Stability Of Materials Research Articles

Calcite-saturated natrocarbonatites: composition, crystal morphology, and weathering

Interpretation of calcite-dominated fossil carbonatite volcanoes is complicated by the instability of many igneous carbonatite materials on Earth’s surface. One hypothesis suggests that they originate by eruption of alkali-free calcic carbonatite lavas. However, liquid calcite is not thermodynamically stable at atmospheric pressure. A second hypothesis suggests that calcite is secondary and formed after primary nyerereite lost its alkalis to surface water. Here, we experimentally test a combined hypothesis in which solid calcite phenocrysts are suspended in natrocarbonatite lava that solidifies primarily to nyerereite, and determine calcite solubilities in sodic carbonate liquids. Then, we dissolve alkalis in water over several months to show formation of secondary calcite after nyerereite. Textural and geochemical observations from our experiments are consistent with many natural volcanic carbonatites, suggesting that alteration of initially calcite–nyerereite-bearing natrocarbonatites to pure calcite carbonatites was common in Earth’s geological past.

New insights from DFT analysis: Mg vacancies and hydrogen doping in enhancing thermodynamic properties and hydrogen storage performance of Li2BeMgH6

To identify effective hydrogen storage materials, a novel study employing first-principles calculations based on density functional theory DFT on the lithium-based double perovskite hydride Li2BeMgH6. This material, with its innovative and significant attributes, emerges as a potential candidate for hydrogen storage, inspiring experimental researchers to pursue its synthesis for the experimental fabrication of hydrogen storage devices. Notably, it boasts a remarkable gravimetric capacity of 11.35 wt%, coupled with exceptional stability and desorption temperature, surpassing the standards set by the U.S. Department of Energy (DOE) for solid-state hydrogen storage (ΔH = −40 kJ/mol.H2 and Td = 289 K–393 K), with respective values of ΔH = −77.37 kJ/mol H2 and Td = 591 K for the cubic phase and ΔH = −84.64 kJ/mol H2, Td = 647 K for the rhombohedral structure. This comprehensive research aims to demonstrate the thermodynamic stability of this innovative material and improve its hydrogen storage properties in line with DOE requirements. The results obtained highlight the significant impact of two strategies for enhancing hydrogen storage properties in two stable phases (face-centered cubic (fcc) and rhombohedral (R3)): the creation of magnesium vacancy defects and hydrogen doping in the Mg vacancies in the studied system. The first strategy, involving the generation of 6 % defects in the Mg atoms, resulted in a notable improvement in storage properties, with a gain of 50.75 % for the cubic structure and 50.46 % for the rhombohedral structure. The second strategy, which consists of doping the vacant Mg sites with hydrogen, also demonstrated remarkable efficiency, leading to an increase of 50.05 % and 53.07 % in storage performance for the two phases, respectively.

Construction of N-doped carbon/MnO nanoparticles/hollow carbon spheres nested structure with tunable valence state for high-performance aqueous zinc ion batteries enables 10000 cycling stability

The practical applications of manganese-based aqueous zinc ion batteries (AZIBs) have been hindered by issues such as structural collapse, dissolution of active substances, and poor conductivity. Herein, a novel N-doped carbon/MnO nanoparticles/hollow carbon spheres nested structure (HCSs@MnO@NC) is fabricated as the active cathode material for AZIBs by controlled carbothermal reduction strategy. The internal hollow structure mitigates the volume expansion of MnO and improves material stability. The Mn-O-C heterojunction structure accelerates charge transfer and enhances structural stability. By controlling the carbothermal reduction process to adjust the valence state, electrochemical determinations demonstrate that divalent manganese exhibits a higher capacitance contribution rate, which is conducive to a faster ion migration rate. In situ UV–vis is firstly employed to detect the change of Mn2+ concentration in the electrolyte, revealing a Mn2+ deposition phenomenon in addition to the ion embedding mechanism during the initial charge. Owing to these favorable structural characteristics, the prepared HCSs@MnO@NC cathode delivers a specific capacity of 320.5 mAh g−1 at 0.1 A g−1 and maintains an excellent capacity after 10,000 cycles at 3 A g−1. This work can provide a new pathway for constructing advanced AZIBs by optimizing the nanostructure of composite electrode materials.

