Bridging Mechanism Research Articles

Performance of surfactant supplementation on alleviating membrane fouling in treatment of waste activated sludge: Experimental and modeling analyses

In this research, surfactant supplementation was investigated as a novel strategy for alleviation of membrane fouling in waste activated sludge (WAS) membrane filtration process. The effect of WAS pre-treatment with different surfactants on membrane performance were investigated in terms of flux variation, membrane rejection and fouling mechanisms. A generalization form of blocking law was developed to determine membrane fouling mechanism. According to the results, cationic surfactant below critical micelle concentration (CMC) values improved membrane performance, while anionic and non-ionic surfactant showed a negative impact at all dosages. It was observed that WAS pretreatment with 300 mg/L Cetyltrimethylammonium bromide (CTAB) could increase the water flux from 195 to 611 L/m2/h (LMH) and decrease the rejection rate from 93% to 85%, respectively. Although CTAB addition increased the total extracellular polymeric substances (EPSs) amount from 56.16 to 119.6 mg/L which was due to the surfactant solubilization property, the total resistance decreased from 0.33 × 1010 to 0.11 × 1010 m−1. This was attributed to the flock formation induced by CTAB through charge neutralization and bridging mechanism. Modeling simulation of the results indicated that CTAB addition transformed fouling mechanism from cake to intermediate-blocking model. The environmental risk assessment revealed that only 0.3 mg/L surfactant penetrated in permeate which was low ecological risk (risk quotients (RQ) < 0.5) to the aquatic environment. Our finding suggested CTAB treatment at low dosage (0.1 g/L) as a promising and efficient approach for fouling mitigation and improving membrane process for wastewater treatment.

Effects of microbubbles and frother types on first-order flotation kinetics of coarse quartz: a Box–Behnken design study

ABSTRACT This study utilised a Box–Behnken experimental design to examine the influence of various frothers (MIBC, 2-Ethylhexanol, α-Terpineol, and AF-65), dodecylamine (DDA) collector, and microbubbles on coarse quartz flotation performance. The flotation efficiency was evaluated through two key parameters: maximum recovery (R∞) and first-order rate constant (k). The findings revealed that microbubbles substantially enhanced flotation kinetics through synergistic interactions, particularly in combination with aliphatic alcohol frothers. The effectiveness of cyclic alcohol and polyglycol-type frothers varied significantly, depending on microbubble presence, frother concentration, and DDA interactions. While 2-Ethylhexanol achieved the highest recovery (97.71%) in conventional flotation without microbubbles, α-Terpineol exhibited the most pronounced synergistic effect when combined with microbubbles and DDA, reaching 99.71% recovery. In terms of kinetic performance, AF-65 demonstrated exceptional results in the presence of microbubbles and DDA, achieving the highest rate constant of 2.12 min−1. The effectiveness of the bubble bridging mechanism showed considerable variation across different frother types, with aliphatic alcohols exhibiting notable improvements in the presence of microbubbles, particularly at lower concentrations. Although increased DDA concentrations generally resulted in decreased flotation rates, they enhanced overall recovery – an effect that was further amplified by the presence of microbubbles.

Rapid charge transfer via anion bridge strategy for enhanced deep photocatalytic NO oxidation

Surface defect engineering and interfacial heterojunction construction can provide a promising strategy to achieving efficient reactant molecular activation and rapid charge transfer. However, traditional surface defect and interfacial heterojunction could often suffer from the potential space barrier, sluggish electron transfer, and weak reactant adsorption/activation, resulting in unsatisfactory pollutant removal effect. Herein, the anions (WO42−) bridged AgBr/Bi4O5Br2 heterojunction, involves the in situ growth of AgBr onto Bi4O5Br2 with the generation of bromine vacancies (BVs), is designed and synthesized by using a chemical deposition method. By establishing an electron-bridge into the interface of AgBr and Bi4O5Br2, a rapid charge carrier transfer channel is created, efficiently promoting the transport of photogenerated electrons from AgBr to Bi4O5Br2. Importantly, these spatially separated electrons of AgBr-WO42−-Bi4O5Br2 are captured by the active sites (BVs) in Bi4O5Br2to promote reactant activation, resulting in highly stable photocatalytic NO removal (67.7 %) and efficient inhibition of toxic NO2 formation (417.9 ppb → 30.6 ppb). The effective removal of NO2 by other anions, such as PO43-, demonstrates the broad applicability of this approach. This work introduces a synergistic mechanism of electron bridge, built-in electric field and vacancy engineering to create rapid charge carrier transfer channel and molecular activation strategy in designing highly efficient photocatalysts for deep photocatalytic NO oxidation.

