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Silicon oxycarbide (SiOC) ceramics have been used to fabricate microwave-absorbing metastructures, demonstrating impressive absorption capabilities. However, SiOC ceramic metastructures with excellent performance require simple fabrication processes and appropriate mechanical and electromagnetic properties. In this study, a solvent-free photosensitive polysiloxane preceramic was developed by blending methoxy/hydroxy polysiloxanes with acrylates, with a ceramic yield of over 60% after curing using a novel two-step ultraviolet (UV)/thermal method. The composition and microstructure of SiOC ceramics can be designed by controlling the preceramic composition. Dense, crack-free gyroid-shellular shaped triple periodic minimal surface (GS-TPMS) electromagnetic metastructures were fabricated using digital light processing (DLP) 3D printing technology. By designing the porosity of the GS-TPMS structure to 51%, an effective absorption bandwidth that covers the X-band can be achieved at a thickness of 3.1 mm. The honeycomb structure, with a geometric density of 0.69 g/cm3, exhibited a high compressive strength of 107.05 MPa. This paper presents an efficient approach for the prompt and customized fabrication of lightweight ceramic metastructures with outstanding microwave absorption properties. • A solvent-free polysiloxane/acrylate hybrid preceramics is developed for 3D printing. • The UV/thermal two-stage treatment achieved cross-linking curing of the preceramics. • Multiscale design of SiOC ceramics for enhanced microwave absorption properties. • SiOC ceramic metastructures with effective absorption in the X-band are prepared. [ABSTRACT FROM AUTHOR]

Due to the limitations of the Kramers-Kronig relationship, how to achieve ultra-wide effective absorption bandwidth remains a challenge for typical magnetic-dielectric absorbers. In the present work, we have explored the possibility of obtaining ultra-wide absorption bandwidth in FeSiAl composites with help of efficient electromagnetic (EM) simulation software-Computer Simulation Technology (CST). Flaky FeSiAl powders covered by CeO 2 have been prepared, in which EM parameters can be tuned by filling ratio of FeSiAl/CeO 2 in FeSiAl/CeO 2 -paraffin composites. The filling ratio has an effect on impedance matching and EM parameters by the arrangement of particles in the paraffin. The composite with 30 wt% flaky FeSiAl/CeO 2 achieves an effective absorption bandwidth (EAB) of 6.48 GHz and the optimal microwave absorption efficiency of 1499.3 dB GHz/(wt%⋅m) at 1.9 mm. Integrated with a macroscale honeycomb structural design, the FeSiAl/CeO 2 composites based metastructure exhibits broadband microwave absorption with an EAB of 14.224 GHz covering from 3.776 GHz to 18 GHz and reflection loss of-65.61 dB at 8.5 GHz. The excellent performances of the designed absorber are ascribed to multiple loss by integrating EM parameters of flaky FeSiAl/CeO 2 and the geometry parameters of honeycomb metasrtucture. The present work makes flaky FeSiAl/CeO 2 composites possible to achieve broadband microwave absorption. [ABSTRACT FROM AUTHOR]

A simple in-situ method was proposed to synthesize surface coating of SiC nanowhiskers on cordierite honeycombs by aluminothermic, silicothermic, and carbothermic reduction reactions. The surface coating of SiC nanowhiskers was synthesized by controlling the partial pressure of SiO gas on the surface of honeycombs, based on the pore-forming process using aluminium(Al) agent. Increasing the porosity of the honeycombs provided aisles to volatilize SiO gas, and the growth of SiC nanowhiskers changed from inside the honeycomb wall to on the honeycomb surface. SEM and TEM observations revealed that the relatively high porosity (≥45%) and sintering temperature (1250–1300 °C) were necessary for obtaining surface coating of SiC nanowhiskers, and the nanowhisker-coating having the smooth morphology and a thickness of ∼150 µm was obtained at 1250 °C. Compared with cordierite honeycombs without SiC nanowhiskers, SiC nanowhiskers inside the honeycomb walls could improve the compressive strength and thermal conductivity with increasing rates of 121% and 123%, respectively, and the surface coating of SiC nanowhiskers increased the specific surface area of the honeycombs by 241 times. [ABSTRACT FROM AUTHOR]

Peculiarities of sintering of foamy ceramic filters based on submicron aluminum oxide powders with additions of titanium oxide and manganese dioxide nanopowders are considered. The processes of removal of polymeric and binder paraffin material during sintering have been studied. The physical and mechanical properties of the obtained porous permeable filters with a foamy structure were analyzed in details. At a sintering temperature in an air atmosphere of 1350 °C, sufficiently high physical and mechanical properties were obtained, which made it possible to use the developed filters as catalyst carriers for vehicle exhaust gases. Bench comparative tests have shown that ceramic filters with a foamed structure are promising catalysts for afterburning car exhaust gases instead of ceramic honeycomb blocks of catalyst carriers. The developed technology allows reducing the sintering temperature of porous foam ceramic filters to 1350 °C and replacing expensive high-temperature ceramic heaters with cheaper nickel-chromium ones. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with high mortality. The Food and Drug Administration-approved drugs, nintedanib and pirfenidone, could delay progressive fibrosis by inhibiting the overactivation of fibroblast, however, there was no significant improvement in patient survival due to low levels of drug accumulation and remodeling of honeycomb cyst and interstitium surrounding the alveoli. Herein, we constructed a dual drug (verteporfin and pirfenidone)-loaded nanoparticle (Lip@VP) with the function of inhibiting airway epithelium fluidization and fibroblast overactivation to prevent honeycomb cyst and interstitium remodeling. Specifically, Lip@VP extensively accumulated in lung tissues via atomized inhalation. Released verteporfin inhibited the fluidization of airway epithelium and the formation of honeycomb cyst, and pirfenidone inhibited fibroblast overactivation and reduced cytokine secretion that promoted the fluidization of airway epithelium. Our results indicated that Lip@VP successfully rescued lung function through inhibiting honeycomb cyst and interstitium remodeling. This study provided a promising strategy to improve the therapeutic efficacy for IPF. [Display omitted] • Inhaled nanoparticles were fabricated to enhance drug lung delivery. • Verteporfin inhibited the formation of honeycomb cysts. • Pirfenidone inhibited the remodeling of alveoli interstitium. • This study provided a promising strategy to improve antifibrotic efficacy. [ABSTRACT FROM AUTHOR]