Measurement of Covalent Bond Formation in Light-Curing Hydrogels Predicts Physical Stability under Flow.

Photo-crosslinking hydrogels are promising for tissue engineering and regenerative medicine, but challenges in reaction monitoring often leave their optimization subject to trial and error. The stability of crosslinked gels under fluid flow, as in the case of a microfluidic device, is particularly challenging to predict, both because of obstacles inherent to solid-state macromolecular analysis that prevent accurate chemical monitoring and because stability is dependent on size of the patterned features. To solve both problems, we obtained 1H NMR spectra of cured hydrogels which were enzymatically degraded. This allowed us to take advantage of the high-resolution that solution NMR provides. This unique approach enabled the measurement of degree of cross-linking (DoC) and prediction of material stability under physiological fluid flow. We showed that NMR spectra of enzyme-digested gels successfully reported on DoC as a function of light exposure and wavelength within two classes of photo-cross-linkable hydrogels: methacryloyl-modified gelatin and a composite of thiol-modified gelatin and norbornene-terminated polyethylene glycol. This approach revealed that a threshold DoC was required for patterned features in each material to become stable and that smaller features required a higher DoC for stability. Finally, we demonstrated that DoC was predictive of the stability of architecturally complex features when photopatterning, underscoring the value of monitoring DoC when using light-reactive gels. We anticipate that the ability to quantify chemical cross-links will accelerate the design of advanced hydrogel materials for structurally demanding applications such as photopatterning and bioprinting.

Multiple Carbazole-Benzonitrile (CzBN) Derived TADF Molecules Targeting Efficient and Stable Blue OLEDs.

Thermally activated delayed fluorescence (TADF) materials have emerged as a promising avenue for developing efficient and stable blue organic light-emitting diodes (OLEDs) without incorporating heavy metals. Among the numerous donor-acceptor architectures explored, the carbazole (Cz) and benzonitrile (BN) combination has demonstrated exceptional potential for blue OLED applications. Herein, we delve into the recent advances in TADF materials based on the Cz-BN framework, with a particular focus on design strategies to accelerate exciton dynamics and improve material stability through kinetic and thermodynamic optimization. Eventually, challenges associated with the Cz-BN systems in blue OLEDs, as well as prospective research directions that could unlock the full potential of this intriguing category of materials, are also discussed.

Exploring the role of edges in surface functionalization and stability of plasma-modified carbon materials: Experimental and DFT insights

Effective surface functionalization of carbon nanomaterials plays a crucial role in various applications. We investigated the impact of edges on surface functionalization and stability of oxygen-modified carbon materials using a combination of experimental techniques and Density Functional Theory (DFT) insights. Graphenic paper, highly oriented pyrolytic graphite (HOPG), and graphenic flakes were employed as model systems, with oxygen plasma treatment (generator power 100 W, oxygen pressure 0.2 mbar, exposure time 6 – 300 s) serving as the modification method. Surface morphology and chemical composition were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The results revealed the introduction of oxygen functional groups on the investigated carbon surfaces (up to 20 at % by XPS) whereas; the structural integrity of the materials remained intact upon plasma modification (SEM, Raman). Work function was used as a sensitive parameter for monitoring the surface changes (increase by ∼1.4 eV, 1.3 eV, and 1 eV for graphenic paper, HOPG, and graphenic flakes, respectively) while time-dependent measurements revealed distinct kinetic processes governing the decay of functionalization, highlighting the role of surface defects in post-plasma processes. DFT calculations provided molecular-level insights into the surface processes, elucidating the mechanisms underlying the diffusion of hydroxyls, their recombination, and water desorption. Since the calculated activation barrier for recombination on basal graphenic planes (∼1.0 eV) and edges (∼5.5 eV) are distinctly different, it can be thus concluded that the persistent functionalization is due to the surface edges. Our findings contribute to a deeper understanding of surface modification processes of carbon materials and offer rationales for the design of advanced functional nanomaterials with tailored surface properties.