Three-dimensional fracture mechanics model of conch shells with hierarchical crossed-lamellar structures

Conch shells, characterized by a highly mineralized hierarchical crossed-lamellar structure that represents the pinnacle of molluscan evolution, exhibit exceptional crack resistance to protect their soft bodies from predatorial attacks. In this paper, we present a three-dimensional fracture mechanics model to establish a correlation between fracture toughness and the crossed-lamellar structure, elucidating the hierarchical crack bridging mechanism of aragonite lamellae. We find that increased fracture toughness is achieved through the energy dissipation contributed by the interfacial debonding of both first-order and second-order lamellae. The conch shells demonstrate outstanding resistance to cracking in two principal directions, featuring a locally stacked structure of flat plates that effectively withstand complex loads. The vertically alternating stacking structure of macroscopic layers of equal thickness inspires a biomimetic design with more balanced mechanical properties, accompanied by enhanced crack resistance observed as the lamellae become thinner. The theoretical results are in good agreement with relevant experimental measurements. This work not only sheds light on the physical mechanisms responsible for the remarkable fracture toughness of crossed-lamellar structures but also provides guidelines for designing high-performance biomimetic structural materials.

Improving the interfacial bonding strength of a silane anticorrosion film on copper surfaces using small-molecule corrosion inhibitors

The weak binding ability of silane to copper surfaces restricts its use in copper anticorrosion. In this study, the P–OH groups in etidronic acid (HEDP) were utilized to establish chemical bonds with copper and to react with 3-mercaptopropyltrimethoxysilane (PropS-SH), serving as a bridging mechanism to enhance the anchoring of silane onto copper surfaces. Moreover, the presence of HEDP promoted the condensation of silane, leading to the formation of a denser and thicker film with outstanding corrosion resistance. SEM results indicated that the thickness of the PropS-SH/HEDP film was about 125 nm, and defects at the copper–film interface were repaired. Electrochemical tests demonstrated that the PropS-SH/HEDP film exhibited remarkable corrosion resistance, achieving an anticorrosion efficiency of 99.95 %. Immersion testing showed that the PropS-SH/HEDP film was capable of withstanding immersion in a 3.5 wt% NaCl solution for 10 days, displaying a durability 5 times greater than that of the standalone silane film.

Experimental and theoretical studies on the shear resistance of reinforced engineered cementitious composite beams with GFRP rebars and natural fibers

In this work, an attempt is made to produce a ductile construction system using natural fiber-based engineered cementitious composite (ECC) beams where the conventional longitudinal steel reinforcements are replaced using glass fiber-reinforced polymer (GFRP) bars. In total, sixteen medium-scale reinforced ECC beams were tested under an un-symmetric three-point bending configuration to generate shear failure. The parameters considered as a part of the experimental program include (a) type of longitudinal reinforcement (steel or GFRP) and (b) type of natural fiber (flax, hemp, kenaf and pineapple). In addition, a detailed analytical study was performed using the Architectural Institute of Japan (AIJ) method, and a modified equation was proposed for predicting the shear behavior of FRP reinforcement using ECC beams. Test results reveal that the use of GFRP reinforcements resulted in the reduction of peak load from 33.6% to 65.4% when compared to similar steel-reinforced R-ECC beams. However, the failure mode was highly ductile due to the excellent fiber bridging mechanism, multi-crack formation and effective stress redistribution at the crack tip. The predictions obtained from the modified AIJ method improved the accuracy of shear capacity FRP-reinforced ECC sections when compared to the experiments.

