Search

Purpose: Paper aims to evaluate the efficiency of traditional chitosan, nano chitosan, and chitosan nanocomposites for consolidating aged papyrus samples. Cellulose-based materials, such as papyrus sheets and paper, which are the most common types of writing supports for works of art in many museums and archive. They are subjected to different types of deterioration factors that may lead to many conservation problems. Consolidation treatment is one of the most common conservation treatments, which should have perform after much testing to select the appropriate consolidants. Design/methodology/approach: This research paper aims to evaluate the resistance of traditional chitosan, nanochitosan and chitosan/zinc oxide nanocomposite as an eco-friendly papyrus strengthening. Untreated and treated papyrus was thermally aged and characterized via scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). Antimicrobial activity of the papyrus specimens was also determined against four tested pathogenic bacteria by disc diffusion method: MRSA, Staphylococcus aureus, E. coli and P. aeruginosa. Findings: The results revealed that chitosan nanocomposite showed a remarkable enhancement of papyrus tensile properties and presence of ZnO prevents the effects of biodeterioration. Originality/value: Zinc oxide nanoparticles enhance the optical properties and increase the chemical reactions between the consolidating material and the treated papyrus. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the efficiency of using some polymers at different concentrations in the consolidation of vegetable-tanned leather artifacts. Design/methodology/approach: New vegetable-tanned leather samples were prepared. The consolidants used were polyacrylamide (PAM) and polymethyl methacrylate/hydroxyethyl methacrylate (MMA-HEMA). Accelerated heat aging was applied to the untreated and treated samples. Analytical techniques used were Fourier transform infrared spectroscopy (FTIR), digital microscope, scanning electron microscope (SEM), change of color and mechanical properties. Findings: The characteristic FTIR bands showed the effect of accelerated heat aging on the molecular structure of the studied samples, but treated and aged treated samples used were better than aged untreated samples. Microscopic investigations (digital and SEM), and mechanical properties proved that 2% was the best concentration for polymers used. The change in the total color difference of the treated and aged treated samples was limited. Originality/value: This study presents the important results obtained from PAM and poly(MMA-HEMA) used for the consolidation of vegetable-tanned leather artifacts. The best results of the studied polymers can be applied directly to protect historical vegetable-tanned leathers. [ABSTRACT FROM AUTHOR]

Controlled development of novel materials fosters innovation in the electrical sector. The hybrid materials based on magnetic nanocellulose are intriguing since they have many uses in electronics, catalysis, medicine, and ecology. The study investigated the structure and morphology of hybrid nanomaterials made from nanocellulose and cobalt ferrite. The nanocellulose was prepared by TEMPO-oxidation and the cobalt ferrite was prepared by sol-gel auto-combustion method. Using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques, it was determined how nanocellulose loading affected the crystal structure of the synthesized composite. To ascertain the variation in the component concentrations, scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDAX) are used. Composite with a higher concentration of nanocellulose fibers (NCF) show lesser particle size, and this may account for the smaller size of nanocellulose fibers, and attachment of nanocellulose nanofibers over the surface of porous cobalt ferrite (CF) found in SEM images. [ABSTRACT FROM AUTHOR]

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

Isolation of Lactic Acid Bacteria (LAB) from various sources has previously been carried out to obtain strains that produce high of exopolysaccharide (EPS). Isolate K2, which was LAB isolated from longan (Dimocarpus longan) fruit, can produce EPS. This study aimed to identify isolate K2, and evaluated the effect of supplementation carbon sources (glucose, fructose, sucrose, and lactose) and pH of media (4, 5, 6, 7, and 8) on EPS production. Isolate K2 was identified as Weissella confusa molecularly based on 16S rDNA, the type of carbon source, and the pH of media had significant effects (P<0.05) on EPS production. W. confusa K2 produced EPS that was highest on media with the supplementation of sucrose as a carbon source and produced the lowest EPS on lactose. The amount of EPS produced by W. confusa K2 under alkaline was higher than under acidic, the highest EPS of 47.703 g/L at pH 8 and the lowest EPS at pH 4 of 1.858 g/L. The physical properties showed EPS has good solubility in water with the solubility and Water Holding Capacity (WHC) at 40.533% and 354% respectively. Based on Surface morphology of EPS with Scanning Electron Microscope (SEM) analysis, the surface structure of EPS was a porous polymer matrix. Fourier Transform Infrared Spectrophotometer (FTIR) results of EPS showed the presence of absorption bands as characteristic of carbohydrates, such as the presence of O-H, C-H, C=O, C=C, C-O-C groups, and glycosidic bonds. [ABSTRACT FROM AUTHOR]

Cu-containing silicon oxycarbide (SiOC) ceramic composites have been prepared by thermal pyrolysis of polymeric precursors and subsequent spark plasma sintering at 1600 °C. The resulting composites consist of SiO 2 , SiC, free carbon, and Cu-Si alloys. The microstructure of the composites has been identified via optical microscope and SEM. The mechanical properties, including the Vickers hardness, nano-indentation hardness, and Young's modulus, of the SiOC composites have been assessed via indentation methods. The effects of Cu content on the tribological properties of the composites have additionally been investigated under different sliding frequencies against Al 2 O 3 spheres at room temperature. It is shown that the introduction of the Cu-Si alloys is effective in reducing the friction coefficient of the material system, which decreases linearly from 0.27 of monolithic SiOC to 0.15 of SiOC with 7 wt% Cu content at 1 Hz. Raman spectroscopy has highlighted the friction-driven evolution of the free carbon phase in the SiOC ceramics. Finally, a correlation between the sliding frequency, Cu-Si content, and tribological properties of SiOC is established. [ABSTRACT FROM AUTHOR]

Bi-layer foamed glass-ceramic has the advantages of both dense and foamed structure which lead to low bulk density and high mechanical strength. We propose a new one-step method to produce bi-layer foamed glass-ceramic using the asynchronous oxidization of B 4 C and SiC. The parent glass is prepared by melting-quenching method, followed by foaming through powder sintering route with addition of B 4 C and SiC. The bi-layer structure and formation of bi-layers are investigated by scanning electron microscope (SEM), X-ray computed tomography, 11B NMR, and high temperature melting observation system (HTMOS). The results show that during the sintering process, the oxidization of B 4 C in top layer at low temperature forms boron oxide and helps the formation of glass melt in the top layer. The oxidization of SiC at high temperature leads to foaming in the top layer. The prepared bi-layer foamed glass-ceramic has low bulk density of 1.06 g·cm−3 and high flexural strength of 26.15 MPa. [ABSTRACT FROM AUTHOR]