A significant challenge in electrolyte-supported solid oxide fuel cells (SOFCs) pertains to the substantial thickness of the electrolyte, resulting in elevated operational temperatures that hinder commercial viability. In this research, we utilized digital light processing (DLP) 3D printing technology to fabricate ultra-thin honeycomb electrolyte-supported SOFCs and subsequently evaluated their performance. Through the use of ultraviolet absorbers, we achieved a shallow curing depth (60.3 μm), which facilitated the creation of ultra-thin electrolyte samples. We investigated the mechanical properties of electrolytes with various honeycomb structures, finding that the square honeycomb structure exhibited the highest mechanical integrity, with an average failure load of 1.01 N. Finally, we assessed the electrochemical performance, observing a substantial power density of 215.4 mW/cm2, representing a twofold increase compared to the 114 mW/cm2 achieved by the same method in a flat primary cell. [ABSTRACT FROM AUTHOR]

Porous honeycomb mullite ceramics were controllably fabricated in-situ using stereolithography 3D printing. The effects of the dispersant type and content on the rheological behavior of the mullite precursor slurry were investigated. Additionally, the influence of the debinding atmosphere (air and argon) on the quality of the samples and formation of cracks was also studied. The results indicated that oleic acid (OA), 3-glycidoxypropylthrimethoxysilane (KH560), and disperbyk (BYK111) displayed the capability to create low-viscosity and highly stable slurries. Among these KH560 was proved to be the most effective. The mullite precursor slurry containing 4 wt% KH560 dispersants exhibited a shear thinning behavior. It displayed a viscosity of 0.26 Pa·s at a shear rate of 30 s−1. The mullite ceramic parts displayed good a dimensional resolution at an exposure dose of 5.47 mJ/cm2. During the debinding process, the printed parts were susceptible to cracking and deformation in air, but remained devoid of defects in argon. When the samples were sintered at 1600 °C, the corundum phase transformed almost completely into the mullite phase. The linear shrinkage values were 5.81%, 6.33%, and 10.26% in the O-X, O–Y and O-Z directions, respectively. [ABSTRACT FROM AUTHOR]

In this study, Al 2 O 3 honeycomb sandwich structures with different core geometries (square, triangular, circular) have been fabricated through an additive manufacturing system based on the stereolithography (SLA) method. The debinding procedure was performed under both nitrogen and air atmospheres. The impacts of the debinding atmosphere and core geometry on the densification and mechanical properties were investigated. The stiffness and flexural strength of the ceramics were examined experimentally using an impulse excitation of vibration technique and a three-point bending test, respectively. The specific stiffness and specific strength of the ceramics were also evaluated, with the core geometries taken into consideration. The outcomes showed that higher densification was achieved when the ceramics were exposed to debinding in nitrogen. The stiffness values were found to be similar for the same debinding condition within the honeycomb sandwich structures, irrespective of the core geometry. Notably, the highest specific stiffness (98 MNm/kg) was achieved for the samples subjected to debinding in nitrogen with a square core geometry. Furthermore, ceramics with square cores for debinding in a nitrogen atmosphere also demonstrated the highest performance in terms of specific strength (110 kNm/kg) within the honeycomb structures. This study demonstrated that Al 2 O 3 honeycomb sandwich structures with square cores may be suitable candidates for lightweight-structure demanding applications. [ABSTRACT FROM AUTHOR]

Vitrified-bond diamond composites are materials commonly used for grinding wheels in the grinding process of silicon wafer production. In this study, the mechanism of the in situ honeycomb structure formation in the sintering process of composite materials was explored by changing the binder content without adding a pore-forming agent.The results show when the content of vitrified bond is 55 wt%, the in situ honeycomb structure forms, resulting in a porosity of 60.68 % and bending strength of 23.03 MPa.The X-ray diffraction (XRD), Raman spectroscopy (RS), and thermogravimetry-differential thermal analysis (TG-DTA) results show that no graphitization of diamond grain occurs during sintering. The bonding ability between the vitrified bond and diamond grain, along with the microstructure of vitrified-bond diamond composites, was studied using scanning electron microscopy (SEM). Moreover, the results of energy spectrum analysis (EDS) show that the diffusion and segregation of Na at the interface between the diamond particles and the vitrified bond improve the bonding strength, and the vitrified bond can effectively bond with the diamond particles. Finally, the formation mechanism of the honeycomb structure was elucidated using the surface and interface sintering theory. [ABSTRACT FROM AUTHOR]

• Impact response of stiffened sandwich FGPM doubly-curved shell with re-entrant honeycomb auxetic core is studied. • The interaction between the impactor and shell utilizes equivalent spring-mass (SM) model consisting two-degrees-of freedom. • The facesheets are made from FGPM and the shell structure is modeled by first order shear deformation theory. • The impact performance of re-entrant honeycomb auxetic core is compared with regular hexagonal honeycomb core. Owing to unique deformation behavior and high capacity of energy absorption, auxetic structures have garnered significant research attention. To reveal the energy-absorbing properties of the auxetic structure, the impact response of stiffened sandwich functionally graded porous materials (FGPM) doubly-curved shell with re-entrant honeycomb auxetic core is studied by the established analytical model in the present work. The material properties in the thickness direction of FGPM face sheets are adjusted according to the volume fraction of constituents by power law and exponential law, while the core layer is made of the re-entrant honeycomb auxetic core with negative Poisson's ratio. On the basis of the Hertz theory for elastic impacts and the first-order shear deformation theory (FSDT), an analytical model is developed to study its impact phenomenon. Equations of motion are derived using Hamilton's principle, which are further solved analytically using Navier's technique of assuming unknown variables in the double trigonometric series. The time-dependent contact force is obtained by applying the spring-mass (SM) model consisting two-degrees-of freedom. Afterward, the transverse central displacements of the stiffened sandwich FGPM doubly-curved shell are calculated by adopting the Duhamel integration. The impact force and transverse displacements are compared with the previously published results, indicating that the theoretical results agree with the previously published results. Parametric analyses have been carried out to investigate the effect of variation of various parameters such as volume fraction exponents, radii of principal curvatures, porosity volume fraction, core layer inclined angle on the impact response of the sandwich shell. Additionally, the results show that compared with the traditional hexagonal honeycomb core type, the stiffened sandwich FGPM doubly-curved shell with re-entrant honeycomb core type has significant advantages in impact energy absorption. This work may provide an extensive reference and valuable guidance in the impact design and application of auxetic sandwich shell structures. [ABSTRACT FROM AUTHOR]

