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Energy-dispersive x-ray spectroscopy and high-angle annular dark-field in a Cs-corrected scanning transmission electron microscope are employed to characterize the atomic-scale strain distribution in the active region of the InAs-based interband cascade laser. For the first time, energy-dispersive x-ray spectroscopy is utilized for the quantitative calculation of the zero-strain region, by which the geometric phase analysis of high-angle annular dark-field imaging has been carried out. The strain distribution of the active region with high accuracy has been obtained. The analysis of the out-of-plane strain shows that the active region in the InAs-based interband cascade laser is strain-compensated, while a certain degree of elemental intermixing still exists in the active region. This detailed strain distribution can provide valuable insights into the optimization of the growth conditions for the active region such as growth temperature, V/III flux ratio, and growth process to minimize the elemental intermixing and obtain a better performance interface while maintaining the strain-compensated state. [ABSTRACT FROM AUTHOR]

Over the last two decades, Electron Energy Loss Spectroscopy (EELS) imaging with a scanning transmission electron microscope has emerged as a technique of choice for visualizing complex chemical, electronic, plasmonic, and phononic phenomena in complex materials and structures. The availability of the EELS data necessitates the development of methods to analyze multidimensional data sets with complex spatial and energy structures. Traditionally, the analysis of these data sets has been based on analysis of individual spectra, one at a time, whereas the spatial structure and correlations between individual spatial pixels containing the relevant information of the physics of underpinning processes have generally been ignored and analyzed only via the visualization as 2D maps. Here, we develop a machine learning-based approach and workflows for the analysis of spatial structures in 3D EELS data sets using a combination of dimensionality reduction and multichannel rotationally invariant variational autoencoders. This approach is illustrated for the analysis of both the plasmonic phenomena in a system of nanowires and in the core excitations in functional oxides using low loss and core-loss EELS, respectively. The code developed in this manuscript is open sourced and freely available and provided as a Jupyter notebook for the interested reader. [ABSTRACT FROM AUTHOR]

Low-energy ion beam irradiation, combined with the introduction of impurities, presents a promising approach for nanopatterning silicon (Si) surfaces. In this research, we investigate the surface evolution of Si (100) surfaces irradiated by 75 eV helium (He) plasma, in the presence of tantalum (Ta), traditionally regarded as an impurity incapable of initiating pattern formation, as evidenced in prior studies. The Ta impurities are pre-deposited onto the Si surfaces using the magnetron sputtering method, which offers a more controlled and quantifiable approach compared with the conventional co-deposition route. After irradiation at 800 K, dense cone arrays are produced on the Si surface. The growth of the cones is explored for fluence spanning (1–10) × 1025 m−2. The cross-sectional scanning electron microscope images indicate that the cone lengths and base width are well characterized by t1/2 dependence. The kinetics of the cone growth follow Fick's law, characterized by an effective diffusive mechanism with the coefficients of diffusion: D = 6.49 ± 0.83 × 10−16 m−2 s−1. Transmission electron microscope observations reveal that the cone has distinct inner and outer parts with different microstructures and a clear interface. The growth mechanism of these cones is elucidated as a composite process involving preferential sputtering, the destabilizing influence of He bubbles, and the migration of adatoms. [ABSTRACT FROM AUTHOR]

Manufacturing nanocrystals with desired structures is the basis for realizing designed properties in their applications. As an important top‐down fabrication technique, although electron beam (e‐beam) has been well used for atomic etching on one hand, it is still challenging to precisely repair the undesired crystal defects on the other. Herein, utilizing the e‐beam probe in a spherical aberration‐corrected scanning transmission electron microscope, the possibility of e‐beam in the atomic‐level‐controllable construction/repair of crystalline defects in ruthenium oxide (RuO2) nanocrystals is systematically explored. It is found that the functional duality of beam effects can be well controlled, with the domination of either constructing or repairing defects in atomic scale, by tuning e‐beam parameters. With the aid of real‐time observation of the atom‐by‐atom repairing process via in situ scanning transmission electron microscopy and density functional theory calculations, the e‐beam‐assisted repairing mechanism is revealed. This work is anticipated to provide insights into controllable top‐down manufacturing nanomaterials at the sub‐nanoscale by e‐beam. [ABSTRACT FROM AUTHOR]

The green synthesis of silver nanoparticles (SNPs) using aqueous extracts of five plants viz., Ocimum americanum, Azadirachta indica, Allium sativum, Eucalyptus hybrida, Zingiber officinale were evaluated for their antifungal property against Penicillium digitatum, a green mould pathogen of citrus fruits. The five plant species were selected from a screening of aqueous extracts from 16 plant species. The efficacy of aqueous extracts, at 50 % concentration, ranged from 14.44–68.52 % inhibition in mycelia growth of P. digitatum. Among SNPs, O. americanum was found most efficacious, at 1000 ppm concentration, with 80.7 % mycelial inhibition followed by A. indica with 77.4 % mycelial growth inhibition of fungal pathogen. Further, physical and structural characterization of SNPs of O. americanum and A. indica was carried out. The characterization analysis executed via transmission and scanning electron microscope revealed size distribution and nanoparticles were spherical to irregularly shaped ranging from 22.8–250 nm in O. americanum and 26.5–500 nm in A. indica. In UV‐visible spectrophotometer, the absolute absorption peak was recorded at 448 nm and 442 nm for O. americanum and A. indica, respectively. FTIR analysis of SNPs of A. indica and O. americanum confirmed the presence of carboxyl, amide group and secondary amines which were the main constituent of proteins. The novelty of the present study is in the green synthesis of silver nanoparticles with potential in the management of postharvest pathogens of fruit crops. The synthesis of SNPs used in this study is simple, environmentally benign and cost‐effective using aqueous extract of native plants. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) have excellent flexibility, unique optical transmittance and high conductivity. The polyol process is appropriate for preparing AgNWs due to its simplicity, effectiveness, low cost, and high yield. This work aims to investigate the effect of preparation parameters of the polyol process on the silver nanowires properties. The parameters include the controlling agent, molecular weight of the polyvinylpyrrolidone (PVP), the temperature, and the reducing agent. The amount of silver nanoparticles formed during preparation was used to determine the optimum preparation conditions. The transmission electron microscope (TEM) images showed minimal amount of Ag nanoparticles when using mixed molecular weight of PVP-40K, and PVP-1.3M at 150 °C with the assistance of copper chloride as a controlling agent. The prepared AgNWs had an average length of 3.7 µm and aspect ratio of 15.3. The fabricated electrodes were characterized using a scanning electron microscope (SEM) and four probe resistivity measurements. The electrical measurement of the AgNWs electrodes indicated that the surfactant thickness is a critical parameter in having low sheet resistance electrodes. Also, the optical transmission was affected by the amount of nanoparticles. The prepared electrode with high concentration of AgNWs and a minimal amount of nanoparticles exhibited 80% optical transmission. [ABSTRACT FROM AUTHOR]

The crystal structure of La 0.7 Sr 0.3 Mn 1−x Al x O 3 (LSMAO) with x = 0,0.025,0.05,0.075 and 0.10 ceramics prepared by the Sol-gel method were investigated by employing the XRD technique. The XRD patterns analysis by employing the Rietveld analysis confirms the nonexistence of secondary crystal phase/s and, materials are crystallized to the R-3c(167) space group. The microstructural properties were studied using scanning electron microscope (SEM) and transmission electron microscope (TEM). The dielectric property, AC conductivity, complex impedance spectroscopy and complex electrical modulus have been studied over a wide range of frequencies (103 Hz–107 Hz) at different temperatures from 313K to 393K. The Non-Debye type relaxation process has been observed in synthesized samples confirmed from the Nyquist plot. The Cole-Cole plots were employed to estimate the individual grain and grain boundary contributions. The Maxwell-Wagner (MW) polarization model provides an explanation for the greater values of dielectric constant at the lower frequencies. The present study explores the technological usefulness of LSMAO. [ABSTRACT FROM AUTHOR]

