ABSTRACT Triply periodic minimal surface (TPMS) structures have been rapidly adopted in engineering applications due to their superior mechanical properties, geometric continuity, and suitability for additive manufacturing. This study investigates the influence of the unique morphologies in four representative TPMS unit cells (Primitive, Gyroid, Neovius, and IWP) on brittle crack propagation. Two geometry‐driven concepts are proposed: (1) the prediction of crack propagation along geodesic lines on the surface and (2) the evaluation of damage localization through the distribution of cross‐sectional area along the loading direction. A mathematical framework is developed to compute analytical geodesics on curved surfaces and to compare them with numerically obtained crack paths. In addition, the areas of irregular cross‐sectional shapes in each TPMS unit cell are analyzed to assess how cross‐sectional variation influences compressive resistance. The base material of the TPMS structures is alumina ceramic modeled in finite element (FE) analysis using the Johnson–Holmquist II constitutive model. The results demonstrate that the numerical crack propagation paths are highly consistent with the analytical geodesics and that damage localization is governed by regions with small cross‐sectional areas. This approach provides a robust geometric basis for predicting fracture in complex lattice topologies.
ABSTRACT Hydroxyapatite (HA)‐based bioceramics are widely used as collagen biostimulators and dermal fillers. This study provides a direct comparative characterization of two commercially available HA‐based injectable products, identified in this work as Product 1 (Revita Absorbable Implant) and Product 2 (Radiesse Duo). A multimodal analytical framework was employed to assess chemical composition, microstructure, rheology, pH, and osmolality. Methods included Fourier‐transform infrared spectroscopy (FTIR) with ATR, thermogravimetric analysis (TGA), X‐ray diffraction (XRD), scanning electron microscopy (SEM), complemented by particle‐size analysis, rheological measurements, and standard pH and osmolality assays. FTIR and TGA indicate a HA‐dominated composition with auxiliary constituents (water, Na‐CMC, and glycerol) consistent with the reported formulations. XRD patterns are consistent with hydroxyapatite as the predominant crystalline phase, with no detectable secondary phases under the adopted experimental conditions in either product. SEM and laser‐diffraction analyses show spherical HA microstructures with average diameters near 30 µm (33.9 µm for Revita and 35.2 µm for Radiesse). Rheological measurements reveal closely similar complex viscosities, and the measured pH values under the adopted dilution conditions are 7.66 (Revita) and 7.76 (Radiesse), that is, near the physiological range. Osmolality values are elevated relative to isotonic targets: ∼1250 mOsm/kg for Revita and ∼1300 mOsm/kg for Radiesse. Overall, the two products show highly similar chemical composition, predominant crystalline phase, and particle microstructure, with differences primarily arising from the gel matrix, possibly related to differences in Na‐CMC molecular characteristics, which may contribute to differences in rheology and tonicity. The results indicate substantial physicochemical similarity between the two products.
ABSTRACT HfC–SiC is one of the leading thermal insulation ceramics that has the potential to perform well under high thermomechanical loads. In this study, we explore the use of pressureless sintering to produce this material at relatively low temperatures (2100°C) and focus on understanding the effect of adding WC, in the 0 to 20 wt.% range, on its ablation resistance. The sintered samples were evaluated for their relative density, phase composition, morphology, microstructure, Vickers hardness, and bending strength. The relative density and the Vickers hardness increased from 89% to 97% and from 13.0 to 18.4 GPa, respectively, when the WC content increased from 0 to 20 wt.%. A relatively high value of 480 MPa for the bending strength was measured for the sample with 10 wt.% WC, which was attributed to the more refined microstructure. Oxyacetylene torch testing in tandem with cross‐section micrographs and elemental composition mapping revealed that the addition of WC increased protection in an ablative environment. The observed enhanced oxidation protective ability of these UHTCs is linked to the retention of Si during the ablation process to form an amorphous Hf–Si–W–O overlayer. The retention of Si ensures that a glassy and viscous silicate phase is formed on the surface of the sample. This protective oxide phase restricts volatile oxide phase formation and thus reduces surface porosity and oxygen diffusion. In addition, the viscous tungsten‐silicate phase provides self‐healing of surface defects and improves bending strength.
