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Based on mechanical tensile experiments on the CoCrFeNi high-entropy alloy (HEA), this study explores the forming patterns of the eccentrically shaped sub-hemispherical lined explosively formed projectile (EFP) made of the HEA material. The CoCrFeNi HEA material is initially prepared, and mechanical tensile tests are conducted at various temperatures and strain rates. The Johnson–Cook (J–C) constitutive equation for this material is derived by fitting the experimental data. Scanning electron microscopy and the energy dispersive spectrometer characterize the fracture surface of the tensile specimens, providing insights into the mechanical ductility and fracture mechanism of CoCrFeNi HEA. The EFP forming process under various charge configurations is simulated using AUTODYN software, leading to the identification of the optimal charge configuration. In addition, the damage performance is evaluated. This study provides a theoretical basis for applying HEA materials in the field of shaped charges and offers new ideas and methods for designing more efficient shaped charge warheads. [ABSTRACT FROM AUTHOR]

The mechanical and dielectric properties of transformer insulating paper are key factors that require close attention to ensure optimal operation. In this study, a novel approach of enhancing properties by nanocellulose modification was proposed. To investigate the effect of doping, insulating paper with different doping mass fractions of cellulose nanocrystals (CNCs) was prepared, and multiple properties of the sample were characterized. By applying a doping concentration gradient, the non-monotonic trend in performance with doping levels was revealed, and the impact of doping concentration on the data variability was investigated. The effects of CNC doping on the surface pore size of the samples were analyzed by SEM (scanning electron microscopy) and a mercury intrusion method, and the regularity of CNC dispersion uniformity with doping concentration was investigated. The Brunauer, Emmett, and Teller model was employed to fit the water vapor adsorption isotherm data, providing an analysis of the impact of doping on hydrogen bond connections and the moisture adsorption properties. Tensile strength and Young's modulus were measured and analyzed using the Page model and the Halpin–Kardos model. The tensile strength of the 6 wt. % CNC-modified paper was increased by 6.91%. 10 wt. % CNC-modified paper had a Young's modulus increase of 11.98%. 3 wt. % CNC-modified paper has a 28.53% increase in the AC breakdown field strength and an 8.72% increase in the DC breakdown field strength. The influence of CNC on the dielectric properties of the insulating paper was discussed using the Havriliak–Negami (H–N) model. The results indicate that the introduction of CNC can effectively enhance the comprehensive performance of oil-immersed insulating paper. [ABSTRACT FROM AUTHOR]

In approaches to analyze material composition or in processing tasks using ultra-short laser ablation, it is of particular interest how ablated materials are distributed across the solid angle in front of the interaction region. We found that with our sub-10-fs laser in the regime from 10 14 W / c m 2 to 10 17 W / c m 2 , the solid angle of the ablation cone decreases significantly along with the laser intensity in a vacuum environment. For this observation, we used ion-beam analysis to investigate the distribution of tungsten collected on silicon catcher plates arranged across the solid angle of the laser-ablation cone. Moreover, we used other post-mortem tools, such as scanning electron microscopy and confocal laser scanning microscopy, to determine the ablation threshold of F t h = 468 mJ / c m 2 of our tungsten samples. Here, clearly, two laser intensity-dependent ablation regimes can be observed in the detection of a crater depth and a ablation cone angle. [ABSTRACT FROM AUTHOR]

Ag-induced crystallization and layer exchange (AgILE) in a stack of amorphous Si/Ag/quartz substrate has been investigated using optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM), scanning TEM-high angle annular dark field (STEM-HAADF) imaging, and electron tomography, covering length scales from a few tens of micrometers to a few tens of nanometers. The size of Ag grains in the underlying as-deposited Ag film varied from ∼10 to 500 nm. The following processes could be discerned using in situ heating of plan-view samples at 500 °C in STEM: (i) AgILE propagation preferentially along regions of small Ag grains, (ii) formation of pushed-up Ag in the vicinity of AgILE reaction cells, (iii) migration and agglomeration of pushed-up Ag on small and large Ag grains, which tend to inhibit AgILE and promote dendricity, and (iv) dispersion of pushed-up Ag, which tend to reduce dendricity. The resulting dendricity was largely confined to the peripheral regions of the impinging reaction cells and decreased with annealing time. In contrast, dendricity due to AgILE and crystallization at 550 °C is stable and extends right from the center to the periphery of the reaction cells. The microscopic mechanism of AgILE and, in particular, the effect of annealing temperature is investigated. The results are discussed in the light of existing literature and compared with Al-induced layer exchange. Annealing at temperature equal to or slightly less than 500 °C is found to be necessary in the case of AgILE to avoid dendricity and to obtain a continuous Si layer with large Si grains. [ABSTRACT FROM AUTHOR]

Purpose: To compare abutment screw loosening in 24-degree angulation-correcting and straight implants subjected to nonaxial cyclic loading. Materials and Methods: Seven external connection 24-degree angulation-correcting implants (AI) and seven external connection straight implants (SI) were embedded in acrylic resin within a brass housing. A hemispherical titanium fatigue abutment was secured to each implant using a titanium abutment screw tightened to 32 Ncm. Each implant-abutment complex was positioned within a tooth wear machine and subjected to 1,000,000 cycles of 50-Ncm nonaxial loading to simulate 1 year of function. The abutment screw removal torque values were measured before and after cyclic loading, and the differences were statistically analyzed using two-way ANOVA and post hoc pairwise Dunn tests. Scanning electron microscopy and finite element analyses were performed to assess the wear of the abutment screws. Results: The mean torque loss for the AI group was 21.44% (P < .001) compared to 24.56% (P < .001) for the SI group. There was a statistically significant difference between the AI and SI groups (P = .006). Conclusions: Both groups exhibited significant abutment screw loosening. Within the limitations of this study, 24-degree angulation-correcting implants resisted screw loosening significantly more than straight implants. [ABSTRACT FROM AUTHOR]

This article investigated the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. A total of 15 unsintered zirconia ceramic green bodies (10 × 10 × 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-µm aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by Kruskal-Wallis test (P < .05). Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 µm, 1.26 ± 0.10 µm, and 1.69 ± 0.15 µm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths. [ABSTRACT FROM AUTHOR]

Geological samples are inherently multi-scale. Understanding their bulk physical and chemical properties requires characterization down to the nano-scale. A powerful technique to study the three-dimensional microstructure is X-ray tomography, but it lacks information about the chemistry of samples. To develop a methodology for measuring the multi-scale 3D microstructure of geological samples, correlative X-ray micro- and nanotomography were performed on two rocks followed by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) analysis. The study was performed in five steps: (i) micro X-ray tomography was performed on rock sample cores, (ii) samples for nanotomography were prepared using laser milling, (iii) nanotomography was performed on the milled sub-samples, (iv) samples were mounted and polished for SEM analysis and (v) SEM imaging and compositional mapping was performed on micro and nanotomography samples for complimentary information. Correlative study performed on samples of serpentine and basalt revealed multiscale 3D structures involving both solid mineral phases and pore networks. Significant differences in the volume fraction of pores and mineral phases were also observed dependent on the imaging spatial resolution employed. This highlights the necessity for the application of such a multiscale approach for the characterization of complex aggregates such as rocks. Information acquired from the chemical mapping of different phases was also helpful in segmentation of phases that did not exhibit significant contrast in X-ray imaging. Adoption of the protocol used in this study can be broadly applied to 3D imaging studies being performed at the Advanced Light Source and other user facilities.

