Search Results (3,563)

The integration of microstructured current collectors offers a potential pathway to enhance interface properties in solid-state battery architectures. In this work, we investigate the influence of surface morphology on the electrochemical performance of Zn/Na_2.99Ba_0.005OCl/Cu electrodeless pouch cells by fabricating copper thin films on microstructured parylene-C substrates using a combination of colloidal lithography and reactive ion etching. O₂ plasma etching times ranging from 0 to 15 min were used to tune the surface topography, resulting in a systematic increase in root-mean-square roughness and a surface area enhancement of up to ~30% for the longest etching duration, measured via AFM. Kelvin probe force microscopy-analyzed surface potential showed maximum differences of 270 mV between non-etched and 12-minute-etched Cu collectors. The results revealed that the chemical potential is the property that relates the surface of the Cu current collector/electrode with the cell’s ionic transport performance, including the bulk ionic conductivity, while four-point sheet resistance measurements confirmed that the copper layers’ resistivity maintained values close to those of bulk copper (1.96–4.5 µΩ.cm), which are in agreement with electronic mobilities (−6 and −18 cm²V⁻¹s⁻¹). Conversely, the charge carrier concentrations (−1.6 to −2.6 × 10²³ cm⁻³) are indirectly correlated with the performance of the cell, with the samples with lower CCC_bulk (fewer free electrons) performing better and showing higher maximum discharge currents, interfacial capacitance, and first-cycle discharge plateau voltage and capacity. The data were further consolidated with Scanning Electron Microscopy and X-Ray Photoelectron Spectroscopy analyses. These results highlight that the correlation between the surface morphology and the cell is not straightforward, with the microstructured current collectors’ surface chemical potential and the charge carriers’ concentration being determinant in the performance of all-solid-state electrodeless sodium battery systems. Full article

Using a 3D microscope imaging technique that we pioneered for alpha-track imaging of Solid-State Nuclear Track Detectors (SSNTDs), here, we present results from imaging of neutron-induced recoil proton tracks formed by exposing CR39-based detectors to an ²⁴¹Am(Be) neutron source. Detectors were arranged at zero, thirty, and sixty degrees to the source to assess any variation in the tracks according to source orientation. An Olympus (Olympus Corporation Japan) LEXT laser scanning confocal microscope was used to image the SSNTDs. Depth and cross-sectional size measurements were made on nine tracks, with a median (range) of 3.07 μm in depth (min 0.98 μm to max 8.34 μm), width in plan view of 7.49 μm (min 4.00 μm to 14.89 μm max), and breadth in plan view of 8.41 μm (min 4.17 μm to max 11.80 μm). In this study, we have shown our confocal microscopy approach can successfully image the 3D surface of neutron-induced tracks in SSNTDs; the imaging method thus enables the measurement of track cross-sectional dimensions and depth, as well as the identification of angled tracks. Full article

In the quest to produce high-purity alumina, bottom-up engineering via architecting the interior of ceramic with bimodal structures of alumina powders in the absence of any additives has gained considerable attention owing to the simplicity offered. The present work investigated the influence of bimodal structures containing micron (~35 μm) and submicron (~600 nm) Al₂O₃ powders on the formation of dense Al₂O₃ ceramic. To this end, ball-milling was conducted to prepare the desired sizes of powders, followed by two-step sintering in a vacuum at 1450 °C and 1650 °C with 6 h and 4 h holding times, consecutively. The bimodal structures induced the formation of Al₂O₃ ceramic with nearly full densification (>99%; ρ 3.95 g/cm³). Both the coarse and fine-grained moieties synergistically balanced the densification kinetics whilst suppressing abnormal grain growth. The uniform and homogeneous grain size minimized the plasma porosity down to <6.0%, limiting the penetration of plasma during the etching process. Full article

MXenes, a novel class of two-dimensional (2D) transition metal carbides and nitrides, have garnered significant attention due to their exceptional thermal conductivity, electrical properties, and mechanical strength. This review offers a comprehensive overview of MXenes, focusing on their synthesis methods, material properties, tribological performance, and potential challenges and opportunities. Typically synthesized through the selective etching of layered precursors, MXenes offer highly tunable structures, allowing for precise tailoring for specific functionalities. Their outstanding properties, such as high electrical conductivity, chemical versatility, mechanical durability, and intrinsic lubricity, make them promising candidates for various applications, including energy storage, electromagnetic shielding, water purification, biosensing, biomedicine, and advanced tribological systems. While many of these applications are briefly acknowledged, this review primarily emphasizes MXenes’ potential in tribological applications, where recent studies have highlighted their promise as solid lubricants and tribological additives due to their low shear strength, layered structure, and ability to form protective tribofilms under sliding contact. However, challenges such as oxidation resistance, long-term stability, and performance under extreme environments continue to impede their full potential. With less than a decade of focused research, the field is still evolving, but MXenes hold tremendous promise for revolutionizing modern material science, especially in next-generation lubrication and wear-resistant systems. This review explores both the opportunities and challenges associated with MXenes, emphasizing their emerging role in tribology alongside their broader engineering applications. Full article

