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Purpose: This study aims to offer an effective nanocomposite for potential use to consolidate and protect deteriorated archaeological pottery. Design/methodology/approach: Three nanocomposites were used in the experimental study. This study used nano Primal AC33, silicon dioxide (SiO2) and montmorillonite (MMT) nanoparticles to protect and consolidate pottery specimens. Pottery specimens were made at 800°C for this investigation. Consolidation materials were applied with a brush. The properties of the treated pottery specimens were assessed using several methods such as digital and scanning electron microscopes, static water contact angle, color alteration, physical properties and compressive strength. Findings: Microscopic examination indicated the ability of the nano Primal AC33/MMT nanocomposites to cover the outer surface well and bind the inner granules. Concerning specimens with code F treated with nano Primal AC33 5%/MMT 3% nanocomposites, it achieved an increase in contact angle (120°), density (1.23 g/cm3) and compressive strength (561 kg/cm2), as well as a decrease in color change (ΔE = 2.62), water absorption (4.45%) and porosity (5.46%). The novelty of the results is due to the characteristics of nano Primal AC33 5%/MMT 3% nanocomposites used in the current study. Originality/value: This study describes the significant results of the analytical methods used for evaluating consolidation materials used in this study. The findings offer useful information for the protection of archaeological pottery. The investigation indicated that nano Primal AC33 5%/MMT 3% nanocomposites gave the best results. Therefore, it is recommended to use this nanocomposite to consolidate archaeological pottery. As a result, the current work provides a promising first step in conserving archaeological pottery for future studies. [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 paper concerns the influence of heat treatment (annealing, quenching and aging) on the microstructure and hardness of flat bars samples from the CuAl10Ni5Fe4 alloy. The microstructures were observed in light and scanning electron microscopes. The appearance and area fractions of the martensite beta phase and their influence on the mechanical properties were examined. The annealing study at a temperature of 950 °C for 1 hour, followed by rapid quenching in water and subsequent tempering at a temperature of 350-500 °C for 15-120 minutes, demonstrated the potential for a significant increase in the hardness of aluminum bronze from approximately 200 HV3 up to 600 HV3. This suggests new possibilities for the material's applications. [ABSTRACT FROM AUTHOR]

CuS nanostructures with high surface areas were produced through a hydrothermal method using simple materials. These included pure CuS, as well as CuS doped with Fe, Ag, and Mn, as well as dual-doped with Fe/Mn and Ag/Mn. X-ray diffraction (XRD), field-emission scanning electron microscopes (FE-SEM), chemical composition (EDX) analysis, zeta potential, ultraviolet–visible (UV–vis) absorption spectra, and compositional chemicals (FTIR) have been used to characterize the produced nanoparticles. The XRD patterns indicate that the CuS is in hexagonal covellite polycrystalline phases with estimated crystalline sizes of 25.14–14.25 nm. The optical measurements showed that the band gaps ranged from 3.19 to 2.24 eV. The inhibitory effects of pristine CuS, as well as CuS doping with Fe, Ag, and Mn and dual-doping with (Fe/Mn, Ag/Mn), against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, were evaluated using the inhibition zone method. All samples exhibited robust antibacterial activity against all strains. The highest level of inhibition against all strains was observed with a concentration of 4 mg/ml of copper sulfide. Out of all the tested samples, (Ag/Mn) dual-doped copper sulfide showed the highest antibacterial activity against both negative-gram and positive-gram bacteria. Hence, (Ag/Mn) dual-doped copper sulfide might be applied as an antibacterial agent with antibiotics to kill and prevent resistance bacterial development. [ABSTRACT FROM AUTHOR]

• The fragility of leathers is caused by different improper environmental conditions. • Molecular modeling showed good prediction for the application efficiency of PA6 in the consolidation of leathers. • The advantages of polyamide 6 make it suitable for the consolidation of fragile leather. • Some physical characteristics of leather were used for the evaluation of polyamide 6. • 2% and 3% polyamide 6 can be safely applied to historical leathers. This study aims to determine the efficiency of Polyamide 6 in consolidating fragile vegetable-tanned leather artifacts. Through two proposed interaction strategies, molecular modeling calculations demonstrated how the proposed polyamide 6 structure can protect vegetable-tanned leather from deteriorating environmental conditions. The total dipole moment was calculated as a potential descriptor of structure reactivity, and all of PA6 and the two proposed interaction models reveal poor reactive behavior when compared to pristine structures, confirming its capabilities as a protective layer. Furthermore, electrostatic potential maps were created to enhance PA6′s ability to safeguard leather artifacts and transform them into neutral, non-reactive substances. It was also created new vegetable-tanned leather prototypes. Polyamide 6 was produced in various concentrations and impregnated into the aged untreated samples. The evaluation process used some physical qualities (digital and scanning electron microscopes, color change, water absorption, and water vapor permeability). All examinations and investigations revealed that 2% and 3% concentrations produced the best results, while the concentration of 5% produced the worst. As a result, this study suggests employing 2% and 3% concentrations to treat historical and archaeologically fragile vegetable-tanned leather objects. [Display omitted] [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]

NiSi–NiCr thin film thermocouples (TFTCs) have significant application value as contact temperature sensors in cutting temperature measurements owing to their fast response and negligible volume. However, due to the relatively high chemical activity of Ni-based alloys, high-temperature oxidation strongly affects the operational reliability of NiSi–NiCr TFTCs. In this respect, depositing an anti-oxidation coating onto the surface of NiSi–NiCr TFTCs is considered an effective way to protect them in high-temperature environments. In this study, NiSi and NiCr films were deposited on cemented carbides and annealed at 200 °C–600 °C in air. Scanning electron microscope, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and four-probe resistivity tests were used to characterize the microstructure and resistivity of NiSi and NiCr film. Then SiN x O y films were deposited onto the NiSi and NiCr films and compared with uncoated samples after annealing at 600 °C. The effect of SiN x O y films on the thermal stability and thermoelectric output of NiSi–NiCr TFTCs was investigated. The results show that the NiSi film was partially oxidized at 200 °C and entirely oxidized when the temperature exceeded 400 °C. The completely oxidized NiSi films had evident defects and cracks, and the resistivity increased by a factor of over 1000. The NiCr film could not be completely oxidized at 600 °C, which is attributed to the formation of Cr 2 O 3 as an external oxide barrier layer. Below 600 °C, SiN x O y films could effectively protect NiSi and NiCr films from oxidation. Thus, the addition of SiN x O y film increases the maximum temperature at which NiSi–NiCr TFTCs can be used. [ABSTRACT FROM AUTHOR]