Herein, the coating of MnO 2 nanomaterials on the surface of aluminum honeycomb was carried out to meet the requirements of high air velocity, low pressure drop and high activity in ozone removal scenarios. A commercially readily available waterborne silica sol mixed with waterborne acrylate latex was creatively utilized as the binder. A series of coating samples were prepared by spray coating method and evaluated focusing on their adhesion strength and catalytic activity towards ozone decomposition in an air duct at room temperature, by varying MnO 2 /binder mass ratio and number of sprayings. It was found that the adhesion strength of the catalytic coatings on the aluminum honeycomb increased with the increase of binder mass ratio, but the increased binder made the catalyst particles closely packed, resulting in reduced exposure of active sites and decrease of ozone conversion. Accordingly, catalyst slurry with 81.8 wt.% MnO 2 in dry coating and spraying times of two were determined as the optimal process parameters. As-prepared aluminum honeycomb filter with MnO 2 layer of 50 µm thickness achieved ozone conversion of 29.3%±1.7% under conditions of air velocity 3.0 m/sec, relative humidity ∼50%, room temperature (26°C) and initial ozone concentration of 200 ppbV. This filter can be well adaptable to indoor air purification equipment operating at high air velocity with low wind resistance. [Display omitted]. [ABSTRACT FROM AUTHOR]

Recrystallized SiC (R–SiC) honeycomb ceramics were prepared using Al 4 SiC 4 as additives through a two–step sintering process, consisting of pre–nitridation treatment at 1800 °C for 180 min, followed by heat treatment for 60 min at temperatures ranging from 2000 to 2200 °C. The influences of firing temperature on phase compositions, microstructures, porosity, and mechanical properties of honeycomb ceramics were evaluated. The results revealed that AlN, SiC, and C were formed in situ after nitriding at 1800 °C. As the subsequent heat treatment temperature increased from 2000 to 2200 °C, the sublimation rate of submicron SiC increased, as well as AlN solid solubility. AlN diffused into SiC lattice and formed the SiC–AlN solid solution, which accelerated the conversion of 6H–SiC to 4H–SiC. According to first–principles calculations, the formation of solid solution contributed to the sintering process, which performed through the reduction of the surface energy of the grains. In addition, the pore size of specimens increased with elevating the heating temperature, and the distribution transitioned from unimodal to bimodal. Simultaneously, AlN and C activated the SiC lattice and facilitated mass transfer rate. The SiC sintering necks were well–developed at 2200 °C, resulting in the optimized overall performance of SiC honeycomb ceramics with a porosity of 52.7% and compressive strength of 17.98 MPa. [ABSTRACT FROM AUTHOR]

Inspired by the double-helix structure of biological DNA, low-volume fraction and high-strength Al 2 O 3 twisted honeycomb structures with characteristics similar to those of helical structures in the z -axis were prepared by digital light processing 3D printing technology. As the twist angle increased, the compressive strength of the fabricated Al 2 O 3 structure decreased, and the deformation mechanism of the Al 2 O 3 structures gradually changed from stretching-dominated to bending-dominated, which can be predicted by the Gibson–Ashby model. The relationship between the effective elastic modulus and the volume fraction that can be modified by varying the wall thickness was described by the Pabst–Gregorova exponential relationship. The compressive strength of the Al 2 O 3 structure with a twist angle of 0° can reach 62.4 MPa at a volume fraction of 13.3%, providing guidance to optimize lightweight structures of ceramics. [ABSTRACT FROM AUTHOR]

Three metal-organic frameworks including Ce-BDC, In-BDC and In/Ce-BDC and corresponding derived CuO/ZnO/In 2 O 3 /CeO 2 catalysts were prepared. The catalyst-loaded cordierite honeycomb ceramic supports were applied in a microreactor for hydrogen production via methanol steam reforming. The In/Ce-BDC-derived catalyst exhibited a methanol conversion rate of 100%, a hydrogen yield of 0.336 mol/h and an energy efficiency of 54% at 300 °C and an inlet methanol flow rate of 0.112 mol/h. Moreover, CO with content lower than 1.5% and catalytic stability of 30 h was recorded. The high specific surface area and superior redox property of the In/Ce-BDC-derived catalyst were characterized. The increased contents of oxygen vacancies and surface oxygen, in collaboration with the improved solid solubility of CuO and ZnO, were associated with the charge exchange induced by the strong interaction between In 2 O 3 and CeO 2 , leading to the excellent catalytic performance of the In/Ce-BDC-derived catalyst. [ABSTRACT FROM AUTHOR]

Na 4 Mn 9 O 18 whiskers were prepared on the wall of cordierite honeycomb ceramics using the molten salt synthesis, and Na 4 Mn 9 O 18 whiskers were grew on channel surface of cordierite honeycomb ceramics to form hierarchical microstructure for catalytic combustion of soot. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to characterize the structural morphology and phase compositions. Na 4 Mn 9 O 18 whiskers with aspect ratio of 24.4 measured by statistics. It was found that the loading rate of the monolithic catalyst reaches 3.588% while the binding rate after sonication almost no change. Whiskers are tightly combined with the cordierite ceramic substrate by the binding strength experiments and EDS analysis. The oxygen temperature-programmed desorption (O 2 -TPD) measurements were performed to investigate the O 2 adsorption property. The catalytic performance of the samples were examined by semi-quantitative thermal gravimetric analysis (TG-DTG) and temperature-programmed oxidation (TPO). The catalyst performance study demonstrates that Na 4 Mn 9 O 18 whiskers decrease the soot combustion temperature apparently. Experiments show the characteristic temperature could be reduced by increasing the catalyst loading. The Na 4 Mn 9 O 18 decreased the ignition temperature of soot particles oxidation, and the cycle stability experiment confirmed that the sample (0h-m-k) has good structural stability and stable catalytic performance. The coarseness of the interface increased because Na 4 Mn 9 O 18 whiskers grew on the cordierite substrate, and the trapping ability improved. Na 4 Mn 9 O 18 is an important type of catalyst which is rarely studied in catalytic oxidation of soot. This catalyst displays good activity and stability in the soot catalytic oxidation. This unique microstructure has potential application in the DPF field. [ABSTRACT FROM AUTHOR]

Proton-conducting ceramic membranes designed with an asymmetric configuration have received increasing attention for their 100% H 2 selectivity, high thermo-chemical stability, and intrinsic lower cost respect the Pd–based counterparts. The design of the substrate is of paramount importance to increase the gas diffusivity through the porous support. In this work, porous BaCe 0.65 Zr 0.20 Y 0.15 O 3-δ (BCZY) supports were fabricated for the first time via UV-assisted micro-extrusion. Different BCZY-based inks preparation methods were evaluated to obtain high solid loading (> 40 vol%), solvent and dispersant-free eco-friendly formulations. Printable inks with optimal shear thinning behaviour were successfully extruded, depositing up to three stacked layers without defects. Drying and thermal post printing treatments were carefully optimized to obtain defect-free and easy to handle green bodies. The optimization of the whole process leaded to planar BCZY-based supports with a high degree of engineered porosity and suitable mechanical properties to be potentially applied in asymmetric membrane structures. • Proton conductive BCZY ceramics for hydrogen separation were produced. • Solvent- and dispersant- free UV-curable pastes were obtained. • UV-assisted direct ink writing were considered to obtain complex shapes structures. • Honeycomb type structures with a high degree of engineered porosity were produced. • Samples presents promising mechanical properties. [ABSTRACT FROM AUTHOR]

