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Packaging insulation materials with high thermal conductivity and excellent dielectric properties are favorable to meet the high demand and rapid development of third generation power semiconductors. In this study, we propose to improve the thermal conductivity of epoxy resin (EP) by incorporating a three-dimensional boron nitride thermally conductive network. Detailedly, polyurethane foam (PU) was used as a supporter, and boron nitride nanosheets (BNNSs) were loaded onto the PU supporter through chemical bonding (BNNS@PU). After immersing BNNS@PU into the EP resin, EP-based thermally conductive composites were prepared by vacuum-assisted impregnation. Fourier transform infrared spectrometer and scanning electron microscope were used to characterize the chemical bonding and morphological structure of BNNS@PU, respectively. The content of BNNS in BNNS@PU/EP composites was quantitatively analyzed by TGA. The results show that the thermal conductivity of the BNNS@PU/EP composites reaches 0.521 W/m K with an enhancement rate η of 30.89 at an ultra-low BNNS filler content (5.93 wt. %). Additionally, the BNNS@PU/EP composites have excellent dielectric properties with the frequency range from 101 to 106 Hz. This paper provides an interesting idea for developing high thermal conductivity insulating materials used for power semiconductor packaging. [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]

The scanning electron microscope (SEM) recordings of dynamic nano-electromechanical systems (NEMS) are difficult to analyze due to the noise caused by low frame rate, insufficient resolution, and blurriness induced by applied electric potentials. Here, we develop an image processing platform enhanced by the physics of the underlying system to track the motion of buckling NEMS structures in the presence of high noise levels. The algorithm is composed of an image filter, two data filters, and a nonlinear regression model, which utilizes the expected form of the physical solution. The method was applied to the recordings of a NEMS beam about 150 nm wide, undergoing intra- and inter-well post-buckling states with a transition rate of approximately 0.5 Hz. The algorithm can track the dynamical motion of the NEMS and capture the dependency of deflection amplitude on the compressive force on the beam. With the help of the proposed algorithm, the transition from inter-well to intra-well motion is clearly resolved for buckling NEMS imaged under SEM. [ABSTRACT FROM AUTHOR]

A non-destructive method for detecting sub-micrometer-sized micropipes on an entire wafer surface is investigated. Since it is difficult to detect sub-micrometer-sized micropipes due to their small core size, a non-destructively and accurately detecting method is required. To solve the issue, we focus on a characteristic depression generated around micropipes, namely, line-shaped depressions. In this paper, the location of line-shaped depressions is identified by using optical inspection, and the line-shaped depressions are distinguished whether micropipes exhibit line-shaped depression or not by using mirror electron microscope observation as high-resolution inspection. The accuracy of the distinction results is confirmed by scanning electron microscope observation, and electrical characteristics of the P–N diode are fabricated using the inspected wafer. Furthermore, the sub-micrometer-sized micropipes are observed at the sites of leakage current identified by emission microscopy. Additionally, device simulation of the blocking-voltage characteristics of P–N diodes suggests that the increase in leakage current depends on the electric field at the sub-micrometer-sized micropipes, regardless of their core size. [ABSTRACT FROM AUTHOR]

Gastropods forage with their radula, a thin chitinous membrane with embedded teeth, which scratch across the substrate to lose food particles. During this interaction, the risk of loosening particles is obvious without having a specialized mechanism holding them on the tooth surface. As mucus secretions are essential in molluscan life cycles and the locomotion and attachment gels are known to have an instant high adhesion, we have hypothesized that the saliva could support particle retention during feeding. As adhesion of snail saliva was not studied before, we present here an experimental setup to test its particle-binding capacity using a large land snail (Lissachatina fulica, Stylommatophora, Heterobranchia). This experiment was also applied to the gels produced by the snail foot for comparison and can be potentially applied to various fluids present at a small volume in the future. We found, that the saliva has high particle retention capacity that is comparable to the foot glue of the snail. To gain some insight into the properties of the saliva, we additionally studied it in the scanning electron microscope, estimated its viscosity in a de-wetting experiment, and investigated its elemental composition using energy dispersive X-ray spectroscopy reveling higher contents of Ca, Zn and other potential cross-linkers similar to those found in the glue. [ABSTRACT FROM AUTHOR]

In recent years, precision and accuracy for a more precise critical dimension (CD) control have been required in CD measurement technology. CD distortion between the measurement by a critical dimension scanning electron microscope (CD-SEM) and a reference tool is the most important factor for a more accurate CD measurement. CD bias varies by a CD-SEM and a pattern condition. Therefore, it is urgently needed to identify, characterize, and quantify those parameters that may or may not affect the CD measurement by a CD-SEM. The sensitivity of the Monte Carlo simulated CD-SEM images with multiple physical modeling components has been studied previously. In this study, we demonstrate that the work function and elastic scattering potential models have a significant impact on secondary electron emission intensity, but their influence on the shape of the linescan profile is small, and other factors like the optical energy loss function and dielectric function models have even smaller effects. We have evaluated the uncertainty in the linescan profiles of Si line structures with different sidewall angles due to several different physical factors. It is found that when the CD is evaluated by a peak/valley method, the uncertainty of the CD is negligible. Therefore, it is concluded that the CD value and its related uncertainty are not critically related to the physical factors of the present Monte Carlo simulation model but rely dominantly on the line structure and electron beam parameters. [ABSTRACT FROM AUTHOR]

We report on the metrological characterization of the emission from a germanium-vacancy center in diamond under a microfabricated solid immersion lens in a confocal laser-scanning microscope setup. Ge ions were implanted into a synthetic diamond at 3 MeV, and germanium-vacancy centers were then formed by subsequent annealing. Afterward, solid immersion lenses were fabricated in a focused ion beam scanning electron microscope. The photoluminescence was investigated at room temperature in terms of the spectral distribution, the excited state lifetime, the second-order correlation function, and the saturation behavior, proving simultaneous high single-photon purity and high brightness. Two methods were exploited to minimize the residual multi-photon probability: spectral filtering and temporal filtering. According to these results, we assume that Raman scattered photons and emission from neighboring color centers play an important role in the residual multi-photon emission probability. The system efficiency of the single-photon source was investigated and found to be in accordance with the value calculated from all sources of loss in the setup. The branching ratio of the germanium-vacancy center for the decay into the ground state and into metastable state was calculated. The results enable the usage of the single-photon source in future quantum radiometric experiments. [ABSTRACT FROM AUTHOR]

Because of their full compatibility with CMOS technology, HfO2-based ferroelectrics, and especially Hf0.5Zr0.5O2 (HZO), attract a lot of attention. However, the overwhelming majority of measurement techniques provides only information about the cumulative electrical response of many domains of HZO, i.e., at the macroscopic level. So far, only piezoresponse force microscopy technique was applied to visualize distinct ferroelectric domains in HZO and to analyze the local switching behavior in the microscopic level. This work introduces the possibility of using electron beam-induced current (EBIC) technique in the scanning electron microscope to visualize the gradual polarization reversal of HZO and to obtain the local polarization dynamics. We show that although the local EBIC signal is affected by surrounding domains, studying the variations in the ferroelectric response of individual domains as well as the spread of the local stiffness and local imprint is possible by this method. Besides, we show the connection between the EBIC current and an electric field across passive non-ferroelectric layers at interfaces between HZO and metal electrodes, which opens up additional opportunities to use the EBIC technique for investigations of interface-dependent properties of HZO ferroelectrics in the future. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the synthesis of polyaniline (PANI) through electrochemical cyclic voltammetry at varying pH levels and its subsequent adsorption behavior towards Congo red. The products were analyzed using Fourier Transform-infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Results showed that acidic conditions led to faster synthesis rates and complete planes with intercalated flakes, while neutral and alkaline conditions resulted in mostly granular aggregates. PANI synthesized with the maximum adsorption capacity is 58.07mg/g. The interaction between PANI and Congo red occurred through protonation-induced positive charges and electrostatic attraction, as indicated by UV–Vis spectroscopy results. The adsorption process followed the Langmuir model and pseudo-second-order kinetic process, indicating a chemical adsorption process. This study emphasizes the significance of pH conditions in polyaniline synthesis and its potential application in dye removal processes. [ABSTRACT FROM AUTHOR]