Structural materials used in nuclear reactor environments are subjected to coupled extremes such as high temperature, irradiation, and corrosion which act in concert to degrade their functional performance. Connecting alloy microstructure such as grain boundaries, and accumulating point defects with corrosion attack and pore morphology is critical to understanding underlying mechanisms. We uncover the compositional variations and morphology at multiple length scales in corrosion-damaged Ni-Cr alloy after exposure to oxidants in molten fluoride salts. A complex network of dense corrosion pores is detected by surface-level SEM observations. The corrosion pores take on a 1-dimensional morphology and are enriched with Ni and depleted of Cr 1–5 µm from the pore surface. STEM-EDS and 4D-STEM strain maps acquired simultaneously highlight the local variations in composition and structure of a ≤ 200 nm Cr-rich layer identified from a cross-section taken at the bottom of an isolated corrosion pore between the Ni-Cr alloy matrix and the embedded salt. However, the absence of an observed interface between the Ni-Cr alloy matrix and the FCC-structured Cr-rich layer suggests that Cr plating from the salt did not transpire. These findings support a proposed Cr lattice diffusion mechanism rather than Cr-precipitation from the salt to accommodate temperature transient conditions during sample cooling. Through the development of a 1D phase field model, these results are rationalized by formation energies for the Ni- and Cr-oxidation into the molten salt. This study reveals the locally altered microstructure caused by high temperature corrosion in non-steady-state molten salt nuclear reactor environments.

Objectives: The objective was to evaluate the polymerization efficiency of different bulk-fill resin-based composites cured by monowave and polywave light-curing units, by assessment of the degree of conversion and Vickers microhardness at different depths. Method and materials: Two commercially available bulk-fill resin-based composites were used: Filtek One Bulk Fill Restorative (3M ESPE) and Tetric N-Ceram Bulk Fill (Ivoclar Vivadent). The light-curing units utilized were two LED light-curing units: a monowave LED light-curing unit (BlueLEX LD-105, Monitex) and a polywave LED light-curing unit (Twin Wave GT-2000, Monitex). For each test, 20 cylindrical specimens (4 mm diameter, 4 mm thickness) were prepared from each bulk-fill resin-based composite using a split Teflon mold. Ten specimens were light-cured by the monowave light-curing unit and the other ten were light-cured by the polywave light-curing unit according to the manufacturer's recommendations. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATRFTIR) was used to assess the degree of conversion, and a Vickers microhardness tester was used to assess Vickers microhardness. Statistical analysis was performed using three-way ANOVA and Tukey post-hoc tests (P < .05). Results: The degree of conversion and Vickers microhardness in bulk-fill resin-based composites containing only camphorquinone as photoinitiator were similar when cured with either monowave or polywave light-curing units. However, bulk-fill resin-based composites containing a combination of photoinitiators exhibited significantly higher degree of conversion and Vickers microhardness when cured with a polywave light-curing unit. Although all groups showed statistically significant differences between the top and bottom surfaces regarding degree of conversion and Vickers microhardness, all of them showed bottom/top ratios > 80% regarding degree of conversion and Vickers microhardness. Conclusion: The polywave light-curing unit enhanced the polymerization efficiency of bulk-fill resin-based composites especially when the latter contained a combination of photoinitiators, but does not prevent the use of a monowave light-curing unit. [ABSTRACT FROM AUTHOR]

Both shock and shockless compression experiments were performed on laser powder bed fusion (LPBF) Ti–5Al–5V–5Mo–3Cr (Ti-5553) to peak compressive stresses near 15 GPa. Experiments were performed on the as-built material, containing a purely β (body centered cubic) microstructure, and two differing heat treatments resulting in a dual phase α (hexagonal close packed) and β microstructure. The Hugoniot, Hugoniot elastic limit (HEL), and spallation strength were measured and compared to wrought Ti-6Al-4V (Ti-64). The results indicate the LPBF Ti-5553 Hugoniot response is similar between heat treatments and to Ti-64. The HEL stress observed in the LPBF Ti-5553 was considerably higher than Ti-64, with the as-built, fully β alloy exhibiting the largest values. The spallation strength of the LPBF Ti-5553 was also similar to Ti-64. Clear evidence of initial porosity serving as initiation sites for spallation damage was observed when comparing computed tomography measurements before and after loading. Post-mortem scanning electron microscopy images of the recovered spallation samples showed no evidence of retained phase changes near the spall plane. The spall plane was found to have kinks aligned with the loading direction near areas with large concentrations of twin-like, crystallographic defects in the as-built condition. For the heat-treated samples, the concentrations of twin-like, crystallographic defects were absent, and no preference for failure at the interface between the α and β phases was observed. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of sonic oscillation on penetration depth and marginal adaptation of resin-based fissure sealants. Method and materials: Thirty-six extracted human third molars were randomized into three groups: in the HF group, teeth were sealed with a filled-resin-based sealant (Helioseal F); in the Sonic-HF group, teeth were sealed with Helioseal F and subjected to sonic oscillation (Compothixo Device, 140 Hz vibration frequency and ± 150 µm amplitude) before curing; in the CO group, teeth were sealed with an unfilled-resin-based sealant (Clinpro). All teeth were thermocycled for 1,500 cycles at 5°C and 55°C, then sectioned buccolingually into four sections (mesial, two middle, and distal). Sections were evaluated under SEM for marginal adaptation and scored. For penetration depth, three independent measurements from each tooth were recorded under SEM, and data were subjected to statistical analysis. Results: The group subjected to sonic oscillation (Sonic HF) resulted in significantly superior penetration depth and marginal adaptation compared with the HF group, but with no significant difference compared with the CO group. Conclusions: Sonic activation of resin-based sealant increased penetration depth into fissures and marginal adaptation to the enamel wall without decreasing filler load or compromising sealant mechanical properties. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of urethane methacrylate precursor (UMP) on the enzymatic resistance of demineralized dentin (DD) matrices. Materials and Methods: Experimental treatments containing 0 (control), 1, and 5 mmol/L UMP dissolved in an acetone (Ace) solution were formulated. Dentin matrix specimens were demineralized in vitro and immersed in the experimental treatments for 1 h. The treated specimens were then stored in 0.1 mg/mL collagenase solution for 24 h, after which their dry mass loss and hydroxyproline (HYP) release were assessed. The swelling ratios of specimens in each group were also evaluated. The interaction between UMP and the dentin matrix was observed using field-emission scanning electron microscopy (FE-SEM). Endogenous enzyme activity in dentin was evaluated using confocal laser scanning microscopy (CLSM). Results: Compared with the other treatment groups, treatment with 1 mM and 5 mM UMP-Ace significantly decreased the dry mass loss, HYP release and swelling ratio of the DD matrix (p < 0.05). FE-SEM and CLSM observations showed that treatment with UMP-Ace protected the structure of the dentin matrix and decreased porosity within the dentin-collagen network. Conclusion: Treatment with 1 mM and 5 mM UMP-Ace protects DD matrix against collagenase degradation and may be clinically useful for improving the durability of the hybrid layer. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the antibacterial effects of Terminalia catappa Linn (TCL) leaf extracts at different concentrations and the effects of these extracts used as primers on the long-term adhesive properties of two universal adhesives. Materials and Methods: After extract preparation, the antimicrobial and antibacterial activities of TCL against Streptococcus mutans (UA 159) were assessed in microdilution assays to provide the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Additionally, to provide quantitative data on the ability of TCL extract to reduce cell viability, colony forming units (CFU) were counted. To examine adhesive properties, 288 human molars were randomly assigned to 32 experimental conditions (n = 9) according to the following variables: (1) treatment agent: negative control (untreated surface), and primers at concentrations of 1xMIC, 5xMIC, and 10xMIC; (2) adhesives: Scotchbond Universal (SBU) and Futurabond Universal (FBU); (3) adhesive strategy: etch-and-rinse (ER) or self-etch (SE); and (4) storage time: 24 h or after 2 years. Primers were applied for 60 s, upon which the teeth were incrementally restored and sectioned into adhesive-dentin bonded sticks. These were tested for microtensile bond strength (pTBS) and nanoleakage (NL) after 24-h and 2-year water storage, as well as in-situ degree of conversion (DC) at 24 h. The chemical profile of the hybrid layer was determined via micro-Raman spectroscopy. Biofilm assay data were analyzed using the Kruskal-Wallis test; the pH of culture media and the chemical profile were analyzed by one-way ANOVA. The adhesive properties (pTBS, NL, DC) were evaluated using a four-way ANOVA and Tukey's test. Significance was set at 5%. Results: Similar values of MIC and MBC were observed (2 mg/ml), showing bactericidal potential. CFU analysis demonstrated that concentrations of 5xMIC and 10xMIC significantly inhibited biofilm formation (p < 0.001). The application of the TCL primer at all concentrations significantly increased the immediate pTBS and DC, and decreased the immediate NL values when compared to the control group (p < 0.05), regardless of the adhesive and adhesive strategies. Despite an increase in the NLvalues for all groups after2years (p > 0.05), in groups where the TCL primerwas applied, the pTBS remained constant after 2 years for both adhesives, while a decrease in the pTBS was observed in the control groups (p < 0.05). Usually, IOxMIC showed better results than 1xMIC and 5xMIC (p < 0.05). The application of TCL promoted cross-linking; cross-linking rates increased proportionally to the concentration of TCL (p < 0.05). Conclusion: Primers containing TCL promoted bactericidal and bacteriostatic action, as well as cross-linking with dentin, while maintaining the adhesive properties of the adhesive-dentin interface after 2 years of water storage. [ABSTRACT FROM AUTHOR]