ABSTRACT Glass‐ceramic composites are promising heterogeneous materials for the immobilization of high‐level nuclear waste. In this study, a composite containing a monazite‐type rare‐earth phosphate dispersed within a borosilicate glass (BG) matrix was synthesized using the ceramic method by first mixing all of the precursors needed to form the phosphate and glass, followed by annealing. The phosphate phase, La0.5Gd0.5PO4, was selected due to its high chemical durability and capacity to incorporate actinides. Gd is a neutron absorber, which is a good attribute for a nuclear waste form. Characterization of the composite materials was performed using powder X‐ray diffraction (XRD), X‐ray absorption near‐edge spectroscopy (XANES), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectroscopy (EDX). XRD analysis confirmed the formation of a novel co‐substituted monazite phase (i.e., La0.5Gd0.5PO4) dispersed in a glass matrix. XANES analysis provided insight into the local chemical environment of the rare‐earth elements, while SEM and EDX mapping revealed the distribution of the La0.5Gd0.5PO4 crystallites within the borosilicate glass matrix.
ABSTRACT Laminated‐glass transparent armor systems are increasingly employed in impact‐resistant glazing and protective transparent structures, combining ballistic resistance with optical transparency. This review examines the functional role of the main constituent layers in such systems and discusses materials commonly employed in current architectures. Emphasis is placed on float glass strike faces, intermediate transparent layers (including polymethyl methacrylate [PMMA]), polymeric interlayers (polyvinyl butyral, PVB; ethylene‐vinyl acetate, EVA; thermoplastic polyurethane, TPU; and ionomer interlayers such as SentryGlas), and ductile backing solutions (polycarbonate, PC, and hard‐coated polyethylene terephthalate, CPET). The analysis highlights how material selection and stacking sequence influence stress‐wave transmission, damage evolution, energy dissipation mechanisms, and postimpact integrity. The review supports a system‐level interpretation of ballistic response and outlines key considerations for developing lighter, thinner, and more efficient laminated transparent armor solutions.
ABSTRACT To solve the problems of high sintering temperature, uneven grain growth, and limited electrical property optimization in traditional ZnO varistor ceramics, this study adopted microwave sintering (1000°C–1100°C, ZnO matrix with Bi2O3 dopants), using conventional sintering as a reference. Results showed that microwave sintering shortened the cycle and inhibited abnormal grain growth, achieving optimal performance at 1100°C/30 min (potential gradient: 340.82 V/mm, leakage current: 2.16 µA/cm2, nonlinear coefficient: 55.09). Mechanisms were revealed via XRD, SEM, and electrical property tests, providing technical and theoretical support for efficient preparation and performance optimization of ZnO varistor ceramics.
ABSTRACT Bioactive glasses have emerged as promising biomaterials due to their ability to promote osseointegration and accelerate bone regeneration. This study investigates the formulation and characterization of manganese (Mn)‐doped 85S mesoporous bioactive glass (85SiO2–(15 − x)CaO–xMnO mol%, x = 1, 2, 3, and 4). Morphological and structural analyses confirmed the amorphous and mesoporous structure of the microsized glass particles, showing average pore sizes of 2 nm. Bioactivity was evaluated in vitro in simulated body fluid (SBF), demonstrating the formation of a hydroxycarbonate apatite (HCA) layer on the surfaces, as evidenced by x‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cytotoxicity was assessed in vitro using the MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) assay, revealing that Mn‐doped glasses exhibited no significant cytotoxicity, indicating biocompatibility. Antimicrobial and antifungal properties were also evaluated. The results indicate a composition‐dependent effect of Mn, with 0–2 mol% Mn preserving mesoporosity, sustaining rapid HCA formation, and ensuring cytocompatibility. Within this range, particularly at 2 mol% Mn, the glasses exhibit enhanced antibacterial activity against selected strains, whereas strong antifungal effects are mainly associated with undoped 85S and 1 mol% Mn. In contrast, higher Mn contents (3–4 mol%) reduce specific surface area, delay or suppress HCA formation, and do not provide superior antimicrobial performance. Altogether, these findings define 1–2 mol% Mn as an optimal doping window, highlighting the trade‐off among structural features, bioactivity, and antimicrobial efficacy.