Organic electrode materials are gaining increased attention in energy storage applications, but often encounter challenges such as low capacity and poor cycling stability. This paper explores the utilization of a 1‐D coordination polymer, copper(II)‐2,5‐dihydroxy‐1,4‐benzoquinone (Cu‐DHBQ), as a cathode material for Li‐ion batteries for the first time. Cu‐DHBQ is air‐stable, devoid of coordinated water molecules, and possesses a high theoretical capacity of 266 mAh g−1. With an optimal sodium alginate (SA) binder content of 25 wt%, the Cu‐DHBQ cathode demonstrates a notable initial capacity of 214 mAh g−1 and outstanding cycling stability, retaining 210 mAh g−1 (98% capacity retention) after 200 cycles at a current rate of 100 mA g−1. A comprehensive investigation into the capacity fading mechanisms, the bonding capability of the SA binder, and the interactions between Cu‐DHBQ and SA is conducted using scanning electron microscope (SEM), peel tests, and Fourier transform infrared spectroscopy (FTIR), respectively. Additionally, the electrochemical reaction mechanisms of Cu‐DHBQ are examined using ex situ X‐ray photoelectron spectroscopy (XPS) and FTIR. These findings offer valuable insights into understanding the electrochemical properties of coordination polymers and metal‐organic frameworks based on DHBQ, shedding light on their potential as materials for battery electrodes. [ABSTRACT FROM AUTHOR]

Inspired by the strong adhesion of mussels, basalt fibers (BFs) were modified with polydopamine and then composited with nylon 6. The effect of polydopamine content on the interfacial interactions and mechanical properties of the composites was investigated. In addition, silica nanoparticles were grown on the surface of polydopamine‐modified BFs to investigate the synergistic effect. The study revealed that the mechanical properties of the composites based on polydopamine‐modified BF were gradually enhanced with the increase of the dopamine coverage concentration, and gradually decreased after reaching the peak. 0.5 g/L concentration of dopamine solution modified BFs showed the best enhancement effect on nylon 6, and its tensile strength could reach 133.1 MPa, which was 28.5% higher than that of the unmodified composites. The tensile strength of the composites modified with both dopamine and silica nanoparticles reached 157 MPa, which was 51.7% higher than that of the unmodified composites. In addition, scanning electron microscope images of fracture sections confirmed the strong interfacial interaction between BF and PA6. Highlights: The surface roughness of BF was increased by nano‐SiO2.Hydrogen bonding was formed between PDA and PA6.Physical interlock was formed between nano‐SiO2 and PA6.Tensile strength increased by 51.7% with both nano‐SiO2 and PDA.Stronger interfacial interaction leads to higher thermal stability. [ABSTRACT FROM AUTHOR]

This study elucidates the thermal-induced bandgap broadening (TBB) phenomenon in copolymer organic semiconductors (OSCs). From the perspective of device physics, the diketopyrrolopyrrole-based copolymer was employed as the semiconductor layer to fabricate a back-to-back Schottky junction structure. Characterization through the analysis of I–V curves enables the qualitative exploration of the correlation between bandgap and temperature in copolymer OSCs. Then, technology computer-aided design was utilized to explore the influence of thermal-induced bandgap broadening on the back-to-back Schottky I–V curves. Subsequently, the variable temperature UV-VIS-NIR absorption spectra of the copolymer OSCs were analyzed, providing quantitative evidence of the thermal-induced bandgap broadening phenomenon and confirming its recoverability. Through the research of the Schottky junction and absorption spectra, we verified the consistency of the TBB phenomenon in both the electrical and optical bandgaps. From the scanning electron microscope images of the copolymer OSC films, it is found that the thermal-induced bandgap broadening phenomenon is mainly caused by thermal expansion and increased disorder of copolymer molecules. This study highlights a physical phenomenon of copolymer OSCs that is different from most inorganic semiconductors, and such insight offers a theoretical perspective for the application and thermal stability investigation of copolymer devices under high temperature conditions. [ABSTRACT FROM AUTHOR]

The thixomolding technology offers distinct advantages for producing magnesium matrix composites with intricate geometries. This study explores the effects of incorporating hybrid SiC–Al2O3 particles on the microstructure, deformation, fracture, and mechanical properties of a thixomolded Mg–10Zn alloy. The composite exhibits a homogeneous distribution of Al2O3 and SiC particles within the matrix. The addition of SiC–Al2O3 reinforcements helps reduce the content of primary α -Mg solid and refine the microstructure. The composite demonstrates a yield strength of 186 MPa, an elastic modulus of 48.6 GPa, and a respectable elongation of 6.8%. The digital image correlation measurement was performed at the sample scale, unveiling overall deformation characteristics. Crystal plasticity finite element method was employed for high-fidelity microstructure, showcasing mesoscale deformation feature such as the deformation mechanism of grains adjacent to reinforcements. It was found that SiC–Al2O3 particles prevent the formation of large shear band, benefiting the ductility of the material. The post-mortem analysis using scanning electron microscope near the fracture position reveals micro-cracks inside the SiC particles. Notably, the SiC/Mg interface shows no signs of cracking, while some Al2O3/Mg interfaces are separated. Reinforcement cracking is correlated to the stress it withstands, and the mesoscale deformation analysis reveals that the reinforcement stress is increased when non-basal slip in grains adjacent to the reinforcement becomes difficult to be activated. This work serves as an example for developing Mg matrix composites through the thixomolding process. The findings of this study provide valuable insights for the design of high-performance thixomolded Mg-based composites [ABSTRACT FROM AUTHOR]

Phosphoric acid-based geopolymer (PGEO) belongs to acidic material and has many applications in environmental disposal. The curing method has an important impact on the mechanic performance of geopolymers, the existing research concerning PGEO synthesized from fly ash (FA) and phosphoric acid (PA) are performed on the specimens cured at sealed environment, but no related research on the PGEO cured at an open environment is found. Therefore, to investigate the mechanic performance, pH and of PGEO cured in an open environment, the unconfined compressive strength tests were conducted on PGEO specimens cured in an open environment, and its mechanism was investigated using Scanning Electron Microscope, X-Ray diffraction, and Fourier transform infrared reflection (FTIR) tests. Moreover, the thermogravimetric was measured using the thermogravimetric tests. The results showed that in the scope of this study, the compressive strength of the PGEO decreased with the PA concentration and the liquid–solid ratio (L/S) increasing. When the L/S was a fixed value, as the curing time increased, an obvious strength loss was observed for the PGEO with the content of 40 and 50%, but the compressive strength increased first and then, reduced for the PGEO with the content of 40 and 50%, a maximum strength was obtained at 60 days of curing. The open curing for the PGEO is not conducive to the later growth of compressive strength. As the PA concentration and L/S increased, the pH descended. As the curing time lengthened, the pH first raised and then droped, the maximum pH was obtained at 60 days. Furthermore, the compressive strength increased with the pH with a good correlation. The microscopic analysis showed that the crystalline compounds AlSiP3, Ca2P2O7(H2O)2, molecular sieve SAPO-20 (Al0.47Si0.13P0.4)O2, AlPO4-5 (AlPO4), CaHPO4, and AlPO4 in PGEO were detected. Overall, the open curing environment is not conducive to PGEO, and sealed curing should be used in engineering applications. [ABSTRACT FROM AUTHOR]