Ultrathin ceramic veneers are a viable therapeutic option to manage esthetic challenges in the anterior zone. Proper conditioning of the intaglio surface of porcelain veneers is essential to achieve an adequate bonding. In clinical practice, this is typically done with chemical etching using an acid-containing agent, such as hydrofluoric acid. While it is well established that the etching effect is dependent on etching time and the acid concentration, little is known about the impact of etching time and the veneer fabrication method. The purpose of this pilot study was to evaluate, using scanning electron microscopy (SEM), the effect that different etching-time protocols have on the intaglio surface characteristics of ultrathin ceramic veneers fabricated with either the platinum foil technique or the refractory die technique. Several replicas of an ultrathin feldspathic ceramic veneer for a maxillary central incisor were fabricated. Individual specimens were processed according to different intaglio surface-etching protocols: no etching, etching for 90 seconds, etching for 120 seconds, and etching for 150 seconds (9.6% hydrofluoric acid used for all etching groups). It was observed that the 120-second etching protocol resulted in a favorable microroughness surface pattern in the platinum foil group. This pattern was comparable to that obtained by etching for 90 seconds with hydrofluoric acid the intaglio surface of veneers fabricated with the refractory die technique. Increasing the etching time to 150 seconds did not result in a more favorable roughness pattern. [ABSTRACT FROM AUTHOR]

This study investigated the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives. A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (pTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey's honestly significant difference, and chi-square tests. The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05). Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the piTBS and nanoleakage, likely by affecting the structure of the hybrid layer. [ABSTRACT FROM AUTHOR]

This article investigated the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. A total of 15 unsintered zirconia ceramic green bodies (10 x 10 x 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-p.m aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by the Kruskal-Wallis test (P < .05). Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 µm, 1.26 ± 0.10 µm, and 1.69 ± 0.15 µm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effects of desensitizing MI Varnish (GC America) applied before or after bleaching on the mineral component of enamel and surface topography. The coronal portions of 10 freshly extracted bovine teeth were segmented for a total of 40 specimens. Enamel specimens obtained from each tooth were randomly divided into four groups (n = 10): Group A = no bleaching; Group B = bleaching with 40% hydrogen peroxide (HP); Group C = MI Varnish applied before bleaching; and Group D = MI Varnish applied after bleaching. The calcium (Ca) and phosphorus (P) levels of the specimens in each group were determined by energy dispersive spectroscopy (EDS). Morphologic changes were observed using scanning electron microscopy (SEM). One-way ANOVA and Tukey HSD tests were used for statistical analyses (α = .05). The mean Ca content of Group B was significantly lower than those of Groups A, C, and D (P < .05). The mean Ca content of Group C was significantly lower than that of Group A (P < .05). There was no significant difference in Ca content between the other groups (P > .05). The mean P content of Group A was significantly higher than those of Groups B to D (P < .05). There was no significant difference in P content between Groups B to D (P > .05). Application of MI Varnish before or after in-office bleaching was effective in reducing mineral loss. However, applying MI Varnish after bleaching was more effective. [ABSTRACT FROM AUTHOR]

Purpose: To compare the fracture resistance of five different groups of chairside CAD/CAM molar crowns fabricated from various lithium disilicate ceramic materials (LDC): one conventional precrystallized CAD/CAM LDC, two novel precrystallized LDCs, and one fully crystallized LDC tested both with and without optional sintering. Materials and Methods: A total of 60 chairside CAD/CAM lithium disilicate molar crowns (n = 12 per group) with 1.5-mm occlusal thickness and a 1.0-mm chamfer finish were designed and fabricated with a chairside CAD/CAM system (CEREC, Dentsply Sirona). The restorations were divided into five groups: (1) IPS e.max CAD; (2) Amber Mill; (3) Straumann n!ce; (4) Straumann n!ce with optional sintering; and (5) Supreme CAD. Restorations were cemented using conventional resin luting cement and primer system to 3D-printed resin dies. Bonded restorations were loaded for 100,000 cycles with 275-N force, and the load at break (LB) and peak load (PL) until fracture were measured. SEM images of fracture surfaces on the printed dies were obtained. Results: Fracture resistance was significantly different depending on the material. Supreme CAD showed the highest fracture resistance (LB: 1,557.2 N; PL: 1,785.8 N), followed by Amber Mill (LB: 1,393.0 N; PL: 1,604.2 N) and IPS e.max CAD (LB: 1,315.7 N; PL: 1,461.9 N). Straumann n!ce without (LB: 862.4 N; PL: 942.9 N) and with the optional sintering (LB: 490.4 N; PL: 541.0 N) showed significantly lower fracture resistance than the others. Conclusion: The fracture resistance of chairside CAD/CAM lithium disilicate molar crowns varied depending on the material, and the novel materials did not perform as well as the conventional equivalents. Fully crystallized lithium disilicate ceramic block materials showed lower fracture resistance than precrystallized counterparts and should be used with caution in the clinic, especially with optional sintering. [ABSTRACT FROM AUTHOR]

ScN in the rock salt structure is a well-investigated material due to its desirable properties like the high hardness or large thermal conductivity. Recent computations by Adamski et al. [Appl. Phys. Lett. 115, 232103 (2019)] showed that ScN/GaN heterostructures exhibit an outstanding polarization gradient which would be beneficial for polarization induced electron gases. The pseudobinary semiconductor Sc x Al 1 − x N, when maintaining the cubic rock salt structure, could be beneficial for tailoring the polarization gradient using the Sc dependency of material properties. The structural properties of rs-Sc x Al 1 − x N are not fully discovered yet, thus in this work, DC-magnetron sputtered cubic rock salt Sc x Al 1 − x N thin films with 0.55 < x < 1.00 were grown and analyzed on ScN(111)/Si(111). The epitaxial relation of ScN(111) thin films on the Si(111) substrate is determined to be ScN[110] ∥ Si[100]. Furthermore, concentration dependent properties like the lattice parameter of Sc x Al 1 − x N were measured [a(ScN) = 4.50 Å, a(Sc0.55Al0.45N) = 4.30 Å] and the stress σ within the layers was determined. The crystal quality was evaluated using ω -scans, revealing FWHM = 1.14 ° for Sc0.95Al0.05N. The diameters of the columns were determined by atomic force microscopy and scanning electron microscopy and they are range from 34 to 59 nm for 0.55 < x < 1.00. At x = 0.55 , Sc x Al 1 − x N columns in the hexagonal wurtzite as well as cubic rock salt structure were detected. This information about the structural specifications of Sc x Al 1 − x N in the rock salt structure forms the basis for further investigations and experimental confirmation of the electric properties of ScN/GaN heterostructures or even a Sc x Al 1 − x N/GaN based approach for improved structures for high-electron-mobility transistors. [ABSTRACT FROM AUTHOR]