Organic dyestuff are mostly toxic compounds that pose serious dangers to the environment. Adsorption using low-cost adsorbents is the most favorable method for its economic aspects. Recently, geopolymers have been introduced as an effective adsorbent for dyes and heavy metals. In this investigation, the synthesis of geopolymers from fired brick waste (Homra) was studied with full characterization using X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Brunauer–Emmett–Teller, Energy dispersive X-ray, Scanning electron microscope tests and Transmission electron microscopy. The synthesized nano-Homra geopolymer (NHGP) was then subjected to the removal of one of the most used basic dyes, Methylene Blue (MB). Adsorption optimization was applied using Response surface methodology to study dye adsorption by the synthesized nano-geopolymer. The independent variables studied were: temperature, contact time, and concentration of dye in the elimination process, which were varied in the range of (25–60 ℃), (10–180 min), and (20–300 mg/L) respectively. The results obtained from ANOVA indicated that the maximum removal efficiency of 95% and adsorption capacity of 80.65 mg/g at a temperature of 59 ℃, contact time of 163 min, and an initial concentration of 254 mg/L. The results showed that the data obtained from the adsorption of MB onto NHGP was compatible with the Pseudo second order (R2 = 0.9838) and Langmuir isotherm model (R2 = 0.9882). [ABSTRACT FROM AUTHOR]

Background: Toxoplasmosis, caused by Toxoplasma gondii , poses serious health issues for humans and animals. Individuals with impaired immune systems are more susceptible to severe toxoplasmosis. Pregnant women infected by T. gondii can face the possibility of birth defects and miscarriages. While pyrimethamine and sulfadiazine are commonly used drugs in clinical practice, concerns over their side effects and resistance are on the rise. A spider peptide XYP1 isolated from Lycosa coelestis had potent anti-T. gondii effects, but it had a high synthesis cost and strong cytotoxicity. Methods: This study intended to modify XYP1 for producing derived peptides via amino acid truncation and substitution. The anti-T. gondii effect was evaluated by trypan blue staining assay and killing experiment of RH strain tachyzoites. The CCK8 and hemolysis assays were used to compare their safeties. The morphological changes of T. gondii were observed by scanning electron microscope and transmission electron microscope. In addition, the mechanism of XYP1 against T. gondii through RNA-sequencing was further explored. Results: In vivo and in vitro experiments revealed that XYP1-18 and XYP1-18-1 had excellent anti-T. gondii activity with lower cytotoxicity and hemolysis activity than XYP1. XYP1, XYP1-18, and XYP1-18-1 were able to disrupt the surface membrane integrity of T. gondii tachyzoites, forming pores and causing the disruption of organelles. Furthermore, RNA-sequencing analysis indicated that XYP1 could stimulate the host immune response to effectively eliminate T. gondii and lessen the host's inflammatory reaction. Conclusions: XYP1-18 had lower cytotoxicity and hemolysis activity than XYP1, as well as significantly extending the survival time of the mice. XYP1 played a role in host inflammation and immune responses, revealing its potential mechanism. Our research provided valuable insights into the development and application of peptide-based drugs, offering novel strategies and directions for treating toxoplasmosis. [ABSTRACT FROM AUTHOR]

The detailed study on impact of Yb3+ on spectroscopic and 1.54 μm broadband emission of Er3+ doped transparent oxyfluroborosilicate glass ceramics (GCs) with embedded CaF2 nanoparticles was presented. The studied GCs were prepared by controlled crystal nucleation and growth process at 450 °C/1 h. Thermogravimetry and differential scanning calorimetry results showed good thermal stability and fiber drawing capacity. The scanning electron microscope and transmission electron microscope studies confirmed the formation and the uniform distribution of CaF2 nanoparticles. Various radiative and laser characteristic features were calculated within the frame work of Judd–Ofelt theory. The NIR emission at 980 nm pumping showed an intense and broad emission band due to Er3+:4I13/2 → 4I15/2 transition. The emission spectra showed a quenching in luminescence beyond 3 mol% of Yb3+ doping confirming the optimized Er3+ and Yb3+ ratio as 1:3 for enhanced emission. The stimulated emission cross-sections and quantum efficiency decrease with increased Yb3+ doping due to concentration quenching and cross-relaxation transfer of energy among Er3+ and Yb3+ ions. The experimental investigations suggest that the BSEr1Yb3GC has higher proficiency for 1.54 μm broadband fiber lasers and optical amplifiers in S and C band communication windows. [ABSTRACT FROM AUTHOR]

In this study, the polygonal structure of WO3 nanoparticles was constructed by the hydrothermal route, and the prepared materials were utilized for supercapacitor applications. The synthetic materials are WO3 nanoparticles in their monoclinic phase, according to the X-ray diffraction data. The morphologies of the WO3 samples are polygonal like and scanning electron microscope and transmission electron microscopy have confirmed it. To investigate the supercapacitance behavior of polygonal WO3, various techniques were used, such as galvanostatic charge–discharge, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The polygonal WO3 nanoparticle modified on Ni-foam as a working electrode has a specific capacitance value of 870 F g−1 at 0.25 A g−1. The polygonal structure of WO3 nanoparticle-coated Ni-foam electrodes was very stable compared to other fabricated electrodes over the 10,000 cycles. The fabricated polygonal structure of the WO3 electrode has high capacitance retention (100.2%) and high coulombic efficiency (99%). The polygonal structure of WO3 makes it a particularly effective electrode material and a substantially better candidate for energy storage, especially supercapacitors. [ABSTRACT FROM AUTHOR]

We present the band gap engineering and morphological tuning of BaAl2O4:0.1% Sm3+, x% Tb3+ nanophosphors synthesized by citrate sol–gel method. Herein, the samarium (Sm3+) concentration is kept constant at 0.1%, while the concentration of terbium (Tb3+) is tuned from 0.5 to 2.5% with steps of 0.5%. X-ray diffraction confirms the hexagonal crystal structure of the BaAl2O4:0.1% Sm3+, x% Tb3+ nanophosphors. The reduction in crystallite size from 38 to 31 nm is noticed after doping and co-doping. Scanning electron microscope micrographs display evolution in morphology from multimodal grain-like structures to agglomerated pointy nanorods. Energy dispersive X-ray spectroscopy confirms all the main elements, although Sm is not detected due to the low content incorporated into the lattice. Transmission electron microscope results reveal that the particle size and shape can be controlled by varying concentrations of Tb3+. Diffuse reflectance spectra with the aid of the Kubelka–Munk function, reveal the energy band gap in the range of 2.6–5.3 eV. Under the excitation wavelength of 235 nm, photoluminescence studies reveal eight emission peaks located between 380 and 641 nm characteristic of Tb3+ ions. Upon the excitation wavelength of 402 nm, the emission spectra show four peaks positioned at 564, 601, 648 and 708 nm attributed to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2,4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 transitions of Sm3+ ions, respectively. From the colour coordinate results, this nanophosphor can successfully play a significant role in green, yellow and red LED applications. [ABSTRACT FROM AUTHOR]

In the current study, silver nanoparticles (AgNPs) incorporated Polyamide 66 (PA66) nanofiber mat as a photocatalyst which was prepared using electrospinning technique for degradation of methyl orange (MO). Considering the lack of reported studies on the influence of the ultrasonication on the size and stability of AgNPs, the purpose of the study was to produce a small size of AgNPs and compare it with the continuous stirring method. It is reasonable to report that the advantage of ultrasonication is to generate relatively smaller AgNPs (u-AgNPs) compared to fabrication by continuous stirring method (s-AgNPs). Helichrysum arenarium (HA) extract was used as a reducing agent as well as a capping agent in green synthesis of AgNPs. AgNPs were characterized by UV–visible spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscope (TEM). PA66/u-AgNs nanofibers were then successfully electrospun and characterized by using scanning electron microscope (SEM), FT-IR, thermal gravimetric analysis (TGA), and water contact angle measurement (WCA). Fabricated PA66-based nanofiber mat with smooth surface and uniform diameters (330–340 nm) was used as a catalyst in MO degradation. PA66/u-AgNP nanofibers were also evaluated for antibacterial performance and showed significant inhibition against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. According to these findings, it is expected that the fabricated novel PA66/u-AgNP nanofibers can be announced as a promising potent and applied to the wastewater applications. [ABSTRACT FROM AUTHOR]