Bone tissue engineering procedures require the use of a scaffold with a sufficiently porous structure, which serves as a three‐dimensional template for cell attachment, followed by tissue regeneration and vascularization both in vitro and in vivo. This study aimed to create scaffold material with a unique hybrid forming that met these parameters. Slip casting and freeze‐drying processes were used with a hybrid forming approach to create a bone scaffold based on hydroxyapatite (HA) mimicking the structure of cortical and cancellous bones, respectively. HA was synthesized by the wet chemical precipitation method. Fourier‐transform infrared spectroscopy, dynamic light scattering, X‐ray diffraction, thermogravimetric analysis‐differential thermal analysis, Brunauer‐Emmett‐Teller, He Pycnometer, and scanning electron microscope analyses were performed to characterize the scaffold. According to analysis results, HA particle size was found at 137.8 nm. The optimum sintering temperature was determined to be 1300°C. The specific surface area of the HA powder was measured as 55.11 m2/g. The total open porosity of the hybrid scaffold was calculated as 70%. Scaffold successfully substituted both cancellous and cortical layers of bone regarding structural characteristics, porosity, and mechanical strength. Considering morphological characteristics, a hybrid scaffold might facilitate vascularization, osteoinduction, and osteoconduction. Research findings suggest that the hybrid design strongly resembled natural bone and is suitable for both load‐bearing and non‐bearing bones. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) are desirable materials widely applied as adsorbent for wastewater treatment. This study synthesizes and applies a novel structured ZIF with organic ligand of 2-methyl imidazole and metal salt of copper (II) sulfate as adsorbent. Its morphology and structure were investigated using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, field emission scanning electron microscope, energy dispersive X-ray spectrometry, and mapping analysis. After structural analysis, the adsorbent structure was simulated and determined using Avogadro and Gaussian software. The removal efficiency of prepared ZIF in the removal of methyl orange from aqueous solution was evaluated. The effect of pH, the concentration of the dye in solution, dosage of the adsorbent, and the contact time between adsorbent and solution on the methyl orange removal were examined using central composite design of response surface methodology in five levels. The maximum dye removal of 99% was obtained for 2 g adsorbent/L, pH of 3.3, and initial dye concentration of 121 mg/L after 127 min contact time. In addition, to reduce the economic costs and energy consumption, the synthesis time was also reduced and used to show the applicability of the adsorbent prepared and understand its advantages and disadvantages in removing methyl orange dye from aqueous solutions. This molecular adsorbent is stable, and it can be stored for months. On the other hand, this ZIF can be easily recovered and reused many times. In this research, after five times of recovery, there was no significant change in the effectiveness of the adsorbent. [ABSTRACT FROM AUTHOR]

Performance evaluation of electrode material in terms of metal removal rate and relative electrode wear is very much essential to assess the quality of components machined by the electric discharge machining process. Electrode materials perform differently due to their composition, electrical conductivity, and thermo-mechanical properties. Therefore, detailed experimental investigations have been carried out to understand the effect of different copper alloys, current, voltage, and pulse on time on the metal removal rate and relative electrode wear during the electric discharge machining process. Taguchi L9 orthogonal array has been employed using Cu-Cr-Zr, Cu-Cd, and Cu-Be as tool material. The results reveal that Cu-Cr-Zr is the most suitable tool material for spark erosion machining of AISI D2 die steel to depict low electrode wear and high metal removal rate. The best machining conditions obtained with Cu-Cr-Zr tool material for maximum metal removal rate and minimum relative electrode wear are current 15 Amp, voltage 80 V, and pulse on time 36 µs. Scanning electron microscope is used for analysis of all the three electrode materials against different machining conditions. The role of tool material and electric discharge machining process parameters in developing micro-cracks, deposition on the tool surface, and recast layer formation were demonstrated. [ABSTRACT FROM AUTHOR]

The dowel-bearing properties of a newly laminated flattened-bamboo (LFB) composite for engineering use was studied in this research by using the 5% bolt diameter offset method. The effects of specimen dimensions, bolt diameter, density, and bolt placed direction were included. Computed tomography (CT) and scanning electron microscope (SEM) were used to identify the failure type. The test results indicate that the parallel-to-grain dowel-bearing strength of LFB generally increased with an increasing density. When the bolt was placed along the LFB's radial direction, the parallel-to-grain dowel-bearing strength approximately remained a constant (52 MPa) with the change of specimen dimensions and bolt diameter, while when the bolt was along the tangential direction, the dowel-bearing strength increased with the raising ratio of specimen thickness and bolt diameter. The first failure type was a crushing failure of bamboo fiber underneath the bolt, it happened when bolt diameter was small (12 mm and 14 mm) and placed along LFB's radial direction. The second type was a splitting failure due to the lateral force generated by the bolt embedded into specimen, bamboo fiber splitting failure dominated for specimens with bolt along radial direction, while when bolt along tangential direction, glue layer splitting happened. The measured dowel-bearing strength was compared to the predictions obtained from equations in current wood specifications and articles. The results indicated that, except for the predicted values from the NDS equation (max error = 36%), which showed relatively reasonable agreement with the test values, the remaining predicted values exhibited discrepancies with the test values. To obtain proper predicted values, equations include density and ratio of specimen thickness and bolt diameter were proposed for calculation of LFB's parallel-to-grain dowel-bearing strength. [ABSTRACT FROM AUTHOR]

The central Sichuan Basin, located in western China, holds great significance in terms of hydrocarbon production, especially in relation to complex carbonate reservoirs, notably the Qixia Formation of the Middle Permian epoch. However, the comprehensive evaluation of this geological formation presents considerable challenges due to complex lithology, limited availability of reservoir property data at various scales, inadequacies in data integration, and the absence of a reliable reservoir ranking system for development decision making. Previous studies primarily relying on conventional data at the reservoir level, such as well logs and geological information, have proven insufficient in accurately characterizing the reservoir. This is especially evident without precise lithological information and detailed knowledge of microscale properties, which are crucial for effective reservoir evaluation. To address these challenges, this study integrates advanced technologies like X-ray diffraction, micro-CT and scanning electron microscope (SEM) techniques in digital drill cutting analysis at the microscale. A novel scoring system has been developed using a prominent component analysis (PCA) approach and an expert scoring system, which incorporates existing conventional well log data and digital cutting analysis. This scoring system has been validated using actual production data, thus establishing a robust evaluation methodology for assessing the exploration potential and optimizing development strategies for carbonate gas reservoirs in the Qixia Formation. The innovative approach, which incorporates parameters at both micro- and macroscales, holds promising potential in facilitating future exploration and development efforts. [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]

A Ti-Fe-Si-Cr-Nb alloy was fabricated using laser metal deposition (LMD) technique. The laser power and scanning speed were varied during fabrication to optimize the processing parameters. The thermal behavior during LMD processing was modeled and simulated by means of COMSOL Multiphysics 6.0 software. The samples produced were characterized using an optical microscope, X-ray diffractometer, and scanning electron microscope coupled with energy dispersive spectroscopy. The microhardness and wear behavior of the alloy were tested using a diamond indenter and ball-on-disk wear machine. The results obtained showed that the alloys exhibited similar dendritic microstructure for all processing parameters. The formation of cracks and pores were evident mainly in samples that were produced at high scanning speed and low laser power. A decrease in microhardness was noticed when the laser power was increased, while an increase in scanning speed yielded samples with high microhardness values. The alloy showed good tribological behavior, but no clear relationship between the wear resistance of the alloy and the variation of the laser processing parameters could be established. [ABSTRACT FROM AUTHOR]