The importance of glass and glass-ceramic nuclear waste forms has been reaffirmed in recent years by the growing interest in nuclear power as a reliable energy source. Determination of processing methods for the disposal of halide-containing wastes will be essential for the advancement of nuclear technologies such as non-aqueous fuel reprocessing. Phosphate-based dechlorination and subsequent vitrification of radioactive salt waste into an iron-phosphate waste form have been identified as a potential processing scheme for electrochemical processing waste. The impact of H3PO4-based dechlorination of complex salt mixtures on the vitrification process and structure of the final iron-phosphate waste form has not yet been investigated. In this work, iron-phosphate glass-ceramics were made from simulant salt waste (48LiCl-33KCl-19NaCl mol%) dechlorinated with the H3PO4-based method. The glass-forming region was compared to that of traditionally prepared Na2O-Fe2O3-P2O5 systems. For a candidate glass-forming composition, the processing scheme presented here was determined to favor Fe3+ species. The O/P molar ratio was consistent for the candidate composition when dechlorinated at 400 degrees C and 600 degrees C in air and argon environments, indicating glass network connectivity was maintained despite variations in processing parameters. The results presented here validate processing schemes requiring iron-phosphate waste form synthesis following H3PO4-based dechlorination.
ABSTRACT One of the causes of global boiling, which has been inducing abnormal weather around the world, is the enormous power consumption of data centers, especially in arithmetic logic unit (ALU) operations and memory data transfers. We aim to achieve ultralow‐power consumption by replacing Si‐based cache memories with analog in‐memory computing (AiMC) and random‐access memories using crystal indium oxide, which enables field‐effect transistors (FETs) with excellent on‐state characteristics, including a mobility of up to 142.7 cm2/V s, and an off current lower than that of a Si FET by 11 orders of magnitude. We are also studying ultralow‐power artificial intelligence (AI) ALUs using AiMC FETs in the subthreshold regime. This report will introduce the trend of these technologies. Further development of devices based on these technologies will achieve high integration and power saving, which is expected to be important countermeasures against global boiling.
This study investigates zinc oxide (ZnO)-functionalized silicon carbide (SiC) ceramic membranes for biodiesel purification, focusing on phosphorus, sulfur, and metallic impurity removal. Flat-disc SiC membranes, with similar to 37% porosity, were prepared via controlled dip-coating and characterized by x-ray diffraction (XRD), SEM, x-ray fluorescence (XRF), air permeability, and liquid permeation tests (isopropyl alcohol, IPA; on-spec biodiesel). Air permeation analysis yielded Darcian (k 1) and non-Darcian (k 2) permeability coefficients of 3.27 +/- 0.19 & times; 10-15 m2 and 5.68 +/- 0.19 & times; 10-12 m, respectively. Crossflow microfiltration of crude and neutralized biodiesel at 3 bar and similar to 25 degrees C showed acceptable permeance with IPA (10.7 +/- 2.2 L/h m2 bar) and on-spec biodiesel (5.63 +/- 1.69 L/h m2 bar). However, severe flux decline occurred with crude biodiesel, indicating fouling. Critically, ZnO-SiC membranes effectively reduced calcium (64.5-16.6 mg/kg), sodium (8.2-0.96 mg/kg), and phosphorus (25.8-8.6 mg/kg) to compliant levels. Sulfur removal was minimal, suggesting ZnO limitation against stable organosulfur compounds under mild conditions. These findings position ZnO-functionalized SiC membranes as robust polishing systems for selective metal and polar contaminant removal, while highlighting the need for integrated catalytic or hybrid strategies for sulfur reduction.