The self-supported Co–Fe LDH@Ni(OH)2 material is successfully prepared on a foam nickel substrate through two hydrothermal processes. The phase structure and microstructure of the electrode material are investigated through X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses. The electrode materials undergo electrochemical and electrocatalytic tests using an electrochemical workstation. This study demonstrates that the specific capacitance of the Co–Fe LDH@Ni(OH)2 is 2626 mF cm−2 at 1 mA cm−2. Supercapacitors made of LDH@Ni(OH)2 electrode material operate exceptionally well. Both the power density and the energy density are 0.755 mW cm−2 and 32.5 μWh cm−2, respectively. As a catalyst material for electrochemical splitting of water, CoFe-LDH@Ni(OH)2 exhibits distinguished electrocatalytic properties. The overpotential is 242 mV at 50 mA cm−2 in HER, while that is 149 mV at 20 mA cm−2 in OER. Meanwhile, the CoFe-LDH@Ni(OH)2 electrocatalytic material also performs extremely well in the overall water electrolysis testing. The voltage is 1.65 V at 25 mA cm−2, which shows strong cyclic stability. The material provides a reliable guarantee for sustained and stable operation in various application scenarios. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of atomic fracture mechanisms in 2D materials is essential for their practical applications, yet this knowledge is currently limited. To address this gap, an aberration‐corrected scanning transmission electron microscope (STEM) to induce new cracks in suspended monolayer transition metal dichalcogenides (TMDs) using broad electron beam illumination, is employed. During characterization, a low‐dose electron beam to avoid irradiation damage, allowing to observe the atomic fracture behavior in these materials, is utilized. The STEM experiments reveal a novel atomic fracture pattern along the zigzag direction, resulting in a distribution where half of the chalcogen atoms (S or Se) adhered to the molybdenum‐terminated (Mo‐T) edge and the other half to the chalcogen‐terminated (S‐T or Se‐T) edge. Density functional theory (DFT) calculations suggest that this fracture mode produces a pair of edges with the lowest formation energy. Additionally, molecular dynamics (MD) simulations support the observed fracture behavior under a mixed mechanical loading mode of “I+III” with both in‐plane and out‐of‐plane stress, originating from the ultrathin nature and nonplanar deformation in suspended 2D materials. This research offers new insights for the development of 2D fracture mechanics and is pivotal for designing devices incorporating 2D materials. [ABSTRACT FROM AUTHOR]

2D materials have received a lot of interest over the past decade. Especially van der Waals (vdW) 2D materials, such as transition metal dichalcogenides (TMDCs), and their heterostructures exhibit semiconducting properties that make them highly suitable for novel device applications. Controllable mixing and matching of the 2D materials with different properties and precise control of the in‐plane twist angle in these heterostructures are essential to achieve superior properties and need to be established through large‐scale device fabrication. To gain fundamental insight into the potential control of these twist angles, 2D heterostructures of tungsten disulfide (WS2) and graphene (Gr) grown by bottom‐up synthesis via metal‐organic chemical vapor deposition (MOCVD) are investigated using a scanning transmission electron microscope (STEM). Specifically, the combination of conventional high‐resolution imaging with scanning nanobeam diffraction (SNBD) using advanced 4D STEM techniques is used to analyze moiré structures. The latter technique is used to reveal the epitaxial alignment within the WS2/Gr heterostructure, showing a direct influence of the underlying Gr layers on the moiré structure in the subsequent WS2 layers. In particular, the importance of grain boundaries (GBs) within the underlying WS2 and Gr layers on the structure of moiré patterns with rotation angles below 2° is discussed. [ABSTRACT FROM AUTHOR]

Herein, the effect of high rotational speed fast multiple rotations rolling (FMRR) on the microstructure, mechanical properties, and wear resistance of an Al–Si–Cu alloy coating friction surfaced on AA1050 aluminum alloy is investigated. The FMRR process is performed at a rotational speed of 3000 rpm with traverse speeds of 50, 80, 110, and 140 mm min−1. The microstructure, mechanical properties, and wear resistance are examined by optical microscope, scanning electron microscope, electron backscatter diffraction, transmission electron microscope, nanoindentation test, microhardness test, and pin‐on‐disc wear test. The results show that as the traverse speed increases from 50 to 140 mm min−1, surface roughness decreases from 6.3 ± 0.3 to 3.2 ± 0.2 μm. Additionally, with the increase in traverse speed, the coating height increases from 3.8 ± 0.3 to 4.7 ± 0.4 mm, while the coating width decreases from 37.1 ± 1.1 to 25.4 ± 1.3 mm. Furthermore, as the traverse speed increases from 50 to 140 mm min−1, the average hardness of the FMRR‐processed layer increases from 5.6 ± 0.6 to 10.2 ± 0.6 GPa. At a traverse speed of 140 mm min−1, the wear resistance of the FMRR‐processed layer increases by 20% compared to the Al–Si–Cu alloy consumable rod. [ABSTRACT FROM AUTHOR]

Background: As a vital soil-borne pathogenic bacterium, Ralstonia solanacearum can cause wilt disease in multiple Solanaceae plants. Several phages, such as ϕPB2, could infect R. solanacearum acting as a potential biological control agent in soil. In addition, some nanoparticles, especially copper preparation, also showed high toxicity on R. solanacearum with low toxicity on plant. However, whether they can be administered in combination and how effective they are in inhibiting the plant disease caused by R. solanacearum is known very little. Results: In this work, the characterization of CuONPs using scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction ascertained the presence of CuONPs which were nanometer particle of 83 nm. Then it was found that combined application of CuONPs with phage (ϕPB2) was superior to that of ϕPB2 or CuONPs alone in controlling tobacco bacterial wilt, with the CuONPs (250 mg/mL) and phage (106 PFU/mL) ratio being the best, at 79.1%. The combination of CuONPs and ϕPB2 also showed no obvious toxicity on tobacco growth than control like single application of CuONPs or ϕPB2. Furthermore, the transcriptome changes of R. solanacearum analysis indicated that the combination application and single allocation of CuONPs could inhibit "biofilm formation", molecular function, biological processes, cellular components, metabolic process, and so on. In addition, the combination application showed higher inhibition of motility and biofilm, and better enhancement of cell membrane permeability, protein leakage, MDA concentration, and enzyme activity of their respiratory chain dehydrogenase than single application of CuONPs or phage (ϕPB2). Transcriptomes analysis also supported that the addition of ϕPB2 enhanced the toxicity of CuONPs by influencing the ABC transporters and quorum sensing, metabolic processes, and cellular biosynthetic processes of R. solanacearum. Conclusion: In total, our work not only proposed a novel way to increase the bactericidal effect of nanomaterials by adding phage, but also discovered the influence, synergistic effects, and mechanisms, which is useful to design novel way to combat phytopathogenic bacteria in the complicated environment. [ABSTRACT FROM AUTHOR]

