ru(EXN)3(H2O)3] (2), and [Ir(EXN)3(H2O)3] (3). Using scanning electron microscope (SEM) analysis and Xray powder diffraction (XRD), the nano-scale range of the Pt(IV), Ru(III), and Ir(III) complexes has been determined. Results of in vitro cytotoxicity were examined using MCF-7 cells (human breast cancer cell line) and HepG-2 cells (human hepatocellular carcinoma) that had been grown. The cytotoxic activity of the metal complexes demonstrated a cytotoxic effect against the growth of human breast and liver cancer cell lines. [ABSTRACT FROM AUTHOR]

Manganese slag (MS) containing a certain amount of active hydration substances may be used as a kind of cementitious material. In the present study, we measured the mass, the relative dynamic modulus of elasticity (RDME), and the flexural and compressive strengths of MS high-performance concrete (MS-HPC) with added basalt fibers exposed to NaCl freeze–thaw cycles (N-FCs), NaCl dry–wet alternations (N-DAs), and Na2SO4 dry–wet alternations (NS-DAs). Scanning electron microscope energy-dispersive spectrometer (SEM-EDS) spectra, thermogravimetric analysis (TG) curves, and X-ray diffraction spectroscopy (XRD) curves were obtained. The mass ratio of MS ranged from 0% to 40%. The volume ratio of basalt fibers varied from 0% to 2%. We found that, as a result of salt action, the mass loss rate (MLR) exhibited linear functions which were inversely correlated with the mass ratio of MS and the volume ratio of basalt fibers. After salt action, MLR increased by rates of 0~56.3%, but this increase was attenuated by the addition of MS and basalt fibers. Corresponding increases in RDME exhibited a linear function which was positively correlated with MS mass ratios in a range of 0~55.1%. The addition of MS and basalt fibers also led to decreased attenuation of mechanical strength, while the addition of MS led to increased levels of flocculent hydration products and the elements Mn, Mg, and Fe. CaClOH and CaSO4 crystals were observed in XRD curves after N-DA and NS-DA actions, respectively. Finally, the addition of MS resulted in increased variation in TG values. However, the opposite result was obtained when dry–wet actions were exerted. [ABSTRACT FROM AUTHOR]

Bi(2/3)‐xSmxCu3Ti4O12 (BSCTO x = 0.05, 0.10, and 0.20) ceramics are synthesized using semi‐wet technique and an extensive investigation into their structural, morphological, and elemental properties, alongside dielectric and impedance behaviors, is meticulously carried out. X‐ray powder diffraction analysis unequivocally confirmed the formation of a monophasic BCTO cubic phase without any discernible secondary phases. and the crystallite size of the BSCTO ceramic, obtained by X‐ray diffraction using Debye Scherrer formula, range from 62 to 81 nm. Rietveld analysis reveals that ceramics have a body centered cubic structure with space group Im‐3. The Scanning electron microscope image displays the dense microstructure of the ceramics, while EDX analysis unveils the elemental composition of resulting products. Doping with Sm3+ induced a notable reduction in grain size, as observed through Scanning electron microscope and Atomic Force Microscope analyses, indicating Sm3+ hindered grain growth during sintering, potentially resulting in reduced dielectric constant (ε′). Dielectric constant and dielectric loss of the composition (x = 0.2) are found to be ≈$ \approx $152 and 0.04, respectively at room temperature (1 kHz). Impedance characteristics revealed a substantial increase in grain boundary resistance, leading to improved dielectric loss. The AC conductivity of BSCTO ceramics exhibited a frequency‐dependent increase satisfying to Johncher's power law. [ABSTRACT FROM AUTHOR]

Complex oxides La 0. 9 7 Ba 0. 0 3 MnO3, La 0. 7 3 Ba 0. 2 7 MnO3 and La 0. 5 Ba 0. 5 MnO3 were synthesized and their structural properties were studied. The structural investigation of the samples is done by incorporating X-ray diffraction (XRD) and scanning electron microscope (SEM) technique at room temperature. The Rietveld method was successfully used for the analysis of the obtained diffraction spectra. It was determined that these compounds have a perovskite structure. Partial substitutions La→Ba do not disturb the ideal perovskite structure and the cubic crystal structure with the space group Pm-3m is preserved. Crystallographic parameters, lattice parameters and interatomic distances were determined for each compound. As a result of SEM studies, it was determined that the size of crystallites in LaxBa 1 − x MnO3 solid solutions ranged from 2 to 10 μ m. [ABSTRACT FROM AUTHOR]

Summary: Ultrasonication is a novel, green, and sustainable method to modify the native starch for improved functionality and pronounced industrial applications. In the present study, the impact of ultrasonication power (40%, 50%, and 60%) on black wheat starch was observed on functional and pasta‐making attributes. Ultrasonication induced surface and microstructural alterations with minimal impact on the overall integrity of starch granules. The sound waves disrupted starch granules through cavitation and starch degradation by radial attack. Scanning electron microscope (SEM) images revealed that ultrasonication disrupted the starch granules and a porous structure was developed. The treatment induced fissures and pores formation leading to structural rearrangements without any impact at the molecular level. With the increment in the power of ultrasonication, the scratching and fissures on the starch granules are increased which further modifies the starch functionality. Due to structural disruption of long amylopectin helices into short‐chain amylopectin and dextrin resulted in a more crystalline structure of starch, the results were supported by X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra. This alteration in starch structure increased the amylose concentration, solubility, and swelling capacity of modified starch. Pasta prepared with modified starch shows improved cooking and textural properties. [ABSTRACT FROM AUTHOR]

Thermoluminescence (TL) response of newly synthetic silicon-activated Ca9AlP7O28 nanophosphor doped with different concentrations (0.3–10 mol%) (abbreviated as CAP: Six) were prepared by the sol–gel method. The optimum concentration of Si ions for the best TL response was found to be 0.3 mol% (CAP: Si0.3), which was selected for subsequent dosimetric measurements. Phase purity and the crystal structure of the CAP: Si0.3 sample were identified and verified using X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis, where results obtained confirmed the successful synthetic method used in the preparation of the nanophosphor samples. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) mapping revealed the localization of constituent elements and indicated the homogeneous distribution of Si-ions as well as the feasibility of dopants in the herein sample. The dosimetric properties of the CAP: Si0.3 sample, including glow curve structure, reproducibility, repeatability, dose–response and fading effect, were extensively investigated. The gamma irradiated CAP: Si0.3 sample exhibited a simple glow curve of a single prominent peak centred at 222 ± 1.33°C with considerably high TL intensity (1.22 relative to MTS-700 TLD detector). The relative standard deviation (RSD) of peak areas of CAP: Si0.3 were 5.25 and 2.7% for reproducibility and repeatability studies, respectively. These values of RSD were <10%, so they were acceptable internationally. A good linear dose–response relationship was achieved over a dose range of up to 20 Gy with an excellent correlation coefficient of R2 = 0.9969 and a calibration factor of F = 51.75 × 107 a.u./Gy. Almost no fading was registered from the studied CAP: Si0.3 sample after irradiation. Zeff values were found to be in the range 11.62 to 11.61, which are closely related to that of natural bone (11.3 to 11.8). Minimum detectable dose of CAP: Si0.3 had a value of 11 μGy. The outstanding features of this herein-prepared sample make it a good TLD nanophosphor, very suitable for personnel and environmental dosimetry of γ-radiation within the studied dose range. [ABSTRACT FROM AUTHOR]