In this present investigation, novel hybrid magnesium composites were synthesized by the inclusion of self-lubricating (BN/MoS 2) and ceramic (ZrO 2) particulates with the help of the powder metallurgy technique. ZE41 magnesium (Mg–4Zn-1RE-0.7Zr) was applied for a broad range of components, including the gearbox casing, the framework of the door, and transmission in aircraft like the Sikorsky UH-60 and the Boeing 727. Apart from its structural application, its usage was limited because of its deficient wear and mechanical properties. This research focuses on enhancing the potential applications of the ZE41 magnesium alloy by improving its mechanical and tribological characteristics. The design of the experiment scheme was applied to explore the effect of individual reinforcements and their synergistic effects on various properties of prepared composites. Microstructural inspection was employed to inspect the morphological characteristics of prepared specimens through scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). By analysing SEM, EDS, and X-ray diffraction patterns, the microstructural evaluation reveals uniform phase dispersion and the existence of reinforcements with some minor defects. As a result of the inclusion of reinforcements in composites, the hardness of the reinforced specimen improved to 39.65%, while the wear rate of the reinforced specimen decreased to 40.90% compared with monolithic alloy. A multi-objective grey relational analysis (GRA) optimization method was used to perform a detailed tribological analysis on Specimen G (ZE41 mg + 3% ZrO 2 + 3% MoS 2). According to the results of GRA, the optimized rate of wear and frictional coefficient were achieved on sliding velocity (4 ms−1), sliding distance (2000 m), and load (10 N). The worn surface micrograph reveals that the reinforced composite underwent abrasion and delamination wear, while the unreinforced alloy experienced plastic deformation. [ABSTRACT FROM AUTHOR]

Tefillin are Jewish ritual artifacts consisting of leather cases, containing inscribed slips, which are affixed with leather straps to the body of the tefillin practitioner. According to current Jewish ritual law, the tefillin cases and straps are to be colored black. The present study examines seventeen ancient tefillin cases discovered among the Dead Sea Scrolls in caves in the Judean Desert. All seventeen cases display grain surfaces with a very dark, nearly black appearance. We start with a hypothesis that the cases were intentionally colored black in antiquity using either a carbon-based or iron-gall-based paint or dye. The aim of this study is to test this hypothesis by subjecting these tefillin cases to a battery of examinations to assess the presence of carbon and iron used as pigments, and of organic materials which may have been used as binding agents in a paint. The tests deployed are: (1) macroscopic and microscopic analyses; (2) multispectral imaging using infrared wavelengths; (3) Raman spectroscopy; (4) Fourier transform infrared spectroscopy (FTIR); and (5) scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy. The results of these tests found no traces of carbon-based or iron-gall-based pigments, nor of organic compounds which may have served as binders in a paint. These results suggest that our posited hypothesis is unlikely. Instead, results of the SEM examination suggest it more likely that the black color on the surfaces of the tefillin cases is the result of natural degradation of the leather through gelatinization. The Judean Desert tefillin likely represent tefillin practices prior to when the rabbinic prescription on blackening tefillin was widely practiced. Our study suggests that the kind of non-blackened tefillin which the later rabbis rejected in their own times may well have been quite common in earlier times. [ABSTRACT FROM AUTHOR]

In recent years, the number of studies focusing on the additive manufacturing has increased seriously to elucidate the critical points such as physical, chemical, and mechanical properties. Contrary to common trends and for the first time in the literature, this experimental endeavor aims to comprehend the combined impact of reinforcement type and heat treatment on the wear features of additively manufactured polyamide 6 (PA6) composites. As reinforcement materials, glass, and carbon fibers were utilized and all samples were created through the fused filament fabrication. Half of the samples were subjected to annealing treatment after the main production, and characterization works were performed using a fused emission scanning electron microscope, differential scanning calorimetry, and dynamic mechanic analysis. From the outcomes, it is seen that heat treatment has a positive effect on the hardness, and wear resistance of the composites. Besides, glass fiber‐reinforced samples display lower friction coefficient and lower volume loss results than other samples. For all samples, secondary annealing causes a positive impact on wear endurance in most cases. On the other side, the wear mechanism of the tested samples changes with the test force level and reinforcement type. At lower test forces, abrasive wear‐induced debris parts are detected on the deformed surfaces of PA6 and carbon‐added samples, but this case is opposite for the highest force of 40 N. Highlights: Additive manufacturing was underlined as a promising way to create polymer composites with high dimensional accuracy.The combined effect of secondary annealing and reinforcement type on the wear resistance of 3D‐printed PA6 composites was examined for the first time in the literature.Carbon and glass fibers were compared to explore their effect on friction coefficient and wear behavior of polymer composite samples produced via FFF technology.Hardness and surface roughness measurements were used to comprehend the dry sliding wear results.Depending on the increasing test force levels and reinforcement type, deformation, and abrasion mechanisms were analyzed. [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]

Silicon carbide fiber reinforced silicon carbide ceramic matrix composite (CMC SiC f /SiC) has the advantages of high temperature resistance, corrosion resistance, high strength, low density, and oxidation resistance. It is a high-performance advanced material in aerospace, energy and other fields. However, due to its high hardness, brittleness and anisotropy of fiber structure, the research on application-oriented high-quality processing technology has become a hot issue. In this paper, a new process of rotational thirteen-beam coupling nanosecond laser processing of CMC-SiC f /SiC was studied. The rotational thirteen-beam coupling ablation experiments were carried out on CMC-SiC f /SiC workpiece. A laser beam is divided into thirteen beams and rotated around the beam center by using a beam splitter element. The morphology, structure and composition of ablation holes at different speeds were observed and analyzed by laser confocal microscope, scanning electron microscope, and X-ray energy dispersive spectrometer. It is found that the characteristics of rotational beam coupling have a significant effect on the laser ablation morphologies. The results show that the ablation region of CMC-SiC f /SiC is elliptical due to the fast heat transfer of fibers. The energy density distribution of the waist section of the Gaussian like beam after beam coupling is similar to the "W" shape, and the central energy is lower than the surrounding energy, and the ablation holes also show a similar "W" shape. With the increase of rotational speed, the hole depth first decreased and then increased, the hole diameter and roundness first increased and then decreased, and the hole section was "W" shaped. The ablation area can be divided into five parts: the white granular SiO 2 solid coverage area, the recast layer, the lower recast layer, the molten layer, and the heat affected zone. The rotational characteristics will make the reaction intensity of the whole ablation area more uniform in the circumferential direction. The formation mechanism and element distribution of each part were explored. The research work in this paper will provide a new technical way for the high-performance application of CMC-SiC f /SiC. [ABSTRACT FROM AUTHOR]

The effectiveness of silicon carbide (SiC) planarization mostly relies on the chemical and mechanical effects during chemical mechanical polishing (CMP). Nevertheless, the alumina (Al 2 O 3) abrasive only provides a mechanical effect and is incapable of achieving a high-efficiency polishing of SiC. To address this issue, a series of novel Al 2 O 3 @MnO 2 composite abrasives were prepared by encapsulating varying amounts of manganese dioxide (MnO 2) on Al 2 O 3 abrasive, and the polishing performance on SiC wafers was evaluated. The X-ray diffraction (XRD) and scanning electron microscope (SEM) images, along with the size and zeta potential data, show that MnO 2 is successfully coated on the surface of Al 2 O 3 , and the dispersion of Al 2 O 3 @MnO 2 composite abrasive is significantly improved when compared with the pure Al 2 O 3. Furthermore, the CMP experiment and surface profile analysis demonstrate that the material removal rate (MRR) can reach a maximum value of 640.47 nm/h when using a 0.05 wt% MnO 2 -coated Al 2 O 3 composite abrasive, which is 76 % higher than that of traditional Al 2 O 3 abrasive. Furthermore, the average surface roughness (Sa, arithmetic mean height) of SiC is reduced to 0.73 nm. X-ray photoelectron spectroscopy results reveal that the surface of SiC is oxidized and forms a chemical bond known as Mn–O–Si after CMP. The results of the friction coefficient test and contact angle test indicate that slurries containing composite abrasive have exceptional wettability and a higher friction coefficient. Under the synergistic chemical and mechanical effects, SiC is oxidized to soft oxide and then removed circularly to reach excellent flatness. [ABSTRACT FROM AUTHOR]