Greener fabrication of nanostructures has received remarkable attention due to their sustainability, cost-effectiveness, simplicity, and eco-friendliness. Opuntia ficus-indica-derived mucilage has not been exposed well to fabricate nanostructures. Thus, in this present investigation, we successfully synthesized tungsten trioxide (WO3) nanostructures using Opuntia ficus-indica-derived mucilage as bio-templates because it is more economical and environmentally friendly. Also, the fabricated WO3 nanostructures cytotoxic features and their photothermal effects were studied. The WO3 nanostructures were investigated using diverse analytical instruments: X-ray diffractometer (XRD), scanning electron microscope and, transmission electron microscope. Based on the structural and morphological characteristics of the WO3 nanostructures, they have sphere-like morphologies with diameters of 100 - 200 nm. As revealed by XRD, monoclinic crystalline WO3 nanostructures were formed. In vitro assays were used to assess the effect of WO3 nanostructures on cell viability and morphological features of cells. Based on in vitro assays, fabricated WO3 nanostructures showed slightly toxic behaviour in a human breast cancer cell line (MCF-7 cells). In contrast, after exposure to NIR lasers, the viability of WO3 nanostructures treated cells decreased significantly. Because the WO3 nanostructures have an excellent photothermal effect, which triggers cell death in cancer cells. Thus, the fabricated WO3 nanostructures can be used as a photothermal agent for cancer therapy [ABSTRACT FROM AUTHOR]

As a typical toxic substance in environmental water, phenolic pollutants, represented by p-nitrophenol, pose a great threat to the ecological environment. In this study, using WCl6 and oxalic acid as raw materials, a novel p-nitrophenol (PNP) sensor fabricated by tungsten phosphide (WP) nano-particles, has been successfully designed and constructed, which expanded the application of WP nano-materials in the field of electroanalysis. The successful synthesis of WP has been confirmed by a series of characterization techniques such as X-ray diffraction, scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. The electrochemical experiments were all carried out in phosphate buffer solution with the pH of 6.5. The WP nano-particles can electrocatalytically oxidize PNP to produce a current for the detection of PNP. The reaction sites of PNP are predicted by Gaussian 09 and Multiwfn. Prominent performance has been recorded for PNP sensor, attaining a wide linear range from 10.00 to 6500.00 μM, a low detection limit of 1.59 μM with the reliable selectivity, repeatability, and stability. Gratifyingly, the prepared sensor could satisfy the requirements of PNP determination in actual environmental water, such as tap water and rainwater. [ABSTRACT FROM AUTHOR]

Supramolecular nanoparticles containing peptides and drugs have recently gained recognition as an effective tumor treatment drug delivery system. A multitarget drug termed pemetrexed is effective against various cancers, including nonsmall cell lung cancer. The work aims to establish the capability of pemetrexed gold nanoparticles (PEM‐AuNPs) to induce apoptosis and explore molecular changes. X‐ray diffraction, Fourier‐transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscope, and transmission electron microscope were used to investigate the synthesized nanoparticles. The MTT assay was utilized to investigate the anticancer properties of PEM‐AuNPs at varying concentrations (50, 100, and 200 µM). PEM‐AuNPs demonstrated a decrease in cell viability with 55.87%, 43.04%, and 25.59% for A549 cells and 54.31%, 37.40%, and 25.84% for H1299 cells at the respective concentrations. To assess apoptosis and perform morphological analysis, diverse biochemical staining techniques, including acridine orange‐ethidium bromide and 4′,6‐diamidino‐2‐phenylindole nuclear staining assays, were employed. Additionally, 2′,7′‐dichlorofluorescein diacetate staining confirmed the induction of reactive oxygen species generation, while JC‐1 staining validated the impact on the mitochondrial membrane at the IC50 concentration of PEM‐AuNPs. Thus, the study demonstrated that the synthesized PEM‐AuNPs exhibited enhanced anticancer activity against both A549 and H1299 cells. [ABSTRACT FROM AUTHOR]

Appropriate protection and guiding are crucial during peripheral nerves repair. New generation nerve guidance conduits (NGCs) should not only provide mechanical support for the damaged nerve but also support healing processes. One of the most promising tissue regeneration applications is fibrous biomaterials since they are characterized by high porosity, flexibility, and strength. Additionally, they enable cell adhesion and proliferation. In this study, novel fibrous nanocomposites were obtained by applying the electrospinning technique, using polylactic acid (PLA) as a polymeric matrix which was further modified with metallic nanoparticles coated with conductive polymers. Such an approach resulted in the obtainment of biomaterials with a potential ability to conduct nerve impulses. The chemical structure of the obtained composites, as well as the morphology of ready products and separate nanocomponents, were investigated using Fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and scanning electron microscope (SEM) techniques. Furthermore, conductive and swelling properties in various media were determined. Finally, biomaterials were confirmed to be non-cytotoxic to L929 mouse fibroblasts and 1321N1 human glial cells. Based on the presented results, it can be concluded that nanofibrous nerve guidance conduits have all the key properties in the process of peripheral nerve regeneration and may constitute an important step in novel NGCs development. [ABSTRACT FROM AUTHOR]

Surface properties of bearing steel and other small automotive parts are generally modified in an effort to enhance its hardness and wear characteristics. In the current study, tantalum and graphite powders are added to surface of steel during tungsten inert gas (TIG) arcing to create in situ tantalum carbide to improve reinforcement to the modified surface in addition to the hard martensite matrix. Numerical simulation using COMSOL software was performed to estimate the thermal profile and validated by the experimental observation. The microstructural characteristics of the matrix were examined using optical, scanning and transmission electron microscope (OM, SEM and TEM). High resolution transmission electron microscope (HRTEM) along with electron energy loss spectrum (EELS) mode was employed to understand the type of carbide particles formed. It was found that the top modified surface contains TaC particles which enhances the hardness. The extent upto which different zones like fusion and heat affected zone, base metal, etc formed after the arcing was established both by microscopic examination and micro-hardness mapping. Modified surfaces show a notable increase in hardness from 100 to 150 percent relative to the base material. The weight loss during wear testing for different modified surfaces was significantly reduced by two to four times when compared to the substrate, indicating the presence of an effective wear resistance mechanism in the modified surfaces. [ABSTRACT FROM AUTHOR]

The Guinier–Preston (GP) zones have an important influence on the improvement of the age-hardening level of alloy. We here prepare six kinds of Mg-6Zn-5Al (ZA65) magnesium alloy samples to investigate the microstructural evolution, precipitation behavior, and strengthening mechanism using an optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), and micro-hardness tests. The finding reveals that the GP zones are observed in non-dendritic alloys experiencing pre-aging at 80°C for 24 h, whose formation creates more nucleation sites and accelerate kinetics for precipitated phases. Consequently, the introduced pre-aging has been successful in promoting the increase of the age-hardening level of non-dendritic alloys. The double-aged non-dendritic alloys show a significantly changed microstructure with a high density of long rod-shaped β1′ precipitations, making the age-hardening level of double-aging much better than that of single-aging, and the peak value 90 HV was obtained 4 h in advance, which is an increase of 4 HV compared with that of the direct aged non-dendritic alloy. The strengthening mechanism of non-dendritic alloys is mainly summarized as grain boundary strengthening, GP zone strengthening, and the shearing strengthening of β1′ and β2′ precipitations. Among these, the GP zone strengthening is a fundamental contributor to improving the age-hardening level. [ABSTRACT FROM AUTHOR]

Combining Ceramic and metal phases by explosion treatment is difficult on account of the low toughness and plasticity of the ceramic phases. To solve the problem, fine Yttria-Stabilized Zirconia (YSZ) powders were selected as an example in this work. It can be observed that part of the YSZ powders would agglomerate to spherical large particles spontaneously and YSZ layer can combine with steel substrates strongly after explosion treatment as expected. It can be explained by finite element modeling that YSZ powders were more likely to combine the steel substrate when large and small particles coexisted. Moreover, the interface between YSZ and steel substrates was investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). It was found that numerous sharp corners were generated at the interface during explosion process which possessed high resilience, and they improved the bearing capacity of the interface. In microcosm, semi-coherent boundaries and amorphous phases were detected at the interface which led to the strong metallurgical bonding between the two phases. In general, this work offers a feasible method to combine ceramic and metal substrate efficiently in a simple way. [ABSTRACT FROM AUTHOR]