As an emerging micro-pollutant, p -arsanilic acid (p -ASA) exist widely in the environment, and it can form highly toxic arsenate and arsenite during the migration and transformation process, which greatly increases the risk of arsenic pollution in the ecosystem. Additionally, three-dimensional (3D) porous block materials have the advantage of stronger adsorption performance, faster adsorption rate and easy recovery, showing broad application prospects in water pollution control. Hence, the aminozed collagen fibers foam (ACFF) with 3D porous block structure was synthesized. The maximum adsorption capacity of ACFF for p -ASA was 476.19 mg·g−1 due to the rich honeycomb porous structure and the synergistic effect of electrostatic attraction, hydrogen bonding effect and amphiphilicity. Moreover, ACFF is not only easy to recycle, but also has good elastic recovery and regeneration performance. The pore size of ACFF was concentrated in the range of 25–5000 nm, and the porosity was 71.66%. ACFF may be an adsorbent with great potential for the removal of organoarsenic contaminants in water. [Display omitted] [ABSTRACT FROM AUTHOR]

The supercritical water gasification (ScWG) technology is a promising alternative for H 2 -rich gas production from renewable sources, such as residual glycerol from biodiesel manufacture. Combined with heterogeneous catalysts, the ScWG process can achieve improved selectivity towards the desired products and high conversion efficiency in short reaction times. In this work, the efficiency of a synthesized Ni-based catalyst supported in cordierite (CRD) honeycomb structure on the ScWG of glycerol was evaluated and compared with two commercial automotive catalysts. Initially, to determine the best experimental conditions, the ScWG experiments were conducted in the absence of catalysts at constant conditions pressure (25 Mpa) and volumetric flow rate (10 mL min−1). The temperature range of 400–700 °C and glycerol feed composition between 10 and 34 wt% were evaluated. The catalysts evaluated were characterized by SEM-EDS, XRD, N 2 adsorption/desorption, XRF, WDS and TGA. The liquid and gaseous products were analyzed by TOC and gas chromatography, respectively. Results indicated that Ni/CRD catalyst showed the highest H 2 yield (5.38 mol H 2 per mol of glycerol fed) and long-term stability. Additionally, a comparison between the experimental results on the ScWG of glycerol and simulated thermodynamic equilibrium data was also reported. Thus, results demonstrated the great potential of the prepared catalyst to improve H 2 -rich gas production from glycerol gasification. [Display omitted] • ScW technology was applied for glycerol gasification to produce H 2 -rich gas. • Best conditions chosen for performing catalytic tests were 600 °C and 10 wt%. • Catalysts based on cordierite honeycomb structure was evaluated. • Commercial automotive catalysts were also tested. • Highest H 2 yield and long-term stability was achieved using Ni based catalyst. [ABSTRACT FROM AUTHOR]

In this research work, laser powder bed fusion (LPBF) based stainless steel 316L (SS316L) was fabricated and its corrosion behaviour was analysed for the oil-gas piping application. The Field Emission Scanning Electron Microscopy (FESEM) analysis of the LPBF SS316L specimen revealed the presence of 1–2 μ m size honeycomb structure and 2–10 μ m size tabular structures. Nano-size particles in the range of 100 nm–500 nm were formed between the two tabular cells as well as their boundary regions in the LPBF SS316L specimen. The energy-dispersive X-ray spectroscopy (EDS) analysis of the nanoparticle confirmed the presence of Si with a percentage of 1.4% along with 15.9% of Cr and 1.6% of Mo that have the characteristic of dispersion strengthening of the LPBF SS316L specimen. In addition, the δ-ferrite phase was observed in tabular structure boundaries and intercellular regions of solute in the LPBF SS316L specimen. Moreover, among the three crystallographic orientations {001}{101}and {111}, no domination behaviour was observed from the Electron Backscatter Diffraction (EBSD) study. The Transmission Electron Microscopy (TEM) analysis confirmed the presence of nano twin structures that had a span of several nm on the FCC austenite unit cell. These twins came under the {111} category twining that often occurred in FCC metals. A potentiodynamic polarization test was conducted on the LPBF SS316L specimen at five different time periods (i.e., 0, 7, 15, 34 and 56 h) and it was assessed that the 0 and 15 h immersion specimens exhibited superior corrosion resistance compared with other LPBF SS316L specimens. The Nyquist plot revealed that the 0 and 15 h immersion specimens offered the highest resistance value of 1846.1Ω and 1720.3 Ω, respectively against corrosion. The Bode plots of the LPBF SS316L specimen followed a similar trend as the Nyquist plots. [ABSTRACT FROM AUTHOR]

• The nonlocal effects are accounted for when evaluate the equivalent modulus of micro/nano-honeycombs. • For regular hexagonal honeycombs, the smaller the length, the more significant the nonlocal effects. • The present method has a good universality, which is applicable to both macro and micro/nano scale honeycombs. When the structural size of honeycomb enters micro/nano scale, the influence of nonlocal effects on the mechanical responses becomes non-negligible, which should be taken into account when evaluate the mechanical properties of micro/nano-honeycombs. To this end, a novel method for predicting the equivalent elastic moduli of micro/nano-honeycombs is proposed. In this method, the two-phase local/nonlocal model is introduced into the constitutive equations and the analytical solution of the equivalent moduli is derived according to the energy equivalent principle. It is illustrated by the numerical examples that the results of the present method are lower than those of the classical elasticity theory, which is consistent with the phenomena observed in the experiment, effectively showing the nonlocal effects. The magnitude of nonlocal effects can be influenced by the geometrical size of the honeycomb. The smaller the geometric size of the honeycomb is, the more significant the nonlocal effects are. With the increase of the geometrical size of honeycomb, the nonlocal effects gradually weaken, and the numerical values predicted by the present method gradually approach the equivalent moduli values of the macro-scale honeycombs. Hence the present method has a good universality that can be used in both macro and micro/nano scale honeycombs. [ABSTRACT FROM AUTHOR]