Magnetoelectric composite materials, which exhibit both ferroelectric and ferromagnetic properties simultaneously, have attracted considerable interest for their potential in various applications such as microelectronics, memory devices, and spintronics. In this study, we investigated the synthesis, structural, morphological, electrical, and magnetic properties of multiferroic CoFe2O4/0.65BiFeO3-0.35PbTiO3 (CFO/65BF-35PT) composite thin films. These films were prepared using a high ferroelectric, morphotropic phase boundary (MPB) composition, 65BF-35PT, combined with a high magnetostrictive compound, CFO. Multilayered CFO/65BF-35PT composite films were spin-coated onto fluorine-doped tin oxide (FTO)/glass substrates using the sol-gel method, with variation in the solution molarity to achieve different layer thicknesses. Structural analysis revealed a perovskite phase for 65BF-35PT and a spinal structure for CFO, with the presence of rhombohedral and tetragonal polymorphs confirming MPB composition. Scanning electron microscope images demonstrated uniform growth of 1 μm thick composite films. Ferroelectric hysteresis loops exhibited considerable leakage current at room temperature, increasing with higher CFO content, while current versus voltage plots revealed ohmic conduction at low applied fields and space charge limited current (SCLC) conduction at high fields in all composite films. The crossover field between ohmic and SCLC conduction decreased with increasing CFO content. Moreover, room-temperature magnetic hysteresis loops showed a decrease in saturation and coercive field with increasing CFO concentration, and the temperature-dependent magnetization response indicated a monotonic decrease, with magnetization vanishing around 800 K, confirming the magnetic order of CFO. Our findings demonstrate that stable ferroelectric and ferromagnetic phases can be achieved at low temperatures by depositing composite films containing CFO/MPB on a low-cost FTO substrate. [ABSTRACT FROM AUTHOR]

A cobalt ferrite (CoFe2O4) nanoparticle is harvested through sol–gel method. The various percentage of PVP (2.5, 5.0, 7.5, 10.0 and 12.5%) was added to the initial solutions and is acted as a chelating agent. Through X-Ray diffraction examinations results confirmed the single phase CoFe2O4 and had bigger crystallite size. The functional analysis is found through Fourier transform infrared spectroscopy (FTIR) studies. The optical analysis carried out through UV–visible spectrometer and a direct bandgap were determined. The surface features and its content of elements in the samples were found through scanning electron microscope (SEM) with energy dispersive (EDAX) analysis. The detailed magnetic characteristics of the resulting sample were found through vibrating sample magnetometer (VSM). Through TG/DTA measurements the decompositions and anionic oxidation—reduction were analysed. The dielectric constant and related parameters with respect to applied frequency are discussed through LCR measurement. The electrochemical behavior of the samples was tested through cyclic voltameter setup. And finally concluded with the merits and demerits. [ABSTRACT FROM AUTHOR]

The cutting edge radius is a significant parameter of a micromachining tool. When it is not sufficiently sharp, ploughing, which affects the whole machining process and workpiece quality, will occur. It is then essential to be able to estimate the value of the cutting edge radius accurately. In this paper, a three-dimensional strategy that can be used to measure the microturning tool edge radii is presented. The strategy is based on robust cylinder fitting that is applied to a 3D point cloud of the tool. It is implemented in C++ with Open Computer Vision and Point Cloud Library. It was validated using a virtual point cloud, resulting in errors of 0.42% and 1.11% without noise and with noise, respectively. Additionally, uncertainties of 0. 045 μ m and 0. 082 μ m were obtained. It was successfully applied to six microturning inserts: three unused tools and three used tools. The point clouds were obtained with two different 3D surface reconstruction techniques, focus variation with a photon microscope and a multi-view stereo with a scanning electron microscope. The obtained results were more coherent, i.e., they were less dispersed; for example, in non-used tools, the range was [ 3. 11 μ m– 3. 90 μ m] and for the conventional circle fitting the range was [ 2. 62 μ m– 4. 38 μ m]. The traditional method is indirect: the 3D point cloud is sliced into 2D point clouds (profiles) fitted with circles. This 3D-2D process might result in errors. The proposed method is a direct 3D approach with no slicing step. • Importance of tool edge radii in the overall quality of micromachining. • Development of a method for accurate measurement of micro turning tool edge radii from 3D point cloud. • A method based on robust 3D fitting that avoids the 3D-2D process, which is a potential source of errors. • A semi-automatic and practical tool edge radii measurement method. [ABSTRACT FROM AUTHOR]

The fibers from four wheat varieties (FT, XW 26, XW 45, and KW 1701) were selected and chemically modified with NaOH, epichlorohydrin, and dimethylamine to improve the adsorption capacity for anionic dye. The structure of the fibers with or without modification was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectrometry. The modified products were studied from the aspects of adsorption capacities, adsorption kinetics, and thermodynamics to provide a reference for the utilization of wheat bran. By SEM, more porous and irregular structures were found on the modified fibers. The XRD results showed that the crystals from the original fibers were destroyed in the modification process. The changes in fibers' infrared spectra before and after modification suggested that quaternary ammonium salts were probably formed in the modification process. The maximum adsorption capacity of wheat bran fibers for Congo red within 120 min was 20 mg/g for the unmodified fiber (XW 26) and 93.46 mg/g for the modified one (XW 45). The adsorption kinetics of Congo red by modified wheat bran fiber was in accord with the pseudo-second-order kinetic model at 40 °C, 50 °C, and 60 °C, indicating that the adsorption process might be mainly dominated by chemisorption. The adsorption was more consistent with the Langmuir isothermal adsorption model, implying that this process was monolayer adsorption. The thermodynamic parameters suggested that the adsorption occurred spontaneously, and the temperature increase was favorable to the adsorption. As mentioned above, this study proved that the wheat bran fiber could possess good adsorption capacities for anion dye after chemical modification. [ABSTRACT FROM AUTHOR]

The paper presents a methodology that combines experimental measurements and mathematical-physics analyses to investigate the flow behavior in a nozzle-equipped aperture associated with the solution of its impact on electron beam dispersion in an environmental scanning electron microscope (ESEM). The shape of the nozzle significantly influences the character of the supersonic flow beyond the aperture, especially the shape and type of shock waves, which are highly dense compared to the surrounding gas. These significantly affect the electron scattering, which influences the resulting image. This paper analyzes the effect of aperture and nozzle shaping under specific low-pressure conditions and its impact on the electron dispersion of the primary electron beam. [ABSTRACT FROM AUTHOR]

The chiral H8-BINOL derivatives R-1 and R-2 were efficiently synthesized via a Suzuki coupling reaction, and they can be used as novel dialdehyde fluorescent probes for the enantioselective recognition of R/S-2-amino-1-phenylethanol. In addition, R-1 is much more effective than R-2. Scanning electron microscope images and X-ray analyses show that R-1 can form supramolecular vesicles through the self-assembly effect of the π-π force and strong hydrogen bonding. As determined via analysis, the fluorescence of the probe was significantly enhanced by mixing a small amount of S-2-amino-1-phenylethanol into R-1, with a redshift of 38 nm, whereas no significant fluorescence response was observed in R-2-amino-1-phenylethanol. The enantioselective identification of S-2-amino-1-phenylethanol by the probe R-1 was further investigated through nuclear magnetic titration and fluorescence kinetic experiments and DFT calculations. The results showed that this mechanism was not only a simple reactive probe but also realized object recognition through an ICT mechanism. As the intramolecular hydrogen bond activated the carbonyl group on the probe R-1, the carbonyl carbon atom became positively charged. As a strong nucleophile, the amino group of S-2-amino-1-phenylethanol first transferred the amino electrons to a carbonyl carbocation, resulting in a significantly enhanced fluorescence of the probe R-1 and a 38 nm redshift. Similarly, S-2-amino-1-phenylethanol alone caused severe damage to the self-assembled vesicle structure of the probe molecule itself due to its spatial structure, which made R-1 highly enantioselective towards it. [ABSTRACT FROM AUTHOR]