Background: A major challenge in adhesive dentistry, often leading to restoration failure, is microleakage. This in vitro comparative study was designed to assess microleakage at the tooth–composite interface. The investigation aimed to compare the sealing efficacy of two commonly used adhesive systems. Methods: Standardized Class I cavities were prepared on 20 extracted human molars and randomly divided into two groups (n = 10 each). Group A was treated with a fifth-generation total-etch adhesive (OptiBond™ Solo Plus, Kerr Corporation, Orange, CA, USA), and Group B received a seventh-generation self-etch adhesive (Adhese® Universal VivaPen®, Ivoclar Vivadent AG, Schaan, Liechtenstein). All restorations were completed using Herculite XRV composite resin. Microleakage was evaluated using dye penetration analysis after immersion in 2% methylene blue for 10 days, followed by longitudinal sectioning and microscopic measurement at 500× magnification. Results: The fifth-generation adhesive group showed a mean microleakage of 0.2503 ± 0.1921 mm, while the seventh-generation group recorded 0.2484 ± 0.1764 mm. Statistical analysis using an independent t-test revealed no significant difference between the groups (p = 0.696). Conclusions: Both adhesive systems demonstrated comparable performance in minimizing microleakage under standardized conditions. Although the total-etch group exhibited slightly lower numerical values, the difference was not statistically significant. These findings suggest that both adhesive approaches can be clinically effective when applied appropriately. Full article

Background: Reduced bond strengths in hypmineralised enamel have been reported with increased restorative failures. This study aimed to investigate the shear bond strengths of resin composite to hypomineralised enamel and dentin bonded with two different adhesive systems and pre-treatments. Methods: Thirty-six freshly extracted first permanent molars with MIH and 17 sound third molars were used for shear bond strength tests in enamel and dentin. Specimens of control groups were bonded to resin composite using Scotchbond^TM Universal Plus and Adper^TM Scotchbond 1XT. MIH-affected enamel specimens of six test groups were pre-treated with various chemical agents, such as 35% phosphoric acid, 5% NaOCl, resin infiltration with ICON^®, or a combination of these agents prior to bonding with composite resin using Scotchbond^TM Universal Plus. Bonded specimens were subsequently sheared at a crosshead speed of 1.0 mm/min, after which their fracture modes were recorded. The mean bond strengths of all groups were compared using a one-way analysis of variance test (ANOVA) and a Bonferroni–Holm analysis was performed for pairwise comparison between the groups. The association between modes of failure was examined with Pearson’s chi-square test. Results: Mean shear bond strength values were highest for sound dentin specimens (Group SD 2) bonded with Scotchbond^TM Universal Plus (23.76 ± 7.68 MPa). Sound enamel specimens (Group SE 2) exhibited significantly higher mean bond strength values than MIH-enamel specimens (Group HE 2) when bonded with Scotchbond^TM Universal Plus (19.68 ± 6.25 vs. 11.53 ± 3.29 MPa, p < 0.001). Oxidative pre-treatment followed by resin infiltration significantly improved bond strengths to hypomineralised enamel (Group HE 6) (17.84 ± 2.98 MPa, p < 0.05). Bond strengths to sound and hypomineralised enamel and dentin did not differ significantly for both adhesives. Conclusions: Within the limitations of an in vitro study, oxidative pre-treatment in combination with resin infiltration seems to be beneficial when planning adhesive restorations with composite in hypomineralised enamel. Both Scotchbond^TM Universal Plus and Adper^TM Scotchbond 1XT can be used for bonding of resin composite to MIH-affected enamel and dentin. Full article