In this work, the medium-low grade calcium-magnesium phosphate ore in Zhijin, China, was investigated through systematic mineral processing studies using a scanning electron microscope, x-ray fluorescence spectrometer, and BGRIMM process mineralogy analyzer in combination with the ImageJ software and flotation experiment. The aim of this study was to suggest a process flow to optimize the flotation index of Zhijin phosphate ore. The effect of the liberation properties of fluorapatite on flotation behavior were analyzed with various particle sizes under different grinding fineness. Based on the characteristics of fluorapatite, we propose a double reverse flotation process with two routes for coarse- and fine-grained ore, respectively. The results showed that the flotation process can effectively improve the grade of phosphate ore and reduce the MgO content. As the degree of liberation increases, the flotation index increases first, and when the liberation degree reaches a certain value, the flotation index decreases. The maximum grade of fluorapatite was obtained for a grinding fineness of 82.86%, while the maximum grade of P2O5 was obtained for the − 53 + 38-μm particle size for flotation concentrate at various particle sizes. [ABSTRACT FROM AUTHOR]

In order to study the effect of the preparation process on the microstructure and mechanical properties of metal hollow sphere composites (MHSCs), they were fabricated using different preparation processes (different holding times) by a pressure casting method. The physical parameters of the MHSCs were measured using a direct measurement method, and the phases and microstructure of the MHSCs were observed using an X-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and transmission electron microscope (TEM). Moreover, the mechanical properties of MHSCs were analyzed by a Zwick/Roell Z2.5 microhardness tester and a universal testing machine. The microscopic morphology and composition analysis results showed that the microstructures of MHSCs varied by holding time, while the mechanical properties test results implied that the microhardness of the transition layer and the matrix increased with the extension of the holding time. However, the MHSCs held for 10 min exhibited the best compression performance. These observations indicated that the compressive properties of MHSCs were mainly dependent on the transition layer and the matrix, excluding the influence of metal hollow spheres, and that the transition layer had a significant impact on the compression performance of MHSCs. [ABSTRACT FROM AUTHOR]

Tungsten-copper composites are used in harsh environments because of their superior material properties. This work addresses a tungsten-copper composite made of 20 wt.% copper, which was subjected to grain refinement by high-pressure torsion, whereby the deformation temperature was varied between room temperature and 400 °C to tailor the grain size. Deformation was performed up to microstructural saturation and verified by hardness measurement and scanning electron microscopy. From the refined nanostructured material, micro-cantilever bending beams with cross-sections spanning from 5 × 5 to 35 × 35 µm2 were cut to examine possible size effects and the grain size influence on the fracture behavior. Fracture experiments were performed in situ inside a scanning electron microscope by applying a quasi-static loading protocol with partial unloading steps. Inspection of the fracture surfaces showed that all cantilevers failed in an inter-crystalline fashion. Nevertheless, remaining coarser tungsten grains impacted the resultant fracture toughness and morphology. Cantilevers fabricated from the 400 °C specimen exhibited a fracture toughness of 220 ± 50 J m 2 . For the room temperature cantilevers, a fracture toughness of 410 ± 50 J m 2 was observed, which declined to 340 ± 30 J m 2 for cantilevers < 10 × 10 µm2, confirming a size effect. The increased fracture toughness is attributed to the delamination-like structures formed in the room temperature sample. [ABSTRACT FROM AUTHOR]

Electrocatalytic n-valeraldehyde oxidation reaction was an inexpensive and eco-friendly method to control n-valeraldehyde contamination and produce high value-added octane. However, low-cost and readily available electrocatalysts with high current efficiency were urgently needed. Herein, two-dimensional porous carbon derived from pollen with enlarged interlayer distance was built by alkali activation method, applying in electrocatalytic n-valeraldehyde oxidation reaction. The enlarged interlayer distance was verified by X-ray diffraction (XRD) and high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM). Electrocatalytic experiments consequences showed activated biomass derived carbon possessed a higher electrocatalytic activity and octane selectivity than unactivated catalyst. Systematic tests and in situ infrared experiments demonstrated that enlarged interlayer distance was positively correlated with specific surface area of catalysts, large specific surface area provided abundant absorption sites, facilitated the adsorption for n-valeraldehyde, and further promoted the transformation of n-valeraldehyde to octane. This work also provides a new avenue for creating high-performance electrocatalysts in terms of lattice engineering. [ABSTRACT FROM AUTHOR]

A sulfur-containing polyphosphonate compound, polysulfonyldiphenylene phenylphosphonate (PSPPP), was prepared based on diphenylphosphine and bisphenol S, and applied to flame retarded polyethylene terephthalate (PET). The flame retardancy and thermal stability of PSPPP/PET composites were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimeter and thermogravimetric analysis (TGA). LOI value increased from 20.5% for pure PET to 29.2% for flame retardant PET with 8 wt.% PSPPP, and 8%PSPPP/PET passed UL-94 V-0 rating. The cone calorimeter test displayed that PSPPP not only inhibited the maximum combustion strength of PET composites but also suppressed the smoke release. TGA results indicated that PSPPP significantly enhanced the char yield of composites and the thermal stability of residues at higher temperature. The flame retardant modes of action of PSPPP were confirmed by experiments using TGA-Fourier transform infrared (TGA-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), Hot-Stage FTIR, and scanning electron microscope (SEM). PSPPP played a role of flame retardant in condensed phase and gas phase. During combustion, PSPPP continuously released phosphorus-oxygen-free radicals with quenching effect, thus playing the gas phase flame retardant effect. On the other hand, the transesterification reactions between PSPPP and PET promoted the formation of dense carbon layer and led to high barrier effect. [ABSTRACT FROM AUTHOR]

The American cockroach, Periplaneta americana (Linnaeus, 1758) (Blattodea: Blattidae), is one of the most common pests that thrive in diverse environments and carries various pathogens, causing critical threats to public health and the ecosystem. We thus report in this study the first observation of decapitated American cockroaches as a result of infestation with scuttle fly parasitoids. Interestingly, behavioral alterations in the form of zombification-like behavior could be observed in cockroaches reared in the laboratory before being decapitated, implying that the insect targets cockroach heads. To identify this parasitoid, cockroaches' corpora were isolated in jars, and apodous larvae were observed. Larvae developed into small coarctate pupae, and adults emerged. The scuttle flies were collected and exhibited tiny black, brown, to yellowish bodies. The fly was initially identified based on its morphological properties as a member of the order Diptera, family Phoridae. To provide further insights into the morphological attributes of the phorid species, the fly was examined using a scanning electron microscope (SEM) and then identified as Megaselia scalaris accordingly. SEM analysis revealed the distinctive structure of M. scalaris concerning the head, mouth parts, and legs. Specifically, the mouth parts include the labrum, labellum, rostrum, and maxillary palps. Although further investigations are still required to understand the complicated relationships between M. scalaris and American cockroaches, our findings provide a prominent step in the control of American cockroaches using M. scalaris as an efficient biological control agent. [ABSTRACT FROM AUTHOR]