Plant-Based Flocculants as Sustainable Conditioners for Enhanced Sewage Sludge Dewatering

With the aim to establish clean and sustainable sludge treatment, green conditioning using natural flocculants has recently gained a growing interest. In this study, a variety of plant materials, namely Moringa (Moringa oleifera) seeds, Fenugreek (Trigonella foenum-graecum) seeds, Potato (Solanum tuberosum) peels, Aloe (Aloe vera) leaves, Cactus (Opuntia ficus indica) cladodes, and Phragmites (Phragmites australis) stems, were evaluated for their potential bioflocculant activity in conditioning sewage sludge. They were thoroughly characterized to determine their active flocculating compounds. Sludge dewaterability was evaluated by assessing various sludge parameters, including specific resistance to filtration (SRF), dryness of filtration cake (DC), and total suspended solid removal (TSS) from sludge filtrate. The collected results from various physicochemical characterizations of plant materials suggest that the main flocculating agents are carbohydrates in Cactus and Fenugreek and proteins in Moringa, Potato, and Phragmites. Additionally, all tested plant-based flocculants demonstrated effective dewatering performance. Interestingly, compared to the chemical flocculant polyaluminum chloride, Moringa and Cactus showed superior conditioning effects, yielding the lowest SRF values and the highest DC. As a result, the use of these natural flocculants improved sewage sludge filterability, leading to a significant removal of total suspended solids from the filtrate. The conditioning properties of Moringa and Cactus can be attributed to their high protein and sugar content, which facilitates the effective separation of bound water from solids through charge neutralization and bridging mechanisms. Thus, green conditioning using plant-based flocculants, particularly Moringa and Cactus materials, presents a promising and eco-friendly approach to enhance sewage sludge dewatering for safer disposal and valorization.

A rate-dependent crack bridging model for dynamic fracture of CNT-reinforced polymers

Carbon nanotubes (CNTs) improve the fracture toughness of polymer-based matrix composites by bridging the crack growth path. This research presents a finite element (FE) rate-dependent crack bridging model of Mode-I dynamic crack growth in CNT-reinforced polymers accounting for rate of loading and rapid crack growth. Two distinct CNT bridging and matrix cracking damage mechanisms are taken into account in the fracture process zone (FPZ) accounting for the dissipation of fracture energy. A viscoelastic-viscoplastic material model is adapted for the matrix phase to capture the strain rate effects. The crack in the matrix phase is modeled using cohesive zone elements characterized by experimental data. A rate-dependent traction-separation law obtained from CNT pull-out simulation at relevant crack opening speeds is used to simulate the CNT bridging in the FPZ. Considering the given traction-separation law as a constitutive equation, the CNTs are replaced with non-linear spring elements to facilitate the FE simulation of crack bridging with numerous CNTs in the FPZ. The proposed rate-dependent FE model for crack bridging enables the study of the effect of key CNT factors such as length, orientation, waviness, volume fraction, and agglomeration on fracture energy dissipation at various crack speeds. The developed model can simultaneously consider the interactive effects of all CNT parameters which is useful for considering all processing-induced uncertainties in analyzing the effects of CNTs on the dynamic fracture toughness of nanocomposites.

NFTs for accessing, monetizing, and teleporting digital twins and digital artifacts in the metaverse

Digital twins and digital artifacts have become integral components of metaverse platforms, providing users with a rich, immersive, and interactive digital experience through the deployment of diverse digital twins and digital artifacts such as 3D avatars, images, and objects. To date, a significant challenge persists in the lack of practical mechanisms to enable seamless teleportation and cross-metaverse interoperability for these digital twins and digital artifacts. There is also a lack of trusted monetization methods that facilitate trading and leasing of digital twins and digital artifacts. To address these important challenges, this paper proposes a blockchain and Non-Fungible Token (NFT)-based solution that facilitates the integration and teleportation of these digital twins and digital artifacts by providing trusted metadata, verifying ownership, and ensuring the authenticity of digital creations in the virtual world. Key to our solution is the introduction of a bridging mechanism that enables cross-metaverse interoperability, allowing for the portable transfer of NFTs across decentralized metaverse platforms. In addition, our solution focuses on empowering original digital creators by enabling the monetization of their creations through the ownership management capabilities offered by NFTs. To reliably and securely store the metadata and content of tokenized digital twins and digital artifacts, we integrate into our solution the Interplanetary File System (IPFS), a decentralized storage system. To demonstrate the feasibility of our solution, we have developed and deployed all necessary smart contracts that govern the main functionalities and interactions of the proposed system on the Ethereum Goerli Testnet. We present our proposed system architecture, accompanied by informative sequence diagrams, algorithms, and testing details. We discuss how our proposed solution attains the main objectives outlined in the paper. We evaluate our proposed solution in terms of cost and security. We have made the complete source code of our smart contracts publicly available on GitHub.