Background/Objectives: This study aimed to evaluate the efficacy of a 445 nm diode laser in enhancing enamel resistance to acid-induced demineralization and to investigate the associated compositional and structural modifications using scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA), and X-ray diffraction (XRD) crystallographic analysis. Methods: A total of 126 extracted human teeth were used. A total of 135 (n = 135) enamel discs (4 × 4 mm) from 90 teeth were assigned to either a laser-irradiated group or an untreated control group for SEM, ESCA, and XRD analyses. Additionally, 24 mono-rooted teeth were used to measure pulp temperature changes during laser application. Laser irradiation was performed using a 445 nm diode laser with a pulse width of 200 ms, a repetition rate of 1 Hz, power of 1.25 W, an energy density of 800 J/cm², a power density of 3980 W/cm², and a 200 µm activated fiber. Following acid etching, SEM was conducted to assess microstructural and ionic alterations. The ESCA was used to evaluate the Ca/P ratio, and XRD analyses were performed on enamel powders to determine changes in phase composition and crystal lattice parameters. Results: The laser protocol demonstrated thermal safety, with minimal pulp chamber temperature elevation (0.05667 ± 0.04131 °C). SEM showed that laser-treated enamel had a smoother surface morphology and reduced acid-induced erosion compared with controls. Results of the ESCA revealed no significant difference in the Ca/P ratio between groups. XRD confirmed the presence of hydroxyapatite structure in laser-treated enamel and detected an additional diffraction peak corresponding to a pyrophosphate phase, potentially enhancing acid resistance. Results of the spectral analysis showed the absence of α-TCP and β-TCP phases and a reduction in the carbonate content in the laser group. Furthermore, a significant decrease in the a-axis lattice parameter suggested lattice compaction in laser-treated enamel. Conclusions: Irradiation with a 445 nm diode laser effectively enhances enamel resistance to acid demineralization. This improvement may be attributed to chemical modifications, particularly pyrophosphate phase formation, and structural changes including prism-less enamel formation, surface fusion, and decreased permeability. These findings provide novel insights into the mechanisms of laser-induced enhancement of acid resistance in enamel. Full article

The adhesion G protein-coupled receptor ADGRE5/CD97 is upregulated in many cancers, representing a potential drug target in oncology/immuno-oncology. Yet, ADGRE5′s activation and signaling mechanisms remain poorly understood. Here, we used enhanced bystander bioluminescence resonance energy transfer (ebBRET)-based biosensors and three strategies to characterize human (h) ADGRE5 signaling. First, a synthetic tobacco etch virus (TEV) protease-cleavable receptor chimera enabling controlled tethered agonist (TA) exposure at the GPCR proteolysis site (GPS) revealed signaling through Gα12 and Gα13, along with the recruitment of β-Arrestins 1/2 (β-Arrs). Second, we investigated WT hADGRE5 signaling elicited by Gingipain K (Kgp), an endopeptidase that cleaves hADGRE5 upstream of the GAIN domain. Kgp mirrored TEV-induced signaling but also promoted Gαz and Gα11 activity. The abolition of hADGRE5′s GPS did not block Kgp-induced receptor activation, revealing a GPS cleavage-independent mechanism of action. Finally, we developed an assay to study hADGRE5 mechanical stimulation (MS) using β-Arr2 as a readout. MS promoted β-Arr2 recruitment in hADGRE5-expressing cells, and this response was lost upon abolition of the GPS. A neutralizing antibody to the hADGRE5 ligand CD55 significantly dampened MS-induced β-Arr2 engagement. Overall, this study advances our understanding of hADGRE5′s signaling and highlights the receptor’s plasticity in activating pathways via both GPS cleavage-dependent and -independent mechanisms. Full article

Crystal twinning, a common growth phenomenon, can substantially affect material performance in fields such as semiconductors, nonlinear optics, and drug development, yet its elimination during crystallization is challenging. This study presents a method for the controlled synthesis of ZSM-5 zeolite as either single crystals or twinned crystals using kaolin as the primary raw material. The method leverages the etching effect of ammonium fluoride (NH${⁠}_4$F) on the aluminosilicate structure derived from pre-treated kaolin. By adjusting the concentrations of NH${⁠}_4$F and the structure-directing agent tetrapropylammonium bromide (TPABr), pure ZSM-5 single crystals and twinned crystals were selectively synthesized. Conventionally, NH${⁠}_4$F is employed to introduce defects into zeolite structures. In contrast, this work demonstrates its utility in controlling crystal habit. The synthesis utilizes kaolin, an abundant and low-cost aluminosilicate mineral, to provide the entire aluminum source and a portion of the silicon source, offering an economical alternative to expensive precursors like aluminum isopropoxide. The resulting single and twinned crystals exhibited high crystallinity, demonstrating the viability of using natural minerals to produce high-quality zeolites. The physical and chemical properties of the kaolin-derived ZSM-5 were characterized and compared to those of ZSM-5 synthesized from conventional chemical reagents. A growth mechanism for the formation of single and twinned crystals is also proposed. Full article