Measurements of transport phenomena are constantly plagued by contact resistance, prohibiting the sample's intrinsic electrical or thermal conductivity from being accurately determined. This predicament is particularly severe in thermal transport measurements due to the inability to meet similar impedance requirements for a four-probe method used in electrical resistance measurements. Here, we invent a three-probe measurement method that makes an accurate determination of thermal conductivity possible for nanomaterials. Incorporating electron beam heating provided by a scanning electron microscope (SEM) on a diffusive thermal conductor not only quantifies the thermal contact resistance, which may introduce an error of more than 270% to a sample's thermal conductivity, but also eliminates several device uncertainties that may contribute an additional 17% error in a measurement. The method also enables local temperature measurements, revealing nanoscale structural variations unfound by SEM. The high accuracy of the technique would make standardization of nanoscale thermal transport measurement possible. [ABSTRACT FROM AUTHOR]

Bismuth telluride (Bi2Te3), due to its thermoelectric properties, is an interesting semiconducting material for optoelectronics and energy conversion devices; still, it has limited stability and durability. Under high pressure, we can fine-tune its performance, potentially enhancing its capabilities. The presented work uses the semi-automatic Reddy tube to explore the behavior of bismuth telluride under dynamic pressure. Commercially available bismuth telluride was purchased and subjected to different numbers of shock pulses of 100, 200, 300, and 400 with 2 MPa transient pressure and 864 K transient temperature. XRD, Raman, UV-DRS, PL, and SEM were used to characterize Bi2Te3 and shock-loaded Bi2Te3. The XRD and Raman study confirms that the Bi2Te3 underwent phase transition from Bi2Te3 to Bi4Te5 (rhombohedral to hexagonal) at 300 shock pulses. The optical property of Bi2Te3 was determined using UV-DRS and PL; the bandgap and PL intensity changed with respect to the number of shock pulses. A scanning electron microscope was used to analyze sample morphology. Our findings reveal the reversible phase transition of bismuth telluride from Bi2Te3 to Bi4Te5 under dynamic shock waves, something that has not been reported earlier. Using traditional synthesis methods, Bi4Te5 consume a lot of time, leading to impurities and problems of sample quality. Our results reveal that a rapid and reversible phase transition and unique response to dynamic shock waves will allow excellent technological applications without requiring lengthy and complex synthesis methods, offering enhanced stability and potential advancements in energy conversion devices. The process detailing how shock waves initiate the phase transition is explained. [ABSTRACT FROM AUTHOR]

Nucleic acid modifications have attracted increasing attention in recent years since they have been found to be related to a number of diseases including cancer. Previous studies have shown that the early development of endometrial cancer (EC) is often accompanied by changes in methylation levels of related genes, and the expression of related proteins that regulate reactive oxygen species (ROS) shows significant differences in EC cells and tissues. However, it has not been reported whether nucleic acid modifications related to methylation or ROS can serve as biomarkers for EC. Accurate quantification of these nucleic acid modifications still has challenges because their amounts in urine are very low and the interferences in urine are complicated. In this study, a novel dispersive solid-phase extraction (DSPE) method based on chitosan-carbon nanotube-Al2O3 (CS-CNT-Al2O3) has been established for the analysis of 5-hydroxymethyluracil (5 mU), 5-methyl-2′-deoxycytidine (5-mdC), 5-hydroxymethyl-2′-deoxycytidine (5-hmdC), 5-formyl-2′-deoxycytidine (5-fdC), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in EC patient urine samples coupled with UHPLC-QE-Orbitrap-MS/MS and HPLC–UV. Firstly, the synthesis of the CS-CNT-Al2O3 nanocomposite was conducted by a sono-coprecipitation method and was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and Fourier transform infrared (FTIR). Under the optimal extraction conditions of DSPE, we successfully quantified 5 mU, 5-mdC, 5-hmdC, 5-fdC, and 8-OHdG in urine samples from 37 EC patients and 39 healthy controls. The results showed that there were significant differences in the levels of 5-mdC, 5-hmdC, 5-fdC, and 8-OHdG in EC patients compared to the healthy control group. The receiver operator characteristic (ROC) curve analysis was carried out to evaluate the potential of 5-mdC, 5-hmdC, 5-fdC, and 8-OHdG to distinguish EC patients from healthy volunteers. The area under the curve (AUC) for 5-mdC, 5-hmdC, 5-fdC, and 8-OHdG was 0.7412, 0.667, 0.8438, and 0.7981, respectively. It indicated that 5-mdC, 5-hmdC, 5-fdC, and 8-OHdG had certain potential in distinguishing between EC patients and healthy volunteers and they could act as potential non-invasive biomarkers for early diagnosis of EC. Moreover, the present study would stimulate investigations of the effects of nucleic acid modifications on the initiation and progression of EC. [ABSTRACT FROM AUTHOR]

Lead-free antiferroelectric AgNbO3 ceramics have garnered extensive attention due to their rapid charge/discharge capabilities and environmentally friendly nature, holding immense potential for energy storage applications. However, the practical utilization of AgNbO3 has been hindered by its low energy storage density. This study employed an A/B-site co-doping strategy, which yielded positive effects on the energy performance of AgNbO3 ceramics. By modifying the A/B-sites with equivalent amounts of Bi3+ and Y3+ ions, enhanced maximum polarization, improved breakdown field, and slimmer hysteresis loops were simultaneously achieved, as the combined effects of refined grain size, wider optical bandgap, and randomly distributed antiferroelectric nanodomains, which were verified through the scanning electron microscope, transmission electron microscope, and ultraviolet–visible spectrum. As a consequence, a high energy storage density of 5.40 J/cm3 accompanied by an energy storage efficiency of 56.5% was achieved in the Ag0.97Bi0.01Nb0.994Y0.01O3 ceramic under a relatively low electric field of 190 kV/cm. This study underscores the effectiveness of A/B-site aliovalent co-doping as a viable strategy for developing high-performance ceramic capacitors for energy storage applications. [ABSTRACT FROM AUTHOR]