Nanostructured ZnNiBi-NO3-Layered Double Hydroxides (LDHs) was synthesised, followed by the simple co-precipitation method using Zn(NO3)2.6 H2O, Ni(NO3)2.6 H2O and Bi(NO3)3 as the precursors. Synthesised LDHs was characterised by various techniques such as infrared (IR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray (EDX) and thermal gravimetric analysis (TGA). ZnNiBi-NO3 LDHs were applied as efficient adsorbents for speciation analysis and preconcentration/separation of Cr(VI)/Cr(III) ions in aqueous samples prior to their trace determinations by microsample injection system-coupled flame atomic absorption spectrometry (MIS-FAAS). ZnNiBi-NO3 LDHs worked well for speciation and preconcentration/separation of Cr(VI)/Cr(III) ions at an optimum of pH 3.0 and adsorbent dosage of 400 mg. LOD and LOQ of Cr(VI) ions were calculated to be 0.03 and 0.10 μg L−1, respectively with a preconcentration factor of 400. The total saturation capacity of ZnNiBi-NO3 LDHs for Cr(VI) ions was investigated and found to be 46.0 mg g−1. The mthod was reproduced with RSD ≤1.4% of five replicates. The accuracy of method was evaluated by analysing 10–100 μg L−1 Cr(VI) ions standard solutions, and Cr(VI) ions were recovered ≥96.9% with RSD ≤2.4%. The developed method worked well on wastewater samples. [ABSTRACT FROM AUTHOR]

There has been immense development in the production and use of recyclable materials for dye degradation which are advancing in a wide perspective to minimise the environmental impacts. Therefore, an efficient, eco-friendly, magnetically separable and recyclable catalyst is being reported that has the potential to remove dyes [Tropeolin000, Congo red and Orange G] from wastewater. The catalyst has a backbone containing Zinc, Cobalt and Iron in the ratio Zn0.5Co0.5Fe2O4 with a coating of polyaniline that enhances its dye degradation capability. These synthesised PANi-coated ferrites have been characterised by FTIR, XRD, SEM and EDX techniques, and the photocatalytic activity has been explored using UV–Vis spectrophotometer at ambient conditions. A dye removal efficiency of as high as more than 99.9% has been reported for dye Orange G and above 90% for Tropeolin000. The mechanistic pathway that can be involved in the dye degradation has also been discussed. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the major heavy metal pollutants that can cause serious health problems to humans and the environment. This indicates that its concentration should be known to learn its levels in various environmental systems, and a powerful and economical analytical technique should be there to do so. In this study we report a simple, rapid, cost-effective and environmentally friendly colorimetric sensor based on biosynthesised AgNPs using Parthenium hysterophorus leaf extract. The biosynthesised AgNPs were characterised by UV-vis, FTIR, XRD, SEM and EDS techniques. These nanoparticles were utilised to develop colorimetric sensor for Pb(II) detection. The developed AgNPs-based colorimetric sensor was sensitive and selective towards Pb(II) with the limit of detections of 2.8 and 0.08 µM by visual and UV-vis detection techniques, respectively. The method also exhibited excellent linearity (R2 = 0.9959) within 0.5 to 100 µM concentration range and precision (intra-day and inter-day %RSD values were 2.78% and 3.40%, respectively). The practical application of the developed AgNPs-based sensor was investigated for colorimetric detection of Pb(II) in various real-world samples such as wastewater effluents, leakage, fresh water, tap water and soft drink. The percent recoveries of the tested samples ranged from 99.5–108% indicating the potential applicability of the technique. In general, the nano-sensor is green, exhibited a potential sensitivity and applicability, and hence, recommended for the detection of Pb(II) ions in various water samples. [ABSTRACT FROM AUTHOR]

We introduced a voltammetric bisphenol A (BPA) sensor based on NiCo2O4/reduced graphene oxide (rGO) nanocomposite loaded on the screen-printed electrode surface (NiCo2O4/rGO/SPE). NiCo2O4/rGO was characterised using various techniques, including X-ray diffraction (×RD), Raman spectroscopy and scanning electron microscopy (SEM). We used differential pulse voltammetry (DPV) to detect BPA concentrations. We evaluated the key analytical features of NiCo2O4/rGO/SPE for the BPA detection and the effects of important experimental parameters on the voltammetric efficiency. The voltammetric response of the proposed electrode was evaluated towards BPA. We demonstrated that the produced electrode has a wide linear dynamic range (0.03 to 475.0 μM) and a detection limit as low as 0.01 μM at S/N = 3. [ABSTRACT FROM AUTHOR]

Chitosan-magnetite nanocomposite (CM) was synthesised using the one-step procedure, reducing the synthesis time and the complexity of the process. The synthesized CM was characterised by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM). The nanocomposite was used to remove eriochrome black T (EBT) from the aqueous solution. The effects of pH, adsorption time, initial concentration of EBT, dose, and temperatures were studied. The experiment data were analysed by pseudo-first-order, pseudo-second-order, Elovich, and intra-particle-diffusion kinetic models. Among these models, the pseudo-second-order was the best fit model and the adsorption rate constant of EBT was 0.007 g/mg.min. The adsorption isotherms were studied by fitting the experimental data to the Langmuir, Freundlich, and Temkin models. The results indicated that the Langmuir model was the fittest model for describing the isotherms of the EBT adsorption on CM. When the temperature increased from 293 to 313K, the maximum adsorption capacity of EBT decreased from 291.2 to 83.5 mg/g. The thermodynamic study showed that the ETB adsorption process onto CM was a spontaneous and exothermic process with ∆G0, ∆H0 negative. The EBT dye adsorption mechanism was discussed, involved interactions, such as electrostatic attraction and H-bonding. CM could be regenerated and reused to adsorb anionic dye. [ABSTRACT FROM AUTHOR]

In this study, Adsorption characteristics of uranium from nitrate media onto a commercially accessible strong cation exchange resin, Marathon C, were investigated. The characteristics of Marathon C, before and after adsorption of uranium, were determined using scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The influence of the different parameters, which may affect the process of uranium adsorption process from synthetic solutions and applying on real sample from uranium purification unit, had been tracked. Specifically, impacts of initial uranium concentration (40–300 mg/L), PH (1–8), phase ratio (0.2–1.2 g/L), contact time (2–360 min.) and temperature (& 25–50°C) on uranium removal, were studied. In addition, the sorption kinetics and equilibrium parameters were assessed. At the optimum conditions, the adsorption capacity of uranium at PH 4, 1 g Marathon C/L and 120 min were found to be nearly 131.58 mg g−1 at room temperature (& 25°C). The kinetics and isotherm studies could show that the uranium adsorption onto Marathon C is following the models of pseudo-second-order and Langmuir isotherm, respectively. The thermodynamic parameters had indicated that the adsorption of uranium is an exothermic and spontaneous process (∆H = −64.27 ± 0.01, ∆G = −22.57 ± 0.02). The detected results of uranium adsorption could reveal that Marathon C is a suitable material for adsorption of uranium from nitrate media and applying on real sample from uranium purification unit. [ABSTRACT FROM AUTHOR]