The preparation of calcium carbonate whiskers by gas‐liquid contact method using low‐grade dolomite refining solution and CO2 as raw materials has attracted widespread attention. The effects of reaction temperature, Mg2+ concentration and pH value on the morphology, particle size, aspect ratio and crystal form of CaCO3（Calcium carbonate） whiskers are investigated in detail. SEM (Scanning Electron Microscope) and XRD (X‐ray powder diffraction) are combined to analyze the calcium carbonate whiskers. The results demonstrated that under the conditions such as 100 °C, Mg2+ concentration of 0.05 mol L−1 and pH value of 9.5, calcium carbonate whiskers with uniform distribution, aspect ratio of 15–20, and purity of 99.38% can be prepared. Through Material Studios simulation software and critical nucleation energy analysis, it is confirmed that the morphology of calcium carbonate whiskers emerged to be a long hexagonal prism. Mg2+ in the refined solution would adhere to the surface of calcium carbonate during carbonization, inhibit the formation of calcite phase, and promote the growth of face clusters connected by vertex angles between CaCO3 crystals. The initial pH condition determines the solubility of CO32− and the supersaturation of the solution, which in turn affected the formed calcium carbonate crystal form. [ABSTRACT FROM AUTHOR]

The current study demonstrates the effect of Ni-substitution on the structural, dielectric and ferroelectric properties of Ba0.90Sr0.10Ti1-xNixO3 (where x = 0.000, 0.005, 0.015 and 0.025) ceramics, synthesized by solid-state reaction approach. A pure perovskite phase with tetragonal structure has been confirmed by X-ray diffraction (XRD) analysis. Scanning electron microscope (SEM) images revealed change in microstructure. The dielectric behavior of the prepared ceramics was investigated as a function of temperature (30–150°C) at different frequencies. The results indicate that there is an increase in dielectric constant (ϵRT) and low dielectric loss (tanδRT) were obtained at room temperature by substitution of Ni2+ ions in BST ceramics, offering a promising material for capacitor applications at room temperature. Room temperature P-E loops were recorded at different applied electric fields and typical hysteresis loops were obtained. Improvement in the values of Pr and Pmax was observed by substitution of Ni2+ ions. [ABSTRACT FROM AUTHOR]

The economic spray pyrolysis process were used to prepare Zinc oxide thin films. Ahigh - quality thin film is obtained by optimizing factors that include concentration, flow rate, nozzle to substrate distance. The temperature is differed between 350°C to 450°C. The structural and optical qualities were studied through physical investigation. According to XRD, the films have a hexagonal crystal structure. A scanning electron microscope reveals the material's uniform deposition &adhesion across a glass substrate. A direct band gap of about 2.4 to 2.6 eV was obtained for different temperatures. [ABSTRACT FROM AUTHOR]

In the present work, we studied the impact of excess Na addition on the structure of the standard NASICON ion conductor along with Na ion transport mechanisms. In this sense, NASICON ceramic membranes (NZSP) were prepared by a simple chemical synthesis method, the solid state reaction (SSR), using an excess of 5% Na (Na3.15Zr2Si2PO12) and an excess of 10% Na (Na3.3Zr2Si2PO12), in order to improve the conduction properties of the ceramic membrane. The characterization of the NZSP nanoparticles was performed by measuring the particle size by dynamic light scattering (DLS), the morphology of the NASICON samples pre-sintered at 1100 °C was analyzed by the SEM method (scanning electron microscope), and X-ray diffraction (XRD) analysis was used to investigate the crystal structure of samples, while the surface area was measured using the BET technique. The electrical properties (i.e., ionic conductivity) were evaluated by impedance spectroscopic methods at room temperature (RT). Following the experiments for NASICON membranes without Na excess, with 5% Na excess, and with 10% Na excess synthesized at different pressing forces and sintering temperatures, it was found that membranes with a 10% Na excess, sintered at 1175 °C for 10 h, presented a good ionic conductivity (4.72 × 10−4 S/cm). [ABSTRACT FROM AUTHOR]

Post‐synthetic modification using acid (HNO3) and base (NaOH) are utilised to synthesize hierarchical micro‐mesoporous zeolites with different pore structure. To investigate structural change in materials, X‐ray diffraction (XRD), Scanning electron microscope (SEM), Inductive coupled plasma‐optical emission spectrometry (ICP‐OES), 29Si and 27Al MAS NMR, and N2 adsorption‐desorption isotherms techniques were employed. Acid base titration, and ammonia‐temperature programmed desorption (NH3‐TPD) was performed to evaluate acidic characteristics of materials. As revealed by characterisation, the structure was well preserved after the modification. Hierarchical materials along with parent materials have been evaluated in the toluene alkylation with benzyl alcohol producing mono‐benzylated toluene. All zeolite samples were proved to be catalytically active by their result in the alkylation reaction. Acid treated samples were compared with base treated and parent samples. The results indicate that, base modification significantly increases the mesoporous pore volume in all zeolite as compared to acid modification. Moreover, the highest benzyl alcohol conversion was found to be 98 % in the base modified Beta, with the highest mono‐benzylated toluene selectivity (69 %). Reaction optimization was also studied by altering reaction duration, temperature, and catalyst amount. The reaction products were analysed using Gas Chromatography (GC) and confirmed using Gas chromatography mass spectrometry (GC‐MS). [ABSTRACT FROM AUTHOR]