Compared with cold spraying and electroplating, laser cladding is also an efficient and reliable surface modification technique to prepare pure copper coating, yet with uniqueness such as the combination of forming metallurgical bonding with substrate and high deposition rate. As such, pure copper coating with different overlap rates was successfully prepared on the Q245R substrate. The surface quality, defects quantity, phase composition, grain orientation, and corrosion behavior were investigated by surface profiler, scanning electron microscope, energy dispersive spectrometer, X-ray diffraction, electron backscattered diffraction, and electrochemical analysis. As the overlap rate increases, the surface roughness decreases then increases, and the pores and unfused defects disappear then reappear. The grain formation changes from columnar to equiaxed crystals and then to columnar crystals, with the orientation of grains shifting from 100 to 101 direction. Further analysis revealed that the pure copper coating with a 70% overlap rate possesses fewer pores, unfused defects, and no interfacial cracks, thus the best compactness. Moreover, the pure copper coating with a 70% overlap rate in 3 mol/L NaCl solution exhibits the best corrosion resistance. [ABSTRACT FROM AUTHOR]

Shellac, a naturally degradable material, was used as a carrier to load some functional and active compounds in the packaging fields. It is rarely used directly as a substrate to prepare packing films due to its unsatisfactory solubility and mechanical properties. In this research, ammonia was used as a solvent to dissolve shellac which helped form a smooth and tough shellac film via the interaction between shellac and ammonia. Moreover, a shellac composite film was formed by additional cellulose nanofibers (CNF). The properties of the shellac composite films (SAmCxPS) were regulated by modulating the concentrations of ammonia and CNF. The prepared films were characterized by a scanning electron microscope (SEM), NanoS Zetasizer, thermogravimetric analysis (TGA), and UV-Vis spectrophotometer, and their tensile strength was also determined. The results revealed that the shellac composite films were successfully prepared and were very thermally stable. The maximum tensile stress of the shellac composite films with 0.9 wt% CNF could reach 20.5 MPa. Such a high tensile stress indicated significantly improved mechanical properties. Moreover, the shellac composite films also showed good UV barrier properties, which reduced the ripeness of the fruit. Overall, the improvement in the stability and mechanical and UV barrier properties of shellac can broaden its application in the field of packaging. [ABSTRACT FROM AUTHOR]

Glass fiber‐reinforced resin matrix composites have good mechanical and impact resistance properties, while with particle co‐reinforcement, a synergistic effect can further improve their performance. In this paper, continuous glass fiber‐reinforced nylon 6 (GF/PA6) and continuous glass fiber (GF) with glass beads (GBs) co‐reinforced nylon 6 (GB–GF/PA6) were prepared to investigate the co‐reinforcement mechanism and the synergistic effect of particle and fiber. A quantitative parameter of the residual impact force divided by the critical force Pr/Pcr, as the damage degree of the low‐velocity impact, is defined to evaluate the impact resistance of the composite. The results indicate that the damage of GB–GF/PA6 was lower than that of GF/PA6, and the synergistic effect reaches the most obvious at the GB addition of 10 wt%. Scanning electron microscope (SEM) and x‐ray computed tomography (XCT) images disclose that GB impedes the type II crack spread in the matrix and fiber/matrix interface. With the type II cracks reducing, the materials' resistance to delamination can be significantly enhanced. For the composite structure, in which 10 wt% GB and 60 wt% GF are introduced, the flexural strength, shear strength, and pendulum impact strength were tested with the maximum values of 379.4 MPa, 53.1 MPa, and 219.0 J/m2, respectively. This composite structure design, presenting a continuous GF and GBs co‐reinforce effect, offers a manufacturing process that is easily scalable to achieve excellent characteristics. [ABSTRACT FROM AUTHOR]

Manufacturing and investigating metallic‐glass‐fiber‐reinforced epoxies is an important new attempt to present their potential to contribute to the aviation industry. In order to explore the energy absorption in novel CoFeSiB metallic‐glass‐fiber/epoxy resin composites, CoFeSiB/epoxy resin composite cylinders with different fiber volume fractions were prepared by a hot‐pressing method. The amorphism of the metal fibers was analyzed using x‐ray diffraction. The quasi‐static compression tests were performed on different fiber oriented samples with a diameter of 3.6 mm and a height of 7.2 mm. The sample with the fiber orientation [0°/90°] has a higher energy absorption capacity, compared to the one with the fiber orientation [0°/0°]. The dynamic‐ compression tests were performed on the [0°/0°] samples with a diameter of 3 mm and height of 6 mm at different air pressures. The compression fracture surfaces were examined by scanning electron microscope. Then the energy absorption mechanism of the composites was investigated. This study is of great significance for the energy absorption in amorphous metal fiber/epoxy composites. [ABSTRACT FROM AUTHOR]

High-performance Sr 0.99 La 0.01 TiO 3 ceramics were synthesized using a conventional solid-phase method, and Sr 0.99 La 0.01 TiO 3 percolated (SLT10-P) samples with excellent resistivity were obtained by coating with an oxidant and heat treatment. In this work, simultaneous excellent dielectric properties (16667 of dielectric permittivity, 0.016 of loss tangent at 1 kHz) and high resistivity (1.44 × 1011 Ω·cm at DC100V) was achieved in SLT10-P ceramics at room temperature by modulating the duration of thermal treatment. X-ray Diffraction and scanning electron microscope analyses proved the diffusion of the oxidant in the grains and grain boundaries during the heat treatment. The increase in grain boundary resistance is mainly due to the fact that the insulating layer formed by the oxide ions entering the grain boundary hinders the long-range movement of electrons. In addition, the diffusion of oxygen from the air into the ceramic during the heat treatment process also contributes to the insulation of grain boundaries. [ABSTRACT FROM AUTHOR]

Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to discuss the corrosion loss and morphology of the pit and rust layer of carbon steel. It was found that the corrosion process is largely influenced by the cyclic shedding of surface corrosion products, in addition to being controlled by the mechanism of oxide film shedding and pit evolution. A corrosion mechanism (the mechanism of rust layer shedding) is proposed. As a result, in this paper, the corrosion process of the test steel is simulated by the cellular automata. It was set up that the mechanism of oxide film shedding, the mechanism of pit evolution, and the mechanism of rust layer shedding in Cellular Automata Simulation. The optimal time ratio and simulation parameters were found, and a predictable cellular automata corrosion simulation model was built, providing a solution for carbon steel's service life prediction. [ABSTRACT FROM AUTHOR]