To operationalise the heterogeneous photocatalysis process, the present study investigated the efficiency of TiO2-P25 nanoparticles immobilised on glass beads using the heat attachment method to remove cefazolin (CEF) as an antibiotic contaminant. The characteristics of the glass beads coated with TiO2-P25 nanoparticles were probed by the Scanning Electron Microscopy (SEM) technique. The immobilised TiO2-P25 nanoparticles manifested considerable efficiency in CEF removal in different operational conditions. The impact of various parameters, such as the ultraviolet light radiation time, initial concentration of CEF, light source power, inlet liquid volumetric flow rate, and pH of the solution, on the efficiency of CEF removal were examined. The results reveal that the removal percentage goes up as the irradiation time, volumetric flow rate, pH of the solution, and light source power increase while declining with a rise in the initial concentration of CEF. According to the findings, an initial CEF concentration of 20 mg L−1 is entirely removed by 40 min UV irradiation with a 16 W light source, the volumetric flow rate of 300 mL min−1, and the pH of 9.5. The reaction rate constant and adsorption coefficient of CEF on immobilised TiO2 were estimated at 0.622 mg L−1 min−1 and 0.095 mg−1 L via Langmuir- Hinshelwood kinetics. The outcomes of the mineralisation studies also display a considerable reduction of TOC and evolution of significant mineralisation products, like $$NO_3^ - $$ N O 3 − , $$NO_2^ - $$ N O 2 − , $$NH_4^ + $$ N H 4 + , and $$SO_4^{2 - }$$ S O 4 2 − . The experimental results were modelled by artificial neural networks (ANN). Comparing the experimental results with the ANN-predicted data shows the acceptable efficiency of modelling with ANN. The minimum MSE, R2 value for all data (validation, training, and test), and R2 value for simulated data were obtained at 0.00027811, 0.9971, and 0.9809, respectively. The relative importance of the parameters affecting the process evaluated by the ANN weights indicates that the irradiation time is the most important factor in the photocatalytic removal of CEF. [ABSTRACT FROM AUTHOR]

In this work, we describe a simple strategy for the preparation of a low-cost electrode material based on polypyrrole (PPy) film grown on an insulating cellulosic paper substrate via in-situ oxidative polymerisation technique and functionalised by silver nanoparticles (AgNPs) uniformly dispersed on its surface. The properties of the obtained AgNPs-PPy composites were characterised using X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray analysis. The electrocatalytic activity of the prepared electrode was investigated for the electroreduction of nitrate using cyclic voltammetry in 0.1 M KOH solution. Results demonstrated that the incorporation of AgNPs into the PPy matrix improves significantly the catalytic behaviour of this film. The effect on the electrode response of the amount of the incorporated AgNPs was also investigated. This paper highlights a simple procedure for the making of low-cost paper electrodes for the efficient reduction of nitrates. [ABSTRACT FROM AUTHOR]

Pollution as a result of coloured compounds has become one of the main concerns in terms of health and environment. Metal-organic frameworks (MOFs) are compounds consisting of metal ions or clusters coordinated with organic ligands, which have proved promising to reduce the relevant environmental challenges. In this research, the MIL-101(Cr)@ZnO as an adsorbent was synthesised by hydrothermal synthesis in order to remove cationic dye Methylene Blue (MB) from aqueous solutions. Then, the MIL-101(Cr)@ZnO was characterised by means of X-ray diffraction (XRD), Fourier transform (FTIR), and scanning electron microscopy (FESEM). In order to assess the efficiency of adsorption, the kinetic and thermodynamic studies on the adsorption process were also conducted. Pseudo-first-order and pseudo-second-order kinetic models were applied with the aim of describing the kinetic behaviour of adsorption and the Langmuir and Freundlich isotherm models were used for analysing laboratory equilibrium data. It was demonstrated with the help of the adsorption kinetics and equilibrium adsorption data that the adsorption process of MB is more consistent with the pseudo-first-order kinetic model and the Freundlich model, respectively. The maximum adsorption capacity of MB obtained for this adsorbent was 285.714 mg/g. Based on the thermodynamic values, the adsorption process of the above mentioned pollutant is an endothermic and spontaneous process. The overall results of the study demonstrate that the MIL-101(Cr)@ZnO adsorbent can be considered as a potential candidate for the removal of coloured pollutants from water. [ABSTRACT FROM AUTHOR]

The present investigation was targeted to remove toxic heavy metal lead (Pb(II)) from synthetic solution with ultra-sonicated turmeric leaves powder (UTLP) as sorbent. The responsible functional groups for adsorption of Pb(II) onto UTLP were investigated using Fourier Transform Infrared (FTIR) spectroscopy, and the adsorption was confirmed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS) analysis. The Central Composite Design (CCD) method was used to scrutinise the effective parameters. Based on the optimisation results, the maximum % biosorption (97.36) of Pb(II) was attained under optimum conditions of pH: 4.92, biosorbent dosage (BD): 0.44 g and initial solution concentration (ISC): 37.93 mg/L. The experimental findings were fitted with Langmuir and Freundlich and Temkin isotherms. Sequel to isotherm data, the Freundlich model gave good fit with R2 = 0.99 and a maximum adsorption capacity of 36.49 mg/g. The pseudo-second-order model was found to be the most significant for kinetic data analysis. The thermodynamic parameters such as Gibb's energy change (∆G0), enthalpy change (∆H0) and entropy change (∆S0) were estimated, and it was found that the process was spontaneous and endothermic in nature. Furthermore, the desorption study was conducted with 0.1 N HNO3 to estimate the ease of regeneration behaviour of UTLP. Conclusively, the results revealed that UTLP is prominent and cheap biosorbent for removal of Pb(II) from aqueous medium. [ABSTRACT FROM AUTHOR]

Laser directed energy deposition (L-DED) typically uses a 1 – 3 mm diameter laser spot size to melt feedstock material. Smaller spot sizes can benefit L-DED in certain applications (i.e., repair), by creating smaller beads. This study examined how a 0.3-mm-diameter laser spot affects the bead formation, microstructure, and mechanical properties (as-built) of 18Ni-300 maraging steel. The main printing parameters (i.e., laser power, scan speed, powder flow rate) were varied in different combinations to optimize for single-track bead geometry, before printing cubes. Parameters for optimal bead aspect ratio (AR) and dilution (D) had an average energy and mass density of 74.5 J/mm2 and 0.018 g/mm2. Compared to larger laser spot diameters, the use of a 0.3-mm laser size influenced bead characteristics (i.e., AR, D, dominant parameters). Additionally, cube fabrication resulted in cubes with ≥ 99% density but had external geometric defects. Titanium oxides were identified through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) and were attributed to the smaller interaction volume between the laser beam and powder streams with a small laser spot size that plays a significant role within the processing window defined. Additionally, analysis of tensile fracture surfaces showed the oxide particles significantly impacted tensile properties, resulting in premature failure compared to expected values. Electron backscatter diffraction (EBSD) and thermal simulations demonstrated that locations with the highest cooling rate had the highest amount of retained austenite (RA) and finest microstructure. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A new gelator (BAzo‐Chol) comprising a diazocine core and two cholesterol units linked via carbamate groups has been designed and synthesized. Its gelation ability in several kinds of organic solvents is identified. Investigations with scanning electron microscopy (SEM), transmission electron microscopy (TEM), rheological measurements, and UV‐vis absorption and 1H NMR spectroscopy reveal that BAzo‐Chol can self‐assemble into elastically interpenetrating one‐dimensional nanostructures in organogels through a cooperative effect of the π‐π interactions, hydrogen‐bonding, and van der Waals forces. Moreover, the unconventional Z/E conformational transitions of these organogels, due to the inclusion of diazocine, endow the BAzo‐Chol gels with excellent photo‐responsive gel‐sol transition and remarkable visible light‐induced chromic properties. Lastly, due to its sensitive response to visible light accompanied by distinct changes in both colour and transparency of the gel‐sol transitions, the potential application of the current gelator in smart windows is signified. [ABSTRACT FROM AUTHOR]