The presence of pharmaceutical pollutants in the environment has become a growing concern due to their persistence and toxic nature. In response to this issue, semiconductor photocatalyst materials have emerged as promising candidates for environmental pollutant removal, particularly under solar light irradiation. In this study, we developed a novel zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite through a simple and facile method. The fabrication process involved a multistep approach wherein Fe3O4, CuS, and CuWO4 were incorporated onto the surface of pure zeolite nanoparticles. X‐ray diffraction, scanning electron microscope, transmission electron microscope, ultraviolet–visible diffuse reflectance spectroscopy, Fourier transform infrared, photoluminescence, and vibrating sample magnetometry were analyzed. The results demonstrated that the zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite exhibited a synergistic integration of excellent properties, indicative of the successful construction of a heterostructure within the nanocomposite. Furthermore, the photocatalytic efficiency of the nanocomposite was evaluated for the degradation of the pharmaceutical pollutant fluoroquinolone levofloxacin (LEVO), and it outperformed individual photocatalysts. Notably, the zeolite/Fe3O4/CuS/CuWO4 nanocomposite achieved an impressive degradation rate of approximately 82.67% of LEVO after 120 min of exposure. Importantly, the synthesized nanocomposite demonstrated excellent reusability, with a photodegradation efficiency of 60.45% after the fifth cycle of LEVO degradation, as there was no significant loss in photocatalytic activity over repeated cycles. Furthermore the highest total organic carbon removal efficiency estimated is 57.43% for heterojunction nanocomposite. These findings highlight the potential of the zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite as an effective, eco‐friendly photocatalyst for pharmaceutical pollutant removal from the environment. [ABSTRACT FROM AUTHOR]

Lately, children's daily consumption of some products, such as cereals and candies, has been rising, which provides a compelling rationale for determining any metallic substances that may be present. Monitoring the concentration of certain metals, like nickel, in these products is necessary due to medical issues in humans when consumed regularly. So, in this work, a novel and highly selective carbon paste as a Ni(II) ion-selective sensor was prepared and investigated using ceramic magnesium aluminum spinel nanoparticles as the ionophore and tritolyl phosphate (TOCP) as a plasticizer. A modified co-precipitation method was used to synthesize the spinel nanoparticles. X-ray diffraction, scanning electron microscope with EDAX, transmission electron microscope, and BET surface area were used to determine the phase composition, microstructure, pores size, particle size, and surface area of the synthesized nanoparticles. The spinel nanoparticle was found to have a nano crystallite size with a cubic crystal system, a particle size ranging from 17.2 to 51.52 nm, mesoporous nature (average pore size = 8.72 nm), and a large surface area (61.75 m2/g). The composition ratio of graphite carbon as a base: TOCP as binder: spinal as ionophore was 67.3:30.0:2.7 (wt%) based on potentiometric detections over concentrations from 5.0 × 10−8 to 1.0 × 10−2 mol L−1 with LOD of 5.0 × 10−8 mol L−1. A measurement of 29.22 ± 0.12 mV decade−1 over pH 2.0–7.0 was made for the Nernstian slope. This sensor demonstrated good repeatability over nine weeks and a rapid response of 8 s. A good selectivity was shown for Ni(II) ions across many interferents, tri-, di-, and monovalent cations. The Ni(II) content in spiked real samples, including cocaine, sweets, coca, chocolate, carbonated drinks, cereals, and packages, were measured. The results obtained indicated no significant difference between the proposed potentiometric method and the officially reported ICP method according to the F- and t-test data. In addition to utilizing ANOVA statistical analysis, validation procedures have been implemented, and the results exceed the ICP-MS methodology. [ABSTRACT FROM AUTHOR]

In this paper, the deformation behavior of UNS S32750 (S32750) duplex stainless steel during low cycle fatigue was studied by controlling the number of cycles. The microstructure of the specimens under different cycles was characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The microhardness of the two phases was measured by a digital microhardness instrument. The results showed that the microhardness of ferrite increases significantly after the first 4000 cycles, while the austenite shows a higher strain hardening rate after fatigue fracture, and the microhardness of ferrite and austenite increases by 23 HV and 87 HV, respectively. The two-phase kernel average misorientation (KAM) diagram showed that the continuous accumulation of plastic deformation easily leads to the initiation of cracks inside the austenite and at the phase boundaries. The evolution of dislocation morphology in the two phases was obviously different. With the increase in cycle number, the dislocation in ferrite gradually transforms from dislocation bundles and a dislocation array to a sub-grain structure, while the dislocation in austenite gradually develops from dipole array to an ordered Taylor lattice network structure. [ABSTRACT FROM AUTHOR]

Polar discontinuities occur in oxide heterostructures due to varying net charges in the sub-unit cell layers. These polar discontinuities lead to structural reconstruction and often create diverse functionalities. This work constructs polar discontinuous in La0.67Sr0.33MnO3/SrCuO2 (LSMO/SCO) heterostructures on a (001)-orientated SrTiO3 (STO) substrate under different configurations. By changing the growth order of LSMO and SCO, we found two different compensating mechanisms for polar discontinuity. When LSMO is grown on SCO, interfacial polarity discontinuities result in the generation of a large number of oxygen vacancies within the LSMO film. Thus, the LSMO magnetism deteriorates. For the SCO/LSMO/SCO trilayer, the SCO capping layer can recover the LSMO magnetism. The scanning transmission electron microscope results show an atomic reconstruction at the SCO-on-LSMO interface and several oxygen vacancies at the SrO sublayer. The interface reconfiguration releases the polar energy, thereby inhibiting the generation of oxygen vacancies and improving the ferromagnetism of the LSMO film. Our work studies the impact of polar discontinuity at the interface, providing insights into the effects of interface polar discontinuities on functional materials. [ABSTRACT FROM AUTHOR]

Previous studies on the austenite grain growth were mostly based on a fixed temperature, and the relationship between the austenite grain and austenitizing parameters was fitted according to the results. However, there is a lack of quantitative research on the austenite grain growth during the heating process. In the present work, based on the diffusion principle of the controlled Ti microalloying element, the diffusion process of carbonitrides containing Ti during the heating process was analyzed. Combined with the precipitation model and the austenite growth model, the prediction model of austenite grain growth of Ti microalloyed steel during different heat treatment processes was established. The austenite grain size versus the temperature at four different heating rates of 0.5, 1, 10, 100 °C/s was calculated. The grain growth behavior of austenite during the heating process of Ti microalloyed steel was studied by optical microscope, scanning electron microscope and transmission electron microscope. The experimental data of the austenite grain size was in good agreement with the calculation by the proposed model, which provides a new idea for the prediction of austenite grain size in non-equilibrium state during the heating process. In addition, for Ti-containing microalloyed steels, the austenite grain size increased with the increasing heating temperature, while it changed little by further prolonging isothermal time after certain heating time, which was related to the equilibrium degree of the precipitation and the dissolution of Ti element. The austenite grain coarsening temperature of the tested Ti microalloyed steel was estimated within 1100~1200 °C. [ABSTRACT FROM AUTHOR]

Heavy metal poisoning is the most prevalent health hazard at hazardous waste sites, affecting a large population on daily basis, with arsenite poisoning ranking third in terms of prevalence and severity. Therefore, the main objective of this study is to develop a novel, highly efficient sensor for detecting trace amounts of arsenite (AsIII) in human serum by utilising reduced graphene oxide/gold nanoparticles (rGO/AuNPs) based nanocomposite structure. In this work, a screen-printed carbon electrode (SPE) was modified using rGO/AuNPs nanocomposite to detect AsIII in human serum. The detection data were recorded and analysed using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV), whereas transmission electron microscope (TEM), scanning electron microscope (SEM) as well as Fourier transform infrared (FTIR) spectroscopy were used to determine the surface morphological features and the presence of significant elements/groups in the prepared nanocomposite structure. Under the optimised conditions, the linear regression coefficient (R2) for the DPV response of the fabricated electrode (rGO/AuNPs@SPE) was observed to be 0.98. The rGO/AuNPs@SPE demonstrated remarkable sensor response for AsIII with detection limits of 10 ppb via DPV in standard samples, due to the synergistic effect of rGO and AuNPs based nanocomposite. The sensitivity of the sensor was found to be 0.0142 Appb−1cm−2 for 100–1000 ppb concentration range of AsIII. The rGO/AuNPs@SPE sensor also displayed good stability and reproducibility when used in AsIII spiked human serum samples in which the limit of detection was observed at 100ppb. The porous structure of rGO on the sensing interface efficiently improves the electrode's adsorption and conductivity, while citrate capped AuNPs offer the functional groups required for maximum adsorption of AsIII. Hence, the developed electrochemical sensor (rGO/AuNPs@SPE) can be used very precisely and reliably in various applications for trace level detection of AsIII in human serum. [ABSTRACT FROM AUTHOR]