This study investigates the optical and structural properties of nitrogen-doped Carbon Quantum Dots (NCQDs) on Titanium dioxide (TiO2). We synthesized the NCQDs via direct pyrolysis using varying amount of nitrogen precursor. We used a UV-visible, Fluorescence and Fourier Transform Infrared spectrophotometer, X-ray diffractometer (XRD), and Scanning Electron Microscope (SEM) to probe the samples. The introduction of nitrogen enhanced the intrinsic activities and electron dynamics of the CQD films, leading to improved confinement, charge extraction, and light harvesting. The optical response of the NCQDs strongly hinged on the nitrogen doping content. Sensitizing different amounts of NCQDs on TiO2 surface reduced their bandgap energies. XRD analysis confirms the preservation of the TiO2 anatase phase nanoparticle after the introduction of NCQDs, with no substantial changes to the crystal lattice and phase purity of the resulting photoanodes, indicating the presence of NCQDs on the surface. However, the deposition of NCQDs decreased the crystallite size. SEM images show well-dispersed morphologies with non-clustered NCQDs films. NCQDs can serve as promising photosensitizers in photovoltaic devices. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate six commercially available abutment screws by characterising roughness parameters, microstructure and mechanical properties. Six abutment screws from each implant system, were used. The surface roughness parameters (S a , S q , S sk , S ku , S pk , S k and S vk) were identified by an optical interferometric profiler. Microstructural observations and crystallographic analysis were performed using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) device for elemental analysis and an X-ray diffractometer (XRD), respectively. The Martens Hardness (HM), Indentation Modulus (E IT), elastic index (η IT) and Vickers hardness (HV) of all specimens were determined by instrumented indentation testing (IIT). The results were analyzed by one-way ANOVA and Tukey multiple-comparison tests (a=0.05). EDX and XRD showed the abutment screws to be mixed α- and β-phase titanium alloys. Microstructural analysis revealed a fine homogeneous microstructure without porosity, consisting of fine dispersoid rods of β-phase embedded in a continuous α-phase matrix. Statistically significant differences were found among the mechanical properies and surface roughness parameters apart from S q , S pk and S vk. The tested abutment screws showed significant differences in the probed properties, and, thus, differences in their clinical behaviour are anticipated. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) nanoparticles were prepared by green synthesis process using extract of leaf from buckthorn and tin (IV) chloride pentahydrate (SnCl4·5H2O). The materials calcined at 400 °C for 3 h to produce of SnO2 NPs. SnO2 nanoparticles were characterized by X-ray diffraction, scanning electron microscope, optical microscope, and optical spectroscopy techniques.The result of XRD showed formation tin oxide nanoparticles with tetragonal crystal structure. The optical properties were enhanced with rising concentration from 1.25gm/100 ml to 5gm/100 ml. The optical absorbance (A) enhanced of 42.3% at λ = 340 nm (UV-spectrum), 55.8% at λ = 540 nm (VIS-spectrum) and 53.3% at λ = 840 nm (NIR-spectrum). The energy gap is reduced from 3.31 eV to 3.16 eV while the SnO2 concentration increases from 1.25gm/100 ml to 5gm/100 ml. The obtained results showed that SnO2 thin film are appropriate for numerous electronic, photocatalytic and photonics fields. The SnO2 thin film employed for self cleaning against organic dyes. The results indicate that the SnO2 NPs are very important to apply as a coating nanolayer for self cleaning to obtain on cleaning environment. [ABSTRACT FROM AUTHOR]

Despite numerous studies focused on the hydrothermal (HT) synthesis of fly ash zeolites (FAZs), this method still has many limitations, the main of which is the low yield of zeolites. Hydrothermally synthesized zeolites are typically multiphase and exhibit low purity, which limits their applicability. Pure-phase zeolites have been primarily prepared from filtrates after alkaline mineralization of fly ashes, not directly in suspension. In addition, the published methodologies have not been tested in a wider set of samples, and thus their reproducibility is not confirmed. The aim of the study is to propose a reproducible methodology that overcomes the mentioned limitations. The influence of the Si/Al ratio (1.3:1–1:2), the type and concentration of the activator (2/4 M NaOH/KOH/LiOH), the reagent (30% LiCl), the duration (24–168 h), and the temperature (50–180 °C) of the synthesis phases were studied. The sequence of the synthesis phases was also optimized, depending on the type of heat transfer. The fly ashes were analyzed by wavelength-dispersive X-ray fluorescence (WD XRF), flame atomic absorption spectrometry (F-AAS), and X-ray diffraction (XRD). The energy intensity of the synthesis was reduced through the application of unique microwave digestion technology. Both microwave and combined (microwave and convection) syntheses were conducted. FAZs were identified and quantified by XRD analysis. This study presents a three-stage (TS) hydrothermal synthesis of pure-phase sodalite in suspension. Sodalite (>99 wt.%) was prepared from nine fly ashes under the following conditions: I. microwave phase: 120 °C, 150 min, solid-to-liquid ratio (S/L) 1:5, Si/Al ratio 1:1.5, and 4 M NaOH; II. convection phase: 120 °C, 24 h, S/L 1:40, and the addition of 30 mL of 30% LiCl; and III. crystallization: 70 °C for 24 h. The formation of rhombododecahedral sodalite crystals was confirmed by scanning electron microscope (SEM) images. [ABSTRACT FROM AUTHOR]

The modification mechanism of low-molecular-weight organic acids on a single-chain silicate mineral (wollastonite) was investigated through a leaching method. Solid and liquid samples were analyzed using atomic absorption spectrophotometer (AAS), X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR). After 720 h of reaction, the results revealed that the dissolution concentration of Si (2200 μmol/L) in citric acid solution is more than that (1950 μmol/L) in oxalic acid. In the composite acids (citric acid and oxalic acid), the dissolution concentration of Si release from wollastonite reached the maximum value of 3304 μmol/L. The dissolution data of Si in wollastonite were fittingly described by the parabolic equation (Ct = a + bt1/2), with the highest correlation coefficients (R2 > 0.993), in the presence of the low-molecular-weight organic acids. The dissolution data suggested that the dissolution reaction process of Si was consistent with the diffusion-controlled model. Citric acid exhibited a higher affinity for attacking the (200) surface, while oxalic acid was prone to dissolve the (002) crystal face. The synergistic effects of oxalic acid and citric acid led to the weakening of the XRD diffraction peak intensity of wollastonite. When exposed to composite acids, the surface of wollastonite was covered with insoluble reactants that restricted the substance diffusion and hindered the reaction. This study offers valuable theoretical insights into the modification or activation of wollastonite by composite low-molecular-weight organic acids. [ABSTRACT FROM AUTHOR]

To evaluate the impact of speed sintering on the microstructure and optical properties of 3 and 5 mol% yttria-partially stabilized monolithic zirconias. 120 plate-shaped zirconia specimens (10x10x 0.4 mm) were prepared from three commercial 5 mol% yttria-partially stabilized zirconia blocks (5Y-PSZs); Katana UTML (Kuraray Noritake), Cercon xtML (Dentsply Sirona), and Zolid FX white (Amann Girrbach), and two commercial 3 mol% yttria-partially stabilized zirconia blocks (3Y-PSZs); Lava Plus (3 M ESPE) and InCoris (Sirona, GmbH). Specimens were either conventional sintered (CS) using a 7-hour program or speed sintered (SS) using a quick 90-minute program. The microstructure was inspected with a scanning electron microscope (SEM), and phase fractions were detected using x-ray diffraction analysis (XRD). Translucency (TP 00), and contrast ratio (CR) were obtained using a spectrophotometer (VITA Easyshade V). Color difference (ΔE 00) between both sintering processes was calculated with the CIEDE2000 formula. ΔE 00 up to 1.8 was set as the acceptability threshold. Data were analyzed using two-way ANOVA, Krusakll-Wallis, and Mann-Whitney U tests. (n = 12, α =.05). Grain size was significantly decreased after SS for all tested materials (P <.0001). The average grain sizes of 5Y-PSZs were significantly larger than those of 3Y-PSZs. The atomic structure, microstructure, and transparency of CS and SS were all affected by the amount of yttria, the size of the crystals, and tetragonality. SS significantly reduced TP 00 (F = 7135.95, P < 0.0001) and increased CR (F = 453.21, P < 0.0001). The CS Katana presented the highest TP 00 and lowest CR value. ΔE 00 between the CS and SS groups were clinically acceptable except for Lava, which had values above the set threshold (1.89). SS altered the grain size and internal structure of the tested materials, which was reflected in translucency. • Variations in yttria concentration, crystal size, and tetragonality between CS and SS within each material which affected the atomic structure, microstructure, and translucency. • The lightness decreased and chroma increased after speed sintering in 3 and 5 mol% yttria-partially stabilized monolithic zirconia. • The final color of monolithic zirconia restorations may be adversely affected by zirconia manufacturers. [ABSTRACT FROM AUTHOR]