The performance of apparently biocompatible implanted bovine bone grafts may be compromised by unresolved chronic inflammation, and poor graft incorporation leading to implant failure. Monitoring the intensity and duration of the inflammatory response caused by implanted bone grafts is crucial. In this study, the ability of demineralized (DMB) and decellularized (DCC) bovine bone substitutes in initiating inflammatory responses to peripheral blood monocyte-derived macrophages (PBMMs) was investigated. The response of PBMMs to bone substitutes was evaluated by using both direct and indirect cell culture, reactive oxygen species (ROS) generation, apoptosis, immunophenotyping, and cytokine production. Analysis of DMB and DCC substitutes using scanning electron microscope (SEM) showed a roughened surface with a size ranging between 500 and 750 μm. PBMMs treated with DMB demonstrated cell aggregation and clumping mimicking lipopolysaccharide (LPS) treated PBMMs and a higher proliferation ability (166.93%) compared to control (100%) and DCC treatments (115.64%; p<0.001) at 24h. This was associated with a significantly increased production of intracellular ROS in PBMMs exposed to DMB substitutes than control (3158.5 vs 1715.5; p<0.001) and DCC treatment (2117.5). The bone substitute exposure also caused an increase in percentage apoptosis which was significantly (p<0.0001) higher in both DMB (27.85) and DCC (29.2) treatment than control (19.383). A significant increase in proinflammatory cytokine expression (TNF-α: 3.4 folds; p<0.05) was observed in DMB substitute-treated PBMMs compared to control. Notably, IL-1β mRNA was significantly higher in DMB (21.75 folds; p<0.0001) than control and DCC (5.01 folds). In contrast, DCC substitutes exhibited immunoregulatory effects on PBMMs, as indicated by the expression for CD86, CD206, and HLDR surface markers mimicking IL-4 treatments. In conclusion, DMB excites a higher immunological response compared to DCC suggesting decellularization process of tissues dampen down inflammatory reactions when exposed to PBMM. [ABSTRACT FROM AUTHOR]

This study investigated the suitability of recycled asphalt pavement and polyethylene wastes as coarse aggregate in asphaltic concrete by evaluating the impact of the use of polyethylene polymer wastes and recycled asphalt pavement composite as aggregates on the physical and mechanical properties of the asphaltic concrete. The physical characteristics of the aggregate and bitumen were determined using relevant parametric tests. Recycled asphalt pavement was used to make asphaltic concrete samples using LDPE at 5%, 10%, 15%, RAP at 5% and HDPE at 5%, 10%, 15%, and a mixture of LDPE + HDPE at 5+5%, 7.5+7.5% and 10+10% RAP at 5% as additives. Marshall Stability test was conducted to assess the mechanical strength of the asphaltic concrete, and the results included information on the aggregate's stability, flow, density, voids filled with bitumen, voids filled with air, and voids in mineral aggregate. In addition, the surface and crystal structure of the aggregates was studied by carrying out a microscopic examination with a Scanning Electron Microscope (SEM) and X-Ray diffraction (XRD). The results obtained from this study demonstrated that RAP, HDPE & LDPE are viable conventional aggregate substitute for asphalt concrete production. [ABSTRACT FROM AUTHOR]

In recent years, advances in materials engineering based on adaptive electronics have found a new paradigm to optimize drawbacks in signal processing. A two-layer MnO/ZnO:Zn heterostructure envisioned for frequency adaptive electronic signal processing is synthesized by sputtering, where the use of internal states allows reconfigurability to obtain new operating modes at different frequency input signals. X-ray diffraction (XRD) analysis is performed on each layer, revealing a cubic structure for MnO and a hexagonal structure for ZnO:Zn with preferential growth in [111] and [002] directions, respectively. Scanning electron microscope (SEM) micrographs show that the surface of both materials is homogeneous and smooth. The thickness for each layer is determined to be approximately 106.3 nm for MnO, 119.3 nm for ZnO:Zn and 224.1 nm for the MnO/ZnO:Zn structure. An electrical characterisation with an oscilloscope and signal generator was carried out to obtain the time-response signals and current-voltage (I–V) curves, where no degradation is detected when changing frequencies within the range of 100 Hz to 1 MHz. An equivalent circuit is proposed to explain the effects in the interface. Measurements of switching speeds from high resistance state (HRS) to low resistance state (LRS) at approximately 17 ns, highlight the device's rapid adaptability, and an estimated switching ratio of approximately 2 × 104 indicates its efficiency as a memristive component. Finally, the MnO/ZnO:Zn heterojunction delivers states that are stable, repeatable, and reproducible, demonstrating how the interaction of the materials can be utilised in adaptive device applications by applying frequencies and internal states to create new and innovative design schematics, thus reducing the number of components/connections in a system for future sustainable electronics. [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]

The aim of this research is to investigate basalt as a natural mineral-based fibre together with a vitrimeric resin as a sustainable alternative to standard composite materials. Vitrimers combine the properties of thermoset and thermoplastic polymers, enabling the repair of specimens and hence prolonging the lifetime of the composite material. The micro-mechanical characteristics between the basalt fibres and the vitrimer resin are reported and shown to match those of a standard Skyflex K51 epoxy resin. Discontinuous (4 mm) basalt fibres were employed to produce aligned discontinuous fibre-reinforced composites (ADFRCs) using the high-performance discontinuous fibre (HiPerDiF) technology. The mechanical characteristics of the laminates were investigated through tensile testing and the fracture zones were analysed under a scanning electron microscope. By normalising the results by their respective fibre volume fraction, it was discovered that the vitrimer–basalt ADFRCs exhibited, on average, a 4% higher strength and a 25% higher stiffness compared to their basalt epoxy counterparts. The repair potential of the vitrimer ADFRC specimens was explored during low-temperature compression repair. Two approaches were tested using double-sided local- and full-patch repair. Both successfully recovered a significant amount of their prime strength. In conclusion, the potential of the sustainable vitrimer–basalt composite is shown by its competitive mechanical performance. Combining this with the manufacturing flexibility, repair potential, and recyclability of the material, the vitrimer–basalt composite seems to be a competitive alternative to standard glass epoxies. [ABSTRACT FROM AUTHOR]

Polymers generally form incompatible mixtures that make the process of recycling difficult, especially the mechanical recycling of mixed plastic waste. One of the most commonly used films in the packaging industry is multilayer films, mainly composed of polyethylene (PE) and polyamide (PA). Recycling these materials with such different molecular structures requires the use of compatibilizers to minimize phase separation and obtain more useful recycled materials. In this work, commercial polyisoprene–graft–maleic anhydride (PI-g-MA) was tested as a compatibilizer for a blend of PE and PA derived from the mechanical recycling of PE/PA multilayer films. Different amounts of PI-g-MA were tested, and the films made with 1.5% PI-g-MA showed the best results in terms of mechanical properties and dart impact. The films were also characterized thermally via thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), using Fourier-transform infrared spectroscopy (FTIR), and morphologically using a scanning electron microscope (SEM). Other parameters, such as tearing and perforation, were analyzed. [ABSTRACT FROM AUTHOR]