Background: In everyday dentistry, monolithic single crowns can be cemented with self-adhesive resin cements. The aim of this in vitro study was to evaluate how the marginal adaptation of full monolithic zirconia-reinforced lithium silicate (ZLS) single crowns is influenced by three different self-adhesive resin cements. Methods: Forty-five typodont teeth fully prepared for full monolithic crowns were divided into three groups (fifteen each) for the use of three different self-adhesive resin cements. A fourth control group (Temp-bond) was created by taking five teeth from each group before cementation with self-adhesive resin cements. All forty-five abutments were scanned using a Primescan intra-oral scanner (IOS), followed by computer-aided design (CAD) and computer-aided manufacturing (CAM) of zirconia-reinforced lithium silicate (ZLS) full crowns using a four-axis machine. Initially, the crowns of the control group were fixed to the abutments using Temp-bond, and the marginal gap was evaluated using a scanning electron microscope (SEM). After removing the control group crowns from the abutments, fifteen crowns in each group were cemented using a different self-adhesive resin cement and observed under SEM for evaluation of the marginal gap. A Kolmogorov–Smirnov test was performed, indicating no normal distribution (p < 0.05), followed by Mann–Whitney tests (α = 0.05). Results: The total mean marginal gap of the temp-bond control group was significantly lower compared to all three groups of self-adhesive resin cement (p < 0.0005). The total mean marginal gap of the G-cem ONE group was significantly lower compared to the TheraCem group (p < 0.026) and RelyX U200 group (p < 0.008). The total mean marginal gap of the TheraCem group was significantly higher than the G-cem ONE group (p < 0.026) but showed no significant difference with the RelyX U200 group (p > 0.110). Conclusions: All four groups showed a clinically acceptable marginal gap (<120 microns). Although all three groups of self-adhesive resin cement showed a significant increase in the marginal gap compared to the temp-bond control group, they were within the limits of clinical acceptability. Regarding the marginal gap, in everyday dentistry, it is acceptable to use all three self-adhesive resin cements, although the G-cem ONE group exhibited the lowest marginal gap for ZLS single crowns. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the impact of adding 1% processed coconut meal (hydrolyzed copra meal, HCM) to the diets of weaned pigs, comparing it to regular coconut meal (CM) and a control diet with no coconut meal. Processed to enhance digestibility, HCM showed better digestion than CM. Both treatments supported a diverse gut microbiome, with potential benefits for producing beneficial fatty acids crucial for gut health. More research is needed to fully evaluate HCM's impact on pig growth and health, but initial findings suggest that incorporating HCM could enhance digestive health and overall well-being in young pigs. This study aimed to compare the effects of hydrolyzed copra meal (HCM) inclusion at 1% on its in vitro digestibility and the microbiota and cecum fermentation using the gut microbiota of weaned swine, targeting microbial community and short-chain fatty acids (SCF). For this reason, three treatments were considered: control (no copra meal), 1% non-hydrolyzed copra meal (CM), and 1% HCM. Non-defatted copra meal was hydrolyzed and analyzed (reducing sugars and total carbohydrates) in our laboratory. For digestion, microbiota identification, and fermentation assays, fresh fecal samples from two weaned pigs (1 month old) were used. Three replicates of each treatment were employed. HCM was more digestible, with approximately 0.68 g of hydrolysate recovered after simulated digestion compared to 0.82 g of hydrolysate recovered from CM. This was shown by Scanning Electron Microscope (SEM) images. Also, the three swine shared the majority of microbial species identified at the phylum and family levels. There were no differences (p > 0.05) between treatments in the microbial community and SCFA during fermentation. However, higher Chao-1 and Shannon indexes were observed in CM and HCM treatments. HCM was also found to be capable of preserving Actinobacterota and Proteobacteria at the phylum level, while at the family level, both treatments may help Lactobacillaceae, Peptostreptococcaceae, Lachnospiraceae, and Ruminococcaceae survive in the long term. Also, there was a potential trend of increasing acetic acid and butyric acid in the CM and HCM treatments. While HCM shows promise in potentially modulating the gut microbiota of weaned swine, additional research is required to investigate the effects of higher doses of HCM on swine performance parameters. [ABSTRACT FROM AUTHOR]

In this study, the authors performed a strength analysis of seven groups of commercially available materials based on SLS incremental technology. Test samples were made with Original PRUSA SL1S printers, with 10 samples of each type from 7 resins selected for testing. The tests were carried out on an MTS Bionix machine in a static tensile test, during which the basic mechanical properties were determined. This is also a preliminary study to determine material constants in the Johnson-Cook strength model. The authors then performed numerical simulations to mirror the experimental tests in order to tune the rheological model. In addition, a fracture criterion was determined based on a hybrid FEM/SPH numerical method. This allowed for the expansion of material libraries currently used in numerical simulations, as well as the sensitivity of the materials' models. In subsequent studies, in order to determine the nature of material destruction, analysis of fracture surfaces was performed using a scanning electron microscope (SEM). The final study was a biocompatibility test to assess the biological properties of the material. The conducted research made it possible to determine the strength properties of resins currently used in 3D printers, expand the libraries of material models in the computational environment (with an error rate of less than 5%), as well as observe the nature of the cracks formed and biocompatibility in the context of predicting the use of these materials for biomedical applications. [ABSTRACT FROM AUTHOR]

This study investigates the impact of mechanical alteration on resin composite surfaces and its subsequent effect on repair bond strength. A total of 100 resin composite disks were prepared and were allocated for 24 h or 1 year of artificial aging. Specimens were embedded in epoxy resin, and the composite surfaces were mechanically altered using either diamond burs or air abrasion with aluminum oxide or glass beads. A universal bonding material was applied and a 2 mm circular and 3 mm high repair composite cylinder were prepared using a Teflon mold. Then, the specimens were tested for their shear bond strength, and the de-bonded specimens were observed under a scanning electron microscope to determine the failure pattern. SPSS 26.0 statistical software was used to analyze the data. Two-way ANOVA showed a statistically significant effect of mechanical alteration and aging on the shear bond strength of S-PRG-filler-based resin composite (p < 0.05). Surface modification with a fine diamond bur showed a significantly higher bond strength in both 24-h- and 1-year-aged specimens. Surface modification with alumina significantly increased the bond strength of 1-year-aged specimens; however, it was statistically insignificant for 24 h-aged specimens. Mechanical alteration with a fine diamond bur and 50-micron alumina can improve the repair bond strength of the composite. [ABSTRACT FROM AUTHOR]

Natural extracts, such as those from the residues of the Olea europaea industry, offer an opportunity for use due to their richness in antioxidant compounds. These compounds can be incorporated into porous polymeric devices with huge potential for tissue engineering such as bone, cardiovascular, osteogenesis, or neural applications using supercritical CO2. For this purpose, polymeric scaffolds of biodegradable poly(lactic-co-glycolic acid) (PLGA) and chitosan, generated in situ by foaming, were employed for the supercritical impregnation of ethanolic olive leaf extract (OLE). The influence of the presence of chitosan on porosity and interconnectivity in the scaffolds, both with and without impregnated extract, was studied. The scaffolds have been characterized by X-ray computed microtomography, scanning electron microscope, measurements of impregnated load, and antioxidant capacity. The expansion factor decreased as the chitosan content rose, which also occurred when OLE was used. Pore diameters varied, reducing from 0.19 mm in pure PLGA to 0.11 mm in the two experiments with the highest chitosan levels. The connectivity was analyzed, showing that in most instances, adding chitosan doubled the average number of connections, increasing it by a factor of 2.5. An experiment was also conducted to investigate the influence of key factors in the impregnation of the extract, such as pressure (10–30 MPa), temperature (308–328 K), and polymer ratio (1:1–9:1 PLGA/chitosan). Increased pressure facilitated increased OLE loading. The scaffolds were evaluated for antioxidant activity and demonstrated substantial oxidation inhibition (up to 82.5% under optimal conditions) and remarkable potential to combat oxidative stress-induced pathologies. [ABSTRACT FROM AUTHOR]