A series of nanocrystalline Ni1−xMnxCexFe2−xO4 (x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.1) were prepared using the citrate auto-combustion method. X-ray diffraction (XRD) indicates that the spinel materials formed in a cubic single phase up to the sample x = 0.02. The average crystallite size is reduced from 61 to 31 nm due to the suppression of grain growth upon cerium occupation at the octahedral site. The cubic spinel structure was confirmed by Fourier-transform infrared (FT-IR) analysis. Scanning electron microscope (SEM) showed agglomerated and rod-shaped structures at various concentrations. AC conductivity and dielectric properties were measured over a frequency range of 20 Hz to 8 MHz. The AC conductivity increases with an enhancement in frequency. The prepared materials have great potential for utilization in microwave devices. The magnetic parameters were estimated from the measured hysteresis loops at room temperature and 100 K using a vibrating sample magnetometer (VSM), which indicated that the samples were suitable for magnetic memory device applications. [ABSTRACT FROM AUTHOR]

Tin-containing silicon oxycarbide (SiOC/Sn) nanobeads are synthesized with different carbon/tin content and tested as electrodes for magnesium-ion batteries. The synthesized ceramics are characterized by thermogravimetric-mass spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, N2 sorption analysis, scanning electron microscope, energy-dispersive X-ray, and elemental analysis. Galvanostatic cycling tests, rate performance tests, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) tests, and ex situ XRD measurements are conducted. Results of battery performance tests present a high capacity of 198.2 mAh g-1 after the first discharging and a reversible capacity of 144.5 mAh g-1 after 100 cycles at 500 mA g-1. Excellent rate performance efficiency of 85.2% is achieved. Battery performances in this research are influenced by surface area, and tin contentof the SiOC/Sn nanobeads. EIS, CV tests, and ex situ XRD measurements reveal that higher surface area contributes to higher capacity by providing more accessible Mg2+ ion storage sites and higher rate capability by improving the diffusion process. Higher Sn content increases battery capacity through reversible Mg-Mg2Sn-Mg alloying/dealloying process and improves the rate performances by increasing electrical conductivity. Besides, SiOC advances cycling stability by preventing electrode collapse and enhances the capacity due to higher surface capacitive effects. [ABSTRACT FROM AUTHOR]

In this study, analyses were carried out to investigate the structural, mechanical and electrochemical behaviors of untreated and bioglass (BG)-coated Ti45Nb materials. The samples were coated with a mixture of 63s BG powder and phosphate ester (PE) at concentrations of 0.2, 0.4, 0.8, and 1 g using the electrophoretic deposition (EPD) method. Then, the structural, mechanical, and electrochemical properties of the untreated and coated samples were determined and characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM) devices. It was concluded that the 0.2 g coating provided resistance to corrosion for the Ti45Nb material more effectively than the others did. [ABSTRACT FROM AUTHOR]

Sago starch (SS) was blended with natural rubber (NR) using nanoclays, namely montmorillonite (MMT), kaolinite (KAO), and kaolinite modified by dimethyl sulfoxide (KAO-D) to enhance its physical and mechanical properties. Each nanoclay was incorporated at 2, 4, 6, and 8 wt%, respectively. The SS80NR20 (80 wt% of sago starch and 20 wt% of natural rubber) biocomposites were characterized by solubility of water, water vapor transmission, mechanical and thermal properties. The constituent interaction and morphology of the SS80NR20 biocomposites were also presented by using X-ray diffraction (XRD) technique and scanning electron microscope (SEM). The findings demonstrated that the inclusion of clays significantly improved both the water resistance and tensile properties when compared to the SS80NR20 blend. In the SS80NR20 biocomposites, MMT at 6 wt% exhibited the lowest moisture content, solubility in water, and water vapor transmission. As the amount of nanoclay in the biocomposites increased, their tensile strength dramatically increased whilst their strain at break had a tendency to diminish. Strong interaction by establishing the intercalated structure of MMT, and KAO within SS80NR20 biocomposites were attributed to both physical and mechanical properties, while the weak interaction at the interface of SS and NR was attributed to KAO-D. [ABSTRACT FROM AUTHOR]

In this study, the magnetic photocatalyst Scendesmus/Fe3O4/TiO2 was synthesized, and its sonophotocatalytic properties in relation to the degradation of the Red195 dye were evaluated. Particles were characterized using a scanning electron microscope (SEM), Fourier's transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and a vibrating-sample magnetometer (VSM). At a pH of 5, a photocatalyst dosage of 100 mg, an initial R195 concentration of 100 mg/l, an ultrasound power of 38W, and an exposure time of 20 min, the maximum Red195 removal efficiency (100%) was achieved. After five cycles of recycling, the composite's sonophotocatalytic degradation stability for R195 remains above 95%. Experiments on scavenging indicate that electrons (h+) and hydroxyls (OH-) are indispensable decomposition agents. The removal of R195 by Scendesmus/Fe3O4/TiO2 is consistent with the pseudo-first-order kinetic, Freundlich, and Henderson's isotherm models, as determined by kinetic and isotherm investigations. The negative activation enthalpy of the standard (ΔH°) illuminates the exothermic adsorption mechanism. The increase in standard Gibbs activation free energy (ΔG°) with increasing temperature reveals the process is not spontaneous. As indicated by the negative value of the standard entropy of activation (ΔS°), activation of the reactants resulted in a loss of freedom. [ABSTRACT FROM AUTHOR]