Microwave absorbing (MA) materials with yolk-shell structures have been extensively studied in impedance matching. However, the impedance matching achieved by the complementary effect of the core and the shell does not determine the reflection of the microwaves upon the occurrence at the first incidence. The interaction between the outer layer of materials and the electromagnetic waves significantly impacts the MA properties of materials. In this study, the impedance matching improvement method of the shell structure was further explored by preparing CoFe 2 O 4 @HCN (honeycomb carbon with N-doping) through the hydrothermal method followed by hydrolysis, polymerization, etching, and annealing. The resulting structure with heteroatoms doping provided the novel CoFe 2 O 4 @HCN with excellent impedance matching and multiple loss mechanisms contributing to MA process. The absorber with a filler loading of 40% exhibited an RL min of −68.03 dB with a matching thickness of 2.5 mm. The efficient absorbing bandwidth reached 5.92 GHz (a change from 11.92 to 17.84 GHz) at 1.99 mm thickness. Interestingly, these findings look promising for future synthesis and application of yolk-shell structure microwave absorbers. [ABSTRACT FROM AUTHOR]

A new honeycomb-shaped La 0·5 Sr 0·5 Fe 0·9 P 0·1 O 3-δ (LSFP) material has been proposed as a cathode for proton-conducting solid oxide fuel cells (H–SOFCs). Compared with conventional LSFP, the honeycomb-shaped does not change the crystal structure or the electronic structure of the material but offers a much higher surface area. The unique honeycomb structure allows the easier diffusion of air and H 2 O evaporations in the cathode, thus benefiting the application of LSFP as a cathode for LSFP. The honeycomb LSFP cathode's fuel cell shows a peak power density of 1474 mW cm−2 at 700 °C, which is higher than the conventional LSFP cell. In addition, the fuel cell performance is also the highest ever reported for H–SOFCs based on the Sr-doped LaFeO 3 (LSF) cathodes, making a new life for the first-generation LSF cathode for H–SOFCs. The distribution of relaxation times (DRT) analysis for the cell reveals that the honeycomb-shaped cathode improves the oxygen reduction reaction (ORR) at the cathode, thus improving the cathode kinetics. • A honeycomb-shaped La 0·5 Sr 0·5 Fe 0·9 P 0·1 O 3-δ (LSFP) material has been prepared. • The honeycomb structure improved the surface area. • The cell using the honeycomb LSFP cathode showed higher fuel cell performance. • The performance enhancement mechanism was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical architected materials achieve enhanced mechanical properties. • A deep learning approach based on an attention-based diffusion model is capable of providing both, forward and inverse predictions. • We discover hierarchical microstructure candidates for a specified nonlinear mechanical response. • We demonstrate single-shot end-to-end performance in both forward/inverse directions across the entire deformation regime. • Biologically inspired materials design for high-throughput discovery specifically for diverse nonlinear constitutive relationships is provided. Inspired by natural materials, hierarchical architected materials can achieve enhanced properties including achieving tailored mechanical responses. However, the design space for such materials is often exceedingly large, and both predicting mechanical properties of complex hierarchically organized materials and designing such materials for specific target properties can be extremely difficult. In this paper we report a deep learning approach using an attention-based diffusion model, capable of providing both, forward predictions of nonlinear mechanical properties as a function of the hierarchical material structure as well as solving inverse design problems in order to discover hierarchical microstructure candidates for a specified nonlinear mechanical response. We exemplify the method for a system of compressively loaded four-hierarchy level materials derived from a family of honeycomb structures, where patterns of distributed buckling events are unitary deformation events that control small- and large-scale deformation behavior. Our model offers exquisite single-shot end-to-end performance in both forward and inverse directions across the entire range of deformation regime, and is capable of rapidly discovering multiple solutions that satisfy a design objective in accordance with the known physical behavior elucidated by, and validated with, coarse-grained simulations. The model provides an effective way towards biologically inspired materials design for high-throughput discovery in order to achieve diverse nonlinear constitutive relationships. [ABSTRACT FROM AUTHOR]

• A novel composite auxetic sandwich plate was fabricated. • Modal experiments were conducted to research the free vibration behaviours. • Moduli of composite reentrant honeycomb core were deduced. • Effects of relative density and dimensions on natural frequencies were studied. The free vibration behaviours of carbon fiber composite sandwich plates with reentrant honeycomb cores were explored by experiment, theory and finite element method (FEM) in present study. The composite sandwich plates with reentrant honeycomb cores were designed and fabricated through hot-press and secondary forming technology. The modal characteristics of composite auxetic honeycomb sandwich plates were tested under simply supported boundary conditions. Furthermore, the influences of relative densities and dimensions on the natural frequencies of composite auxetic honeycomb sandwich plates were studied. The equivalent moduli of the unit cell of reentrant hexagonal core were deduced. The free vibration control equation was derived to gain the natural frequencies of the sandwich plates by Zig-Zag theory. The theoretical results of the natural frequencies were obtained and compared with the experimental results and finite element calculation results. The results showed that the theory and FEM could estimate the natural frequencies of this kind of sandwich plates accurately. The natural frequencies of the sandwich plates raised as the increasing of relative densities and influenced by dimensions of the core. [ABSTRACT FROM AUTHOR]

Although autologous bone grafting is widely considered as an ideal source for interbody fusion, it still carries a risk of nonunion. The influence of the intervertebral device should not be overlooked. Requirements for artificial spinal devices are to join the vertebrae together and recover the original function of the spine rapidly. Ordered mineralization of apatite crystals on collagen accelerates bone functionalization during the healing process. Particularly, the stable spinal function requires the ingrowth of an ordered collagen and apatite matrix which mimics the intact intervertebral microstructure. This collagen and apatite ordering is imperative for functional bone regeneration, which has not been achieved using classical autologous grafting. We developed an intervertebral body device to achieve high stability between the host bone and synthesized bone by controlling the ordered collagen and apatite microstructure. This was an in vivo animal study. Intervertebral spacers with a through-pore grooved surface structure, referred to as a honeycomb tree structure, were produced using metal 3D printing. These spacers were implanted into normal sheep at the L2–L3 or L4–L5 disc levels. As a control group, grafting autologous bone was embedded. The mechanical integrity of the spacer/bone interface was evaluated through push-out tests. The spacer with honeycomb tree structure induced anisotropic trabecular bone growth with textured collagen and apatite orientation in the through-pore and groove directions. The push-out load of the spacer was significantly higher than that of the conventional autologous graft spacer. Moreover, the load was significantly correlated with the anisotropic texture of the newly formed bone matrix. The developed intervertebral spacer guided the regenerated bone matrix orientation of collagen and apatite, resulting in greater strength at the spacer/host bone interface than that obtained using a conventional gold-standard autologous bone graft. Our results provide a foundation for designing future spacers for interbody fusion in human. [ABSTRACT FROM AUTHOR]