Herein, a green synthesis methodology for making copper oxide (CuO) nanoparticle clusters in a cost-effective and simple way is reported. While cuprous sulfate pentahydrate is used as a source of copper, the outer layer of green peas (Pisum Sativum) is used as a source of phenol. Extracting the phenol from pea peels is a simple process that uses water as a solvent. Copper salt is reduced by the phenolic content that is so produced. Both physicochemical and microscopic characterization Scanning Electron Microscope (SEM), and Energy-dispersive X-ray (EDX) analysis were performed on the particles. A variety of pea-peeling samples were used during the procedure's several executions to ensure reproducibility. The preparation process was appropriate, as the outcomes were identical. Analyses were also conducted on the produced particles' electrochemical activity as an application. A well-defined and organized redox reaction was seen at E' = +0.25 V against Ag/AgCl which were also shown to be highly electro-active. With the benchmarked redox mediator (5 mM ferricyanide), the particles also produced an outstanding redox peak at E1/2 = -0.01 V vs. Ag/AgCl. In a common reducing organic reaction, such as the reduction of p-nitro phenol to p-amino phenol, they were also found to be effective catalysts. Additionally, tests were conducted on the produced particles for their anti-bacterial and antifungal properties. Overall, a simple method for the formation of commercially viable CuO nanoparticle clusters is developed with the potential for diverse applications. [ABSTRACT FROM AUTHOR]

The mechanochemical ball milling process at 650°C for 5 h formed the single‐phase Bi2VO5.5 powder, which was tested as a catalyst for methylene blue (MB) dye degradation. X‐ray diffraction validated phase formation. A scanning electron microscope inspection verified the presence of grains with irregular shapes. Piezocatalytic MB dye degradation with a.4 g BV sample was ∼67% after 90 min in a ball mill and ∼49% after 180 min in an ultrasonicator. Utilizing a.4 g BV sample, the 90‐min investigation of piezocatalysis using a ball mill showed an 18% increase in degrading performance compared to the findings of the 180‐min study of piezocatalysis using ultrasonication. Ball mill employed piezocatalysis evaluation utilizing.4 g Bi2VO5.5 with 15 balls produces an excellent k value of.0109 min−1. Based on the results of a scavenger test, hole (h+) is the primary species in the ball mill‐induced piezocatalysis. [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]

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]

Nowadays, researches on the use of alkali metal salts as friction‐reducing and anti‐wear oil additives are continuing. In this study, the tribological effects of heavy metal containing MoS2 and alkali metal salt CaF2 additives on pure engine oil (20W50) were investigated using block‐on‐ring tester configured as surface contact geometry. The tests were performed at various contact loads, revolutions, and additive ratios. The crystal structure of the additives and their effects on surface quality and surface roughness analysed by x‐ray crystallography, scanning electron microscope and profilometry. Moreover, Energy dispersive spectrometry was used for element detection on worn surfaces. Results indicated that additives of MoS2 and CaF2 can reduce the friction, increase the capacity of load‐carrying and the wear resistance of surfaces. The additives improved the operation of the base oil in boundary lubrication zone by increasing the tribofilm forming effect. It was observed that the CaF2 additive exhibited more stable friction behaviour, while the MoS2 additive has better protective effects against scratches on the block surface. [ABSTRACT FROM AUTHOR]

The applications of Si 3 N 4 ceramics are hindered by their brittleness and susceptibility to fracture, despite their high strength and wear resistance. To address this challenge, layered ceramics were prepared using lamination and plasma sintering techniques, inspired by the structure of shell pearl layers. The bio-inspired layered ceramics were alternately arranged with Si 3 N 4 as the matrix layer (hard) and BN as the interfacial layer (soft). During the study, ceramic specimens with different microstructures were obtained by modulating the layer thickness ratio (ratio of Si 3 N 4 to BN) and sintering temperature. The microstructure of the specimens was characterized using SEM (Scanning Electron Microscope) and EDS (Energy Dispersive Spectrometer). The mechanical of various specimens were assessed by measuring the flexural strength and fracture toughness. The results of the investigation revealed that the mechanical characteristics of the samples reached their optimum state (with a toughness of 13.51 ± 1.56 MPa m1/2 and a strength of 429 ± 4.28 MPa) when the ratio of Si 3 N 4 to BN was 5:1, and the sintering temperature was maintained at 2000 °C. [ABSTRACT FROM AUTHOR]

Machining of silica glass is a challenging task due to its physical properties like brittleness, electrically insulated, etc. Although with the use of electrochemical discharge, it is possible to make holes and channels in silica glass, but the generation of spark discharge and removal of materials is a complex phenomenon in the electrochemical discharge process. Several research works were carried out previously to control the spark discharge as well as machining accuracy using rotational tool, the addition of ultrasonic vibration, including a magnetic field, and the use of different electrolytes, etc. A novel tool feeding technique i.e. using a horizontal tool and vertically upward tool feeding technique was used during milling on glass. The effects of voltage, the tool feed rate (TFR) and the concentration of electrolyte on the material removal rate and machining quality were studied in this work. The machined channel was examined under an optical measuring microscope as well as scanning electron microscope. The machining surface was also observed using a coherence correlation interferometry image to analyze in-depth surface topography of machined channels. Material removal rate and Ra value of the bottom layer were measured. The material removal rate of 6.097 µg/min was noticed at 25 wt% of electrolyte concentration, 40 µm/s of TFR and 45 V of applied voltage. The bottom layer's surface roughness (Ra) was found as low as 0.222 µm (Ra) at parametric conditions of 40 V, 40 µm/s TFR, and 15 wt% electrolyte concentration by employing the developed novel tool feeding technique. [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]