Introduction: We compared the effects of heat on the physicochemical properties of recently developed calcium silicate-based sealers (CSBSs), including BioRoot Flow, BioRoot RCS, and AH Plus Bioceramic sealer, with those of the epoxy-resin-based sealer (ERBS) AH Plus. Methods: The flow, film thickness, setting time, and solubility of sealers were evaluated at 37 °C and 100 °C using ISO 6876/2012. Furthermore, pH and calcium ion release were evaluated at these temperatures. In addition, the mass change in sealers at a high temperature was assessed via thermogravimetric analysis. Then, the chemical composition and components of the sealers were analyzed using a scanning electron microscope and Fourier-transform infrared spectroscopy (FTIR). Results: BioRoot Flow, AH Plus Bioceramic, and AH Plus complied with ISO standards in terms of flow and film thickness, both before and after heat application. However, BioRoot RCS exhibited significantly increased film thickness at 100 °C. The setting times of all sealers were significantly reduced at 100 °C. The solubility of CSBS was >3%, exceeding the ISO 6876/2012 standard, both before and after heat exposure. Conversely, the solubility of AH Plus complied with the standard, regardless of the thermal condition. For 4 weeks, CSBS showed a significantly higher pH than AH Plus at both 37 °C and 100 °C. After heat treatment, calcium release decreased in Bioroot RCS and BioRoot Flow, while AH Plus showed no significant differences before and after treatment. However, CSBS consistently exhibited significantly higher calcium release than AH Plus at both temperatures. An FTIR analysis revealed that the chemical composition of the sealers did not change at the high temperature, whereas a thermogravimetric analysis demonstrated a >5% weight reduction in CSBS and a 0.005% weight reduction in AH Plus at 100 °C. Conclusions: BioRoot Flow, AH Plus Bioceramic, and AH Plus possess favorable physicochemical properties, which make them suitable for application under thermal conditions. At a high temperature, BioRoot RCS did not exhibit changes in its chemical composition. However, its film thickness was increased, and pH and solubility were reduced. Therefore, caution is needed when it is applied at high temperatures, such as during the warm obturation technique. [ABSTRACT FROM AUTHOR]

Microplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental V–I curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale. [ABSTRACT FROM AUTHOR]

Today, increasing dyes pollution is of great importance for life. Leaving the dyes used in industries such as textiles without being discharged pollutes other water sources. In order to prevent this, different methods are used in the literature. In this study, SrAl2B2O7, a borate metal, was used to remove methyl blue (MB), an anionic dye, by batch adsorption method. Strontium aluminoborate (SrAl2B2O7) was prepared using a solution combustion method at 950 °C for 4 h in air. The prepared adsorbent was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The particle morphology of the adsorbent was investigated using scanning electron microscope (SEM). By using N2 adsorption–desorption, the Brunnauer, Emmet, and Teller (BET) specific surface area was found to be 1.9578 m2 g−1. The surface charge of the dye-adsorbed SrAl2B2O7 was determined based on zeta-potential measurements. Langmuir (R2=0.9897), Freundlich (R2=0.985), Dubinin & Radushkevic (R2=0.976), Scatchard (R2=0.881), Temkin & Pyzhev (R2=0.978) isotherms were calculated in the study. SrAl2B2O7 showed good adsorption performance for methyl blue (MB) with maximum adsorption capacities of 29.069 mg g−1 (Langmuir). Adsorption processes were also studied in detail. Thermodynamic and kinetic models; pseudo-first-order (R2=0.415), pseudo-second-order (R2=0.999), Elovich (R2=0.968) showed that adsorption using SrAl2B2O7 in MB removal is endothermic and pseudo-second order. [ABSTRACT FROM AUTHOR]

A pair of polyaniline (PANIs) samples was prepared from HCl or H2SO4 electrolytes containing 0.01 M of aniline, and then subjecting them to electropolymerization. The morphology, structure, and properties of the samples were characterized using scanning electron microscope, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The results demonstrate that the capacitance and morphology of the product depend exclusively on the reactive medium used. The PANI was used as a material electrode in a supercapacitor, and the electrochemical performance of the elaborated electrodes was evaluated using cyclic voltammetry, galvanostatic charge/discharge measurement, and electrochemical impedance spectroscopy. The optimal results for the specific capacitance of the PANI films were achieved under a 5-mVs−1 scan rate, ranging from 410.35 F/g for the FTO/PANI-H2SO4 to 758.72 F/g for the FTO/PANI-HCl. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing effectively enhances production in the unconventional oil and gas industry. As we all know, proppant plays a vital role in the hydraulic fracturing. In this paper, the effects of proppant type, particle size, concentration, closure pressure, and other factors are studied by laboratory experiments. Based on the actual triaxial simulation device (TSD), quartz sand, ceramic, and coated sand are used as proppant, while sandstone, coal rock, shale, and granite are selected as the stone slate to experiment. The surface of the proppant was imaged by a surface profiler (SP) and scanning electron microscope (SEM) to compare the microscopic surface characteristics before and after the experiment. The particle size macroscopic distribution was measured by Mastersizer 2000. The results and innovation are as follows: This paper investigates the proppant crushing for hydraulic fracturing and provides an alternative evaluation method for proppant selection. The crushing laws of proppant under different pressures and stone slate are compared by using the experimental device. It is reliable for quartz sand to replace ceramic in deep layer of the field application. It also overturns the previous thinking. We believe this found holds the key toward systematically optimizing the development of unconventional reservoirs. [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]

In the current research, new metal complexes have been synthesized by using the greener synthetic approach in which 3‐Nitroaniline reacts with the elements of group‐IIB and group‐IVB. According to this method, ligand and metals were dissolved in 1,4‐dioxane and stirred at room temperature for a specific time period. The method for the preparation of metal‐base complexes is quite simple and cost‐effective. To identify the synthesized compounds various physio‐chemical analytical techniques were used such as Melting point, FT‐Raman Spectroscopy, FT‐IR Spectroscopy, Thermogravimetric analysis, and Scanning electron microscope (SEM) that provide significant data about the general structural characteristics of synthesized compounds. The percentage degradation efficiency of synthetic dyes was obtained as 57 %, 66 %, and 97 % using the synthesized compounds as photocatalysts. A statistical tool, RSM was used for the optimization of parameters (Concentration of Dye, Dose of Catalyst, and contact time). [ABSTRACT FROM AUTHOR]

The lithium metal battery is likely to become the main power source for the future development of flying electric vehicles for its ultra-high theoretical specific capacity. In an attempt to study macroscopic battery performance and microscopic lithium deposition under different pressure conditions, we first conduct a pressure cycling test proving that amplifying the initial preload can delay the battery failure stage, and the scanning electron microscope (SEM) shows that the pressure is effective in improving the electrode's surface structure. Secondly, we analyze how differing pressure conditions affect the topography of lithium deposits by coupling the nonlinear phase-field model with the force model. The results show that the gradual increase in the external pressure is accompanied by a drop in the length of the dendrite and the migration curvature in the diaphragm, and the deposition morphology is gradually geared towards smooth and thick development, which can significantly reduce the specific surface area of lithium dendrite. However, as cyclic charging and discharging continue, the decrease in the electrolyte diffusion coefficient results in higher internal stress inside the battery, and thus the external pressure must be increased so as to achieve marked inhibitory effects on the growth of the lithium dendrite. [ABSTRACT FROM AUTHOR]