A nanometric Rh overlayer exhibits excellent three-way catalytic activity under stoichiometric conditions. However, dynamic changes in the air-to-fuel (A/F) ratio under experimental conditions deteriorates the catalytic activity caused by the lack of oxygen storage/release capability of Rh. In this study, we first report that the surface modification of the Rh overlayer by a small amount of Ce using a sequential metal deposition technique based on the pulsed arc-plasma method enhances its three-way catalytic activity under A/F perturbation conditions. X-ray photoelectron spectroscopy and X-ray absorption fine structure measurements revealed that the redox behavior of the surface Ce contributed to an oxygen storage/release and buffered the A/F change. The Ce-modified Rh overlayer with a metal honeycomb structure exhibited high activity for the three-way catalytic reaction even under A/F perturbation conditions at high space velocity. This novel catalytic converter is expected to be significantly process and energy saving compared to the conventional catalytic converter. Thus, the oxygen storage/release performance, heat resistance, and low-temperature activity can be improved by controlling the surface composition. [Display omitted] • Sequential metal deposition technique based on pulsed arc-plasma method. • Surface of the Rh overlayer was modified by a small amount of Ce. • Redox behavior of the Ce contributed to an oxygen storage/release. • Ce-modified Rh overlayer exhibited high activity for three-way catalytic reaction. [ABSTRACT FROM AUTHOR]

The effect of a nano-honeycomb cathode on the performance of a microtubular solid oxide fuel cell is investigated. We successfully prepared nano-honeycomb cathodes with high unsealing pore porosity (∼64.6%) and high structural strength by freeze casting, which improved the adsorption and dissociation of oxygen. We added gadolinium doped ceria (GDC) nanopowder to the lanthanum strontium cobalt ferrite (LSCF) cathode material. The cell performance of the nano-cell structure of the GDC-LSCF cathode is significantly improved compared to a traditional GDC-LSCF cathode with a spongy porous structure. At 750 °C, the current density is 1450 mA cm−2 and the power density is 475 mW cm−2, which is better than that of conventional cathode structures. We discussed the effects of the honeycomb structure on the cell, including the migration of silver paste as a cathodic collector to the GDC-LSCF interface and the improvement of the activity of the oxygen electrodes. • The fabricated nano-honeycomb cathode had a large surface area and large pore channels. • I–V–P curves indicated the success of the HC-MTSOFC compared to TC-MTSOFCs. • Scanning electron microscopy determined the silver diffusion after 10 h of operation. [ABSTRACT FROM AUTHOR]

Herein, a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS 2 quantum dots (MSQDs) and 3D honeycomb-like conjugated triazine polymers (CTP) (namely, CTP-MSQD). The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property, while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators. The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI) reduction and H 2 evolution, featured a rate of 0.069 min−1 and 1070 µmol/(hr∙g), respectively, which were 8 times than those of pure 3D-CTP (0.009 min−1 and 129 µmol/(hr∙g)). We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion. [Display omitted]. [ABSTRACT FROM AUTHOR]

[Display omitted] In two-dimensional (2D) ferromagnets, anisotropy is essential for the magnetic ordering as dictated by the Mermin-Wagner theorem. But when competing anisotropies are present, the phase transition becomes nontrivial. Here, utilizing highly sensitive susceptometry of scanning superconducting quantum interference device microscopy, we probe the spin correlations of ABC-stacked CrBr 3 under zero magnetic field. We identify a plateau feature in susceptibility above the critical temperature (T C) in thick samples. It signifies a crossover regime induced by the competition between easy-plane intralayer exchange anisotropy versus uniaxial interlayer anisotropy. The evolution of the critical behavior from the bulk to 2D shows that the competition between the anisotropies is magnified in the reduced dimension. It leads to a strongly frustrated ferromagnetic transition in the bilayer with fluctuation on the order of T C , which is distinct from both the monolayer and the bulk. Our observation demonstrates unconventional 2D critical behavior on a honeycomb lattice. [ABSTRACT FROM AUTHOR]

The highest incidence of death in systemic sclerosis due to pulmonary disease raises the need for early detection and treatment. The study aim is the assessment of interstitial pulmonary disease by Multi Detector High Resolution CT (MDCT) and finds its relationship with the other disease parameters and the Pulmonary Function tests (PFT). A prospective cross-sectional study was performed in Assiut University Hospitals from May 2018 to January 2020 and included 62 consecutive SSc female patients. Demographic, clinical, Laboratory, PFT and MDCT assessment were conducted for all participants. The coarseness of fibrosis was 8.32 (range 0.0–17), the average proportion of ground-glass opacification was 28.3% (range, 0.0%–75%). Honey-comb pattern was seen in (52.5%). Mean Extent of disease was 46.25 ± 3.7 (range 5–81). Restrictive deficit found in 42 patients. Significant relation was found between the extent of disease and the percentage predicted FVC (r = 0.373, p 0.018) and FEV1/FVC (r = 0.593, p 0.000) and coarseness of fibrosis and proportion of ground glass opacification correlated inversely with VC (r = −0.385, p = 0.014, r = −0.376, p = 0.017 respectively), Rayanud's phenomena, modified Rodnan Skin Score and Medsger's general are positively correlated with MDCT disease extent. Scoring of systemic sclerosis (SSc) related interstitial lung disease (SSc-ILD) could be applicable as one of the important tools for disease assessment. [ABSTRACT FROM AUTHOR]

Aluminum honeycomb is newly introduced in the tether-net launcher device to attenuate the large recoil force and impact generated on the platform. The stress–strain of aluminum honeycomb is first obtained through the quasi-static compression experiment to study the mechanical properties. The compression simulation model is then established using the crushable foam plasticity model. By comparing the simulation and experiment results, the error of plateau stage force is 0.33%, which validates the accuracy of the simulation model. After that, the internal ballistic responses of the launcher are gained by the equivalent classical interior ballistic equations. The dynamic launch model is built through the integration of the above models. It is verified by the dynamic launch experiment, with the average recoil error being 5.9%. Finally, the recoil performance of the launcher with or without aluminum honeycomb buffer is studied. The results show that aluminum honeycomb can reduce the average launch recoil force by 17.23%, with little effect on launch velocity, demonstrating good energy absorption ability. [ABSTRACT FROM AUTHOR]