BACKGROUND: Polyvinylidene fluoride (PVDF) with piezoelectric properties, good biocompatibility and nontoxicity make it a suitable candidate for periosteal repair. OBJECTIVE: To evaluate the cytotoxicity of PVDF bionic periosteum by electrospinning with zinc and magnesium ions in vitro. METHODS: Pure PVDF, zinc-doped PVDF, magnesium-doped PVDF and Zinc-magnesium ion PVDF piezoelectric bionic periosteum were prepared by electrospinning technology, respectively. They were named PVDF, PVDF-Zn, PVDF-Mg and PVDF-Zn-Mg, in which the mass fraction of zinc and magnesium ions were all 1%. Osteoblasts and vascular endothelial cells were co-cultured with four groups of bionic periosteum. Cell compatibility of bionic periosteum was determined by alkaline phosphatase staining, CD31 immunofluorescence staining, and scanning electron microscopy. RESULTS AND CONCLUSION: (1) Osteoblasts: Alkaline phosphatase staining after 7 days of culture showed that the PVDF-Zn group secreted more alkaline phosphatase than the other three groups. Under a scanning electron microscopy, after 1 day of culture, the cells had a certain spread on the surface of PVDF-Mg and PVDF-Zn-Mg bionic periosteum, and the pseudopod extended to all sides. On day 3, the cell edge of each group extended pseudopods to the material. By days 5 and 7, the cells were fully spread, well grown and firmly covered the surface of the fibers, and the cellular pseudopods extended around and into the interstitial space of the fibers. CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed an increasing trend over time and the relative proliferation rate of cells at 1, 3, 5, and 7 days was ≥75%, and the cytotoxicity was ≤ grade 1. (2) Vascular endothelial cells: CD31 immunofluorescence staining for 3 days showed that the cells adhered and spread well on the bionic periosteum of each group and connected with each other, and the number of cells in the PVDF-Zn-Mg group was more than that in the other three groups. Under scanning electron microscope, the cells began to adhere to the surface of each group of fibers after 1 and 3 days of culture. On day 5, the cells were well spread on the surface of the fibers and extended obvious pseudopods. On day 7, the cells on the PVDF-Mg and PVDF-Zn-Mg bionic periosteum grew in multiple layers and extended the pseudopod into the fibrous void. CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed a downward trend over time, and the relative proliferation rate of cells at 1, 3, 5 and 7 days was ≥125%, and the cytotoxicity was grade 0. (3) The results showed that Zn-Mg electrospun PVDF piezoelectric bionic periosteum had good cytocompatibility. [ABSTRACT FROM AUTHOR]

To perform quality assessments of both metal alloys and many other engineering materials, measurements of the volume fractions of phases or microstructure components are utilized. For this purpose, quantitative analysis of the evaluated components' distribution on metallographic specimens is often employed. Phases or components of the microstructure are identified based on the variation in signal received in the band of light seen. Problems with the correct identification of measurement results in this spectral band can be caused by the inhomogeneity of the etching when the alloy components are segregated. Additional uncertainty arises when the analyzed image pixel contains a boundary between grains of different phases. This article attempts to use the results of local chemical composition measurements as a source signal for quantitative evaluation of phase composition. For this purpose, quantitative maps of elemental concentration distributions, obtained with a Tescan Mira GMU high-resolution scanning electron microscope in QuantMap mode, were used as input data for the phase composition evaluation of an EN AC 46000 alloy sample. The X-ray microanalysis signal generation area may contain grains of more than one phase. Therefore, evaluation of the phase fractions in areas of individual measurements were calculated by looking for the minimum of the objective function, calculated as the sum of the squares of the deviations of the results of measurements of the concentration of individual elements from the weighted average values of solubilities of these elements in the phases. [ABSTRACT FROM AUTHOR]

Bimetallic composites have a wide range of application prospects in various industries. Different bonding temperatures, as one of the influencing factors, directly affect the bonding effectiveness as well as the performance and application of the materials. Using metallurgical bonding techniques ensures a strong bond at the interface of bimetallic materials, resulting in high-quality composite pipe billets. This paper describes an Incoloy825/P110 steel bimetal composite material made by the solid–liquid composite method. By utilizing ProCAST 14.5 software for simulation and deriving theoretical formulas, an initial range of temperatures for bimetallic preparation has been tentatively determined. And this temperature range will be utilized for on-site experiments to prepare bimetallic samples. After the preparation process is completed, samples will be selected. The influence of the external mold temperature on the interface bonding of Incoloy825/P110 steel solid–liquid composite material is studied using an ultra-depth three-dimensional morphology microscope and a scanning electron microscope. Through research, the optimal preheating temperature range for the solid–liquid composite outer mold of Incoloy825/P110 bimetallic composite material has been determined. The casting temperature of the inner mold has a significant impact on the interface bonding of this bimetal composite material. As the casting temperature of the inner mold increases, the interface thickness gradually increases. At lower temperatures, the interface thickness is lower and the bonding is poorer. At higher temperatures, melting may occur, leading to coarse grains at the interface. When the temperatures of the inner and outer molds are within a certain range, a new phase appears at the interface. Indeed, it increases the strength of the interface bonding. Due to co-melting of the bimetal near the interface, element migration occurs, resulting in increased Ni and Cr content at the interface and enhanced corrosion resistance. [ABSTRACT FROM AUTHOR]

To evaluate the effects of an ammonia-based and a water-based silver-containing solutions on bonding performance and matrix-metalloproteinases (MMPs) activity of a universal adhesive to dentin after 1 year of artificial aging. Mid-coronal dentin surfaces of 60 sound human molars were exposed and the following groups were formed according to the surface pre-treatment and etching mode of the universal adhesive (Zipbond Universal, SDI) (n = 10): G1) Zipbond in the self-etch mode (ZSE); G2) Riva Star (SDI) applied before ZSE; G3) Riva Star Aqua (SDI) applied before ZSE; G4) Zipbond in the etch-and-rinse mode (ZER); G5) Riva Star applied before ZER; G6) Riva Star Aqua applied before ZER. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test at baseline (T 0) and after 12 months (T 12) of artificial storage. Scanning electron microscope (SEM) and energy dispersive spectroscopy analysis (EDS) were also conducted. Three additional molars per group were processed for the in situ zymography analysis at T 0 and T 12. Data were statistically analyzed (p < 0.05). Dentin pre-treatments and aging decreased bonding values, regardless of the etching mode (p < 0.05). No differences in µTBS were observed between the two silver-containing solutions, both at T 0 and T 12. Riva Star Aqua and etching significantly increased the MMPs activity, independent of the storage period (p < 0.05). Dentin surface pre-treatment with silver-containing solutions negatively affects the bonding performances of resin composite restorations placed with a universal adhesive. However, the ammonia-based product Riva Star might show better stability in the long term, due to lower activation of MMPs. • Silver-containing solutions lower bond strength of resin composite to sound dentin; • Riva Star might show better hybrid layer stability in the long term; • Riva Star Aqua has never been investigated before. [ABSTRACT FROM AUTHOR]