In this study, ceramic membranes were produced from compositions containing natural raw materials (clay and talc), alumina, and peanut shell powder (PSP) as a pore-forming additive. The disc-shaped ceramic membranes were fabricated by uniaxial pressing and sintered at 1100, 1150, and 1200 degrees C. The sintered samples were characterized by X-ray diffraction (XRD), porosity, density, mechanical strength, mercury porosimetry, and scanning electron microscopy (SEM). Distilled water flux tests were conducted in a tangential flow system to evaluate the permeability of the ceramic membranes. The X-ray diffraction results indicated the presence of sapphirine and cordierite. It was found that the incorporation of PSP up to 30 wt.% promoted an increase in the porosity, pore size, and permeability of the membranes. The membranes with 20 wt.% and 30 wt.% of PSP sintered at 1150 degrees C were highlighted in this study. These membranes were observed porosity of 40% and 49%, similar pore sizes of 6.2 & micro;m, and flexural strength values of 22 and 17 MPa, respectively. Moreover, tests with distilled water conducted at 0.5 bar showed fluxes of 2791 and 2316 L & centerdot;h-1 & centerdot;m-2, respectively. The results suggest the use of these membranes in effluent treatment.
The growth mechanism of alpha-hemihydrate gypsum (alpha-HH) in Na2SO4 solution is still undefined. In this work, we constructed the solution-crystal models to investigate the growth morphology of alpha-HH in Na2SO4 solution system by molecular dynamics simulation. The attachment energy (AE) model was used to predict the growth behavior of alpha-HH, revealing that the (002), (200), (110), and (1-10) crystal faces are dominant, with the (002) face exhibiting the highest attachment energy and predicted fastest growth rate. Molecular dynamics simulations of alpha-HH in Na2SO4 solution with varying mass fractions (2%-12%) revealed that the interaction energy between the solution layer and crystal faces follows the order: (002) > (1-10) approximate to (110) > (200). Radial distribution function analysis indicated the presence of hydrogen bonds, chemical bonds, van der Waals forces, and electrostatic interactions between the solution layer and crystal faces. Notably, the diffusion coefficients of Na+ and SO42- ions were highest on the (002) crystal face, suggesting enhanced diffusion on this face. These findings provide insights into the structural and morphological transformations during alpha-HH crystal growth, offering a foundation for optimizing growth conditions, manipulating crystal size and morphology, and ultimately guiding the production of high-quality alpha-HH crystals.
The slag foaming practice enables high energy efficiency in the electric arc furnace, and its optimization is based on empirical knowledge and process modeling. Thus, it is essential to predict the physical properties of slags, as this phenomenon depends on their density, surface tension, and viscosity. Although thermodynamic calculations provide insights into the chemical composition of slags in equilibrium with liquid steel and refractories, and commercial software packages (such as FactSage) include modules to estimate slag viscosity, there are limitations regarding the chemical species considered and the properties that can be forecasted. In this study, predictive models of surface tension, density, and viscosity are evaluated for their ability to estimate experimental properties of metallurgical slags. These models, developed for glass compositions using machine-learning algorithms, were subsequently validated on slags in this work. On the basis of their performance and limitations, a framework coupling FactSage and GlassNet was proposed and applied to investigate potential slag conditioners for controlling foamy slag. The tested candidates were silica sand, sodalite, and steel scale, and their effects on the characteristic times of foam collapse (or aging) were predicted in the results.