The current treatment for periodontitis is aimed at resolving gingival inflammation, whilst complete periodontal tissue regeneration is not predictable, and it represents a therapeutic challenge. Injectable biomaterials hold tremendous potential in dental tissue regeneration. This study aimed to investigate the ability of an injectable thermosensitive β-tricalcium phosphate (β-TCP) and chitosan-based hydrogel to carry cells and promote periodontal tissue regeneration. In this study, different concentrations of β-TCP-loaded chitosan hydrogels were prepared (0%, 2%, 4%, or 6% β-TCP, 10% β-glycerol phosphate, and 1.5% chitosan). The characteristics of the hydrogels were tested using rheology, a scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), degradation, and biological analyses. The new biomaterial showed a sol–gel transformation ability at body temperature and exhibited excellent chemical and physical characteristics, whilst the existence of β-TCP enhanced the structure and the properties of the hydrogels. The SEM confirmed the three-dimensional networks of the hydrogels, and the typical rheological properties of strong gel were observed. The EDX and XRD validated the successful incorporation of β-TCP, and similar patterns between different groups were found in terms of the FTIR spectra. The stable structure of the hydrogels under 100 °C was confirmed via DSC. Biological tests such as Alamar Blue assay and Live/Dead staining confirmed the remarkable biocompatibility of the hydrogels with pre-osteoblast MC3T3-E1 and human gingival fibroblast (HGF) cells for 14 days, and the results were validated with confocal imaging. This preliminary study shows great promise for the application of the β-TCP-loaded thermosensitive chitosan hydrogels as a scaffold in periodontal bone and soft tissue repair. [ABSTRACT FROM AUTHOR]

The rapid breakdown anodizing method was used to produce (Bi, Bi2O3), (Pb, PbO2), and WO3 nanoparticles. These particles are utilized to fabricate gamma-ray shielding. The X-ray diffraction test displayed polycrystalline structures for all samples. Scanning electron microscope images illustrated the formation of (Bi, Bi2O3) and (Pb, PbO2) nanoplates and WO3 semi-sphere particles. Pressures of 318, 477, and 636 MPa were applied to reduce vacancies within the prepared powders and increase their densities. Cylindrical samples with a diameter of 14 mm and different thicknesses were formed. Utilizing gamma rays produced by sources like Am-241 (59.54 keV), Cs-137 (661.6 keV), Co-60 (1173 keV), and Co-60 (1332 keV), the shielding characteristics of the manufactured samples were studied. The linear attenuation coefficient, mass attenuation coefficient, and half-value layer were determined after the gamma flux was measured using a NaI(Tl) detector. The two attenuation coefficients were functions of the source energy, and they had the highest values for (Pb, PbO2) and the lowest for the WO3 sample. The atomic numbers of the elements used and the size of the voids inside the prepared powders played the greatest role in determining the values of the shielding parameters. [ABSTRACT FROM AUTHOR]

Preparation of high-strength densified ceramsites and porous water-retaining ceramsites to replace part of the original gravel aggregates and natural moisturizing materials, respectively, is an effective way for the resource utilization of coal gangue (CG). The pore structure of ceramsites affects their strength, density, porosity, etc. In this paper, CG was used as the sole raw material to prepare ceramsites at different temperatures (600–1220 °C). By using methods of thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscope (SEM), element analysis (EA), heating microscope (HM), and density tester (DT), the evolution mechanism of pore structure in sintered coal gangue ceramsites (CGCs) was discussed. The results showed that there were two key temperatures: 950 °C and 1160 °C. Below 950 °C, the pore structure of CGCs was in a stable state, and the true, apparent, and closed porosity remained around 45%, 32%, and 12%, respectively. At 950–1160 °C, the true and apparent porosity decreased, and the closed porosity and compressive strength increased. Above 1160 °C, its performance deteriorated. During the heating process, the loss of carbon-containing components, phase transition, high-temperature diffusion and densification would change the pore structure. The appropriate temperature range for the preparation of porous water-retaining CGCs was about 950 °C, while that for preparing high-strength densified CGCs was about 1000–1160 °C. It was proved that qualified CGC products with different prospective applications could be prepared in different temperature regimes. [ABSTRACT FROM AUTHOR]

The construction of a simple sensor structure sensitive to sulfur dioxide (SO2) based on multi-walled carbon nanotubes (MWCNTs) functionalized by nitric acid is described in this study. The functionalized MWCNTs were comparatively analyzed by X-ray diffraction, Raman, and FTIR spectroscopy methods, and their morphology was observed by scanning electron microscope (SEM). The sensitivity to 5 ppm SO2 gas is based on the change of resistance of functionalized MWCNTs. Tests on the fabricated sensor were performed at room temperature and defined that functionalized MWCNTs are sensitive to SO2 gas compared with the pristine MWCNTs. [ABSTRACT FROM AUTHOR]

In this paper, we report about the distribution model of Iron (Fe) atoms on Graphene Nano Sheets (GNS). The purpose of this research is to evaluate the performance of Fe/GNS in terms of the distribution of Fe atoms on the graphene surface. GNS and Fe/GNS were prepared with modified Hummer's and impregnation methods, respectively. We found that the morphology of graphite is different compare to GNS where GNS has thin layers and no stacking sheets (Scanning Electron Microscope (SEM) data) and it contains majority Carbon (C) element (more than 90 wt%) (EDX data). The X-Ray Diffraction (XRD) data of GNS shows the appearance weak and broad peak on 2θ = 26.6o indicating GNS was formed, and the sharp peaks on 2θ = 43.84o prove that Fe atoms are well deposited on GNS (XRD data). Both SEM and XRD data prove GNS produced and Fe deposited on GNS. Further, we propose the distribution model of Fe atoms on GNS surfaces based on three steps. The first step is the Fe precursor react with GNS to produce Fe ions. The second step is Fe ions reduce while being deposited on GNS surfaces, generating Fe clusters. Finally, Fe clusters migrate on the surfaces of GNS to form Fe particles. The smallest Fe crystal size in Fe/GNS is at 3.81% Fe (1.5009 nm) and distributed into GNS. Based on those data, GNS was found to affect the properties of Fe metal. [ABSTRACT FROM AUTHOR]

Here, we have synthesized methylammonium based two metal halide perovskites (MHP) such as MAPbBr3, and MAPbI3 using methylammonium bromide, methylammonium iodide, lead bromide, respective at room temperature under certain experimental conditions. All synthesized MHPs have been confirmed through X-ray diffraction technique (XRD), scanning electron microscope (SEM), Fourier transform infra-red (FTIR) and photoluminescence (PL) analysis. Afterward, comparative evaluation on optical sensing capability has been made for both MHPs using PL in different solvents. Importantly, we find out that MAPbBr3 exhibit an excellent optical feature over MAPbI3 in hexane only. Afterward, MAPbBr3 has also been explored to know the sensing capability for nitrobenzene sensing. Our model study confirms that MAPbBr3 is an excellent sensing material with R square (0.87), selectivity (16.9%) and Stern Volmer constant (Ksv=10− 2 × 0.464) for nitrobenzene in hexane. [ABSTRACT FROM AUTHOR]