Deactivated Ca-based sorbent derived from calcium looping CO2 capture as a partial substitute for cement to obtain low-carbon cementitious building materials

Calcium looping CO2 capture is a highly promising technology for carbon capture, utilization, and storage. Nevertheless, the disposal of deactivated calcium-based sorbents following cyclic carbonation and calcination processes presents an unresolved challenge. Concurrently, the development of low-carbon cement products is also a critical priority. Given the calcium-rich composition and carbon-negative nature of the calcium-based sorbent, it is proposed that the deactivated sorbent could be utilized as a partial substitute for cement in the production of building materials. This paper explored the potential of using two types of deactivated calcium sorbent (DPC/DGC) to partial substitute cement for low-carbon cementitious materials production. The effects of partial substitution of cement materials on volume stability, compressive/flexural strength, hydration kinetics, and carbon emission of the composite cementitious materials were investigated. The results indicate that a 5% and 10% replacement of cement with DPC/DGC has modest impact on volumetric stability and compressive strength. The composite cement with 5% DPC replacement achieves a 28-day compressive strength of 48.1MPa, representing a 0.4% increase compared to the 47.9MPa observed in the reference sample. Specimens with 15% DPC/DGC substitution exhibit inferior volume stability and mechanical performance than the control sample. The total hydration heat releases decrease with the increasing substitution ratio due to the dilution effect by the introduction of DPC/DGC. Additionally, substituting cement with Ca-based sorbents significantly reduced the carbon footprint of construction materials. The net carbon footprints for the building materials that containing 1 ton of binder (substitued with 10wt% DPC and DGC) were 152.5kg and 43.5kg, corresponding to reductions of 79.6% and 94.2% compared to reference cement mortar. These carbon footprints are projected to further decrease to -108.5kg and -375.5kg when DPC and DGC were obtained after 100 CO2 capture cycles. A novel technological route combining the high-temperature calcium looping CO2 capture and CO2 mineralization curing was proposed, and the associated challenges of this method were also discussed.

Controllable preparation of lignin-based photothermal composites based on fractionation treatment

Using natural renewable lignin to prepare new photothermal materials can improve the value of lignin, reduce costs, and promote sustainable development. However, the heterogeneity of lignin is an important factor limiting the stability and tunability of lignin-based photothermal materials. In this paper, lignin after fractionation treatment was blended with the Polybutylene succinate (PBS) to obtain an environmental-friendly, tunable and multifunctional photothermal material. The modulation and enhancement of the compatibility, mechanical, thermal, and photothermal properties of PBS/Lignin composites were achieved by adjusting the structure of lignin. The abundant conjugated structure and high near-infrared (NIR) light absorption capability endowed the high molecular-weight lignin with 71.34 % photothermal conversion efficiency, which led to the maximum surface temperature of the as-prepared composite reached 291 °C under NIR light of 0.9 W/cm2. Meanwhile, the composite exhibited favorable light-triggered shape memory behavior (98.2 % fixation rate and 92.6 % recovery rate), effective light-controlled self-healing capability (91.6 % self-repairing efficiency), and significant photothermal antimicrobial activity (90.6 % inhibition of Escherichia coli, 88.1 % inhibition of Staphylococcus aureus) under the stimulation of NIR light. This study serves as a reference for regulating and enhancing the photothermal conversion efficiency of lignin and developing environmental-friendly photothermal materials.