ABSTRACT This study presents the microstructural, chemical, and nanomechanical behavior of multilayer coatings of Cr/CoAlHf/YSZ deposited on Inconel 718 alloy using combined DC/RF magnetron sputtering with a focus on coatings deposited at 300°C for high‐temperature aerospace applications. FESEM and EDS analyses indicate the formation of a multilayer structure with high density and minimal porosity, as well as homogeneous elemental distribution of the Cr, CoAlHf, and YSZ layers, implying that no interfacial diffusion is occurring. X‐ray diffraction (XRD) patterns confirm the formation of stable phases, including ZrO2, Y2O3, Cr, HfO2, and a Co–Cr–Al–Hf solid solution. Nanoindentation shows stable deformation behavior and high load‐bearing capacity, where hardness exhibited an increasing trend from 7.94 to 11.25 GPa in the range of 500–2500 µN, decreasing to 10.70 GPa at 3500 µN, which is explained as the change of reverse indentation size effect (r‐ISE) to conventional indentation size effect (ISE) for the change of applied loads. Nano‐scratch testing at gradually increased ramp loads confirms good coating adhesion, characterized by stable frictional behavior and minimal surface damage. XPS survey analysis confirms the chemical integrity of the multilayer system, with both strong Zr3d and Y3p peaks indicating the YSZ top layer, and distinct signals for Co, Cr, Al, and Hf, indicating the underlying bond coat. Overall, the results reveal that deposition at 300°C is beneficial for favorable microstructural evolution, chemical stability, and enhanced nanomechanical performance, making the CoCrAlHf/YSZ multilayer a promising protective coating for Inconel 718 components exposed to extreme aerospace service environments.
Robust supports functionalized with active catalytic phases present a promising route to enhance photocatalytic hydrogen production. Progress in hydrogen generation strongly depends on the design of structured catalysts with tailored architectures and active interfaces. This study presents macroporous silicon carbide (SiC) structures functionalized with LaNiO3 perovskite as structured catalysts for glycerol photoreforming under visible light. SiC foams were fabricated via the replica method using polymeric templates and sintered at 1000 degrees C, with a vitreous frit residue serving as a flux agent to enable more energy-efficient processing. LaNiO3 was synthesized by a sol-gel route. The materials were characterized by zeta potential, x-ray diffraction, scanning electron microscopy (SEM)/energy-dispersive x-ray spectroscopy (EDS), diffuse reflectance spectroscopy, and surface area measurements. Photocatalytic tests were performed under visible irradiation in an in-house quartz reactor, and hydrogen evolution was monitored using an Arduino-based acquisition system coupled to an MQ-8 sensor. Glycerol, a common byproduct of biodiesel production, was used as a sacrificial agent, highlighting the potential of waste-derived feedstocks for sustainable solar fuel production. Under the tested conditions, the SiC-LaNiO3 structured catalyst produced approximately 90 & micro;mol g(-1) of H-2 in 60 min, outperforming bare SiC (approximate to 57 & micro;mol g(-1)). The improved performance is associated with enhanced visible-light absorption, lower bandgap, increased accessible surface area, and the intrinsic robustness of the structured SiC support.
Perlite is a noncrystalline volcanic rock with rhyolitic composition that expands four to 20 times its original volume when heated, forming a porous structure widely used in filtration, catalysis, and construction. Raw perlite consists of a noncrystalline aluminosilicate matrix and 10-15 wt.% crystalline phase. Semiquantitative data on perlite crystal species and reliable viscosity measurements of its noncrystalline aluminosilicate component remain scarce. Yet, they are crucial for understanding the morphological evolution of the perlite skeleton during high-temperature heating. This study developed two methods for measuring the viscosity of the noncrystalline portion of perlite over a temperature range near and above the estimated glass transition temperature using a combined experimental-modeling approach. Both methods integrate semiquantitative X-ray diffraction (XRD) analysis and simultaneous differential thermal analysis, with viscosity modeled using the Mauro-Yue-Ellison-Gupta-Allan (MYEGA) equation. In the first method, synthesized glass replicating the composition of perlite skeletons is characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and semiquantitative XRD, and its viscosity within a temperature range near and above the estimated glass transition temperature of the noncrystalline component is determined by applying the MYEGA equation to heat flow scanning data. In the second method, the crystalline contribution is subtracted from the heat flow curve using temperature-dependent heat capacity data collected based on crystalline phases characterized by XRD results before applying the MYEGA equation to calculate the viscosity of the noncrystalline perlite skeleton within the temperature range.