Gelatin is a collagen-derived biopolymer with high biocompatibility, commonly used in the production of wound dressing materials. Gelatin-based wound dressings, obtained through different processing methods, come with their own advantages and disadvantages depending on their physical structure. In this study, the effects of gelatin wound dressing materials with two different morphologies on wound healing are investigated in detail. The study investigated that the preparation of gelatin-based wound dressing materials using two different methods, followed by their chemical characterization and examination of their effects on biocompatibility and wound healing. To comprehend the impact of nanofiber structure and porous sponge structure on the wound healing process, the chemical structure of the prepared wound dressings was analyzed using Fourier Transform Infrared Spectrophotometer (FTIR). The morphological structure was visualized through Scanning Electron Microscope (SEM), the thermal properties were determined using Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). Additionally, the in vivo wound healing effects of gelatin-based wound dressings with different structures were evaluated through macroscopic observation and histological analysis in a dorsal region wound-healing rat model, monitored for 21 days. It was observed that wound healing materials with desired nanofiber and porous sponge structures were successfully obtained based on the SEM analysis. The gelatin nanofiber dressing showed a randomly oriented, bead-free, and smooth morphology with an average fiber diameter of approximately 1250 ± 0.35 nm, while the crosslinked gelatin sponge dressing had pore sizes ranging from 20 to 160 μm, and interconnected pore structures. The chemical structure remained unaltered according to FTIR graphs and these results were further supported by DSC and TGA graphs. Results from in vitro biocompatibility studies indicated that the wound dressing materials were biologically compatible, non-toxic, and did not cause irritation or sensitivity to the skin. Regarding in vivo analysis, it was determined that gelatin dressing materials were functional in the wound healing process, without the use of any auxiliary materials. [ABSTRACT FROM AUTHOR]

The FurnaSEM microfurnace was installed in the chamber of a scanning electron microscope to carry out in situ experiments at high temperatures and test its limits. The microfurnace was used in combination with different types of detectors (Everhart–Thornley for the collection of secondary electrons in a high vacuum, gas secondary electron detector for the specific collection of secondary electrons in the presence of gas, and Karmen© detector for the collection of backscattered electrons at high temperature). Experiments carried out on various samples (metal alloys and ceramics) show that the microfurnace operates in both high-vacuum and low-vacuum modes. Temperature ramp rates during temperature cycles applied to the sample range from 1 to 120 °C/min (temperature rise) and 1 to 480 °C/min (controlled and natural cooling). The maximum temperature at which images were recorded up to 25 k × magnification was 1340 °C, with a residual air atmosphere of 120 Pa. The choice of a flat furnace with the sample placed directly above it has enabled innovative experiments to be carried out, such as low-voltage imaging (using a shorter working distance—up to 10 mm—than is possible with conventional furnaces), 3D imaging (by tilting the stage by up to 10°), and high-temperature backscattered electron imaging (using a dedicated detector). [ABSTRACT FROM AUTHOR]

When conducting in situ experiments at high temperatures in a scanning electron microscope using microfurnaces, controlling the temperature of a sample of a few mm3 placed in the hot zone of the furnace can be a complex task. In most cases, the temperature of the sample is estimated by means of a thermocouple placed in the hot body of the furnace, and the assumption made is that the temperature of the furnace is the temperature of the sample. In this work, a detailed understanding of the thermal response of the sample placed in the hot zone of the furnace is proposed. Temperature differences due to contact resistance between the furnace surface and the sample, the nature of the sample, and the sample geometry are calculated with a numerical model and measured experimentally on a dedicated test bench. Three technical solutions (bonding, sandwiching, and mini-crucible) for limiting temperature differences between the furnace surface and sample are proposed and validated by numerical calculations and experimental measurements. [ABSTRACT FROM AUTHOR]

The development of a new heating system dedicated to in situ scanning electron microscope (SEM) experimentation at high temperatures is reported. This system, called FurnaSEM, is a compact microfurnace, enabling heat treatments up to 1300 °C. The choice of materials for the microfurnace is explained. The design of the microfurnace is optimized by iterations of numerical simulations, and the thermal characteristics of the microfurnace are calculated numerically. The numerical results obtained are compared with the thermal characteristics of a manufactured microfurnace, measured on a specially developed dedicated test bench. This test bench includes a working chamber simulating a SEM chamber equipped with a thermal camera. The results obtained during various qualification tests enabled us to determine the main technical characteristics of the FurnaSEM microfurnace: temperature profiles on the sample support surface, energy consumption at high temperatures, and the range of achievable thermal cycles. [ABSTRACT FROM AUTHOR]

Using Camellia oleifera shell as raw materials to preparative SiC ceramics by warm‐press forming and sintering is proposed in this paper. Warm‐press forming before preparing for the C. oleifera shell‐based SiC ceramics is beneficial to obtain the internal uniform and suitable pore structure of the cylindrical sample. Thermogravimetric analysis with differential scanning calorimetry was applied to analyze the pyrolysis behavior of C. oleiefra shell and phenolic resin. The scanning electron microscope and X‐ray diffraction were used to investigate the properties of C. oleifera shell‐based SiC ceramics. Then, the response surface method was applied to establish a multivariate prediction model based on the process parameters of warm‐press forming. And the regression equations of porosity and bending strength of COS‐SiC are obtained. The result demonstrated that the predicted and experimental values can be in good agreement for the model. By comparing the F‐value, it is found that the forming temperature and pressure during the process of warm‐press forming have a more significant influence on the porosity and bending strength of SiC ceramics. The optimization process parameters were obtained as follows: forming temperature 153°C, pressure 35 MPa, and holding time 30 min. [ABSTRACT FROM AUTHOR]

In this work, microporous MgO–Al2O3 refractory aggregates were prepared with Mg(OH)2 and Al(OH)3 via the in situ decomposition synthesis method. The effect of Al(OH)3 addition on the microstructure and properties of microporous MgO–Al2O3 refractory aggregates was investigated with scanning electron microscope and mercury intrusion porosimetry. The results indicated that the improved green density of the samples and the reaction sintering accelerated the mass transport rate with adding Al(OH)3 from 0 to 4.0 wt%. Besides, a small amount of Al3+ diffused into porous MgO particles, accelerating the merging and growth of nanopores in the porous MgO particles. The intra‐particle pore size and the densification degree of microparticles were increased, and thus the strength of the samples was improved. Due to the formation of Kirkendall voids by interdiffusion of Mg2+ and Al3+, the inter‐particle pore size increased. Adding Al(OH)3 from 4.0 to 17.6 wt%, the Kirkendall voids weakened the mass transport rate and improved the inter‐particle pore size. The merging and growth of nanopores in the MgO particles were limited, resulting in the reduced intra‐particle pore size and increased intra‐particle pore number. The densification degree of microparticles was reduced, and thus the strength of the samples decreased. At the Al(OH)3 addition of 4.0 wt%, microporous MgO–Al2O3 refractory aggregates had the best comprehensive properties, a bulk density of 2.48 g/cm3, an apparent porosity of 29.4%, a median pore size of 1.6 μm with 42.2 vol% nanopores and the thermal conductivity of 4.0 W/(m K). [ABSTRACT FROM AUTHOR]