The synthesis and luminescence of a series of NaBi(WO4)2 activated with trivalent lanthanides Tb, Sm and Nd using the solid-state reaction method is reported. All samples were characterised by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL). The XRD study confirmed the tetragonal phase without any secondary phase. Particles of irregular shape ranging between 5 and 20 µm were observed. Elemental composition was obtained from EDAX and results were found consistent with the formula NaBi(WO4)2. The formation of single-phase NaBi(WO4)2 was again confirmed through these results. Elemental mapping indicated that all elements were uniformly distributed. The band gap was evaluated using Tauc's. formula and was found from 5.6 eV to 5.91 eV which is higher than reported values (3.6 eV). For NaBi(WO4)2:Tb, excitation was monitored for 545 nm emission. Emission spectra upon excitation by 488 nm showed prominent lines around 545 and 549 nm. These are due to the transition 5D4 → 7F5. 5 mol.% Tb yielded maximum PL intensity. When 405 nm excitation is used for Sm3+ doped phosphor, lines can be seen in three groups around 564, 600 and 647 nm. The highest emission intensity is observed for Sm3+ concentration of 5 mol.% and quenching was observed for high values. A weak band could be seen in the excitation spectra which is distinct from the f-f lines. The position of this band is close to that observed in the reflectance spectra. Hence it is proposed that there is host sensitization, even though weak, of the lanthanide luminescence in this host. Sensitization is most probably due to Bi3+ → Ln3+ energy transfer. [ABSTRACT FROM AUTHOR]

This research investigates the tribological characteristics and sustainability of WS2 deposited Al 6061-T6 surface under dry sliding conditions and optimizes the wear parameters to enhance the tribological behaviour and discuss its sustainability. The experiment used the Box–Behnken design, which examines the effective interaction between dry sliding parameters and specific wear rate (SWR) and friction coefficient (COF). By varying the load (L), sliding velocity (V) and distance (D), the wear behaviour of WS2 deposition against EN 31 steel was examined through the pin-on-disc experiment. Grooving, debris formation, polishing, tribolayer, ploughing, transfer material, smearing, delamination and pitting are observed through scanning electron microscope (SEM) analysis. For optimum conditions, SEM with energy dispersive spectroscopy was utilized to characterize the worn surface, and X-Ray diffraction (XRD) patterns confirmed the phases of W, WO3, WS2, Al, AlO, Al2S3 and Al4C3. [ABSTRACT FROM AUTHOR]

Phosphorites (PF) have small particle sizes and interesting chemical compositions to be used as filler in asphalt mixtures. The present study assessed the performance that a hot-mix asphalt (HMA) displays when the natural filler (NF) is completely replaced by PF. X-ray diffractometry (XRD), X-ray fluorescence (XRF), and scanning electron microscope (SEM) tests were carried out on NF and PF particles. Asphalt mastic was manufactured using a weight ratio of filler (NF and PF) to asphalt binder of 1∶1.2. Penetration, softening point, viscosity, and linear amplitude sweep test were performed on the asphalt mastic. The following tests were carried out on mixes manufactured with NF (control) and PF (HMA-PF): Marshall, indirect tensile strength, Cantabro, resilient modulus, permanent deformation, and fatigue under stress-controlled mode. Additionally, moisture damage resistance was assessed through the tensile strength ratio (TSR) parameter. The HMA-PF mix displayed a better performance in all the evaluated properties, without increasing the optimum asphalt binder content. PF as fillers could be an interesting alternative in the manufacture of HMA mixtures subjected to high temperature climates. [ABSTRACT FROM AUTHOR]

Co-precipitation, a minimal technique, was used successfully to create a novel (Cr, Cu) dual-doped ZnO nanoparticles (NPs). X-ray diffraction (XRD), energy dispersion X-ray (EDX) analysis, scanning electron microscopes (SEM), and UV–visible absorption spectra had been used to characterize the produced nanoparticle. According to the XRD pattern, the produced NPs have a hexagonal wurtzite structure with a high phase purity. The substitution of Cr increased optical absorption and induced new absorption peaks in the visible regions that correspond to the transitions from 4A2(4F) to CB and 4A2(4F) to 4T1(4F). Absorption of photons in the visible region led to an increase in the photo-generated electron–hole pairs and hence RO-species which are responsible for photocatalytic activity. Therefore, the (Cu, Cr) dual doped ZnO NPs had unique photocatalytic activity under sunlight irradiation. MTT assay was employed to analyse the in-vitro cytotoxicity of Cr-doped Zn0.98Cu0.02O NPs on human normal PBMC. In which, the toxicity is enhanced by a proliferation in Cr concentration and has very small amounts at low concentrations and significantly at high concentrations. The antibacterial characteristics of the synthesized NPs were examined against the bacterial strains P. putida and B. subtilis. [ABSTRACT FROM AUTHOR]

A novel Bi-Mg-O composite nano-catalyst was prepared by using Bi(NO3)3 and nano-MgO. Prepared catalyst was characterized using x-ray diffraction (XRD) analysis, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) technique which confirms its nano-crystalline nature and composition. The synthesized novel catalyst Bi-Mg-O was found to be competent catalyst for the synthesis of spirooxindole derivatives by multicomponent reaction of isatin, dimedone, malononitrile and 4H-pyran derivatives by reaction of dimedone, aryl aldehydes and malononitrile using ethanol as solvent at room temperature. The nanocatalyst proved to be recyclable as it is recycled and recovered for three runs without notable loss in catalytic activity. All synthesized derivatives were obtained in exemplary yields. Novel recyclable nanocatalyst, good yields of products, and benign reaction conditions are the noteworthy aspects of the present protocol. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of M2+/Al (M2+=Ni, Mg) layered double hydroxide (LDH) and intercalated polyoxometalate is presented. We have reported the growth of polyoxometalate on Ni/Mg layered double hydroxide for degradation methylene blue (MB). By considering variables such as pH of dye solution, dye concentration, and time as degradation variables, the efficiency of organic dye degradation and degradation parameters of M2+/Al (M2+ = Ni, Mg) LDH and both composite LDH-polyoxometalate has been identified. X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Scanning Electron Microscope (SEM), and Ultra Violet Diffuse Reflectance Spectroscopy (UV-DRS) spectroscopy confirmed the layered double hydroxide structure. XRD and FTIR analysis confirmed the single-phase of the as-made and polyoxometalate intercalated LDH. SEM images show the formation of aggregates of small various sizes. The material's photodegradation was assessed through methylene blue (MB) degradation process. The result showed that NiAl-Si has a good degradation capacity for MB as compared to NiAl-Pw, MgAl-Si, and MgAl-PW. The result shows that LDH composite presents stability and has good photocatalytic activities toward the reduction of methylene blue. The FTIR measurement confirming the LDH composite structure reveals the materials used in the fifth regeneration. The activity of MB photodegradation pristine were NiAl (45%), MgAl (43%), NiAl-Pw (78%), NiAl-Si (85%), MgAl-Pw (58%), and MgAl-Si (75%), respectively. The LDHpolyoxometalate composite material's capacity to successfully photodegrade, as measured by the percentage of degradation, revealed an increase in photodegradation catalysis and the ability of the LDH to regenerate. [ABSTRACT FROM AUTHOR]