ABSTRACT In contrast to the three‐ and four‐point method as well as the C‐ring tests, the brittle ring test, where ceramic rings are tested under diametral compression, is a simple and time‐saving method for measuring the fracture strength of technical ceramics, as the ceramic samples can be measured as fired without time‐consuming hard machining. The authors evaluate the various formulas that have been established over the past 100 years for determining the fracture strength of ring‐shaped samples and present an adapted formula that is by far best suited for calculating the strength in comparison to the other formulas. This is illustrated using the example of uniaxially dry‐pressed alumina specimens with different ring geometries. If certain conditions are observed, such as a suitable ratio of inner to outer radius and a ring height that is not too large, the brittle ring method is ideal for determining valid strength values of technical ceramics without a great deal of preparation work.
ABSTRACT The foundation of advanced nanotechnology lies in the extensive attention given by researchers to the exceptional properties of nanomaterials. This work incorporates a computational investigation on structural, thermodynamic, and electrical properties of different gallium arsenide nanoclusters—GanAsn, where n = 4, 5, and 6, and the effect of doping with transition metals (TMs) (Cu and Ag) on them using density functional (DFT) theory. Since the structures exhibit no peaks in the imaginary IR frequency range, they tend to form naturally in their stable energy minima. Moreover, doping introduces higher reactivity and structural deformation in pristine nanoclusters, and alternating doping with a TM atom causes a significant impact on the pristine structure. The analyzed charge distribution suggests a remarkable increase in polarity due to TM‐dopants, indicating the capability of electrostatic interactions of the systems with external molecules, an essential feature for developing sensors. In addition to this, the observed molecular orbitals signify the structures as semiconductors, having energy gaps ranging from 1.30 to 2.50 eV. Together, these findings suggest that the studied TM‐doped gallium arsenide nanoclusters are applicable broadly in the next‐generation semiconductor industry.
ABSTRACT The search for versatile, sustainable composites with enhanced antibacterial properties has been driven by the rising threat of antibiotic‐resistant diseases and the need for advanced biomaterials for medication delivery. This work involves the synthesis and thorough characterization of chitosan‐hydroxyapatite (CS‐HAp) composites derived from snail and shrimp shells, respectively, doped with copper (Cu2+) and zinc (Zn2+) nanoparticles. A series of chemical processes, including demineralization, deproteinization, deacetylation, and calcination, was used to produce these composites. Metal doping was incorporated during the fabrication process. Fourier‐transform infrared and X‐ray diffraction analyses confirmed the successful integration and interaction of CS, HAp, and metal ions, and the crystalline structure remained intact during drug loading and release. Antimicrobial tests showed modest antibacterial activity, predominantly against Gram‐positive Staphylococcus aureus, with increased effectiveness at higher metal ion concentrations. Thermogravimetric analysis demonstrated excellent heat stability. Specifically, in Zn‐doped samples, drug release in simulated bodily fluid exhibited an initial rapid phase (80%–90% within 50 h), followed by sustained release. Overall, CS, HAp, and metal ions work synergistically to provide biocompatibility, structural integrity, and controlled drug delivery, as shown by the data.
ABSTRACT Polymers have a vast range of beneficial properties making them desirable coating materials. They are cost‐effective, easy to manufacture, and can be modified for improved properties. Adding an inorganic filler into a polymer coating improves its properties and expands its potential applications. Polymer nanoparticle composite (PNC) coatings possess the qualities of the polymer along with increased versatility and mechanical properties from the inorganic nanoparticle. Polymer and PNC coatings have played an advantageous role in tailoring glass surface properties for a variety of products. They have provided many benefits such as antibacterial and self‐cleaning properties, as well as increased strength. Application of coatings to glass products spans across multiple industries including construction, automotive, pharmaceutical, packaging, and renewable energy. This review will cover common polymers and nanoparticles used for coatings on glass. The structure and properties of these polymers will be reviewed with a short introduction to the general structure of polymers. A brief overview of the mechanisms of adhesion will be followed by the specifics of adhesion between the glass and polymer. Three cost‐efficient coating methods will be detailed with relative advantages and disadvantages. Perspectives on future research and applications will be discussed.