Dual‐Site Bridging Mechanism for Bimetallic Electrochemical Oxygen Evolution

AbstractHeterogeneous dual‐site electrocatalysts are emerging cutting‐edge materials for efficient electrochemical water splitting. However, the corresponding oxygen evolution reaction (OER) mechanism on these materials is still unclear. Herein, based on a series of in situ spectroscopy experiments and density function theory (DFT) calculations, a new heterogeneous dual‐site O−O bridging mechanism (DSBM) is proposed. This mechanism is to elucidate the sequential appearance of dual active sites through in situ construction (hybrid ions undergo reconstruction initially), determine the crucial role of hybrid dual sites in this mechanism (with Ni sites preferentially adsorbing hydroxyls for catalysis followed by proton removal at Fe sites), assess the impact of O−O bond formation on the activation state of water (inducing orderliness of activated water), and investigate the universality (with Co doping in Ni(P4O11)). Under the guidance of this mechanism, with Fe−Ni(P4O11) as pre‐catalyst, the in situ formed Fe−Ni(OH)2 electrocatalyst has reached a record‐low overpotential of 156.4 mV at current density of 18.0 mA cm−2. Successfully constructed Fe−Ni(P4O11)/Ti uplifting the overall efficacy of the phosphate from moderate to superior, positioning it as an innovative and highly proficient electrocatalyst for OER.

Dual-Site Bridging Mechanism for Bimetallic Electrochemical Oxygen Evolution.

Heterogeneous dual-site electrocatalysts are emerging cutting-edge materials for efficient electrochemical water splitting. However, the corresponding oxygen evolution reaction (OER) mechanism on these materials is still unclear. Herein, based on a series of in situ spectroscopy experiments and density function theory (DFT) calculations, a new heterogeneous dual-site O-O bridging mechanism (DSBM) is proposed. This mechanism is to elucidate the sequential appearance of dual active sites through in situ construction (hybrid ions undergo reconstruction initially), determine the crucial role of hybrid dual sites in this mechanism (with Ni sites preferentially adsorbing hydroxyls for catalysis followed by proton removal at Fe sites), assess the impact of O-O bond formation on the activation state of water (inducing orderliness of activated water), and investigate the universality (with Co doping in Ni(P4O11)). Under the guidance of this mechanism, with Fe-Ni(P4O11) as pre-catalyst, the in situ formed Fe-Ni(OH)2 electrocatalyst has reached a record-low overpotential of 156.4 mV at current density of 18.0 mA cm-2. Successfully constructed Fe-Ni(P4O11)/Ti uplifting the overall efficacy of the phosphate from moderate to superior, positioning it as an innovative and highly proficient electrocatalyst for OER.

An overview of tensile and shear failure mechanisms of silicon carbide-based ceramic matrix composites

The successful applications of silicon carbide-ceramic matrix composites (SiC-CMCs) in aeronautical and aerospace industries require deeper understanding of their mechanical behaviors and failure mechanisms. The overview on tension and shear is then presented from meso-mechanics perspective, including matrix cracking, interface de-bonding and sliding, matrix crack propagation as well as fiber bridging. The results reveal that the matrix cracking stress is proportional to the interface sliding stress and the matrix fracture energy. The ratio of tensile to shear stress of the matrix cracking remains constant both in tension and in shear. In addition, the deflection of matrix cracks in the interface depends on the elastic modulus matching parameter, the angle between matrix cracks and interface, as well as the residual thermal stress. The matrix cracks propagate in a random or periodic pattern, which are proportional to the sliding length at the matrix cracking stress. The fiber bridging mechanism, related to the Weibull distribution of the fiber strength, determines the tensile and shear behaviors after the saturation of matrix cracks.