Mycelium materials represent a new class of environmentally friendly materials for structural applications that can grow on low‐cost organic waste while achieving satisfactory thermal or acoustic insulation properties. The aim of this study is to grow a biocomposite of mycelium on flax tows and then use it as a reinforcement with a geopolymer matrix. To achieve this, three species of mycelium were selected, a culture process was carried out, and then samples of the composite were synthesized with a geopolymer matrix. To determine the utility in terms of structural applications, the density, compressive strength, and thermal conductivity of the samples were tested. Scanning electron microscope images were also taken to observe the microstructure. The results indicate that it is possible to produce a mycelium composite with a geopolymer matrix. A lower density was achieved for all samples than for the geopolymer without reinforcement. The coefficient of thermal conductivity was reduced only for the sample with one of the mycelia. The compressive strength for biocomposites was between 12.1 MPa–14.2 MPa, this value is enough for some engineering applications. [ABSTRACT FROM AUTHOR]

The use of aluminum alloys in automobiles is expanding, and the potential for additional increases is significant. Further growth will be determined by improvements in material qualities for existing applications or the discovery of new applications. Alloy A-356 (LM25) is commonly employed for high-quality alloy wheel rims in various motor vehicles, constituting 40% of global car usage. This study introduces 0.2% Cu into the Al–Si–Mg alloy system to enhance the mechanical properties. The alloy blend is cast into a metal mold, subjected to a 4-h cure at 540 °C, quenched with water, and precipitation hardened for 12 h at 1800 °C. Optical and scanning electron microscopes are utilized to analyze the alkali microstructure. The mechanical properties of alloyed and unalloyed castings, including hardness and tensile test results, are examined in untreated and heat-treated states. Fracture surfaces of tensile specimens are scrutinized. Intermetallic compounds formed during solidification are studied using scanning electron microscopy and x-ray diffraction analysis. The tensile strength under unalloyed (LM25) and alloyed (LM25 + 0.2 wt. % Cu) conditions before and after heat treatment [(72, 165.4 and 88.3, 237.1) and (78, 179.6 and 98, 252.9, respectively)] shows a significant increase. [ABSTRACT FROM AUTHOR]

A composite resin containing eggshell particles for the additive manufacturing according to the stereolithography (SLA) printing technology was studied. First, the viscosity properties of the eggshell-particle-reinforced resin were determined. Then, the effect of particle wt% on the hardness, tensile, and compressive behaviors of the composite specimens were investigated. Besides, the optical microscopy images of unreinforced and reinforced 3D printed composites were scrutinized. The cross-sections of the composite were analyzed by the energy dispersion spectrometry and optical and scanning electron microscopes (EDS/SEM) in order to examine its structure in detail. To analyze the damping properties and the elastic modulus determined in tension and free vibration tests were also carried out. [ABSTRACT FROM AUTHOR]

4D scanning transmission electron microscopy (4D‐STEM) is a powerful method for characterizing electron‐transparent samples with down to sub‐Ångstrom spatial resolution. 4D‐STEM can reveal local crystallinity, orientation, grain size, strain, and many more sample properties by rastering a convergent electron beam over a sample area and acquiring a transmission diffraction pattern (DP) at each scan position. These patterns are rich in information about the atomic structure of the probed volume, making this technique a potent tool to characterize even inhomogeneous samples. 4D‐STEM can also be used in scanning electron microscopes (SEMs) by placing an electron‐sensitive camera below the sample. 4D‐STEM‐in‐SEMs is ideally suited to characterize 2D materials and 2D‐like van der Waals heterostructures (vdWH) due to their inherent thickness of a few nanometers. The lower accelerating voltage of SEMs leads to strong scattering even from monolayers. The large field of view and down to sub‐nm spatial resolution of SEMs are ideal to map properties of the different constituents of 2D‐like vdWH by probing their combined sample volume. A unique 4D‐STEM‐in‐SEM system is applied to reveal the single crystallinity of MoS2 exfoliated with gold‐mediation as well as the crystal orientation and coverage of both components of a C60/MoS2 vdWH are determined. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the physical, mechanical, sorptivity, and microstructural properties of high-strength alkali-activated slag (AAS) mixtures that were heat cured for 8 h. AAS mixtures were cured at room conditions, 50°C, and 75°C. Here, 0.25% and 0.50% polyvinyl alcohol (PVA) fiber (by volume) was used to prevent heat-cure cracks and increase flexural toughness. In addition, 200, 400, and 600 kg/m3 quartz aggregates were used instead of quartz powder in the mixtures. In this context, 36 different mixtures were produced for the experimental study. The physical, mechanical, and transport properties of AAS have been greatly improved by heat curing. As the quartz aggregate and PVA fiber content increased, the apparent porosity and water absorption of the mixtures increased also. Accordingly, the unit weights of the mixtures decreased relatively. The compressive strength of AAS varied between 43.5 and 102.5 MPa. In the case of heat-curing at 75°C, the compressive strength increased up to 1.8 times. The flexural strength of AAS was between 6.9 and 14.7 MPa. The PVA fibers prevented the brittle fracture observed in AAS. Whereas the PVA fiber ratio increases both compressive and flexural strength, the opposite situation was obtained for quartz aggregate. In addition, the PVA fibers reduced capillary water absorption. The embodied energy of AAS ranged from 4,998 to 5,768 MJ. The embodied energy of AAS was found to be relatively higher than that of conventional concrete. Withal, the scanning electron microscopes (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) analyses implied that the heat curing considerably improved the geopolymerization. As a result, more than 100 MPa compressive strength and approximately 15 MPa flexural strength can be obtained by using 0.25% PVA fiber in AAS mixtures cured at 75°C. [ABSTRACT FROM AUTHOR]