Structural formations of metal-organic frameworks (MOFs) are predominately composed of empty space pockets inside a honeycomb structure assembled of organic linkers and metal ions, with the exception of a few small pockets of filled spaces. However, these extraordinary filled pockets provide a valuable resource as its applications when it comes through in various active areas. Recently, taking advantage of the rare combination of porosity, high surface area, and charge conductivity incorporated in MOFs applications such as electronic sensors, charge storage devices, electrocatalysts, and others previously outside the scope, but now has been developed. This review envisioned a scenario by presenting a piece of individual and collective established studies and investigations during the last few years for carbon dioxide reduction (CO 2 R) as MOF-based composites adjacent with semiconductor, photosensitizer, and conductive photo-electrocatalysts are discussed. Various strategies have been discussed to improve photo-electrocatalysts' performance by synthesis, bandgap engineering, and mobilizing the catalyst surface for optimizing yield. Moreover, the reaction mechanisms to drive the MOF, operational, improve stability, and evaluation approaches are summarized. To end with a discussion, actual limitations, future perspectives, and concerns are addressed in this review. [ABSTRACT FROM AUTHOR]

Considered a valid alternative to other receiver types, open volumetric receivers for central tower power plants have been developed and researched for multiple decades. 3D-Shaped absorber geometries, made possible by modern manufacturing technologies, particularly offer the promise of high thermal efficiencies. Yet, volumetric absorbers carry the inherent risk of flow instabilities, which can lead to a total failure of the receiver due to local overheating. Therefore, a numerical, multi-dimensional methodology for the flow stability analysis of volumetric absorbers is proposed. The first stage of the methodology applies an 1D LTNE continuum model to quantify the general pressure loss characteristic of an absorber and identifies critical pressure drop levels with potential for flow instability. These levels are tested as part of the second analysis stage using a discrete 3D CFD model against different irradiation and flow perturbations. If the absorber is able to compensate the disturbances, its flow behavior is deemed stable. Otherwise, the absorber geometry is considered susceptible to local overheating due to flow instability. The new methodology has been validated against two reference absorbers with known stable resp. unstable flow behavior. Further, the new approach was applied to analyze the flow stability of two 3D-shaped honeycomb absorber geometries. It was shown that the geometric features of 3D-shaped absorbers can directly improve the flow stability, but do not prevent instabilities automatically. Therefore, a flow stability analysis should be included in design/optimization processes of new volumetric absorbers alongside a maximization of the thermal efficiency. • A new CFD model analyzing the flow stability of volumetric absorbers was developed. • The approach combines an 1D LTNE continuum model with a discrete 3D CFD model. • The model has been successfully applied for the evaluation of 3D-shaped absorbers. [ABSTRACT FROM AUTHOR]

The extracellular matrix (ECM) is a significant component of the brain, constituting up to 20 % of the brain volume and perform multifarious functions during development, maturation and regeneration of the central nervous system (CNS). ECM molecules assemble systematically to form a relatively rigid and unique lattice-like structure, known as perineuronal nets (PNNs). The PNNs usually envelop the cell body and initial axon segment and are characterized by a mesh-like structure extending along dendrites of neurons. PNNs play prominent role in the early neural development, from migration and differentiation to axonal path finding. They regulate plasticity and regeneration in adulthood by surrounding and stabilizing synaptic contacts. In this review, we have focused on the basic structure, distribution and visualization of PNNs and their role during critical periods of development, synaptogenesis and regulation of synaptic plasticity. Furthermore, we have also tried to evaluate the participation of PNNs in the pathophysiology of several brain disorders and their potential in lowering local oxidative stress. Taken together, the concepts outlined in this review emphasize the heterogeneity of PNNs in response to normal physiological and pathological conditions, highlighting the need for future studies on PNNs to target their role in etiology and potential therapeutic interventions in neurological disorders. • Perineuronal nets (PNNs) are differentially distributed in different brain regions. • PNNs actively support the stabilization of synaptic contacts. • PNNs act as molecular brakes for synaptic plasticity. • PNNs protect the neurons from the influence of oxidative stress and harmful agents. • Removal or degradation of PNNs leads to neurological and neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

[Display omitted] • We fabricated carbonate apatite honeycomb scaffolds with vertical uniaxial channels. • At 4 weeks post implantation, all honeycomb scaffolds augmented new bone. • The augmentation happened close to the top surface of the scaffold. • In the following 8 weeks, the height and amount of new bone increased. • HC300 resisted compression from fasciae at 12-weeks post implantation. • Honeycomb structure is inherently suitable for vertical bone augmentation. Cases of intractable dental implant require vertical bone augmentation; however, the predicted bone height and volume are difficult to obtain. In vertical bone augmentation, the contact surface between the scaffold and the bone is limited to the bottom face of the scaffold. Furthermore, the strength decrease caused by scaffold resorption leads to collapse of the augmented site, leading to a decrease in the bone volume and height. To promote bone ingrowth, we fabricated carbonate apatite (i.e., bone mineral) honeycomb (HC) scaffolds with uniaxial channels vertically penetrating the scaffold. Furthermore, we controlled the scaffold resorption rate, eventually the endurability for compression, and the bone height and volume by controlling the strut thickness. The channel aperture was controlled to be 230–260 μm to promote bone ingrowth. Furthermore, the strut thicknesses of the HC scaffolds were adjusted to 100, 200, and 300 μm to control the scaffold resorption; these scaffolds were designated as HC100, HC200, and HC300, respectively. At 4 weeks post-implantation on rabbit calvarium, all scaffolds had already vertically augmented new bone close to the top surface of the scaffold. In the following 8 weeks, the height and amount of new bone in all scaffolds increased. Notably, HC300 was resorbed synchronously with new bone formation, allowing it to endure the compression from the fasciae for 12 weeks post-implantation. Furthermore, HC300 formed larger-diameter blood vessels than those of HC100 and HC200. The HC scaffolds surpassed the various combined scaffolds and growth factors or stem cells in the ability for vertical bone augmentation. Thus, the HC structure is inherently suitable for vertical bone augmentation. Notably, the HC scaffolds with 300-μm-thick struts enhanced both new bone formation and angiogenesis. This study revealed a structurally suitable design for achieving an outstanding outcome in vertical bone augmentation. [ABSTRACT FROM AUTHOR]

A novel network interlacing ZrC-VC ceramic coating was prepared by a pioneering spillover permeation. With the increase of Zr content in the blind vias, the content of ZrC in the coating and the density of the coating all decrease. The density of the coating on C/C–ZrC–SiC substrate is obviously higher than that on C/C substrate. The linear ablation rate of the novel ceramic coated C/C–ZrC–SiC composites was −0.06 μm/s with about 20 and 1.56 times reduction than C/C composites and C/C–ZrC–SiC composites respectively. The improved ablation resistance was attributed to a dense honeycomb ZrO 2 layer filled with liquid vanadium oxide in the ablation center and the improved thermal radiation. [ABSTRACT FROM AUTHOR]