High-strength TiO2/TPU composite fiber based textiles for organic pollutant removal

Effective integration of nanostructured photocatalysts into polymer matrices is crucial for the broad practical application of fiber-based photocatalytic composite textiles. Herein, highly durable TiO2/TPU composite fibers with high TiO2 content (>30 wt. %) were prepared through wet spinning using 1D electrospun TiO2 nanofibers (TNFs). Due to the fiber reinforcement principle, the TNF/TPU composite fibers exhibited superior mechanical properties compared with pure TPU fibers. Furthermore, the TNF/TPU composite fibers with a ratio of 1:2 process impressive degradation efficiency for rhodamine B (RhB). The orientation of 1D TNFs and stronger interface between TNF and TPU matrices not only enable the excellent load sharing and transfer effects following fiber pullout and crack bridging mechanisms, but also improve photogenerated charge transfer efficiency, resulting in high strength and high photocatalytic activity. In addition, enhanced TNF exposure on the fiber is due to the hollow and porous structures of composite fibers, which is advantageous for photocatalytic degradation. Notably, when the RhB concentration exceeded 15 ppm, the TNF/TPU composite fibers exhibited higher degradation efficiency than the TNF powder. Therefore, TNF/TPU composite fiber–based textiles with high photocatalytic activity and strength are promising for overcoming the separation and recovery issues of nanostructured catalysts in practical wastewater treatment applications.

Hydrogen-bond enhanced interior charge transport and trapping in all-fiber triboelectric nanogenerators for human motion sensing and communication

Maximizing charge density output within confined tribolayer areas is crucial for advancing triboelectric nanogenerator (TENG) performance. While conventional methods primarily focus on enhancing current density by modifying the surface properties of tribo-surfaces, the impact of dipole-dipole interactions between polymer molecular chains in the fibrous tribomaterials has been underexplored. This study reveals that intermolecular dipole-dipole interactions, mediated by hydrogen bonding between chitosan and nylon66 molecular chains, serve as effective bridging mechanisms that substantially boost TENG current density. Furthermore, we developed a breathable and antibacterial electrode by depositing silver nanowires (AgNWs) on the tribolayer surfaces. To prevent air breakdown resulting from excessively high current density, multiwalled carbon nanotubes (MWCNTs) were integrated to enhance electron transfer and storage. The structure we constructed achieved an optimized performance with a high voltage of 335 V, current density of 194.5 mA m−2 and power density of 65.1 W m−2, which demonstrates outstanding performance compared to previously obtained results. Finally, the prepared SWS-TENG was attached to the fingertips, wrist, and neck to track the physiological signals of the human state during standing, walking, and running. In addition, the integration of Morse code functionality introduces new possibilities for healthcare, particularly for non-verbal patients, enabling non-invasive communication of symptoms and emotions. This technology demonstrates significant potential as a versatile and non-invasive tool for point-of-care (PoC) and biomedical applications when deployed on various parts of the human body.

Dispersion, solid solution, and covalent bond coupled to strengthen K4169/TiAl composite brazed joints: First-principles and experimental perspective

Ni/TiAl composite brazed joints could significantly reduce the aircraft's weight. However, low interfacial adhesion, coarse and brittle-hard intermetallic compounds (IMCs) seriously limited the application of Ni/TiAl composite joints in the next generation of aerospace applications. So enhanced K4169/TiAl composite joints were investigated by vacuum brazed with (Ni53.33Cr20B16.67Si10/Zr25Ti18.75Ta12.5Ni25Cu18.75) composite filler metal (CFM) designed based on cluster-plus-glue-atom model. The shear strength of the joint reached 485 MPa, comparable to the 491 MPa of TiAl substrate. The flat and brittle-hard diffusion reaction layer between Zones I and II was eliminated, simultaneously generating CrB4 dispersion strengthening due to the CFM developed with the interfacial solid-liquid space-time hysteresis effect. In Zones II and III, IMCs all transformed into Niss(Cr,Fe)[0–88], Niss(Ti, Al)[004], and Niss(Zr,Si)[11–2] of circular and oval shapes through isothermal solidification. Meanwhile, the residual stresses and hardness were distributed in reticulated cladding characteristics. Thereby, lattice distortion led to solid solution strengthening and increased plastic toughness through crack termination and bridging mechanisms, which inhibited dislocations from plugging and crack propagation. Various interfaces in Zone Ⅳ were regulated into semi- and coherent interfaces. Ni3(Ti,Al)/(Ni,Ti,Al) and (Ni,Ti,Al)/AlNi2Ti were composed of higher interfacial bonding energy (2.771 J/m2, 2.547 J/m2) and Ni-Ni covalent bonds. Interfacial covalent bonding and large interfacial bonding energy coupling strengthened Zone IV. Consequently, cracks initiated at the (Ni,Ti,Al)[013]/Ti3Al[010] and expanded rapidly into TiAl substrate. Therefore, applying this method to design CFMs and regulate the phase, grain morphology, and interface's fine structure could provide new pathways for dissimilar hard-to-join metals.