A group of white light‐emitting phosphors SrBi2Nb2O9:xDy3+ (SBN:xDy3+) are prepared by high‐temperature solid reaction. The crystal phase, morphology, and photoluminescence (PL) characteristics of the prepared SBN:xDy3+ are analyzed. The X‐ray diffraction results prove that the synthesized samples are pure phase, in which the shift of the main peak depicted that crystal interplanar distance decreases after Dy3+ replacing Bi3+. The scanning electron microscope results show that the average crystal size of the sample is ≈1–10 μm. Energy dispersive X‐ray spectroscopy shows that the ratio of element composition of the SBN:xDy3+ is similar to the theoretical calculation. The PL excitation illustrates the excitation peaks mainly exist at 389, 399, 426, and 450 nm due to the transitions of Dy3+. For PL, the emission peaks of samples with different doping concentrations are centered at 479 and 573 nm. The ratio of yellow intensity to blue intensity indicates that Dy3+ is located at a high symmetry site, which has the possibility to produce suitable white light. The Commission Internationale de l'Eclairage coordinates of the SBN:xDy3+ are located near the standard white light coordinate. All these results prove that SrBi2Nb2O9:xDy3+ can be a potential material in the white light application. [ABSTRACT FROM AUTHOR]

In this work, the preparation of "Ag" alloying Cu2ZnSnSe4 films using a two‐step process, comprising vacuum evaporated ([Sn/ZnSe/Ag/Sn/ZnSe/Cu] × 2) precursor layer deposition on glass substrates followed by low‐temperature pre‐annealing treatment (PAT) in Se ambiance (200–400 °C) for 30 min and high‐temperature annealing at 500 °C for 1 min, is reported. The low‐temperature PAT provides adequate Se diffusion into precursor layers and plays a pivotal influence on the growth and properties of (Cu,Ag)2ZnSnSe4 films. The Zn/Sn and Se/metals ratios are found to be varied in the range 0.77–1.32 and 1.07–0.86 with PAT (200–400 °C) followed by annealing at 500 °C for 1 min. The precursor layers are pre‐annealed at 300 °C for 30 min, followed by annealing at 500 °C for 1 min, found to be nearly stoichiometric with uniform distribution of constituents. The valence states of the constituents are confirmed by X‐Ray photoelectron spectroscopy. Both X‐Ray diffraction and Raman studies confirm the formation of single‐phase (Cu,Ag)2ZnSnSe4 along (112) orientation with a strong Raman mode at 194 cm−1. Large and well‐defined grains with a mean size of 0.7 μm are seen in the field‐emission scanning electron microscope images. The (Cu,Ag)2ZnSnSe4 films exhibit a direct bandgap of 1.12 eV and p‐type conductivity with high mobility, 5.23 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

This paper presents research results on biocomposites made from a combination of extruded apple pomace (EAP) and potato starch (SP). The aim of this work was to investigate the basic properties of biocomposites obtained from extruded apple pomace reinforced with potato starch. The products were manufactured by hot pressing using a hydraulic press with a mould for producing samples. The prepared biocomposites were subjected to strength tests, surface wettability was determined, and a colour analysis was carried out. A thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and cross-sectioning observed in a scanning electron microscope (SEM) were also performed. The obtained test results showed that the combination of apple pomace (EAP) and starch (SP) enabled the production of compact biocomposite materials. At the same time, it was found that each increase in the share of starch in the mixture for producing biocomposites increased the strength parameters of the obtained materials. With the highest share of starch in the mixture, 40%, and a raw material moisture content of 14%, the material had the best strength parameters and was even characterised by hydrophobic properties. It was also found that materials with a high content of starch are characterised by increased temperature resistance. The analysis of SEM microscopic photos showed well-glued particles of apple pomace, pectin, and gelatinised starch and a smooth external structure of the samples. Research and analyses have shown that apple pomace reinforced only with the addition of starch can be a promising raw material for the production of simple, biodegradable biocomposite materials. [ABSTRACT FROM AUTHOR]

Various contents of carbon fibers (CFs) and potassium titanate whiskers (PTWs) were added to an Fe-based impregnated diamond bit (IDB) matrix to enhance its adaptability to percussive–rotary drilling. A series of mechanical tests were conducted successively to find the effects of the reinforcing materials on the properties of the Fe-based IDB samples. Then, the fracture surfaces of the samples were analyzed via scanning electron microscopy (SEM) and energy-dispersive spectroscopy, and the worn surfaces and abrasive debris of the samples were analyzed using a laser scanning confocal microscope and SEM. The results show that both the CF and PTW can effectively improve the hardness and bending strength of an Fe-based IDB matrix, and those parameters reached their maximum values at the additive amount of 1 wt%. However, the CF had a better enhancement effect than the PTW. Furthermore, the CF improved the impact wear resistance of the IDB matrix, with a minimum wear rate of 2.38 g/min at the additive amount of 2 wt%. However, the PTW continuously weakened the impact wear resistance of the IDB matrix with increases in its content. Moreover, the morphologies of the worn surfaces indicated that the minimum roughness of the CF-reinforced IDB matrix decreased significantly to as low as 4.91 μm, which was 46.16% lower than that without CF, whereas the minimum roughness of the PTW-reinforced samples decreased by 11.31%. Meanwhile, the abrasive debris of the CF-reinforced samples was more uniform and continuous compared to that of the PTW-reinforced samples. Overall, the appropriate addition of CF or PTWs can enhance the mechanical properties of Fe-based IDB matrices, which can be used on different formations based on their impact wear resistance. [ABSTRACT FROM AUTHOR]

In this study, we successfully employed the plasma electrolytic oxidation (PEO) technique to create a uniform white ceramic layer on the surface of the 6061 aluminum alloy using K2ZrF6 and Na2WO4 as colorants. A scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and X-ray diffraction (XRD) were used to characterize the coatings, and we used an electrochemical workstation to test their corrosion protection properties. The corrosion resistance of the coatings was analyzed using potentiodynamic polarization curves. The results showed that K2ZrF6 addition whitened the coating with ZrO2 as the main phase composition, inhibiting Al substrate depletion and enhancing coating corrosion resistance. A small amount of Na2WO4 decreased the coating's L* value, successfully constructing ceramic coatings with L* (coating brightness) values ranging from 70 to 86, offering broad application prospects for decorative coatings. [ABSTRACT FROM AUTHOR]

The fretting wear behaviors of silicone rubber under dry friction and different lubrication conditions are studied experimentally. Water, engine oil, dimethyl silicone oil (DSO), and dimethyl silicone oil doped with graphene oxide (DSO/GO) are selected as lubricants. Under the liquid lubrication conditions, the silicone rubber samples are always immersed in the same volume of lubricant. The contact model of a 440C steel ball and silicone rubber sample is the sphere-on-flat contact. The reciprocating fretting wear experiments are carried out using the reciprocating friction wear tester. A scanning electron microscope and three-dimensional white-light interference profilometer are used to detect the surface wear morphology and obtain the wear volume, respectively. The influences of normal force, lubrication condition, and displacement amplitude on fretting wear behavior are discussed. The fretting wear performances of silicone rubber under different fretting states and lubrication conditions are compared. The results show that for a small normal force, silicone rubber has the best wear resistance under DSO/GO lubrication. While for a large normal force, silicone rubber has the best wear resistance under engine oil lubrication. [ABSTRACT FROM AUTHOR]