[Display omitted] Single-atom catalysts (SACs) have received much attention in the realm of energy and catalytic conversion due to their maximum atomic efficiency. Herein, we report a cascade anchoring strategy for the preparation of a Cu-S 1 O 2 species of single-atom catalyst attached to a carbon carrier containing P and S (Cu-S 1 O 2 SA/CPS) with a content of 12.4 wt%. Over the Cu-S 1 O 2 SA/CPS catalyst, the conversion of 95.8% and selectivity of 87.2% for acetylene hydration could still be achieved at 70 h (T = 200°C, GHSV(C 2 H 2) = 90 h−1 and V H2O /V C2H2 = 4). X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) tests reveal that the Cu atoms of Cu-S 1 O 2 SA/CPS are predominantly coordinated in a trinary manner (Cu-S 1 O 2). Based on high-resolution aberration-corrected high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM), it is demonstrated that the Cu single-atom sites are highly dispersed in Cu-S 1 O 2 SA/CPS. It is evident from the scanning electron microscopy (SEM) that Cu-S 1 O 2 SA/CPS has a two-dimensional layered structure. The specific structure of the active site Cu is primarily attributed to the coordination of S and O atoms, resulting in its superior stability for acetylene hydration towards the synthesis of acetaldehyde. Density functional theory (DFT) calculations confirm that the formation of the Cu-S 1 O 2 site facilitates the activation of acetylene, which is a pivotal step in the acetylene hydration process and considered as the rate-determining step. This article not only introduces an innovative strategy in the synthesis of Cu SACs but also represents a significant breakthrough in the stability of Cu SACs in acetylene hydration. [ABSTRACT FROM AUTHOR]

Ni 1-x Ag x O nanoparticles (NPs) with x = 0.00, 0.02, 0.04, 0.06, and 0.08) were fabricated using the composite hydroxide mediated (CHM) method. The effects of Ag doping on the structural, magnetic, and antimicrobial characteristics of NiO NPs have been reported. The stretching mode of the Ni–O molecules was identified at 443 cm−1 in the Fourier transform infrared spectra. The aggregation of nanoparticles with different sizes and shapes is seen under transmission and scanning electron microscopes. The blocking temperature (T B) peak in zero-field cooled (ZFC) magnetization curves display the magnetization from the core of NPs. This peak is absent for the samples with x = 0.00 and 0.02 , which show instead a small net magnetization from the antiferromagnetic core of these NPs. However, a T B peak was found for the samples with x = 0.04 , 0.06 and 0.08 , at 22, 72, and 65 K, respectively, which indicates that the magnetization is induced from the AFM core of NiO NPs for higher Ag doping. With an increasing concentration of Ag in the NiO NPs, the net magnetization did increase and a maximum was found for x = 0.04 at 300 K. For a higher doping concentration of 8 % Ag, a sharp decrease in magnetization was observed. Furthermore, the efficacy and synergistic effect of Ag doping had been analyzed for the effective improvement of the antibacterial properties of NiO NPs. Pure and Ag-doped NiO NPs were exploited to assess their anti-microbial activity against Enterobacter sp., E. coli, P. aeruginosa, and S. pyrogens. The study revealed that anti-bacterial or anti-biofouling properties were introduced as an additional attribute to NiO NPs by incorporation of Ag ions due to its inherent nature as an antimicrobial agent and enhanced its capability to sterilize microbial pathogens. [ABSTRACT FROM AUTHOR]

The gadolinium vanadate doped with samarium (GdVO4:Sm3+) nanopowder was prepared by the solution combustion synthesis (SCS) method. After synthesis, in order to achieve full crystallinity, the material was annealed in air atmosphere at 900 °C. Phase identification in the post-annealed powder samples was performed by X-ray diffraction, and morphology was investigated by high-resolution scanning electron microscope (SEM) and transmission electron microscope (TEM). Photoluminescence characterization of emission spectrum and time resolved analysis was performed using tunable laser optical parametric oscillator excitation and streak camera. In addition to samarium emission bands, a weak broad luminescence emission band of host VO43− was also observed by the detection system. In our earlier work, we analyzed the possibility of using the host luminescence for two-color temperature sensing, improving the method by introducing the temporal dependence in line intensity ratio measurements. Here, we showed that further improvements are possible by using the machine learning approach. To facilitate the initial data assessment, we incorporated Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP) clustering of GdVO4:Sm3+ spectra at various temperatures. Good predictions of temperature were obtained using deep neural networks. Performance of the deep learning network was enhanced by data augmentation technique. [ABSTRACT FROM AUTHOR]

Alternative fuel sources are necessary in today's economic and environmental climate. Hydrogen fuel arises as an environmentally friendly and energy dense option; however, the volatility of hydrogen gas makes it dangerous to store and utilize. The evolution of hydrogen from hydrogen feedstock materials may prove to overcome this safety barrier, but a catalyst for this reaction is necessary to optimize production. In this work, a composite catalyst comprised of palladium nanoparticles embedded on mesoporous carbon materials (Pd-MCM) was synthesized and characterized by Transmission Electron Microscope (TEM), Powder X-Ray diffraction (P-XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS). Various reaction conditions such as concentration of reactant, temperature, and pH were applied in measuring the catalytic activity of Pd-MCM. Results show the catalytic activity of the Pd-MCM composite catalysts increased with increasing concentrations of sodium borohydride, increasing temperature, and lower pH. The reaction involving the Pd-MCM composite had an activation energy of 27.9 kJ mol−1. Reusability trials showed the Pd-MCM composite remained stable for up to five consecutive trials. [ABSTRACT FROM AUTHOR]

AbstractTo improve the corrosion resistance of 304SS, a polyvinyl butyral/organic montmorillonite-chitosan (PVB/OMMT-Ch) composite coating was prepared by the spin coating method. The Montmorillonite was organically modified with Cetyltrimethylammonium Bromide and compounded with Chitosan to obtain OMMT-Ch. OMMT-Ch filler has been introduced into the polyvinyl butyral coating to improve the corrosion resistance of 304 stainless steel. Scanning electron microscope and transmission electron microscope observations showed that the introduction of chitosan made the montmorillonite layers rounded and loose, and the X-ray diffraction (XRD) results indicated that the interlayer spacing between the montmorillonite layers changed significantly, and the FT-IR results of the chitosan/montmorillonite insertion complexes were in good agreement with those of the XRD analyses, which showed that chitosan successfully inserted between the layers of montmorillonite. The corrosion resistance of the composite coatings in 3.5% NaCl solution was tested by Tafel polarization curves and electrochemical impedance spectroscopy. The results showed that the composite coatings doped with 0.5% OMMT-Ch had the best corrosion resistance with long-lasting protection of more than 160 days. This study suggests a novel approach for nanocomposites for dealing with the 304SS corrosion issue. [ABSTRACT FROM AUTHOR]