The engineering of porous transport layer (PTL)–catalyst layer (CL) interfacial architecture plays a critical role in optimizing the performance of proton exchange membrane water electrolyzers (PEMWEs). Particularly, at the PTL-CL interface, our results reveal that anode catalyst loadings affect the modulation of the PTL surface structure on the overpotentials of PEMWEs. Under high anode catalyst loadings, the magnitude of overpotentials is predominantly governed by the electronic conductivity and mass transport resistance within the CL, where the modifying effects of PTL-CL interfacial contact characteristics become negligible. However, when the catalyst loading is reduced, the PTL-CL interfacial contact characteristics become critical for electron conduction, mass transport, and kinetic reaction. Under low catalyst loadings, the etched PTL demonstrates a maximum reduction of 59 mV compared to the pristine PTL at 4 A/cm², with the former exhibiting a 10 mΩ·cm² reduction. Meanwhile, the etched PTL integrated with a cell demonstrates superior performance in both mass transport and kinetic overpotentials compared to a pristine PTL. This clearly indicates that the surface structure of the PTL plays an increasingly significant role in regulating the overpotentials of PEMWEs as the catalyst loadings decrease. Full article

Lithium–selenium batteries (LSeBs) have potential applications in mobile electronic devices and electric vehicles due to their high theoretical volume specific capacity (3253 mAh cm⁻³). However, their cycling performance is poor because of the serve shuttle effect. Porous carbon can restrict the shuttle effect. However, past porous carbon is cumbersome, expensive, and unsuitable for large-scale production. In this work, we develop an annealing/etching method to convert biowaste (Rapeseed meal) to a N, S co-doped three-dimensional porous carbon (NSPC) which is then used as the Se host for LSeBs. The Se/NSPC composite delivers a specific capacity of 496.5 mAh g⁻¹ for 200 cycles at 0.2 C, corresponding to a high-capacity retention of 91.8%. Moreover, the Se/NSPC composite maintains a high capacity over 200 mAh g⁻¹ after 1000 cycles at a high current density of 2 C. Our work provides an efficient approach to addressing biowaste issues while simultaneously facilitating the mass production of economical Se hosts for LSeBs. Full article

The gas reservoir of the Sinian Dengying Formation (Member 4) in Sichuan Basin exhibits extensive development of inter-clast dissolution pores and vugs within its carbonate reservoirs, characterized by low porosity (average 3.21%) and low permeability (average 2.19 mD). With the progressive development of the Moxi (MX)structure, the existing stimulation techniques require further optimization based on the specific geological characteristics of these reservoirs. Through large-scale true tri-axial physical simulation experiments, this study systematically evaluated the performance of three principal acid systems in reservoir stimulation: (1) Self-generating acid systems, which enhance etching through the thermal decomposition of ester precursors to provide sustained reactive capabilities. (2) Gelled acid systems, characterized by high viscosity and effectiveness in reducing breakdown pressure (18~35% lower than conventional systems), are ideal for generating complex fracture networks. (3) Diverting acid systems, designed to improve fracture branching density by managing fluid flow heterogeneity. This study emphasizes hybrid acid combinations, particularly self-generating acid prepad coupled with gelled acid systems, to leverage their synergistic advantages. Field trials implementing these optimized systems revealed that conventional guar-based fracturing fluids demonstrated 40% higher breakdown pressures compared to acid systems, rendering hydraulic fracturing unsuitable for MX reservoirs. Comparative analysis confirmed gelled acid’s superiority over diverting acid in tensile strength reduction and fracture network complexity. Field implementations using reservoir-quality-adaptive strategies—gelled acid fracturing for main reservoir sections and integrated self-generating acid prepad + gelled acid systems for marginal zones—demonstrated the technical superiority of the hybrid system under MX reservoir conditions. This optimized protocol enhanced fracture length by 28% and stimulated reservoir volume by 36%, achieving a 36% single-well production increase. The technical framework provides an engineered solution for productivity enhancement in deep carbonate gas reservoirs within the G-M structural domain, with particular efficacy for reservoirs featuring dual low-porosity and low-permeability characteristics. Full article