The microstructure and properties of an AlSi10Mg alloy produced by selective laser melting were examined using optical microscopes, scanning electron microscopes, electron backscattered diffraction, and x‐ray diffraction. The results show that the mechanical characteristics of selective laser melting formed AlSi10Mg alloy is superior to those of traditional sand cast AlSi10Mg alloy due to fine grain strengthening and solid solution strengthening. AlSi10Mg alloy formed by selective laser melting is mainly composed of α‐aluminum solid solution, eutectic silicon with network structure and a small amount of Magnesium silicon precipitated phase, and different cross‐sections have unique microstructures and properties. The XOY plane is composed primarily of equiaxed grains with an average grain size of 7.34 μm and a {001} <100> cubic texture, and it has a hardness value of 130.7 HV 0.2. The majority of the YOZ plane, which has a {111}<110> brass R texture and a hardness value of 108.9 HV 0.2, comprises columnar crystals with an average grain size of 8.42 μm. [ABSTRACT FROM AUTHOR]

Nitrogen dioxide (NO 2) exposure can have several adverse health impacts on people, especially the respiratory system. Low selectivity, a lack of long-term stability, and structural and morphological optimization are some challenges associated with using ZnO for NO 2 gas sensing. Therefore, we intended copper (Cu) doping in ZnO to alter its shape and gas-sensing characteristics. This study explores the synthesis, properties, and gas-sensing capabilities of bitter gourd-shaped Cu-doped zinc oxide (ZnO) nanostructures for the detection of nitrogen dioxide (NO 2). A facile hydrothermal synthesis method was employed to synthesize bitter gourd-shaped Cu-doped ZnO nanostructures and comprehensively characterized by several techniques. Comprehensive characterizations of our produced Cu-doped ZnO nanomaterial demonstrated by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), and different energy spectrum. The material was annealed at 400 °C in a controlled dry air environment to improve its suitability for gas sensor applications. A series of temperature-ranging experiments were conducted to get gas-sensing readings from 25 °C to 300 °C. The resulting sensor, founded upon the distinctive morphology of Cu-doped ZnO structures reminiscent of the intricate shape of bitter gourd, unveiled good selectivity with a pronounced affinity for detecting NO 2 gas. Notably, the zenith of its performance was attained at an operating temperature of 200 °C, where its selectivity and sensitivity were most pronounced. Even at a low concentration of 1 ppm, the sensors displayed a maximum response of 3.7, highlighting their high sensitivity. The sensors demonstrated excellent reproducibility, selectivity, and a low detection limit. These findings position bitter gourd-shaped Cu-doped ZnO nanostructures as promising candidates for NO 2 sensing applications across diverse environments. [ABSTRACT FROM AUTHOR]

Based on a novel phenylacetylene capped polyimide (PI) with unique high-temperature resistance, its curing kinetics and thermal decomposition behavior were investigated. The curing mechanism and kinetics were studied by differential scanning calorimetry (DSC), and the activation energy (Ea) and pre-exponential factor (A) of the curing reaction were calculated based on the Kissinger equation, Ozawa equation, and Crane equation. According to the curve of conversion rate changing with temperature, the relationship between the dynamic reaction Ea and conversion rate (α) was calculated by the Friedman equation, Starink equation, and Ozawa–Flynn–Wall (O-F-W) equation, and the reaction Ea in different stages was compared with the results of molecular dynamics. Thermogravimetric analysis (TGA) and a scanning electron microscope (SEM) were used to analyze the thermal decomposition behavior of PI resins before and after curing. Temperatures at 5% and 20% mass loss (T5%, T20%), peak decomposition temperature (Tmax), residual carbon rate (RW), and integral process decomposition temperature (IPDT) were used to compare the thermal stability of PI resins and cured PI resins. The results display that the cured PI has excellent thermal stability. The Ea of the thermal decomposition reaction was calculated by the Coats–Redfern method, and the thermal decomposition behavior was analyzed. The thermal decomposition reaction of PI resins at different temperatures was simulated by molecular dynamics, the initial thermal decomposition reaction was studied, and the pyrolysis mechanism was analyzed more comprehensively and intuitively. [ABSTRACT FROM AUTHOR]

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

The process of superhard particle breakage in the grinding zone of the fluidized bed opposed jet mill is investigated using the CFD-DEM (computational fluid dynamics-discrete element method) coupling method with the Tavares UFRJ Breakage Model in the present study. The effects of structural and operational parameters, such as target plate structure, nozzle position, air inlet velocity, and feed rate, on the equipment stress distribution, airflow velocity, pressure field, particle velocity, and cumulative particle size distribution are thoroughly studied to determine the optimal structural and operational parameters. Experimental validation is conducted, including scanning electron microscope (SEM) observation of particle morphology and analysis of particle size distribution of ground product particles. The simulation results indicate that the wear rate of the structure without a target plate is lower than that of the structure with a target plate in the grinding central zone. Therefore, the structure without a target plate is chosen for further investigation. The cumulative particle size distribution after grinding is influenced by nozzle position, air inlet velocity, and feed rate. The particle D50 is positively correlated with nozzle spacing and feed rate, while it is negatively correlated with air inlet velocity. The optimal grinding effect is achieved when the distance between the nozzle and the center of the grinding zone ranges from 52.5 mm to 72.55 mm, the air inlet velocity is 950 m/s, and the feed rate is 10.5 g/s. Through experimental investigation, it has been observed that when the feed rate is 10 g/s, the particle size distribution becomes more uniform. Furthermore, consistent trends in the cumulative particle size distribution in the experiment and simulation results can be found, which validates the present numerical model. It was observed that particles at low feed rates retain certain angular edges, while particle roundness increases at high feed rates. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) multiferroic composites are more promising candidates for low-power consumption devices, next-generation spintronic devices, and multistate memory devices since they exhibit significantly higher Magnetoelectric interaction over single-phase multiferroics. In this regard magnetic behaviour, dielectric, and magnetoelectric characteristics of a novel Pb-free (1-x) Na 0.5 Bi 0.5 TiO 3 -(x) Ni 0.5 Co 0.5 Fe 2 O 4 , (x = 0, 0.2, 0.4, 0.6, 0.8 & 1) particulate composites were explored. Solid-state synthesis was adopted to prepare the single-phase Na 0.5 Bi 0.5 TiO 3 (NBT), Ni 0.5 Co 0.5 Fe 2 O 4 (NCFO), and their composites. The presence of rhombohedral NBT and cubic inverse spinel NCFO in the composites were confirmed with X-ray diffraction (XRD) patterns. Microstrain (ε) induced in the prepared samples was estimated by using the Williamson-Hall (W-H) method. The piezoelectric NBT phase shows the tensile strain and the ferromagnetic NCFO shows the comprehensive strain. Among all the composites 0.8NBT-0.2NCFO shows a higher strain value of 0.012%, and the decrement in the strain values was observed upon increases in ferrite concentration. Backscattered scanning electron microscope (BS-SEM) images revealed the existence of highly dense uniformly distributed elements and Energy dispersive spectroscopy (EDS) confirmed the existing elements in the composites. UV–vis absorbance spectra disclosed a rise in energy gap values from 1.14 eV to 3.0 eV with increasing NBT percentage. Variations of dielectric permittivity and dielectric loss with respect to AC frequency were studied at room temperature (RT), and the 0.2NBT-0.8NCFO sample shows a high dielectric permittivity of 8500 at ∼100Hz. M − H (Magnetization-Magnetic field) hysteresis loops demonstrate the pure ferrite phase has a coercive field (H c) = 578 Oe, remnant magnetization (M r) = 21.43 emu/g and saturation magnetization (M s) = 71.29 emu/g. The M s and M r values in the composites are enhanced with increasing ferrite percentage. Studies on ME behaviour of (1-x) NBT-(x) NCFO, (x = 0.2,0.4,0.6 & 0.8) show the coupling effect between both the phases at room temperature and the highest coupling coefficient value 3.16mV/Cm. Oe was observed for the 0.8NBT-0.2NCFO further the reasons and mechanisms are discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