A 700 V pulsed laser was used for the surface treatment of Zircaloy-4. Phases including the treatment layer, morphology and the distributions of alloying elements of the treatment layer were detected via X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the laser surface treatment (LST) layer is also α-Zr phase layer, the morphology of the treatment layer was "cauliflower-like" and the Fe-Cr precipitates in the LST layer were dissolved. The corrosion tests of the LST and the no-laser surface treatment (NLST) specimens were conducted in steam at 1100 °C using TGA (NETZSCH STA 449 F). The results showed that LST can enhance the corrosion resistance of the Zircaloy-4 in high-temperature steam. More microcracks distributed in the oxide film formed on the NLST specimen than on the LST specimen. And the volume fraction of the tetragonal zirconia (t-ZrO2) phase in the oxide film on the surface of the LST specimen was higher than that of NLST specimen. The main reason for this phenomena could be attributed to the dissolving Fe-Cr precipitates and higher solid solution of Fe and Cr in the laser treatment layer. [ABSTRACT FROM AUTHOR]

In this paper, the microstructure and mechanical properties of Al-6.5Si-5.5Cu-0.2Zr-0.01Sr-0.06Ti-0.2Ce cast aluminum alloys were investigated in multistage solid solution systems. The microstructure of the alloy was characterized using an optical microscope (OM), scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), x-ray diffraction (XRD) and transmission electron microscope (TEM), respectively. The hardness and conductivity of the alloy were measured using a Vickers hardness and eddy current conductivity testers, respectively, and the tensile properties were described by a drawing machine. The results showed that the mechanical properties of the alloy are the worst under the four-stage solid solution system (G1). With the increase in multistage solution temperature and holding time, θ phase (Al2Cu) was gradually dissolved into α-Al matrix to enhance the effect of dislocation strengthening. When the solution temperature reached 510 °C, the mechanical properties of the alloy were the best, and the tensile strength and elongation were increased to 354.90 MPa and 9.02%, respectively. With the increase in temperature, eutectic Si agglomeration and large area of insoluble phase between metals were found, resulting in the decrease in mechanical properties. [ABSTRACT FROM AUTHOR]

In this work, 2D ferromagnetic M3GeTe2 (MGT, M = Ni/Fe) nanosheets with rich atomic Te vacancies (2D‐MGTv) are demonstrated as efficient OER electrocatalyst via a general mechanical exfoliation strategy. X‐ray absorption spectra (XAS) and scanning transmission electron microscope (STEM) results validate the dominant presence of metal‐O moieties and rich Te vacancies, respectively. The formed Te vacancies are active for the adsorption of OH* and O* species while the metal‐O moieties promote the O* and OOH* adsorption, contributing synergistically to the faster oxygen evolution kinetics. Consequently, 2D‐Ni3GeTe2v exhibits superior OER activity with only 370 mV overpotential to reach the current density of 100 mA cm−2 and turnover frequency (TOF) value of 101.6 s−1 at the overpotential of 200 mV in alkaline media. Furthermore, a 2D‐Ni3GeTe2v‐based anion‐exchange membrane (AEM) water electrolysis cell (1 cm2) delivers a current density of 1.02 and 1.32 A cm−2 at the voltage of 3 V feeding with 0.1 and 1 m KOH solution, respectively. The demonstrated metal‐O coordination with abundant atomic vacancies for ferromagnetic M3GeTe2 and the easily extended preparation strategy would enlighten the rational design and fabrication of other ferromagnetic materials for wider electrocatalytic applications. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles were green synthesised by Falcaria vulgaris extract. Characterisation of samples was carried out by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Investigating factors, such as pH, adsorbent dosage, temperature, contact time and the dose effect of the initial concentration of methylene blue dye, was done on adsorption of methylene blue. The synthesised nanoparticles exhibited a relatively spherical and irregular surface, with a size of about 35 nm, a haematite crystal phase and a saturation magnetisation of 8.3 emu/g. The highest adsorption of methylene blue (76%) was achieved at a pH value of 6, with an optimal adsorbent quantity of 0.004 g/L and a starting concentration of 80 mg/L. The adsorption behaviour of synthesised iron oxide nanoparticles follows from Langmuir isotherm and has a maximum adsorption capacity of 49.169 mg/g. The kinetics of methylene blue dye removal using iron oxide nanoparticles followed a second-order kinetic equation. The adsorption activity of iron oxide nanoparticles showed very little change even after two regeneration cycles. Therefore, the obtained adsorbent regained its adsorption capacity with the help of the photo-Fenton process and is reusable again. [ABSTRACT FROM AUTHOR]

The present research focuses on the effects of different processing routes on the physical and mechanical properties of nano Ti(CN)-based cermets with metallic binders. Tungsten carbide (WC) is added as a secondary carbide and Ni-Co is added as a metallic binder to nano Ti(CN)-based cermet processed via conventional and spark plasma sintering (SPS). A systematic comparison of the composition and sintering conditions for different cermets' systems was carried out to design novel composition and sintering conditions. Nano TiCN powder was prepared by 30 h of ball milling. The highest density of >98.5% was achieved for the SPS-processed cermets sintered at 1200 °C and 1250 °C for 3 min at 60 MPa of pressure in comparison to the conventionally sintered cermets at 1400 °C for 1 h with a two-stage compaction process—uniaxially at 150 MPa and isostatically at 300 MPa of pressure. Comparative X-ray diffraction (XRD) analysis of the milled powders at different time intervals was performed to understand the characteristics of the as-received and milled powders. Peak broadening was observed after 5 h of ball milling, and it increased to 30 hr. Also, peak broadening and a refined carbide size was observed in the XRD and scanning electron microscope (SEM) micrographs of the SPS-processed cermet. Transmission electron microscope (TEM) analysis of the milled powder showed that its internal structure had a regular periodic arrangement of planes. SEM base scattered electron (BSE) images of all the cermets primarily showed three major microstructural phases of the core–rim–binder with black, grey, and white contrast, respectively. With the present sintering conditions, a high hardness of ~16 GPa and a fracture toughness of ~9 MPa m1/2 were obtained for SPS-processed cermets sintered at higher temperatures. [ABSTRACT FROM AUTHOR]

Riboflavin (RF) or vitamin B2 is susceptible to photodegradation. Encapsulation of sensitive components by modified yeast cells is a promising method for their widespread usage at industrial scale. Saccharomyces cerevisiae has been introduced as an appropriate carrier of bioactive compounds. The yeast cell comprises a phospholipid membrane that protects the core from the external environment. In this study, the effect of plasmolysis on efficiency of S. cerevisiae cells in encapsulation of RF were investigated. According to the results, plasmolysis increased the encapsulation efficiency (53.85% versus 58.22% for non-plasmolyzed and plasmolyzed yeast cells, respectively) and loading capacity (14.10 and 16.99% for non-plasmolyzed and plasmolyzed yeast cells, respectively). The loaded intact cells had a tied and intertwined structure while the loaded plasmolyzed cells were seen separately in the Scanning Electron Microscope images. According to the Transmission Electron Microscope images, plasmolysis did not destruct the yeast cells and the cell integrity was retained appropriately after the process but it increased the internal space for encapsulation. In X-ray diffraction analysis, RF had a crystalline structure and its encapsulation within the amorphous non-plasmolyzed and plasmolyzed yeast cells led to slight crystallinity in the structure of complex. The observed spectra of functional groups in Fourier Transform Infrared spectroscopy confirmed the successful entrapment of RF in the yeast cells. Plasmolysis depleted the cell contents susceptible to thermal process through which melting point of the yeast cells increased. Owing to the charged surface of yeast cells, they showed a burst release of RF in the simulated stomach (88% for non-plasmolyzed and 84% for plasmolyzed cells) and intestinal fluid (91% and 96% for non-plasmolyzed and plasmolyzed cells, respectively). [ABSTRACT FROM AUTHOR]