Characteristics of Aliphitic and Aromatic Ion-Exchange Membranes after Electrodialysis Tartrate Stabilization of Wine Materials

Color indication of anthocyanins, FTIR spectroscopy, measurement of surface contact angle values, determination of specific electrical conductivity, as well as voltammetry and parallel measurement of pH of desalted solutions were used to analyze the fouling characteristics of aliphatic (CJMA-3, CJMC-3) and aromatic (AMX-Sb, CMX-Sb) ion-exchange membranes used in electrodialysis tartrate stabilization of wine material. It has been shown that polyphenols form complexes with metal ions on the surface and in the subsurface layers of cation-exchange membranes, which do not interfere with the transfer of cations. Foulants affect the magnitude of limiting currents and enhance water splitting at the surface of all studied membranes, and also reduce the electrical conductivity of anion-exchange membranes. The use of a pulsed electric field instead of a continuous direct electric current, traditional for electrodialysis, weakens the negative impact of foulants on membranes’ electrical conductivity. These data can be useful for selecting membranes and current modes when carrying out electrodialysis tartrate stabilization of wine materials.

Tritrichomonas foetus is not located in the accessory glands, epididymis, or testicles of infected bulls, and post mortem changes influence recovery of organism.

To determine the presence of Tritrichomonas foetus in the accessory sex glands, epididymis, and testicular tissue of T foetus-positive bulls and to assess the impact of post mortem tissue acidity on quantitative reverse-transcription PCR results. 8 bulls were euthanized from June 12 through June 15, 2023, and samples from their accessory sex glands, testicles, and epididymis were collected for T foetus testing. Preputial smegma was obtained before and after euthanasia and tested for T foetus by quantitative reverse-transcription PCR. The pH of the penile and preputial epithelial surfaces was measured. Tritrichomonas foetus was not detected in samples from the testicle, epididymis, or epididymal semen. A post mortem decrease in the pH of the penis and prepuce correlated with a rise in cycle threshold values. Tritrichomonas foetus was not present in samples taken, suggesting its absence in these specific reproductive tissues. A decrease in the pH of the penis and prepuce over time post mortem correlated with an increase in cycle threshold values in the samples. This relationship indicates that changes in pH may impact the detectability or stability of genetic material in these tissues, possibly affecting diagnostic outcomes as time from death progresses. This research enhances the understanding of T foetus pathology in bulls and suggests that epididymal semen recovery could be a viable method for preserving genetic material from valuable bulls that test positive for T foetus. It also emphasizes the need for timely post mortem sampling to ensure accurate detection and management of T foetus in the cattle industry.

Investigation on Mechanical Shock Wave Protective and Thermodynamic Properties of SiO2-Aerogel-Modified Polyurea

In recent years, industrial explosion accidents are frequent, causing serious negative influences on society. Mechanical shock waves, as a typical destructive factor in explosion accidents, can cause serious personal injury and building damage. In addition, actual explosion accidents usually involve heat sources, harming protective materials and personnel. In this study, we designed SiO2-aerogel-modified polyurea and studied the effects of manufacturing pressure process and the concentration of SiO2 aerogel on the mechanical shock wave mitigation and thermodynamic properties of the modified polyurea. The results show that the addition of SiO2 aerogel can improve the mechanical shock wave mitigation performance of polyurea. The maximum peak overpressure and acceleration mitigation rate of the material has reached 17.84% and 62.21%, respectively. The addition of SiO2 aerogel helps to reduce the thermal conductivity of materials and improve the thermal insulation performance, and the atmospheric pressure process is more conducive to improving the thermal insulation performance of materials. The minimum thermal conductivity of the material has reached 0.14174 W/m·K, which is 45.65% lower than that of pure polyurea. The addition of SiO2 aerogel has different effects on the limiting oxygen index (LOI) of polyurea. Using a vacuum process, the LOI value increased with the increase in the SiO2 aerogel concentration, while using atmospheric pressure, the LOI value increased but is always lower than 21% and lower than pure polyurea. Thermogravimetric analysis showed that the addition of SiO2 aerogel under the vacuum process was helpful to improve the thermal stability of materials. However, atmospheric pressure would disrupt the thermal stability, manifested in a decrease in peak degradation temperature, an increase in peak degradation rate, and a decrease in residual mass.

High-Performance Giant InP Quantum Dots with Stress-Released Morphological ZnSe-ZnSeS-ZnS Shell.