In recent years, silver sintering has gained increasing attention in high-power density electronic packaging due to its characteristics such as a high melting point and excellent thermal and electrical conductivity. Micron-sized silver sintering offers a lower cost, but requires a longer processing time and additional pressure, which constrains its application. This paper presents a low-cost sintering process using infrared radiation (IR) as a heat source. By leveraging the unique properties of IR, the process achieves selective heating. The thermal energy can be mainly absorbed by the specific areas requiring sintering. This innovative approach eliminates the need for external pressure during the sintering process. This feature not only simplifies the overall process but also reduces the processing time required for sintering. The silver joints obtained from IR sintering process for 45 min achieved an average chip shear strength of 38 MPa at a temperature of 225 °C, which is higher than the strength of silver joints obtained from a traditional sintering process for 2 h. Additionally, the IR-sintered silver joints have a resistivity of 9.83 × 10−5 Ω·cm and scanning electron microscope (SEM) images of the joints reveal that the sintered joints obtained through the IR sintering process exhibit less porosity compared to joints obtained through a traditional sintering process. The porosity of the IR silver joints at 225 °C is 6.4% and does not change even after 3000 cycles of thermal shock testing, showing outstanding reliability. A GaN power device using IR silver joint also performed better in thermal and electrical performance testing, showing promising potential for the application of micro-silver paste in power electronic devices. [ABSTRACT FROM AUTHOR]

Long-term irrigation promotes the infiltration of water in the thick, stratified loess layer, significantly raising the groundwater table and triggering a series of landslides in loess platform areas. The soil–water characteristic curve (SWCC) of loess buried at different depths affects the unsaturated infiltration process and is intricately connected to the soil's microstructure. The SWCCs, scanning electron microscope (SEMs), and pore size distributions (PSDs) for five sets of undisturbed loess samples at depths ranging from 3.4 to 51.9 m are shown in this paper. The results indicate that the fitting parameter air entry value (AEV) of the SWCC rises from 13.67 kPa to 40.19 kPa as the depth increases from 3.4 to 51.9 m. And the saturated volumetric water content drops by 10.9%, with a notable SWCC shape difference between the transition and residual zones observed. Additionally, the total porosity of undisturbed loess falls by 12% when the depth increases from 3.4 to 51.9 m, while the macropores and mesopores reduce by 3.6% and 12.1%, respectively. These findings highlight the control of the pore structure on the SWCC and emphasize the correspondence between the SWCC and PSD. The conclusions also illustrate that the compaction effect changes the microstructure characteristics of loess, thereby affecting the soil's water retention behavior. [ABSTRACT FROM AUTHOR]

This study investigates the correlation between coercivity (Hc), grain size (d), and dislocation density in the Permimphy alloy (Fe–80%Ni–6%Mo). The samples used in this study were subjected to varying levels of applied strain through processing by high-pressure torsion. The microstructure and the magnetic coercivity were analyzed using a scanning electron microscope, electron backscatter diffraction and vibrating sample magnetometry. The grain size of the samples varied from 30 to 190 nm. This study demonstrated a strong correlation between Hc and microhardness when d > 3 µm. The results show that the coercivity of the Permimphy alloy follows an inverse V-shape with respect to grain size. The coercivity of the samples decreased despite increasing the dislocation density and the hardness when d < 3 µm. This phenomenon is attributed to the ferromagnetic exchange interaction across multiple grains and leads to the alignment of magnetic moments. [ABSTRACT FROM AUTHOR]

A molten salt-assisted method for the synthesis of Eu 3 + -doped bismuth molybdate (BMO: Eu 3 + ) phosphor was proposed. (BMO: Eu 3 + ) phosphors with different phase structures were obtained by changing the calcination temperature. The applications in LED devices and latent fingerprint recognition of the obtained product were explored. The results of structural characterizations and scanning electron microscope (SEM) photographs analysis prove that the products exhibit different crystal structures and morphologies with the change of calcination temperature. Based on the above findings, the as-prepared products have potential applications in the field of WLED and potential fingerprint recognition. [ABSTRACT FROM AUTHOR]

Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense, Tropical Race 4 (TR4) is a soil-borne disease, and it is devastating. At present, the biological control using antagonistic microorganisms to mitigate TR4 is one of the best strategies as a safe and green way. Yunnan has abundant and diverse microbial resources. Using the dual-culture method, the antagonistic endophytic fungi against TR4 were isolated and screened from the root nodule of Dolichos lablab. The effect of the highest antagonistic activity strain on the morphology of the TR4 mycelium was observed using the scanning electron microscope. According to morphological characteristics and sequence analysis, the strain was identified. The biocontrol effect and plant growth promotion were investigated by greenhouse pot experiment. Using the confocal laser scanning microscope and the real-time fluorescence quantitative PCR, the dynamics of TR4 infestation and the TR4 content in banana plant roots and corms would also be detected. In this study, 18 native endophytic fungi were isolated from a root nodule sample of Dolichos lablab in the mulch for banana fields in Yuxi, Yunnan Province, China. The YNF2217 strain showed a high antagonistic activity against TR4 in plate confrontation experiments, and the inhibition rate of YNF2217 is 77.63%. After TR4 culture with YNF2217 for 7 days in plate confrontation experiments, the morphology of the TR4 mycelium appeared deformed and swollen when observed under a scanning electron microscope. According to morphological characteristics and sequence analysis, the strain YNF2217 was identified as Pochonia chlamydosporia. In the greenhouse pot experiment, the biocontrol effect of YNF2217 fermentation solution on TR4 was 70.97% and 96.87% on banana plant leaves and corms, respectively. Furthermore, YNF2217 significantly promoted the growth of banana plants, such as plant height, leaf length, leaf width, leaf number, pseudostemgirth, and both the aboveground and underground fresh weight. Observations of TR4 infestation dynamics in banana roots and corms, along with real-time fluorescence quantitative PCR, verified that YNF2217 inoculation could significantly reduce the TR4 content. Therefore, YNF2217 as P. chlamydosporia, which was found first time in China and reported here, is expected to be an important new fungal resource for the green control of Fusarium wilt of banana in the future. [ABSTRACT FROM AUTHOR]

Hansen solubility parameter theory and rheological laws were employed to investigate the microscopic cross-linked network structure of the wear-resistant elastomer based on ethylene propylene diene monomers (EPDM)-polyamide elastomers (PAE)/graphite. With the condition of the same carbon black content, the wear volume of EPDM-PAE increased after added wax powder and decreased by adding five percent graphite. The role of microscopic cross-linked network on the wear-resistant properties was specifically characterized by a highly linear synergistic relationship between wear volume and cross-link density. The motion ability of micro chain segments has been characterized by the frequency sweep and the influence of the filler network has been represented by the strain sweep. Scanning electron microscope was used to characterize the micro filling structure, while stereomicroscope view was used to explore the wear interface. It was noteworthy that the graphite network layer formed on the abrasive surface on top of the abrasive grit wear transformed the wear mechanism into composite wear. This work was an innovative perspective to study rubber-plastic/solid lubricant-based wear-resistant elastomers, based on microscopic network structures, which could help to obtain new wear-resistant elastomers with specific properties. [ABSTRACT FROM AUTHOR]