Compressive mechanical performance and microscopic mechanism of basalt fiber-reinforced recycled aggregate concrete after elevated temperature exposure

To improve the mechanical properties of recycled aggregate concrete (RAC) after elevated temperature exposure, this study employed basalt fiber (BF) as reinforcing material incorporated into RAC. The replacement ratio of recycled coarse aggregate (RCA), the content of BF, and the temperature were utilized as the change parameters, and 27 groups of basalt fiber reinforced recycled aggregate concrete (BFRRC) specimens were designed to carry out the compressive strength test after elevated temperature. The heating rate was set at 2.5 °C/min to avoid any possible explosion of the cylindrical specimen during the heating process. The specimens were treated for 6h after reaching the desired temperature, and then the furnace door was opened for natural cooling to room temperature. After observing the physical properties of the specimens, the basic mechanical properties test was carried out, and the microscopic mechanism was analyzed in depth by electron microscopy. The results showed that the defects inherent in RCA and the continuous accumulation of elevated temperature damage gradually reduced the compressive mechanical performance of BFRRC but that the toughening and cracking-resistance action of BF effectively improved the compressive mechanical performance of BFRRC. BF enhanced the compressive mechanical performance of RAC through bridging and crack resistance action mechanisms, but the higher the temperature became, the smaller the enhancement was. The cube compressive strength and axial compressive strength of the specimens decreased with the increase of temperature. With the same replacement ratio and fiber dosage, increasing the temperature from 300 °C to 600 °C, the decrease in cube compressive strength and axial compressive strength was the most significant, which was between 36.4 %–48.1 % and 51.1 %–62.6 %, respectively.

Experimental and molecular simulation study on the influence of chain length and anion structure of ionic liquids on the wettability of highly hydrophobic bituminous coal

The wettability of bituminous coal is critical for the coal dust suppression and can be apparently modulated by ionic liquids. However, the modulation mechanism still remains elusive. Here, a combination of macroscopic experiments, mesoscopic characterization, and microscopic simulations (quantum mechanics and molecular dynamics) are leveraged to parse the effect on the wettability of coal dust surfaces of three novel ionic liquids ([C12MIm]Br, [BMIm]Br, [BMIm]Cl) featuring the varying chain lengths and anions in the coal-water system. The results show that the selected ionic liquids exert a distinct bridging function from traditional surfactants which invoke the hydrogen bonding interaction. This ionic liquids-mediated bridging mechanism heavily depends on their chain length structure, which can firstly penetrate deeply the internal pores of coal dusts and then adsorb on the coal surfaces to rapidly strike a dynamic equilibrium. Ionic liquids interacting with coal dust can primarily reduce the energy difference between polar and nonpolar interactions within coal dust, thereby enhancing the electrostatic interactions between coal dust and water molecules and effectively improving coal dust wetting properties. These findings provide a theoretical basis for the rational design of high-performance ionic liquids for coal mine dust control.