In the context of sustainable development and environmental protection, the current study aims to give scientific evidence of the feasibility of replacing natural siliceous sand with crushed limestone sand in concrete. It assesses the effect of this replacement by comparing concretes without natural sand to a reference mix incorporating natural sand. For fixed water-to-cement ratio, cement content, and coarse aggregates proportions, and for different dosages of admixture to reach the same slump, the results proved that the concrete containing natural sand required more admixture to reach the same slump value as the crushed limestone sand concrete. For the same workability, the compressive and flexural strengths were not affected by the total replacement of natural sand with crushed sand. The three types of concrete fell within the same range of durability even though scanning electron microscope (SEM) analysis seemed to reveal a better paste-fine aggregate interface for crushed sand concrete. The concrete properties could be maintained when using crushed limestone sand conforming to the standard grading requirements, as the only fine aggregate in concrete. [ABSTRACT FROM AUTHOR]

This paper describes the methodology of combining experimental measurements with mathematical–physics analyses in the investigation of flow in the aperture and nozzle. The aperture and nozzle separate the differentially pumped chamber from the specimen chamber in an environmental scanning electron microscope (ESEM). Experimental measurements are provided by temperature and pressure sensors that meet the demanding conditions of cryogenic temperature zones and low pressures. This aperture maintains the required pressure difference between the chambers. Since it separates the large pressure gradient, critical flow occurs on it and supersonic gas flow with the characteristic properties of critical flow in the state variables occurs behind it. As a primary electron beam passes through the differential pumped chamber and the given aperture, the aperture is equipped with a nozzle. The shape of the nozzle strongly influences the character of the supersonic flow. The course of state variables is also strongly influenced by this shape; thus, it affects the number of collisions the primary beam's electrons have with gas molecules, and so the resulting image. This paper describes experimental measurements made using sensors under laboratory conditions in a specially created experimental chamber. Then, validation using mathematical–physical analysis in the Ansys Fluent system is described. [ABSTRACT FROM AUTHOR]

One of the challenges of storing hydrogen in saline aquifers is the possible geochemical reactions between host rock, formation solution, and hydrogen. This study investigated the effect of hydrogen treatment on the mechanical properties of sandstone samples from Hulett member of Sundance Formation, a potential underground hydrogen storage host in Wyoming, USA. Cylindrical specimens were treated with brine, brine+50%H 2, and brine+100%H 2 for two weeks at a pressure of 15 MPa and a temperature of 83 °C. X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), uniaxial compression, and triaxial compression tests were conducted on specimens. Results showed that specimens treated with brine+50%H 2 and brine+100%H 2 , on average, exhibited 24 and 41% lower peak strength, respectively, compared to that of specimens treated with the brine. XRD results showed a decrease in dolomite and clay content of specimens after exposure to hydrogen, causing degradation of the mechanical and elastic properties of the specimens. • The effect of hydrogen on the mechanical properties of Hulett sandstone was investigated. • Dolomite and clay dissolution was observed after the treatment with hydrogen. • Specimens treated with hydrogen on average showed 41% lower strength. • An average 43% decrease in elastic modulus was observed after hydrogen treatment. [ABSTRACT FROM AUTHOR]

In situ tensile testing in a scanning electron microscope was used to study the effects of fiber orientation and colony boundaries in laser-refined fully eutectic Al–Si and Al–Si–Sr alloys. In Al–Si alloy, the measured tensile stress–strain response in samples from single colonies is highly dependent on the orientation of Si nanofiber relative to the loading direction. Tensile samples with multiple colonies exhibit improved strain hardening but the measured ductility was limited by cracking along inter-eutectic colony boundaries. The Al–Si eutectic alloys, doped with Sr and processed with finer spot size laser beam, exhibit higher yield strength in samples from single colony due to refined fiber diameter and inter-fiber spacing of nanoscale Si fibers. As a consequence, samples with multiple colonies exhibit sliding or cracking at eutectic colony boundaries before significant uniform elongation developed within the colonies. The low ductility of Al–Si–Sr sample could be ascribed to the reduced shear strength of colony boundary induced by Sr element addition. [ABSTRACT FROM AUTHOR]

Hanseniella chilensis is the only myriapod of the class Symphyla known from Chile. This garden centipede, or pseudocentipede, was described more than 120 years ago based on morphologically incomplete specimens collected in central Chile, a well-known biodiversity hotspot. In this study, we redescribe this species based on morphologically complete specimens collected near the type locality using scanning electron microscope images. Our study provides the description of diagnostic characters hitherto unknown in this species such as macrochaetae of the tergites and spinnerets of the cerci. We also include a new record from central Chile and discuss the presumed presence of this species in Argentina and Madagascar. [ABSTRACT FROM AUTHOR]