Fast, spark-free detection of hydrogen leaks is indispensable for large-scale hydrogen deployment, yet electronic sensors remain power-intensive and prone to cross-talk. Optical schemes based on surface plasmons enable remote read-out, but single-metal devices offer either weak H2 affinity or poor plasmonic quality. Here we employ full-wave finite-difference time-domain (FDTD) simulations to map the hydrogen response of nanohole arrays (NAs) that can be mass-produced by colloidal lithography. Square lattices of 200 nm holes etched into 100 nm films of Pd, Mg, Ti, V, or Zr expose an intrinsic trade-off: Pd maintains sharp extraordinary optical transmission modes but shifts by only 28 nm upon hydriding, whereas Mg undergoes a large dielectric transition that extinguishes its resonance. Vertical pairing of a hydride-forming layer with a noble metal plasmonic cap overcomes this limitation. A Mg/Pd bilayer preserves all modes and red-shifts by 94 nm, while the predicted optimum Ag (60 nm)/Mg (40 nm) stack delivers a 163 nm shift with an 83 nm linewidth, yielding a figure of merit of 1.96—surpassing the best plasmonic hydrogen sensors reported to date. Continuous-film geometry suppresses mechanical degradation, and the design rules—noble-metal plasmon generator, buried hydride layer, and thickness tuning—are general. This study charts a scalable route to remote, sub-ppm, optical hydrogen sensors compatible with a carbon-neutral energy infrastructure. Full article

Electrochemical sensors have been developed based on polyethylene terephthalate track-etched membranes (PET TeMs) modified by photograft copolymerization of N-vinylformamide (N-VFA) and trimethylolpropane trimethacrylate (TMPTMA). The modification, structure and properties of the modified PET TeMs were thoroughly characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, gas permeability measurements and contact angle analysis. Optimal membrane modification was achieved using C = 10% (N-VFA), 60 min of UV irradiation and a UV lamp distance of 10 cm. Furthermore, the modified membranes were implemented in a two-electrode configuration for the determination of Eu³⁺, Gd³⁺, La³⁺ and Ce³⁺ ions via square-wave anodic stripping voltammetry (SW-ASV). The sensors exhibited a linear detection range from 10⁻⁷ M to 10⁻³ M, with limits of detection of 1.0 × 10⁻⁶ M (Eu³⁺), 6.0 × 10⁻⁶ M (Gd³⁺), 2.0 × 10⁻⁴ M (La³⁺) and 2.5 × 10⁻⁵ M (Ce³⁺). The results demonstrated a significant enhancement in electrochemical response due to the grafted PET TeMs-g-N-PVFA-TMPTMA structure, and the sensor showed practical applicability and consistent performance in detecting rare earth ions in tap water. Full article

Beyond its renowned gemological value, diamond serves as a vital economic mineral and a unique messenger from Earth’s deep interior, preserving invaluable geological information. Since the Mengyin region is the source of China’s greatest diamond deposits, research on the diamonds there not only adds to our understanding of their origins but also offers an essential glimpse into the development of the North China Craton’s mantle lithosphere. In this article, 50 diamond samples from Mengyin were investigated using gemological microscopy, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, DiamondView™, and X-ray micro-computed tomography (CT) scanning technologies. The types of Mengyin diamonds are mainly Type IaAB, Type IaB, and Type IIa, and the impurity elements are N and H. Inclusions in diamonds serve as direct indicators of mantle-derived components, providing crucial constraints on the pressure–temperature (P–T) conditions during their crystallization. Mengyin diamonds have both eclogite-type and peridotite-type inclusions. It formed at depths ranging from 147 to 176 km, which corresponds to source pressures of approximately 4.45–5.35 GPa, as determined by the Raman shifts of olivine inclusions. The discovery of coesite provides key mineralogical evidence for subduction of an ancient oceanic plate in the source region. The surface morphology of diamonds varies when they are reabsorbed by melts from the mantle, reflecting distinctive features that record subsequent geological events. Distinctive surface features observed on Mengyin diamonds include fusion pits, tile-like etch patterns, and growth steps. Specifically, regular flat-bottomed negative trigons are mainly formed during diamond resorption in kimberlite melts with a low CO₂ (X_CO2 < ~0.5) and high H₂O content. The samples exhibit varying fluorescence under DiamondView™, displaying blue, green, and a combination of blue and green colors. This diversity indicates that the diamonds have undergone a complex process of non-uniform growth. The nitrogen content of the melt composition also varies significantly throughout the different growth stages. The N3 center is responsible for the blue fluorescence, suggesting that it originated in a long-term, hot, high-nitrogen craton, and the varied ring band structure reveals localized, episodic environmental variations. Radiation and medium-temperature annealing produce H3 centers, which depict stagnation throughout the ascent of kimberlite magma and are responsible for the green fluorescence. Full article