Robust membrane materials with high efficiency have attracted extensive attention in oil/water separation. In this work, carbon particles via candle combustion were firstly adsorbed on the surface of stainless steel meshes (SSMs), which formed a thin hydrophobic coating, and a rough structure was then constructed through chemical vapor deposition and high temperature calcination, with the resultant SSM surface wrapped with uniform silica coating possessing the characteristic of superoleophobicity underwater. Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray powder diffraction (XRD) were used to characterize the modified SSMs. The prepared SSMs were superhydrophilic in air, and they had superoleophobicity underwater (157.4°). The separation efficiency of five oil/water mixtures was above 98.8%, and the separation flux was 46,300 L·m−2·h−1. After it was immersed in 1 mol/L NaOH, 1 mol/L HCl and 3.5 wt% NaCl for 24 h, respectively, the efficiency was still above 97.3%. Further immersion in the solution of dopamine and octadecylamine resulted in the transformation of superhydrophililc/superoleophobicity-underwater SSMs to superhydrophobic SSMs, and the resultant SSMs with reverse surface wettability was also used for the oil/water separation with good separation efficiency and separation flux. [ABSTRACT FROM AUTHOR]

This research explores the welding process of a high-entropy CrMnFeCoNi alloy with iron, unraveling the intricate chemical compositions that materialize in distinct regions of the weld joint. A mid-wave infrared thermal camera was deployed to monitor the cooling sequences during welding. A thorough analysis of the metallographic sample from the weld joint, along with measurements taken using a nano-hardness indenter, provided insights into the hardness and Young's modulus. The element distribution across the weld joint was assessed using a scanning electron microscope equipped with an EDS spectrometer. Advanced techniques such as X-ray diffraction and Mössbauer spectroscopy underscored the prevalence of the martensitic phase within the weld joint, accompanied by the presence of bcc (iron) and fcc phases. In contrast, Young's modulus in the base metal areas displayed typical values for a high-entropy alloy (202 GPa) and iron (204 GPa). The weld joint material displayed substantial chemical heterogeneity, leading to noticeable concentration gradients of individual elements. The higher hardness noted in the weld (up to 420 HV), when compared to the base metal regions (up to 290 HV for CrMnFeCoNi alloy and approximately 150 HV for iron), can be ascribed to the dominance of the martensitic phase. These findings provide valuable insights for scenarios involving diverse welded joints containing high-entropy alloys, contributing to our understanding of materials engineering. [ABSTRACT FROM AUTHOR]

Chloride ions play an important role in the corrosion of bronze through their active reactivity to copper alloys. The corrosion behavior of bronze alloys in NaCl solution was investigated by using X-ray diffraction (XRD), a scanning electron microscope (SEM), and electrochemical tests, with a special emphasis on the corrosion resistance of the α and δ phases in Cu-20 wt%Sn bronze alloys. The experimental results show that the corrosion current density of Cu-20 wt%Sn bronze alloys increases from 1.1 × 10−7 A/cm2 to 2.7 × 10−6 A/cm2 with the increase in the chloride ion concentration from 10−3 mol/L to 1 mol/L. After a soaking duration of 30 days, the matrix corrosion depth reaches 50 μm. The α phase of the alloys is easily corroded in NaCl solution, while the δ phase with high Sn content has strong corrosion resistance. This study provides relevant data for the analysis and protection of ancient bronze alloys. [ABSTRACT FROM AUTHOR]

In a single process, the surface of Ti was transformed into titanium oxide nanowires (TNWs) at room temperature. The rapid breakdown anodizing method (RBA) of producing deposited spherical nanoparticles was modified. Instead, TNWs attached to the Ti metal base were formed. To slow down the reactions of these processes, 25,50, and 75wt % glycerol were added separately to the anodizing solution of RBA. The results of the X-ray diffraction (XRD) tests revealed the amorphous structure of the formed TNWs for all samples. The produced TNWs had the shape of micro bundles with nanowires. Their diameters were less than 50 nm, as shown by scanning electron microscope (SEM) images. The prevalence of titania bundles was more intense when a lower amount of glycerol was used. The tallest length of the nanowires decreased from 32μm to 8μm with the increase of glycerol; so by using a suitable electrolyte solution, the anodizing process can be effective for controlling the size of TNWs. The decrease in atomic percent oxygen with increasing glycerol was confirmed by energy dispersion X-ray (EDX) spectra. [ABSTRACT FROM AUTHOR]

Using the solid-state reaction process, we prepared (Bi,Pb)2Sr2Ca2Cu3O10-δ (Bi-2223 for brevity) ceramics with the addition of zirconium dioxide (ZrO2) nanoparticles. The proportion x of ZrO2 per the total masse of superconductor ranged from 0 wt.% to 0.2 wt.%. We report the intragrain critical current density (Jc), pinning mechanisms, and thermal fluctuations induced excess conductivity. Employing numerous characterization techniques, combining X-rays diffraction, electrical transport measurements, scanning and transmission electron microscopes (SEM and TEM), and DC magnetization hysteresis measurements, we find that the ceramic sintered with 0.1 wt.% ZrO2 nanoparticle showed the best superconducting performance. From the analysis of excess conductivity using Aslamazov–Larkin model, we assessed the crossover temperatures between different regimes of conductivity, the penetration depth, the coherence length, as well as the upper and the lower critical magnetic fields (Bc1, Bc2) at zero kelvin for all the ceramics. Critical current density versus temperature deduced from magnetization measurement is raised by NP-ZrO2 addition. Thereby, NP-ZrO2 strengthened the role of δl pinning cores and enhanced the flux pinning ability. [ABSTRACT FROM AUTHOR]

In order to improve the utilization rate of iron tailings and reduce the cost of grouting materials, the method of replacing river sand and fly ash with iron tailings sand and partially replacing cement with activated iron tailings powder was selected for the test. Using orthogonal test method, factors such as water cement ratio, cement sand ratio, tailings powder, and fly ash content were studied. Research showed that the influence of four factors on the strength of grouting materials was ranked in descending order: water cement ratio, tailings powder, fly ash, and cement sand ratio. Through range analysis, the optimal factor level combination for 28 days was determined to be a water cement ratio of 0. 36, a cement sand ratio of 1 ∶ 0. 6, a tailings powder content of 10%, and a fly ash content of 6%. Through contrast tests, the feasibility of completely replacing river sand and fly ash with iron tailings sand and partially replacing cement with activated iron tailings powder was clarified. Through X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, it was found that under the test conditions, the performance of grouting materials was improved by the production of tricalcium silicate, ettringite and other hydration products during the hydration and hardening process of grouting materials. Incomplete crack and hydration reaction would reduce the strength of grouting material. [ABSTRACT FROM AUTHOR]