In this work, the precipitation behavior and recrystallization behavior of highly alloyed Al-Zn-Mg-Cu alloy with different Zn/Mg ratio were investigated using optical microscope, scanning electron microscope, X-ray diffraction, transmission electron microscope and tensile test. The results indicated that the primary phase increases with Zn/Mg ratio dropping, which increases the nucleation particles and refines the grains. The real solidification path is between Lever law and Scheil model, which is closer to Scheil model. The precipitates are η′ when Zn/Mg ≥ 4.19 in T6 temper. However, it is the co-precipitation of η' and T' when Zn/Mg < 4.19 and the fraction of η' decreases from 100 to 7.6% as Zn/Mg ratio decrease from 4.19 to 1.91. In addition, the impact of residual eutectic phase in a low Zn/Mg ratio alloy on recrystallization behavior and mechanical properties was discussed. Grain boundary primary phases in low Zn/Mg alloys are difficult to completely dissolve during the solid solution. Interestingly, the particle stimulated nucleation occurs preferentially around the second phase and gradually extends to the center of the grain, and there are still low angle grain boundaries in the center of larger original grain. When Zn/Mg > 1.91, the tensile strength increases with Zn/Mg ratio dropping. After Zn/Mg ≤ 1.91, the tensile strength decreases slightly due to the residual second phase. [ABSTRACT FROM AUTHOR]

Strain engineering is an alternative to chemical modification in manipulating functionalities of materials. Here, we report the lattice strain could relax the abrupt phase transition of (Ni1−xFex)1−δS and lead to an excellent negative thermal expansion (NTE) effect. The high-resolution scanning transmission electron microscope and extended x-ray absorption fine structure unambiguously demonstrate that parallel Ni3S4-type nanosheets could be introduced into the matrix lattice by increasing the δ value. By forming the Ni(Fe)-S-Ni(Fe) bonds, the (1–11) plane of nanosheets epitaxially grows on the (002) plane of the hexagonal matrix. Those bonds are strong enough to bear the large lattice mismatch along the interface as the phase transition occurs. As the concentration of nanosheets increases, the weak and inhomogeneous strain in matrix lattice becomes strong and uniform, expanding the NTE window in different ways. This result opens an unconventional avenue for designing NTE materials and extends the research scope of lattice strain as well. [ABSTRACT FROM AUTHOR]

Lithium-doped anatase-TiO2 nanoparticles (LixTi1-xO2 NPs, x = 0, 0.05, 0.10, 0.15 and 0.20) could be synthesized by a simple sol–gel process. X-ray diffraction (XRD) results displayed the tetragonal (space group: I41/amd) of polycrystalline TiO2 anatase phase. The spectroscopy results of Raman and FT-IR confirmed the anatase phase of TiO2 through the specific modes of metal oxides vibration in the crystalline TiO2. Surfaces micrographs by scanning electron microscope (SEM) of agglomerated LixTi1-xO2 NPs showed a spongy like morphology. Transmission electron microscope (TEM) illustrated a cuboidal shape of dispersed NPs with particle size distributed in a narrow range 5–10 nm. Bruanauer Emmett-Teller (BET) results showed the increased surface area of LixTi1−xO2 NPs with increasing Li content. LixTi1-xO2 NPs (x = 0.05–0.20) working electrodes illustrated a pseudocapacitive behavior with excellent electrochemical properties through the whole cycles of GCD test. Interestingly, Li0.1Ti0.9O2 NPs electrode illustrated a high performance in terms of maximum specific capacitance 822 F g−1 at 1.5 A g−1 in 0.5 M Li2SO4 electrolyte, with excellent capacitive retention 92.6% after 5000 cycles GCD test. [ABSTRACT FROM AUTHOR]

The significant impact of Nb on ferrite transformation, both in terms of solute drag effect (SDE) and interphase precipitation, was investigated quantitatively. Ferrite transformation kinetics were characterized using thermal expansion experiments and theoretical calculations. The microstructures were characterized using high−temperature confocal laser scanning microscopy (CLSM), a field−emission scanning electron microscope (FESEM), and a transmission electron microscope (TEM). Under a higher driving force, interphase precipitations were observed in the sample with a higher Nb content. A three−dimensional (3D) reconstruction method was used to convert the two−dimensional (2D) image of interphase precipitation into a three−dimensional model for a more typical view. The SDE and interphase precipitation had opposite effects on the kinetics of ferrite transformation. A lower Nb content showed a strong contribution to the SDE, which delayed ferrite transformation. A higher concentration of Nb was expected to enhance the SDE, but the inhibition effect was eliminated by the interphase precipitation of NbC during interfacial migration. Both the experimental results and theoretical calculations confirmed this phenomenon. [ABSTRACT FROM AUTHOR]

In this paper, the solid-state shear milling (S3M) strategy featuring a very strong three-dimensional shear stress field was adopted to prepare the high-performance polyoxymethylene (POM)/molybdenum disulfide (MoS2) functional nanocomposite. The transmission electron microscope and Raman measurement results confirmed that the bulk MoS2 particle was successfully exfoliated into few-layer MoS2 nanoplatelets by the above simple S3M physical method. The polarized optical microscope (PLM) observation indicated the pan-milled nanoscale MoS2 particles presented a better dispersion performance in the POM matrix. The results of the tribological test indicated that the incorporation of MoS2 could substantially improve the wear resistance performance of POM. Moreover, the pan-milled exfoliated MoS2 nanosheets could further substantially decrease the friction coefficient of POM. Scanning electron microscope observations on the worn scar revealed the tribological mechanism of the POM/MoS2 nanocomposite prepared by solid-state shear milling. The tensile test results showed that the pan-milled POM/MoS2 nanocomposite has much higher elongation at break than the conventionally melt-compounded material. The solid-state shear milling strategy shows a promising prospect in the preparation of functional nanocomposite with excellent comprehensive performance at a large scale. [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]

Corundum and transition alumina powders are commonly produced through the Bayer process—that is, by digestion of bauxite in a sodium hydroxide solution, followed by gibbsite precipitation, which contains significant amounts of Na+ ions. During the de‐hydroxylation of gibbsite, Na+ is associated with retardation of the structural phase transformations between transition alumina and corundum (α‐Al2O3) phases, although the exact role of Na is unclear. The influence of Na+ ions on the phase transformation of γ‐Al2O3 to α‐alumina was investigated by varying the concentration of NaOH in aqueous γ‐Al2O3 suspensions. The phase transformation behavior of γ‐Al2O3 was monitored through thermal analysis, X‐ray diffraction, scanning electron microscope, X‐ray photoelectron spectrometer (XPS), and transmission electron microscope. As the Na concentration in γ‐alumina suspensions increased, the amount of α‐Al2O3 decreased in samples that were heat treated at 1200°C for 2 h. XPS analysis indicated that washing transition alumina powders with NH4OH solutions had decreased the surface concentration of Na+ and facilitated the phase transformation to α‐Al2O3. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (MWCNTs) have significant environmental concerns for soil, water and ecosystems. Since their harmful effects on human health, including respiratory disease, they are considered dangerous substances. Thus, it is required to discover a constructive solution to decrease of MWCNT toxicity. Due to their high degradability, white rot and soft rot fungi have been used in the biodegradation of various pollutants. In this study, we evaluated the ability of native Iranian white and soft rot fungi to degrade MWCNTs mainly by means of dynamic light scattering (DLS) and surface charge measurement. In this regard, growth kinetics, CO2 and protein production, size, surface charge and pH change were measured. Continuous Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) imaging were carried out to detect the process of degradation. The results showed that the morphology, arrangement, size and diameter of MWCNTs were modified due to fungal degradation. The cytotoxicity of treated MWCNTs was determined by the MTT test. The results indicated that native Iranian white and soft rot fungi have a significant ability for degradation of MWCNTs. Furthermore, it could be concluded that fungal treatment could reduce the toxicity of MWCNTs and the best result was achieved in 500 ppm MWCNTs for Trichoderma sp. The activities of oxidative enzymes such as laccase, manganese peroxidase (MnP) and lignin peroxidase (LiP) were measured to determine the mechanism of degradation. Enzyme assays have suggested that these oxidising enzymes especially laccase might play a key role in the degradation of MWCNTs in white rot and soft rot fungi. The overall results confirmed the reproductive ability of Trichoderma sp. WF29 as a soft rot and two white rot fungi Irpex lacteus WF36 and Trametes versicolor to degrade MWCNT. [ABSTRACT FROM AUTHOR]