Indium phosphide (InP) quantum dots (QDs) are increasingly considered potent alternatives to traditional cadmium-based QDs. Notwithstanding, the material stability of InP, especially when juxtaposed with its cadmium-based counterparts, poses significant challenges in its application. Generally, a thick ZnS shell is applied to InP cores to thwart photo-oxidation and diminish nonradiative recombination. Yet, the pronounced lattice mismatch between the InP core and the ZnS shell can introduce lattice defects, consequently attenuating the luminescence efficiency. This makes the cultivation of a flawless thick shell a paramount challenge. In the present research, a synthetic methodology is elucidated to fabricate highly efficient InP QDs with dimensions exceeding 20nm, achieved by alleviating the lattice mismatch strain during the shell growth. By regulating the shell composition and morphology, InP/ZnSe/ZnSeS/ZnS QDs with shield-like morphology are prepared and demonstrate a photoluminescence quantum yield (PLQY) of ≈90%, exhibiting significantly enhanced photostability and thermal stability. This discovery is expected to greatly advance the preparation of highly efficient InP-based or other QDs, expanding their potential in various applications such as environmentally friendly displays and energy-saving lighting.

Entropy-engineered perovskite cathodes: A novel approach for efficient and durable CO2 electrolysis

The application of solid oxide electrolysis cells (SOECs) for high-temperature CO2 reduction reaction (CO2RR) is constrained by the electrochemical activity and stability of the cathode materials. In this study, a series of iron-based perovskite oxides, designed by systematically varying A-site configurational entropy, are investigated as cathode materials for the CO2RR. Experimental results reveal that these high-entropy materials, derived from La1/2Sr1/2FeO3−δ (LSF), exhibit high electrocatalytic activity and durability. Notably, the SOEC with La1/5Sr1/5Pr1/5Ba1/5Ca1/5FeO3-δ (LSPBCF) cathode achieves a remarkable current density of 2.14 A cm−2 at 800 °C and 1.5 V, maintaining excellent stability over 120 h of operation with negligible fluctuations. Density functional theory (DFT) calculations further unveil the electronic structure modulation mechanism of the high-entropy material, revealing that A-site entropy engineering could enhance CO2 adsorption and activation by reducing the oxygen vacancy formation energy. This study underscores the potential of entropy engineering to improve the electrocatalytic performance and stability of other energy conversion systems.

Flexural strength, surface roughness, and color stability of various CAD-CAM denture teeth materials.

To assess the flexural strength (FS), surface roughness, and color stability of additive manufactured (AM) and subtractive manufactured (SM) denture teeth materials, as well as the effect of thermocycling on these properties. Eighty strips (20/material type; 64×10×3.3mm) and 60 discs (15/material type; 12×4mm) were fabricated from four different denture teeth materials (Straumann, Flexcera, Ivoclar, and Candulor). The specimens were divided into two subgroups (nonthermal cycled and 5000 thermal cycled,10 per subgroup), and subjected to a 3-point test for FS using a universal testing machine at a crosshead speed of 5.0mm/min. Surface roughness (Ra, µm) and color differences (ΔE00) of disc specimens were measured before and after thermocycling using a noncontact optical profilometer and a spectrophotometer, respectively. The CIEDE2000 formula was used to calculate the color differences (ΔE00) before and after thermocycling. Data were analyzed using 2-way ANOVA followed by post hoc multiple comparison tests (α=0.05). There was no significant difference in flexural strength between nonthermal cycled SM materials (p=0.15), which were significantly higher than AM materials (p<0.001). The flexural strength values of all tested materials weresignificantly reduced after thermocycling (p<0.05). The material type had a significant effect on the Ra values (p<0.001), whereas thermocycling did not (p=0.81). After thermocycling, all materials exhibited color changes lower than the clinical perceptible threshold (ΔE00=2.7). Thermocycling decreased the FS of denture teeth materials manufactured with AM and SM, but did not affect the surface roughness. The FS values of SM groups were significantly higher than AM materials, irrespective of thermocycling. No clinically significant color changes of the denture teeth material were noted.