With the waste of resources caused by human activities, it has gradually become an increasingly prominent social problem. The development of self-healing polymers in the field of insulation has attracted widespread attention. Develop polymer matrices with efficient healing efficiency and sound insulation properties to achieve green and sustainable resource conservation. In addition, improving the dielectric properties of intrinsic self-healing matrices has been a hot topic. In this work, we developed a new PEI matrix-modified self-healing polymer substrate that provides a breakdown field strength of 240 kV/mm and self-healing properties at room temperature, this has significantly improved the dielectric properties over other previously reported self-healing polymers. In addition to the abovementioned performance, we found significant differences in thermodynamic behavior in the synthesized end-modified polymers. By dielectric characterization (LCR), the breakdown composite can be left at room temperature for 60 min, and the material can recover 80 % of the initial properties without external intervention(This is demonstrated by the fact that its DC conductivity at 60 min of autonomous healing was significantly changed from that of the freshly electrically pierced DC conductivity and remained around 5.38 × 10−11 S/cm for a longer period of time thereafter). The microscopic morphology of the modified PEI matrix was observed by scanning electron microscopy (SEM) and EDS surface elemental analysis, which further supports the existence of metal coordination structures. These findings can further deepen the thinking of self-healing dielectric composites. The work inspired by this may break the limits and take self-healing composite dielectric materials to a new height. [ABSTRACT FROM AUTHOR]

xSrTiO 3 -(1-x)SmAlO 3 (ST-SA) (x = 0.4, 0.5, 0.6) microwave dielectric ceramics were prepared by solid-state reaction method and the microwave dielectric properties (ε r , Q × f , τ f) were studied. The 0.4ST-0.6SA component with better Q × f and τ f was selected and the effects of different ywt % Ga 2 O 3 (y = 0.5, 1.0, 1.5, 2.0, 2.5) doping on the phase structure, microstructure, and microwave dielectric properties of ceramics were investigated. X-ray diffraction analysis showed that Ga3+ mainly replaced Ti4+ site when y ≤ 0.5, and when y > 0.5, Ga3+ start to replace Al3+ site. The best grain uniformity of the ceramics was observed at y = 2.0 by scanning electron microscopy testing. Raman spectroscopy shows that the stability of the oxygen octahedron is improved after Ga 2 O 3 doping with increased Q × f value. The change of Ga 2 O 3 doping amount also affects the dielectric properties of ST-SA ceramics. The optimum Q × f value of the ceramic is improved by about 50% from 10,278 GHz (7.465 GHz, 0.4ST-0.6SA) to 15,712 GHz (6.950 GHz, 0.4ST-0.6SA-2.0 wt% Ga 2 O 3) with improved dielectric properties (ε r = 36.14， τ f = 4.17 ppm/°C). [ABSTRACT FROM AUTHOR]

Expanded polystyrene is widely produced and used due to its properties and, recently, its ability to present π–π interactions has been described. Therefore, this work proposed to use recycled polystyrene for solid phase extraction of 12 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Recycled polystyrene films were formed and characterised by Fourier transform infrared spectroscopy, scanning electron microscopy and affinity experiments. A moderate interaction was found, which allowed its integration in pipette tip-solid phase extraction followed by HPLC-FLD analysis. The method presents limits of detection in the range of 0.05–0.14 ng mL−1 for 12 PAHs analytes, with a precision (expressed as relative standard deviation) <10%. The methodology was applied to tap water samples, and the results were compared to those obtained using the official methodology, with no statistically significant differences. The proposed method is efficient, fast and has a low consumption of organic solvent. [ABSTRACT FROM AUTHOR]

The bonding performance and formation of the interphase region between fiber and matrix have significant effects on the strength and durability of composites. A new approach, involving combined experimental and numerical analyses, has been developed to avoid the shortcomings and scattering associated with local experimental methods. For this purpose, tensile tests are performed on specimens fabricated from a single glass fiber and epoxy resin. The elongations for specified lengths are measured using the digital image correlation (DIC) technic. The size of the fiber diameter and specimen section are also measured from SEM images. The obtained experimental displacements for micro tensile tests are used in an inverse elastic finite element solution to obtain the interphase elastic modulus. It is shown that, considering the interphase thickness of 1.0 μm that is more realistic, the interphase elastic modulus is in the range of 12 ∼ 19 GPa. However, the performed sensitivity analysis shown that considering interphase thickness ranging from zero to 2.0 μm the interphase elastic modulus varies between 9 and 46 GPa. It is shown that the proposed procedure can be used to obtain the overall mechanical properties of the matrix/fiber interphase in long fiber composites. [ABSTRACT FROM AUTHOR]

[Display omitted] The presence of emerging organic micropollutants (OMPs) in drinking and potable waters is a matter of great concern due to the health hazards associated with these. In this work, we present the preparation and application of a thin-film nanocomposite (TFN) membrane containing functionalized graphene oxide to effectively remove low-molecular-weight OMPs from water. Graphene oxide was functionalized with amino silane to enhance its cross-linking capability during the formation of the polyamide active layer via interfacial polymerization of diethylene triamine and trimesoyl chloride. The TEM analysis showed that amino silane functionalized GO had 2–3 layered sheets, while non-functionalized graphene oxide appeared multilayered or stacked. XPS analysis confirmed the successful functionalization of GO. Characterization of the membranes with advanced techniques confirmed the successful incorporation of the GO and its functionalization: spectra from Fourier Transform Infra Red spectroscopy had the characteristic peaks of GO and N H groups; scanning Electron Microscopy (SEM) images showed a continuous presence of GO nanosheets. Contact angle measurements showed the TFN membranes to be more hydrophilic than their thin film composite (TFC) counterparts. Incorporating functionalized oxide nanosheets in the active polyamide layer produced additional water permeation channels, resulting in an improvement of ∼25 % in permeate flux compared to the pristine TFC and the TFN membrane with non-functionalized GO. The removal efficiencies of four OMPs commonly found in natural waters: Amitriptylene HCl (ATT HCl) and Bisphenol-A (BPA), Acetaminophen (ACT), and Caffeine (CFN) were determined for the synthesized membranes. The TFN membrane with functionalized GO outperformed its TFC counterpart with ∼100 % removal for BPA, ∼ 90 % for CFN and ATT HCl, and ∼80 % removal for the low molecular weight ACT. The high-efficiency rejection of OMPs was attributed to the synergistic effects of size exclusion as well as the reduced specific interactions between the functional groups. [ABSTRACT FROM AUTHOR]

Curcumin (Cur) is a bioactive nutraceutical with great potential in biological, nutritional, and medical applications. However, these applications are limited by various factors such as insufficient ingestion, low aqueous solubility, and relatively high toxicity to normal cells. To tackle these obstacles, we synthesized a novel Cur‐modified‐rhamnogalacturonan (RG‐C) nano‐micelle carrier to target‐deliver Cur to hepatocellular carcinoma HepG2 cells via specific recognition of RG‐I by the overexpressed surface galactin‐3 receptor. Fourier transfer infrared, UV–vis, and 1H NMR analyses confirmed the conjugation between RG and Cur RG‐C loaded with Cur (RG‐CC) was formed via self‐assembly in an aqueous solution with a drug loading efficiency of 12.2%. RG‐CC micelle was ellipsoidal or cubic with a size ranging between 100 and 200 nm by scanning electron microscopy observation. Cur release from RG‐CC exhibited a controlled and pH‐dependent manner with 50% at pH 5.0 in contrast to 5% at pH 7.4 after 24 h exposure. RG‐CC possessed more potent anti‐proliferative activity against HepG2 cells than normal embryonic kidney 293T cells. Compared to free Cur, both the anti‐proliferative effect and uptake of RG‐CC were significantly higher in HepG2 cells as revealed from laser confocal microscopy and flow cytometry analyses. RG‐CC was a promising anticancer candidate and deserves further preclinical and clinical investigations. [ABSTRACT FROM AUTHOR]