There is a controversy involved in the models of the formation of serpulid tube microstructures, which either have been formed in similar ways to molluscan structures or in an alternative, unique serpulid way. A scanning electron microscope (SEM) study of the tube microstructure of Crucigera zygophora has been performed. A new serpulid tube microstructure, an aggregative SIOP, has been discovered in C. zygophora, herein termed ASIOP. During the first phase of crystallization, the sparsely located nuclei of the ASIOP structure formed, and in the second phase of crystal growth, the nucleation of spherultic sectors took place on the surface of preformed nuclei. The ASIOP structure differs from SIOP by more sparsely located crystallisation centres (nuclei) and the slower formation (i.e., crystallisation) of basic units. The formation of the ASIOP structure cannot be fully explained by the classical carbonate slurry model. Future comparative studies should show whether molluscan crossed spindle-like structures and serpulid SIOP structures are structural analogues. [ABSTRACT FROM AUTHOR]

In this study, bacterial cellulose (BC) was obtained from Komagataeibacter xylinus S4 and characterized in detail. The effects of a various of carbon sources and media, different pH conditions, incubation temperatures, Surface area/Volume ratios, and incubation durations were determined for BC production. Considering the carbon types, the amount of BC production from high to low was realized as sucrose, fructose, mannitol, xylose, arabinose, and lactose. The highest BC amount (1.303 g/L) was achieved by combining M1A05P5 broth, 30 °C, 1.06 cm-1 Surface area/Volume ratio, pH 3.5 and 21 days. According to scanning electron microscope (SEM) analysis, the cellulose fibril diameters were 34.87-45.97 nm at pH 3.5 and 29.71-102.3 nm at pH 6.5 in M1A05P5. Also, TGA analysis exhibited that the weight loss of BC in the removal of water step initialized between 50 °C and 150 °C and the degradation step initialized between 215 °C and 228 °C. Finally, the electrical conductivity values of the BC samples were determined on the 27-137 °C temperature scale. It was observed that the conductivity was temperature dependent, and the conductivity increased exponentially as the temperature increased. In conclusion, the cellulose from K. xylinus S4 typically showed a semiconducting behavior. [ABSTRACT FROM AUTHOR]

In this study, Chrysothemis pulchella leaf extracts were used to prepare gold nanoparticles (AuNPs) for anticancer and antimicrobial applications. The nanoparticles were characterized using UV-Visible spectroscopy, powder X-ray diffraction method, Scanning and transmission electron microscopic (SEM/TEM) techniques. The UV–vis spectroscopy revealed characteristic absorption band at 527 nm whereas X-ray diffraction analysis showed characteristic crystalline peaks typical of AuNPs and carbon peaks emanating from the plant extract. The energy dispersive X-ray spectroscopic (EDXS) studies showed the following elements: C, O, Na, Mg, Cl, K, Ca and Au. The microscopic analysis using Scanning and Transmission Electron Microscopes showed spherical nanoparticles with average size of 14.7 nm. Cytotoxic tests showed that the AuNPs were toxic to human embryonic kidney (HEK-293) and HELA cells at IC50 dosage of 34.5 and 54.05 µg respectively. The nanoparticles also proved to have broad spectrum antimicrobial properties as they inhibited the growth of some pathogenic micro-organisms. [ABSTRACT FROM AUTHOR]

Acidification, as an effective measure to remove blockages and restore oil well productivity, has received widespread concern. However, conventional acid systems can only be used to unblock near‐wellbore zones and are difficult to act on far‐wellbore reservoirs. In this article, scanning electron microscope, energy‐dispersive X‐ray spectroscope, and X‐ray diffractometer were used to analyze the blockages in the Bai 823 well area, and it was determined that their main components were CaCO3 and FeCO3, which provided the basis for the construction of the unblocking formula. Then, the acid dissolution experiments on the plugging materials showed that the dissolution rate of 10% HCl can reach more than 85% for the scale sample; the acid dissolution experiments on the rock sample showed that the autogenous mud acid has better dissolution performance and better retardation performance for the rock sample, and the effective action time is longer, so it can be used for deeper unplugging of the reservoir. Finally, the process parameters such as the optimal acid concentration, acid dosage, and discharge volume were optimized by establishing the fracture‐matrix acid flow reaction model. Research results indicate that the autogenous mud acid can act on the blockage in the far‐wellbore area to improve the acidification effect. [ABSTRACT FROM AUTHOR]

A new species, Momonides neolandbergi Li & Guo sp. nov. is described in detail, which is the fifth species all over the world in Momonidinae Lundblad, 1941, Momoniidae K. Viets, 1926. The family and subfamily are newly recorded for Chinese fauna. The new species are recorded by camera, optical microscope, and scanning electron microscope. Publication:New species: [ABSTRACT FROM AUTHOR]

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

FIB-SEM tomography is a powerful technique that integrates a focused ion beam (FIB) and a scanning electron microscope (SEM) to capture high-resolution imaging data of nanostructures. This approach involves collecting in-plane SEM images and using FIB to remove material layers for imaging subsequent planes, thereby producing image stacks. However, these image stacks in FIB-SEM tomography are subject to the shine-through effect, which makes structures visible from the posterior regions of the current plane. This artifact introduces an ambiguity between image intensity and structures in the current plane, making conventional segmentation methods such as thresholding or the k-means algorithm insufficient. In this study, we propose a multimodal machine learning approach that combines intensity information obtained at different electron beam accelerating voltages to improve the three-dimensional (3D) reconstruction of nanostructures. By treating the increased shine-through effect at higher accelerating voltages as a form of additional information, the proposed method significantly improves segmentation accuracy and leads to more precise 3D reconstructions for real FIB tomography data. Highlights: FIB-SEM tomography can be used to acquire high-resolution image stacks of nanostructures. Machine learning reduces artifacts and ambiguities introduced in FIB-SEM tomography because of the shine-through effect. Our approach treats the shine-through effect as a valuable additional information for precise reconstruction. Using multi-voltage images, our multimodal ML approach improves 3D reconstruction accuracy. [ABSTRACT FROM AUTHOR]

Subangstrom resolution has long been limited to aberration-corrected electron microscopy, where it is a powerful tool for understanding the atomic structure and properties of matter. Here, we demonstrate electron ptychography in an uncorrected scanning transmission electron microscope (STEM) with deep subangstrom spatial resolution down to 0.44 angstroms, exceeding the conventional resolution of aberration-corrected tools and rivaling their highest ptychographic resolutions. Our approach, which we demonstrate on twisted two-dimensional materials in a widely available commercial microscope, far surpasses prior ptychographic resolutions (1 to 5 angstroms) of uncorrected STEMs. We further show how geometric aberrations can create optimized, structured beams for dose-efficient electron ptychography. Our results demonstrate that expensive aberration correctors are no longer required for deep subangstrom resolution. [ABSTRACT FROM AUTHOR]