Influence of thermal-cycling or staining medium on the surface properties and color stability of conventional, milled, and 3D-printed base materials

The study of denture base resin fabricated by digital technology with surface properties or color stability remains limited. In this study, thermal cycling and staining media (distilled water, artificial saliva, green tea, and Coca-Cola) immersion were used to simulate the intraoral environment to assess the surface properties and color stability of CAD/CAM (milled) and 3D-printed base resin materials, the conventionally polymerized base served as the control group. After thermal cycling, all groups showed increased surface roughness, contact angle (i.e. hydrophilicity) and color difference (∆E), the 3D-printed group had the most significant increase among the 3 groups (P<0.001). While there were no significant difference (or the difference is very small) between the conventional and milled groups. After 7 and 30 days of immersion in four staining media, the ∆E values remained highest in the 3D-printed group (∆E ≥ 3.34) (P<0.001), exceeding the clinically acceptable threshold (∆E = 2.7) at 30 days. Additionally, all groups showed significantly higher ∆E values after 30 days compared to 7 days (P<0.05). The 3D-printed group exhibited a rougher surface, poorer hydrophilicity, and reduced color stability compared to the conventional or milled groups, indicating that further improvements are needed before clinical application.

A green solvent enables precursor phase engineering of stable formamidinium lead triiodide perovskite solar cells

Perovskite solar cells (PSCs) offer an efficient, inexpensive alternative to current photovoltaic technologies, with the potential for manufacture via high-throughput coating methods. However, challenges for commercial-scale solution-processing of metal-halide perovskites include the use of harmful solvents, the expense of maintaining controlled atmospheric conditions, and the inherent instabilities of PSCs under operation. Here, we address these challenges by introducing a high volatility, low toxicity, biorenewable solvent system to fabricate a range of 2D perovskites, which we use as highly effective precursor phases for subsequent transformation to α-formamidinium lead triiodide (α-FAPbI3), fully processed under ambient conditions. PSCs utilising our α-FAPbI3 reproducibly show remarkable stability under illumination and elevated temperature (ISOS-L-2) and “damp heat” (ISOS-D-3) stressing, surpassing other state-of-the-art perovskite compositions. We determine that this enhancement is a consequence of the 2D precursor phase crystallisation route, which simultaneously avoids retention of residual low-volatility solvents (such as DMF and DMSO) and reduces the rate of degradation of FA+ in the material. Our findings highlight both the critical role of the initial crystallisation process in determining the operational stability of perovskite materials, and that neat FA+-based perovskites can be competitively stable despite the inherent metastability of the α-phase.

Surface reconstruction of Co(OH)2 nanosheets through an in-situ PBA etching and sulfuration strategy for enhanced electrocatalytic oxygen evolution reaction

Designing an electrocatalyst for the oxygen evolution reaction (OER) that combines high activity with exceptional stability is a pivotal advancement in sustainable water splitting technology, heralding a novel approach to produce clean, high-purity hydrogen. This paper introduces an innovative strategy centered on the construction of a three-dimensional heterostructure supported on carbon cloth, specifically Fe–CoS2/Co(OH)2/CC. This meticulous strategy begins with the meticulous treatment of Co(OH)2 nanosheets, cleverly inducing the formation of Prussian blue-like compounds through in-situ etching techniques. Subsequently, a direct sulfuration treatment is employed, resulting in a delicate reconstruction of the Co(OH)2 nanosheet surface, ultimately yielding a unique Fe–CoS2/Co(OH)2/CC heterostructure. This composite material exhibits remarkable low overpotential performance, achieving an impressive 235 mV at a current density of 10 mA cm–2, which is comparable to that of established catalysts such as Ruthenium dioxide (RuO2). The exceptional catalytic activity of Fe–CoS2/Co(OH)2/CC is primarily attributed to its unique 3D structure, crafted through the in-situ growth of Prussian blue analogs (PBAs). This structure not only ensures uniform iron doping but also significantly enhances the material's stability and reactivity. Furthermore, the high conductivity of the self-supported carbon cloth electrode facilitates rapid electron transport, further augmenting the overall catalytic efficiency.