This paper utilizes the reaction of phytic acid (PA) and urea (UM) in polyvinyl alcohol (PVA) solution to synthesize flame retardant gasses (CO2, NH3) for the preparation of PVA composite films containing flame retardant microbubbles. The flame retardancy of PVA composite films was assessed using methods including limiting oxygen index (LOI), vertical burning (UL 94), and cone calorimetry. The results indicated an increase in the LOI of the PVA composite film containing flame retardant microfoam from 20% to 30% compared with the pure PVA film, and that UL 94 reached VTM‐0. Furthermore, its peak exothermic rate and total exothermic amount were reduced by 36.25% and 38.92%, respectively, compared with the pure PVA film. The investigation of the flame‐retardant mechanism employed thermogravimetric‐infrared (TG‐IR), scanning electron microscopy (SEM), Raman spectroscopy, and infrared spectroscopy. The results demonstrate that the CO2 and NH3 flame retardant microbubbles within the composite film render it less ignitable at the initial stage, and that the internal UM of the composite film continues to decompose, releasing CO2 and NH3 upon heating. In addition, the acidic substances decomposed by PA during combustion promote the dehydration, cross‐linking, and cyclization of PVA, generating chemical structures such as POC, POP, and PO4 with enhanced thermal stability. This encourages the formation of a continuous, dense charcoal layer and impedes the transfer of oxygen and heat into the interior. [ABSTRACT FROM AUTHOR]

Lignocellulosic fiber‐reinforced composites exhibit enhanced physical properties and eco‐friendliness, which has resulted in extended application of these biocomposite materials in important engineering sectors. In this study, we investigated the synergistic impacts of dune sand (DS)‐based silica (SiO2) and alkali‐treated date palm fiber (ADPF) fillers on the thermophysical and viscoelastic characteristics of epoxy (EP) hybrid composites. A hand layup procedure was employed to produce EP hybrid composites reinforced with 20 wt.% ADPF as well as 5, 7, and 10 wt.% DS. Compared to the other composite samples, the EP matrix reinforced with 20 wt.% ADPF and 10 wt.% DS (HC5) exhibited better thermal (Tmax = 380°C, Tg = 63.13°C) and dynamic mechanical properties (storage modulus = 2700 MPa). Additionally, Cole–Cole plots revealed the excellent interaction between ADPF, DS, and epoxy matrix. Scanning electron microscopy (SEM) measurements further confirmed that the development of an effective interface between DS particles, ADPF fiber, and epoxy matrix caused a decrease in water absorption (1.5%). The best wetting conditions with the lowest thickness swelling (2.8%) were obtained by increasing the DS content up to 10 wt.%. Based on these findings, it can be concluded that, owing to their superior dynamic mechanical characteristics, hybrid composites containing 10 wt.% DS may be employed in important aircraft and aeronautic applications. [ABSTRACT FROM AUTHOR]

Multi‐responsive, self‐healing hydrogels were developed utilizing positively charged polysaccharides, chitosan, and water‐soluble chitosan. This fabrication employed free‐radical synthesized polyacrylic acid and polymethacrylic acid along with the cross‐linker FeCl3, resulting in the generation of polyelectrolyte metal complexes, which enhances the properties of the chitosan‐based hydrogels, particularly their mechanical strength, self‐healing ability, thermal stability, swelling behavior, porous structure, cell viability, and even anticancer activity. Characterization and stability assessment of the hydrogels were performed using FT‐IR, nuclear magnetic resonance, gel permeation chromatography, scanning electron microscopy, rheometer, x‐ray diffraction, thermogravimetric analysis, DSC, and UV spectroscopy. FT‐IR measurements indicated that the facile complexation of the cross‐linker's metal ions (Fe3+) with the carboxylate (COO−), amino (NH), and hydroxyl (OH) groups of the polymers and chitosan chains facilitated rapid gelation. Furthermore, the sustained release of the drug levofloxacin (up to 80%) was observed to increase with increasing pH due to the hydrogels' anionic nature. Biocompatibility and cytotoxicity tests were conducted using the MTT assay on splenocytes and Dalton Lymphoma cancer cell lines. These tests demonstrated the promising potential of these hydrogels for drug delivery applications. [ABSTRACT FROM AUTHOR]

In this research, the visible light active performance of Bi2ZnB2O7 (BBZO) was significantly enhanced through the formation of a composite with few layer MoS2. The resultant MoS2@BBZO catalyst was employed in both photocatalysis and photodetector applications. Comprehensive structural and morphological analyses of the MoS2@BBZO catalyst were conducted using x-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy. The estimated band gaps of BBZO and the composite were found to be 2.8 eV and 1.74 eV, respectively. Rhodamine B degradation studies demonstrated that the catalyst achieved 75% degradation within 30 min. Additionally, the photodetector application was investigated, revealing rapid photo-switching capabilities and an increased photocurrent. [ABSTRACT FROM AUTHOR]

A method to obtain sodium titanate nanoribbons starting from a mixture of brookite and anatase TiO₂ nanopowder is described. As-prepared TiO 2 nanopowder with a major brookite phase was used as a precursor in an alkaline hydrothermal approach, where the temperature was kept at 200 °C. The influence of hydrothermal treatment and consequent annealing temperature (T = 500 °C) on the crystal structure, phase composition, and morphology of samples were investigated by X-ray powder diffraction (XRPD), Raman and FTIR spectroscopy, and electron microscopy techniques (FESEM, HRTEM). All these methods point out that the hydrothermally treated sample, containing the NaTi 3 O 6 (OH)(H 2 O) 2 , Na 2 Ti 3 O 7 , and Na 2 Ti 9 O 19 , is dominated by layer-structured sodium hydroxititanate dihydrate. The annealing leads to the formation of rare sodium titanates, Na 3 Ti 6 O 13 and Na 2 Ti 9 O 19 , with tunnel structures where the hexatitanate with increased sodium content prevails. The photocatalytic activity of synthesized nanostructures was tested in the degradation process of Reactive Orange (RO16) azo-dye upon UV excitation. It appears that photocatalytic activity is lower after hydrothermal treatment, but subsequent annealing makes sodium titanate nanoribbons faster in the degradation of RO16. The research implies that these sodium titanate nanostructures are promising photocatalytic materials and should be considered in the future for removing different pollutants from water. [ABSTRACT FROM AUTHOR]

Obtaining high-purity MAX-phase powders is a challenging issue. Therefore, in this article, the effects of two key parameters, including mechanical activation time (1, 2, and 3 h), and preheating temperature (800 and 1000 °C) were investigated on the formation mechanism of Ti 2 AlC MAX phase using mechanically activated (assisted) self-propagating high-temperature synthesis (MA-SHS) combustion method through thermal explosion mode. For this aim, a powder mixture of titanium, aluminum, and carbon with a stoichiometry ratio of (2:1:1) was used. Differential thermal analysis (DTA) was carried out to evaluate the effect of mechanical activation and preheating temperature of the formation temperature of the target MAX phase. Subsequently, the microstructural, phase analysis, chemical composition, and determination of surface chemical states studies were carried out through scanning electron microscopy (SEM), X-ray energy distribution spectroscopy (EDS) transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectric spectroscopy (XPS), respectively. DTA results illustrated that applying mechanical activation alters the formation temperature, which leads to an increase in the purity of the MAX phase. The quantitative measurements were carried out using the Rietveld method to determine the purity of the achieved MAX phase. The results indicated that samples subjected to 2 h of mechanical activation at a preheat temperature of 1000 °C exhibited to contain 96.1 % of Ti 2 AlC MAX phase, which is the highest value among other specimens and the lowest amount of secondary and oxide phases (3.9 % of TiC) during the combustion synthesis process compared to other samples. [ABSTRACT FROM AUTHOR]