In this paper, we conduct a comprehensive investigation into PVA fiber modified with SiO2 to improve the mechanical properties of oil-well cements. Specifically, SiO2 was coated onto the surface of polyvinyl alcohol fiber (PVAF) as its silicon source via a sol-gel process by using tetraethyl orthosilicate (TEOS), while hydrochloric acid and ammonia were respectively used as the catalyst in the sol (hydrolysis) and the gel (condensation) processes. The PVAF microstructure was then characterized with the scanning electron microscope (SEM), while the effects of the modified PVAF on both mechanical and rheological properties of oil-well cements were examined. Due to the fact that SiO2 can be uniformly coated onto the PVAF surface, such modified PVAF can slightly improve the rheology of the cement slurry, while the raw PVAF exhibits poor dispersion at a high dosage. Compared with those of cement stone without PVAF after curing for 28 days at 60 °C, the flexural strength, compressive strength, and elastic modulus of the cement stone incorporated with the modified PVAFs were enhanced by 37.7%, 66.1%, and 50.0%, respectively. The SEM test (EDX) test, XRD test, and thermogravimetric test prove that the SiO2 coating on the PVAF surface can promote the hydration of cement clinker and can react with Ca(OH)2 to generate CSH gel. The SiO2 grafted onto the surface of PVAFs can improve the bond strength at the fiber/cement matrix interface, thus improving the mechanical properties of cement stone. [ABSTRACT FROM AUTHOR]

The current research article has investigated the synthesis and characterization of novel iron nanoparticles (INPs) from neem and betel leaves extract combination using response surface methodology–central composite design and coated with chitosan–curcumin (CCINPs) as a biocompatible and contrast agent for magnetic resonance imaging (MRI). The coating of INPs with chitosan and curcumin (CCINPs) was carried out using a simple, easy, chemical‐free ultrasonication method and characteristics were confirmed by UV–visible (Vis) spectrophotometer (UV–Vis), Fourier‐transform infrared spectroscopy, X‐ray diffraction, scanning electron microscope, atomic force microscopy, and vibrating sample magnetometer. The biocompatibility of the particles was ensured by conducting hemolytic and cell viability assays. The nanoparticle was found to be nonhemolytic (<5%) up to 150 μg/mL for both INPs and CCINPs. The cell viability was stable (peripheral blood mononuclear cells‐PBMCs) till 48 h at 150 μg/mL of INPs and CCINPs. Both the test results produced were found to be biocompatible and additionally, an in vitro MRI study of INPs and CCINPs demonstrated the efficiency of the nanoparticle as a negative contrast agent with enhanced contrast nature in CCINPs. Thus, overall results indicate that the green synthesized chemical‐free novel CCINPs could be a potential candidate for a wide range of applications such as MRI, drug delivery, and in magnetic fluid hyperthermia. [ABSTRACT FROM AUTHOR]

Wastewater from the textile and dyeing industries contains hazardous dyes. This study aims to determine the effectiveness of magnetic biochar nanocomposites synthesized from khat leftovers (KLs) and coffee husks (CHs) in removing methylene blue (MB) from wastewater. Magnetic biochar nanocomposites were synthesized by pretreating 25 g of biomass with a 12.5 mmol mixture of FeS and FeCl3 at a 1:1 molar ratio, followed by pyrolyzing at 300°C for 1 h. The resulting products were analyzed using X‐ray diffraction, Fourier transform infrared, scanning electron microscope, and Brunauer‐Emmett‐Teller. The results showed that the adsorbents are amorphous, and the activated biochars, are more porous and contain various functional groups such as C‐O, C = C, O‐H, C‐H, and Fe‐O. When 0.2 g of pristine biochars of CH and KL were applied to 20 mL aqueous solutions containing 20 mg/L of MB at pH 7.5 and 25°C, they removed 44.73% and 75.26% of MB, respectively. However, the resulting nanocomposites exhibited a maximum removal efficiency of 99.10% and 99.23% with magnetic iron oxide‐CH biochar nanocomposite (Fe3O4‐CHBNC) and magnetic iron oxide‐KL biochar nanocomposite (Fe3O4‐KLBNC), respectively, with maximum adsorption capacities of 51.02 and 78.13 mg/g. The reusability study also showed removal efficiencies of 77.57% and 83.49% up to six‐cycle reuse. [ABSTRACT FROM AUTHOR]

Pore‐throat structure is a key factor that influences the storage and fluid flow capacity of tight sandstone reservoirs. Taking the tight sandstone reservoir of Xu2 Fm in Zhongba area as an example, the reservoir quality, pore‐throat type and pore size distribution of tight sandstone in the study area were described by casting thin section, scanning electron microscope and high‐pressure mercury injection test. In order to quantitatively characterize the complexity and heterogeneity of pore‐throat structure, fractal analysis was performed using mercury saturation and pore size data. This study mainly reveals the relationship between the geometric shape characteristics and fractal dimension of the binary pore structure of ultra‐low permeability tight sandstone and clarifies the influence of different scale pore throats on reservoir physical properties. The results indicate that the physical properties of the reservoir in the study area are poor, the pores are mainly intergranular pores and dissolution pores, the throat is flake and necked and the pore size distribution range is large. The fractal curve obtained by the mercury saturation method shows a significant turning point, and the pore‐throat system is divided into two types: small‐scale and large‐scale. The fractal dimension of large‐scale pore throat is greater than the three‐dimensional Euclidean space dimension, which does not conform to the fractal theory. The fractal dimension of small‐scale pore throat is closely related to the pore‐throat structure and has obvious fractal characteristics. The geometric shape of binary pore‐throat structure in tight sandstone is the main factor affecting the difference of fractal dimension. The development of small pores in sandstone is positively correlated with the total porosity, but its contribution to permeability is relatively low. The physical properties of tight sandstone are mainly controlled by the development degree of large‐scale pore throat. [ABSTRACT FROM AUTHOR]

This study takes the tight sandstone of the lower sub‐member of the first member of the Eocene Shahejie Formation (Es1x) in the Suning area, Raoyang Sag, Bohai Bay Basin. Furthermore, it determines the rock type of the middle‐deep tight sandstone through lithologic profiling, core observation and log data analysis. The genetic control factors of tight sandstone in the study area are analysed using conventional thin section, pore‐casted thin section and scanning electron microscope, and the characteristics and genetic control factors of tight sandstone reservoirs are summarized. The research results show that the tight sandstones in this area are primarily feldspathic sandstone and feldspathic lithic sandstone, with high quartz contents, around 61.50%. The average porosity of the reservoir in the study area is 4.69%, and the average permeability is 2.92 mD, which are characteristics of low‐porosity and low‐permeability reservoirs. Through research, it has been found that the distribution of sedimentary facies and diagenesis in the study area control the development and distribution of 'sweet spots'. Both compaction and cementation reduce the physical properties of the reservoir, while dissolution can increase porosity, thereby increasing the physical properties of the reservoir; dissolution resulted in an increase of approximately 3.57%–3.69% in the porosity of the tight reservoir in the study area, with an average porosity increase of 3.63%, and is the main controlling factor for the development of 'sweet spots' in the reservoir. The results provide an important basis for guiding the exploration and development of tight sandstone oil and gas in the lower sub‐member of the first member of the Eocene Shahejie Formation (Es1x)in the Suning area. [ABSTRACT FROM AUTHOR]