A New Concept for Cervical Expansion Screws Using Shape Memory Alloy: A Feasibility Study.

In general, sufficient anchoring of screws in the bone material ensures the intended primary stability. Shape memory materials offer the option of using temperature-associated deformation energy in a targeted manner to compensate the special situation of osteoporotic bones or the potential lack of anchoring. An expansion screw was developed for these purposes. Using finite element analysis (FEA), the variability of screw configuration and actuator was assessed from shape memory. In particular, the dimensioning of the screw slot, the actuator length, and the actuator diameter as well as the angle of attack in relation to the intended force development were considered. As a result of the FEA, a special configuration of expansion screw and shape memory element could be found. Accordingly, with an optimal screw diameter of 4 mm, an actuator diameter of 0.8 mm, a screw slot of 7.8 mm in length, and an angle of attack of 25 degrees, the best compromise between individual components and high efficiency in favor of maximum strength can be predicted. Shape memory material offers the possibility of using completely new forms of power development. By skillfully modifying the mechanical and shape memory elements, their interaction results in a calculated development of force in favor of a high primary stability of the screw material used. Activation by means of body temperature is a very elegant way of initializing the intended locking and screw strength.

Non-intrusive parametric hyper-reduction for nonlinear structural finite element formulations

Model Order Reduction (MOR) is a core technology for the creation of comprehensive executable Digital Twins, since it efficiently reduces the computational burden of high-fidelity models. When dealing with nonlinear structural Finite Element analyses, several Hyper-Reduction (HR) approaches have been developed to reduce the computational cost. Nonetheless, HR approaches are typically intrusive in nature, posing challenges when it comes to integration into existing (commercial) software. Recently, data driven Non-Intrusive MOR methodologies have been proposed. However, these techniques often suffer from overfitting and violate key physics properties, leading to unstable behavior. This work proposes to use Scientific Machine Learning to reintegrate critical stability-preserving physics properties. It introduces a data-driven, physics-augmented, parametric approach that combines Proper Orthogonal Decomposition (POD) with a Partially Input Convex Neural Network (PICNN) architecture. The proposed method effectively reduces the computational burden associated with parametric static nonlinear elastic structural problems while retaining material consistency, hyper-elasticity, and material stability properties in the Reduced Order Model. Numerical validation on several structural models subjected to geometrical and material nonlinearities under static loading conditions demonstrates the effectiveness of the POD-PICNN approach. Additionally, three different sampling strategies have been compared to assess their impact on the method performance. The results emphasize that physics-augmentation is required, as it inherently embeds essential physical constraints into the neural network architecture, ensuring stable and consistent behavior, while highlighting its potential for dynamic and multiphysics applications.

Core Double-Shell FeCo@SiO2@PPy Nanocomposites for Tunable and Broadband Electromagnetic Wave Absorption

Electromagnetic wave absorption materials are essential for dealing with military stealth and electromagnetic pollution. However, challenges remain in regards to material stability and achieving broadband absorption. Constructing magnetic-dielectric core-shell structural composites with good morphology is one of the effective strategies to realize high-performance electromagnetic wave absorption. Herein, FeCo@SiO2@polypyrrole (PPy) core double-shell nanocomposite with uniform shell thicknesses is synthesized by environmentally friendly polyol method, sol-gel method and in-situ oxidative polymerization method. FeCo@SiO2@PPy nanocomposites with different PPy shell thicknesses were synthesized, and tunable electromagnetic wave absorption had been achieved. The reasonable combination of magnetic and dielectric components and the design of core double-shell structure optimized impedance matching and attenuation characteristics, resulting in strong and broadband electromagnetic wave absorption (minimum reflection loss: -62.7 dB, effective absorption bandwidth: 7.0 GHz). This work could initiate a new insight into the design and modulation of advanced electromagnetic wave absorption materials with strong and broadband absorption properties.