Ni3C nanosheets and PVA nanocomposite based memristor for low-cost and flexible non-volatile memory devices

Two-dimensional (2D) MXenes have gained extensive attention in the field of memristors due to their high ion mobility, chemical stability and tunable electrical and surface properties. Moreover, MXenes have tunable interlayer bonding which enables enhancement in memristor performance. In this work, we synthesize a novel nanocomposite of Ni3C nanosheets and polyvinyl alcohol (PVA) and fabricate a flexible memristor with Ag/Ni3C-PVA/ITO/PET configuration for non-volatile memory applications. Ni3C nanosheets were synthesized from Ni-MAX (Ni3AlC2) through a solvothermal etching and exfoliation process. The nanosheet like structure of Ni3C is confirmed through Scanning Electron Microscopy (SEM) and Transmission Electron microscopy (TEM). Characterization techniques like X-ray diffraction (XRD), Raman spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR) reveal the crystalline phases, surface functional groups and chemical bonds present in Ni3C nanosheets and Ni3C-PVA nanocomposite. The memristor was fabricated through a facile low cost solution processed based fabrication technique. The Ag/Ni3C-PVA/ITO/PET memristor exhibits bipolar non-volatile switching characteristics. The device with optimised mass ratio of 4:3 (Ni3C: PVA) shows a decent off/on ratio of 2.09 × 102, long retention time of 104 s, and an endurance of 102 DC cycles. The SET voltage of the as-fabricated device is 2.8 V and the RESET voltage is −5.33 V. The flexible memristor exhibits outstanding mechanical robustness over 500 bending cycles. The high charge carrier mobility of Ni3C results in lower switching voltage and the dielectric property of PVA improves data retention and off/on ratio of the memristor. The resistive switching behaviour is explained through conductive metallic bridge mechanism. The conduction mechanism follows Ohmic conduction in ON state and trap controlled space charge limited current (TCSCLC) mechanism in OFF state. The results demonstrate that the nanocomposite with its superior resistive switching effects is suitable for cost-effective, high-performance, flexible non-volatile memory devices.

Delamination bridging response of Z‐pins under mixed mode loading: The influence of carbon and Kevlar Z‐pins

AbstractThis paper presents the effect of varying the type of Z‐pin on the delamination bridging performance of unidirectional composite laminates. Carbon and Kevlar Z‐pins were inserted in thick composite laminates using the pre‐hole insertion Z‐pinning process and their bridging performance characterized across the different mode‐mixity range. The bridging response indicated that Kevlar Z‐pin experienced load reduction driven by interfacial friction (Stage III), which was absent in the Carbon Z‐pin. When Mode II dominated the bridging crack, Kevlar Z‐pin showed partial pullout and fiber shear cracking, while the Carbon Z‐pin exhibited clean transverse fracture. Although the bridging load obtained by the Carbon Z‐pin was twice that of Kevlar Z‐pin, the Kevlar Z‐pin provided a higher interlaminar fracture energy. The superior bridging performance of Kevlar Z‐pin is correlated with the enhanced ductility. Moreover, the resin‐rich area was involved in deformation and provided the extra axial load of Z‐pin.Highlights The comparison of mixed‐mode bridging mechanism between Kevlar Z‐pin and Carbon Z‐pin. Reveal the variation of multi‐directional load and energy consumption with mixed‐mode angle in thick laminates. Detailed scanning electron microscope observation to understand failure characteristics of ductile Z‐pin. Evidence that the extra axial load of Z‐pin provided by resin‐rich area.

Study of the Dynamic Reaction Mechanism of the Cable-Stayed Tube Bridge under Earthquake Action

In order to explore the failure mode of the cable-stayed pipe bridge under earthquake action, taking the structural system of an oil and gas pipeline–cable-stayed pipe bridge as the research object, the full-scale finite element calculation model of the cable-stayed pipe bridge–oil and gas pipeline structural system as well as the finite element calculation model considering the additional mass of the oil and gas medium and the fluid–structure interaction effect were established by using ANSYS Workbench finite element software. The stress and displacement of the cable under the earthquake action were analyzed in the time history, as were the response characteristics of the cable when subjected to both methods. The calculation results show that the overall failure of the pipeline is basically the same under the two methods. Compared with the additional mass method, the solution for the fluid–structure coupling method can be derived through a comprehensive analysis of the flow field and structure, respectively, avoiding the sudden change caused by model simplification or calculation error so that the analysis results can better simulate the actual situation. In summary, the fluid–structure interaction method enables a more precise prediction of the dynamic response of the structure, and the findings of this research can provide a theoretical foundation and technical guidance for optimizing the seismic performance of cable-stayed pipe bridges.