The dissolution mechanism of phases c‐Ti0.5Al0.5N, c‐aluminium nitride (AlN), c‐TiN, and Al2Ti, and elements of the Ti1–xAlxN coatings (for x < 0.6) in 3 wt.% NaCl solution is described based on the results of X‐ray diffraction analysis, energy‐dispersive X‐ray spectroscopy, and scanning electron microscope and previous electrochemical tests. Researchers studied the protective effectiveness of Ti1–xAlxN coatings in 3 wt.% NaCl solution by analyzing the factors: composition, thickness, porosity, total energy of ground state, stresses, structure, and texture. It was first established that the additional c‐TiN phase with Rpmax and Ecormax, and secondary phase Ti0.70–0.82N formed after Al's dissolution in the main phase c‐Ti0.5Al0.5N increases the N content and prevents the Ti dissolution in the Ti1–xAlxN coatings. The phase c‐AlN with icormin reduces the dissolution rate of Al in the c‐Ti0.5Al0.5N phase. The stoichiometric c‐Ti0.5Al0.5N is the most thermodynamically stable phase. The described phase transformations in Ti1–xAlxN coatings during phases dissolution in 3 wt.% NaCl can predict the coating protective effect. A multilayer coating with layers of c‐AlN, c‐TiN, and c‐Ti0.5Al0.5N is recommended for industrial use. [ABSTRACT FROM AUTHOR]

The development of the industry has increased the demand for energy storage, making the provision of energy storage devices essential. The supercapacitor is one of the potential energy storage devices, and carbon aerogel (CA) is a promising candidate for supercapacitor electrode fabrication. Ni-doped nipa palm shell-derived CA (Ni-NS-CA) was used to fabricate the electrode for supercapacitors to save production costs and utilize biomass wastes. Ni-NS-CA was synthesized via a three-step process: Hydrogel making through cross-linking (SA, Ni2+), freeze-drying, and pyrolysis. The characteristics of Ni-NS-CA are analyzed using a scanning electron microscope, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and Nitrogen adsorption–desorption isotherm 77 K. The electrochemical properties of Ni-NS-CA was analyzed via cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. With stable energy storage results (104.15 F g−1) and the electrochemical system based on Ni-NS-CA extends its application to Hg2+ sensing. Moreover, Ni-NS-CA was a potential material to solve oil spills, which has an oil adsorption capacity of 31.24 g g−1. [ABSTRACT FROM AUTHOR]

Cracks generated in sheet coating of water-based slurries are an increasingly important concern in the development of diverse material science, such as fine ceramics, Pt catalysts, and Li transition metal oxides, from an environmental safety perspective. However, a comprehensive understanding of crack formation remains elusive due to the intricately entangled interplay among various characteristics of slurries. Here, we systematically ascertain the causes at work in crack initiation by analyzing the physical parameters of a series of aqueous alumina slurries using machine learning. The analysis reveals a strong correlation between rheological hysteresis and sheet cracking. As a verification of the correlation, the crack suppression by controlling the rheological hysteresis is experimentally confirmed. Furthermore, we visualize the microstructure in the slurry that induces cracks with a liquid-phase scanning electron microscope, clarifying the rheological dynamics. These results disentangle that rheological hysteresis is a good indicator directly reflecting microstructural durability against drying stress. [Display omitted] [ABSTRACT FROM AUTHOR]

Summary: The stability, microstructure and antioxidant capacity of the composite coating solution of chitosan (CS) and oleuropein (OLE, 0.08–0.32%, w/v) were estimated by zeta potential, rheological properties, scanning electron microscope and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging assays. Effects of the composite coating on refrigerated chicken breasts were evaluated by microbial, chemical and sensory assays. The results revealed that the coating solutions were stable, intact and exhibited good antioxidant activities. When chicken samples were stored at 4 °C for 12 days, the microbial population treated with CS + OLE decreased to 5.43–7.59 log CFU g−1 compared with the control (8.41 log CFU g−1). The increase in pH values, total volatile base nitrogen and thiobarbituric acid reactive substances contents, and drip loss rate of chicken samples had also been deferred. Overall, the results indicated that it was feasible to apply CS with OLE to extend the shelf life of chicken breasts. [ABSTRACT FROM AUTHOR]

In this experimental study, we explore the potential enhancements in thermal conductivity while investigating alterations in latent heat and phase change temperature within Composite Phase Change Materials (PCMs). These composites consist of Paraffin Wax (PW) as the base material, incorporating dispersed conducting Polyaniline (PANI) powder in varying concentrations ranging from 1% wt. to 4% wt. The mass fractions of PANI added to PW include 1%, 2%, 3%, and 4%, and the composite PCMs are meticulously prepared through ultrasonication. Examining the surface morphology of Composite Phase Change Materials (PCMs) involved utilizing a Scanning Electron Microscope (SEM), while the determination of thermal conductivity employed a Heat Flow Meter. Additionally, latent heat and phase change temperatures were assessed through Differential Scanning Calorimetry (DSC). The obtained results indicate an augmentation in the thermal conductivity of the composites when compared to Paraffin Wax (PW). Specifically, thermal conductivity exhibited a 40% increase for 1% wt. of PANI, yet experienced a subsequent decline for the remaining weight percentages. Furthermore, the latent heat and phase change temperatures of the composites were observed to decrease in comparison to PW. These composite PCMs with enhanced thermal conductivity, achieved through the incorporation of Polyaniline in Paraffin Wax, are highly potential for several applications in energy storage systems, thermal regulation devices, and heat management technologies. [ABSTRACT FROM AUTHOR]

In this paper, fiber Bragg grating (FBG) sensors were applied to investigate the frost resistance of C60 concrete. First, the growth of both the static and dynamic elastic modulus of C60 concrete with curing age was investigated using an FBG, the standard method, and the resonance method, respectively. Second, to simulate the freezing and thawing conditions in cold regions, the concrete specimens were subjected to air freezing and water thawing using the slow freezing method. The authors explored the effect of freeze–thaw cycles on the mechanical properties of concrete and established a mathematical model relating its mechanical properties to freeze–thaw cycles based on an FBG sensor. Meanwhile, its compressive strength, dynamic elastic modulus, and mass loss rate were tested. Finally, the interface morphology and hydration products of concrete were observed using a scanning electron microscope (SEM) after freeze–thaw cycles. The results indicate that both the static and dynamic elastic modulus of C60 concrete increase with curing age. Its elastic modulus measured by FBG is approximately the same as that measured by the standard method, confirming the viability of using an FBG sensor to measure its elastic modulus. Furthermore, the authors highlighted the dependence of its compressive strength on the freeze–thaw cycles. The relationship of the static elastic modulus to freeze–thaw cycles is similar to that of the dynamic elastic modulus and mass loss rate. A static elastic modulus achieved from an FBG is proposed here to characterize the frost resistance of C60 concrete. [ABSTRACT FROM AUTHOR]

The aim of this research was to produce a film based on the mucilage of Paneerak flower modified with licorice root and copper sulfate nanoparticles. The D-optimal statistical scheme was used to study the antioxidant, antimicrobial, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and thermal decomposition (DSC) properties of the films. The results showed that with the increase of licorice root and copper sulfate nanoparticles, the antioxidant activity of the film increased significantly (p<0.05). The results of the antimicrobial activity of the prepared films showed that the addition of licorice and copper sulfate nanoparticles caused the antimicrobial activity of the film against Escherichia coli and Staphylococcus aureus. X-ray diffraction analysis shows that copper sulfate nanoparticles are physically combined with the mucilage polymer of Paneerak flower and it reduces the crystal structure.Fourier transform infrared (FTIR) results confirm the physical presence of copper sulfate nanoparticles in the polymer matrix. FTIR results also showed weak electrostatic interactions between film components and composites. The results of the scanning electron microscope (SEM) show that the surface of the films containing copper sulfate nanoparticles and licorice root are more heterogeneous than the mucilage of Paneerak flower. Shirin-bian and copper sulfate nanoparticles were able to delay the thermal decomposition of the mucilage of Paneerak flower and increase the thermal stability of the mucilage film. Finally, based on the results, the addition of copper sulfate nanoparticles and licorice root to edible films based on the mucilage of paneerak flower improved antimicrobial, antioxidant, DSC and SEM. [ABSTRACT FROM AUTHOR]