The mechanical properties and microstructure of double-hard-phase TiB 2 –25-wt.%-TiC–20-wt.%-CoNi cermets prepared at different temperatures were investigated by performing scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The results showed that the transverse rupture strength, indentation fracture toughness, hardness, and relative density of the cermets reached the maximum values of 1654 MPa, 11.06 MPa m1/2, 90.1 HRA, and 99.42 %, respectively, when the sintering temperature was 1462 °C. Solid- and liquid-phase sintering occurred at temperatures below and above 1354.5 °C, respectively. The cermets were composed of TiB 2 , TiC, TiB, and CoNi phases when sintered at 1440 °C and below, but the TiB phase disappeared when sintered at 1462 °C and above. Both TiB 2 core–(Ti, Co, Ni)B rim and TiC core–(Ti, Co, Ni)C rim structures appeared in cermets sintered at 1440 °C and above. In addition, a few TiC core–(Ti, W)C inner–(Ti, W, Co, Ni)C outer double rim structures were formed. A coherent interface was found between the (Ti, Co, Ni)B rim and TiB 2 core. A thin CoNi amorphous metallic layer existed at the interface between the (Ti, Co, Ni)C rim and TiC core. In addition, amorphous CoNi was observed in the interfacial region between the CoNi binder and (Ti, Co, Ni)C rim phase and inside the CoNi binder phase. These multi-interface and core–rim structures resulted in excellent strength and toughness of the cermets. [ABSTRACT FROM AUTHOR]

The compatibility between two distinct polymers in the blend is important to maximize various properties of the blends. This study investigated the effects of kaolin modifications through acid and calcination treatments on the compatibility, molecular weight, its distribution, and various properties of poly(lactic acid) (PLA)/poly(vinyl butyral) (PVB) blends. In addition, the incorporation of the modified kaolin as a compatibilizer into the blends enhanced their mechanical and thermal properties, addressing the challenges of immiscibility between distinct polymers. The experimental approach included the utilization of scanning electron microscopy, gel permeation chromatography, differential scanning calorimetry, x‐ray diffraction, Fourier transform infrared spectroscopy, rheometer, and melt flow index to examine the structural, molecular, and thermal, mechanical and rheological behaviors of the composites. The changes in various molecular weights were correlated with other properties. The incorporation of surface‐treated kaolin into the blend improved the compatibility between PLA and PVB, exhibiting a singular melting temperature peak and a less distinct interface between two different polymers. This research contributed to the development of sustainable material solutions by demonstrating the potential of modified inorganic fillers in improving the performance of biodegradable polymer blends. [ABSTRACT FROM AUTHOR]

In this study, chitosan (CH)/polyvinyl alcohol (PVA) hybrid nanofibers incorporating three distinct essential oils lemon, lime, and grapefruit were successfully obtained via the innovative electrospinning technique. Characteristics of the electrospinning polymeric mixture loaded with essential oils using variable ratios of CH/PVA were evaluated. The nanoencapsulation process of citrus essential oils was achieved with 47.67%–88.16% encapsulation efficiency. Notably, the thermal stability of the encapsulated essential oils experienced a significant enhancement after encapsulation. Scanning electron microscopy analysis revealed valuable insights, revealing that an increased amount of incorporated essential oil within the polymeric mixture solutions led to a reduction in the average fiber diameters. The resulting nanofibers demonstrated notable attributes such as antioxidant, tyrosinase inhibitory, and antibacterial activities. The present research demonstrates the ability of CH/PVA hybrid nanofibers obtained through an electrospinning process to preserve citrus essential oils properties quality and reveals a high potential application of nonencapsulated citrus essential oils in biomaterials, food packaging, and advanced cosmetic application. [ABSTRACT FROM AUTHOR]

Coccolithophorid Emiliania huxleyi was isolated to clonal culture from plankton of coastal waters of the Black Sea in February, 2023. Algal virus strain EhV-SS2 affecting this algal species was isolated from coastal waters in May, 2023. By means of scanning electron microscopy, it was shown that viral particles were 124–174 nm in diameter with an icosahedral symmetry. Supercapsid was detected in this strain and its titer was determined (2.5 × 105 virions/mL). The effect of algal virus on E. huxleyi growth and efficiency of PS II (Fv/Fm) at different levels of biogenic elements in the medium was investigated. Throughout the latent period of algal virus (0–101 h), we observed a decrease in the Fv/Fm ratio in the algae as compared with control values. Within time interval from 101 to 168 h, first cells lysed by the virus were revealed in the culture by means of light and scanning electron microscopy. Over the period from 168 to 264 h, lysis intensified and its rate on full f/2 medium was five times greater than in the case of nitrogen or phosphorus deficit. The rate of cell lysis on seawater lacking nutrient elements was two times lower than on the full medium. By the end of the experiment (in 264 h), infected culture displayed functionally active cells sheeted with coccoliths and without them. The percentage of the latter on f/2 medium was 95%, whereas in the case of nitrogen and phosphorus deficit their proportion was small. [ABSTRACT FROM AUTHOR]

Air-entraining agents can introduce tiny bubbles into a filling slurry, thereby improving its fluidity. However, the introduction of bubbles can change the pore characteristics of backfill materials. Pore characteristics can be visually observed using scanning electron microscopy (SEM). SEM images contain a large amount of microstructural characteristic information. However, the analysis of the image information is superficial. We used SEM images to qualitatively analyse the microstructural characteristics of backfill materials, and morphological operations and digital image processing techniques were used to obtain a binarization image for the semi-quantitative analys is of pore distribution. Two fractal theories: box-counting and slit island methods, were used to quantitatively analyse the binarization image to comprehensively analyse the pore characteristics of the backfill materials. The results show that: (1) the pore shape characteristics are obtained quantitatively (Rr = 4.73–5.48, R = 1.46–1.60), and most pores are regular. (2) The pores of backfill materials have good fractal characteristics (R2 > 0.97), which can be quantitatively analysed and studied using the fractal theory (DI = 1.086–1.160 and DB = 1.50–1.62). (3) The research result suggest that the more regular the pore, the smaller its fractal dimension, which is given quantitatively as (D = a*Rr+b*R+c). [ABSTRACT FROM AUTHOR]

This study used tofu wastewater as medium to produce mannoprotein from Candida tropicalis (MCT), Pichia norvegensis (MPN), Aspergillus awamori (MAA), and Rhizopus oryzae (MRO). This study aimed to determine the optimum growth of yeast and mold in tofu wastewater as a medium for mannoprotein production. The purity was determined using FTIR and solid-state NMR spectroscopy. The structural differences were determined using scanning electron microscopy (SEM), and the antioxidant activity was measured using DPPH radical scavenging activity. The highest yield of extract was obtained upon the use of MPN (28.09 ± 6.4%, w/w), followed by MCT (18.73 ± 5.5%, w/w), MRO (2.75 ± 1.7%, w/w), and MAA (2.54 ± 1.7%, w/w). Moreover, FTIR spectroscopy confirmed that MCT, MPN, MAA, and MRO were typical mannoproteins with absorption band at 824, 824, 818, and 812 cm−1, respectively. While the1H NMR spectra revealed the presence of protons at 5.11–5.46 ppm which confirmed the presence of α-(1,2)-mannoprotein for MCT, α-(1,6)(1,2)-mannoprotein for MPN, and α-(1,6)-mannoprotein for MAA, and MRO. Mold-based mannoprotein has a smaller particle size than yeast-based mannoprotein, furthermore, at 4000 ppm, MCT had the greatest DPPH-free radical inhibition value of 49.89%, followed by MRO (44.34%), MAA (40.81%), and MPN (28.54%). [ABSTRACT FROM AUTHOR]