In this study, pure Sr2CeO4 (SCO) and codoped Sr2CeO4:Tm3+, Yb3+ (SCO:Tm, Yb) of powder phosphors were synthesized by a combustion technique. The concentration of Tm3+ was fixed at 0.5 mol %, while the Yb3+ doping concentration was varied from 0 to 7.0 mol %. The crystalline structure, morphology and luminescence properties were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence spectroscopy, respectively. The XRD analysis shows the crystalline orthorhombic phase for all synthesized samples of SCO and SCO: Tm, Yb. The SEM results show that the doped sample with 5.0 mol % Yb3+ has the lowest grain particle size of 1.92 μm. The SCO:Tm, Yb phosphors produce mainly blue and near infrared emission bands centered at 481 nm and 813 nm (under 980 nm, excitation) which corresponds respectively to ¹G4→3H6 and ³H4→3H6 transitions of Tm3+. In addition, the international commission on illumination CIE coordinates were calculated for all samples taking the range of 400 - 700 nm obtaining for the 5.0 mol % Tm3+ doped sample the coordinates: (x,y) = (0.0833, 0.1671) which match with pure blue color. Due to the strong blue and near infrared emissions, the SCO:Tm, Yb phosphors could be good candidates for use in biomarkers or lighting applications. [ABSTRACT FROM AUTHOR]

Different glasses with a variable composition of x Nd 2 O 3.(46-x) B 2 O 3.24.5 Na 2 O.26.5 CaO.2.6 P 2 O 5 (where X = 0–2.0 mol% of Nd 2 O 3) were prepared and studied from the viewpoint of enhancing their bioactivities. All of the as-prepared glasses showed amorphous structures evidenced by the X-ray diffraction (XRD) patterns. On the other hand, XRD patterns of glasses soaked in sodium phosphate buffer solution revealed the formation of a variety of crystalline structures relevant to the formation of carbonated hydroxyapatite derivatives. According to the NMR data, the concentration of BO 3 units increases at the expense of BO 4 with increasing Nd 2 O 3 content. Increasing of (BO 3 /BO 4) molar ratio with increasing Nd 2 O 3 plays the main role of enhancing the bioactivity of borate glasses. The percentage of BO 3 , BO 4, and consequently N 4 fraction (N4 =BO 4 /BO 3 +BO 4) can simply be determined from the deconvolution process of FTIR and NMR spectra. A scanning electron microscope (SEM) and energy-dispersive x-ray (EDX) evaluation of the microstructures support the existence of crystalline HA after immersion. Both EDX and mapping of the sample after prolonged time intervals point to the homogeneity in the HA distribution of the studied sample. [ABSTRACT FROM AUTHOR]

Herein, a novel nanostructure based on cyclic aromatic polyimide with statistical star polymer structure was synthesized via the functionalization of the CuFe2O4 MNPs surface. The polymerization process on the functionalized surface of CuFe2O4 MNPs was performed with pyromellitic dianhydride and phenylenediamine derivatives. All analytical methods such as Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, X-ray diffraction (XRD) pattern, energy-dispersive X-ray (EDX), field-emission scanning electron microscope (FE-SEM), vibrating-sample magnetometer (VSM) were performed to characterize the structure of CuFe2O4@SiO2-polymer nanomagnetic. The cytotoxicity of CuFe2O4@SiO2-Polymer was investigated for biomedical application by MTT test. The results proved that this nanocmposite was biocompatible with HEK293T healthy cells. Also, the evaluation antibacterial property of CuFe2O4@SiO2-Polymer showed that its MIC in Gram-negative and Gram-positive bacteria were 500–1000 µg/mL, so it had antibacterial activity. [ABSTRACT FROM AUTHOR]

Znic-based metal–organic framework materials (ZIF-8) show great potential and excellent performance in the fields of sensing and catalysis. However, powdered metal–organic framework makes it easy to lose in the process of application. Herein, we use a simple blending electrostatic spinning method to combine ZIF-8 particles with polyacrylonitrile (PAN) nanofibers. ZIF-8/PAN composite nanofiber membrane. The ZIF-8/PAN nanofiber membrane is characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption–desorption. The results show that the ZIF-8/PAN nanofiber membrane has the characteristic peaks of XRD and FTIR, which are consistent with those of simulated ZIF-8. The specific surface area of ZIF-8/PAN nanofiber membrane increases from 13.5371 to 711.4171 m2 g−1 due to the introduction of ZIF-8 particles. The sensor using the nanofiber membrane as the gas sensing layer shows good response and linear correlation to different concentrations of acetone gas. The minimum detection limit of the sensor for acetone is 51.9 ppm. The blank control shows that the response of the sensor to acetone is mainly due to the introduction of ZIF-8 particles. In addition, the sensor also shows a good cyclic response to acetone. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of quaternary copper nickel tin sulfide (Cu2NiSnS4) thin films using two different strategies and their physico-chemical properties. The first strategy includes co-evaporation of copper–nickel-tin–sulfur (CNTS) followed by sulfurization and the secondstrategy includes co-evaporation of copper–nickel–tin (CNT) followed by sulfurization. The X-ray diffraction (XRD) study reveals that the film prepared by both strategies has a polycrystalline Kesterite structure. The scanning electron microscope (SEM) analysis shows densely covered CNTS all over the substrate. The optical analysis of both CNTS films exhibits absorption of visible wavelength in an optimal range. The CNTS thin film synthesized using thermal evaporation technique followed by sulfurization has the potential to exhibit better photovoltaic properties for solar cell applications. [ABSTRACT FROM AUTHOR]

Red phosphors play a key role in improving the optical quality of white light emitting diodes (WLEDs). In this work, Eu3+-activated red-emitting pyrophosphate phosphors of NaREP 2 O 7 :Eu3+ (RE = Sc, Lu) were prepared and the comparative investigations on crystal structures and luminescent properties were carried out. The X-ray diffraction (XRD), scanning electron microscope (SEM), and spectroscopy techniques were employed to characterize the materials. The features of crystal structures with regard to the Eu3+ doping were analyzed in detail on the basis of Rietveld crystal structure refinements. It is found that the Eu3+ tends to substitute Lu3+ in the NaLuP 2 O 7 :Eu3+, while in NaScP 2 O 7 :Eu3+ it tends to substitute Na+ due the principle of ionic size matching. The disparate selective occupation behaviour of Eu3+ ion in both crystals has resulted in a certain difference in fluorescence emission nature from each other. The doping concentration of Eu3+ was optimized for the strongest luminescence under near-ultraviolet (UV) excitation. The measurement of temperature-dependent luminescence showed that the emission of NaLuP 2 O 7 :Eu3+ at 150 °C maintained 77% of that at room temperature, and that for NaScP 2 O 7 :Eu3+ is 72%. Under the near-UV excitation, the fluorescence efficiency of the phosphors were assessed. The quantum efficiencies of NSPO:0.125Eu3+ and NLPO:0.125Eu3+ were measured to be 41.6% and 40.8%, respectively. The results imply that the Eu3+-activated pyrophosphate phosphors are promising red-emitting components in WLEDs. [ABSTRACT FROM AUTHOR]