Three metal-organic frameworks Cu-BTC, Zn-BTC, and Cu/Zn-BTC were prepared and impregnated in nitrate solutions to obtain the precursors. After calcination, three metal-BTC-derived CuO/ZnO/CeO 2 /ZrO 2 catalysts were obtained. The samples were characterized and the catalyst-coated cordierite honeycomb ceramics were used in a microreactor for methanol steam reforming at different reaction conditions. Results showed that the Cu/Zn-BTC-derived catalyst exhibited the most fine and uniform particles, the best reducibility, the largest specific surface area, and the optimal surface elemental state due to the difference in the formation mechanisms, resulting in its remarkable catalytic performance. The ceramic support coated with Cu/Zn-BTC-derived catalyst could achieve 100% methanol conversion rate and 0.336 mol/h H 2 output at 260 °C in the microreactor. Stability tests demonstrated that the Cu/Zn-BTC-derived catalyst could maintain its excellent performance without deactivation within 30 h continuous reaction, which was connected with the Ce–Zr–O solid solution with high concentration of oxygen vacancies and surface oxygen. • Metal-BTC-derived catalysts were synthesized and used for methanol steam reforming. • The formation mechanism of catalysts was proposed. • Cu/Zn-BTC-derived catalyst showed the highest methanol conversion and H 2 flow rate. • Cu/Zn-BTC-derived catalyst exhibited superior stability up to 30 h. [ABSTRACT FROM AUTHOR]

Background Context: Therapeutic devices for spinal disorders, such as spinal fusion cages, must be able to facilitate the maintenance and rapid recovery of spinal function. Therefore, it would be advantageous that future spinal fusion cages facilitate rapid recovery of spinal function without secondary surgery to harvest autologous bone.Purpose: This study investigated a novel spinal cage configuration that achieves in vivo mechanical integrity as a devise/bone complex by inducing bone that mimicked the sound trabecular bone, hierarchically and anisotropically structured trabeculae strengthened with a preferentially oriented extracellular matrix.Study Design/settings: In vivo animal study.Methods: A cage possessing an anisotropic through-pore with a grooved substrate, that we termed "honeycomb tree structure," was designed for guiding bone matrix orientation; it was manufactured using a laser beam powder bed fusion method through an additive manufacturing processes. The newly designed cages were implanted into sheep vertebral bodies for 8 and 16 weeks. An autologous bone was not installed in the newly designed cage. A pull-out test was performed to evaluate the mechanical integrity of the cage/bone interface. Additionally, the preferential orientation of bone matrix consisting of collagen and apatite was determined.Results: The cage/host bone interface strength assessed by the maximum pull-out load for the novel cage without an autologous bone graft (3360±411 N) was significantly higher than that for the conventional cage using autologous bone (903±188 N) after only 8 weeks post-implantation.Conclusions: These results highlight the potential of this novel cage to achieve functional fusion between the cage and host bone. Our study provides insight into the design of highly functional spinal devices based on the anisotropic nature of bone.Clinical Significance: The sheep spine is similar to the human spine in its stress condition and trabecular bone architecture and is widely recognized as a useful model for the human spine. The present design may be useful as a new spinal device for humans. [ABSTRACT FROM AUTHOR]

• General analytical expressions for bifurcation stability surface of honeycombs are provided in the symplectic space. • The symplectic eigen-solutions interpret the physical mechanism for the deformation patterns of a swaying buckling mode. • The re-entrant geometry is believed to impose an important influence on the auxetic honeycomb buckling patterns. • Buckling occurs for re-entrant cell subjected to tensional biaxial stress state. • The buckling performances of honeycombs depend strongly on the biaxial stress state but weakly on the relative density. A symplectic stiffness method, based on Hamiltonian variational principle and symplectic eigen expansion, is presented to investigate the buckling of honeycomb structures under a general macroscopic stress state. The analytical closed-form expressions of critical forces are obtained for the possible buckling modes, which satisfy the deformation compatibility conditions for the cell beams, and the lowest value in the stability surface corresponds to the actual buckling force for the honeycomb. The results show that the buckling strengths and modes for the regular and auxetic honeycomb structures depend strongly on the biaxial stress state but weakly on the relative density. For some complex honeycombs, e.g., the triangular and re-entrant cell, the buckling modes change with the increasement of the orders. Considerable attention is focused on the physical mechanism of phase transformation. There is no possibility of a swaying buckling mode when the beam buckles symmetrically, and the re-entrant geometry has an important influence on the auxetic honeycomb buckling patterns. The present symplectic stiffness method is believed to be beneficial for the stability analysis of some frontier engineering fields such as flexible electronics and soft robots. [ABSTRACT FROM AUTHOR]

The preparation method of porous carbon coated honeycomb ceramic monolithic catalysts is limited to traditional ideas. The porous carbon and the active metal particles are formed step by step. We have designed a novel preparation method and constructed a series of nickel-embedded porous carbon-coated (Ni@C) monolithic catalysts with different carbonization temperatures. Through the synchronous formation of porous carbon and active metal particles, the relationship between porous carbon and metal is changed from "supported" to "embedded". The "embedded" structure between nickel particles and porous carbon formed at suitable carbonization temperature is an inseparable whole. Correlation characterization results show that the "embedded" structure has not changed the physical-chemical properties of porous carbon. However, the effect on the physical-chemical properties of nickel particles is very significant. Compared with conventional supported nickel-based monolithic catalysts (NiO/C), embedded nickel particles in the Ni@C monolithic catalyst have four characteristics. They are more uniform particle dispersion, smaller average particle size, more difficult to migrate and stable in metallic Ni0 form in air. Based on these advantages, Ni@C monolithic catalysts show better catalytic activity, stability and convenience in the continuous catalytic hydrogenation of aromatic nitro compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

• Thermal buckling and free vibration of viscoelastic sandwich shell is studied. • The sandwich shell is composed of two FGM skins and an auxetic honeycomb core. • Poisson's ratio of the auxetic honeycomb core is tunable. • Negative Poisson's ratio for the core of the sandwich shell is considered. In this paper, thermal buckling and free vibration of viscoelastic functionally graded sandwich shell with tunable auxetic honeycomb core is investigated. The sandwich shell has functionally graded material (FGM) skins at top and bottom and tunable auxetic honeycomb core at the middle. The viscoelastic behavior of the skins and core are modeled according to complex modulus approach in combination with the elastic–viscoelastic correspondence principle. Poisson's ratio of the auxetic honeycomb core is tunable. It has positive or negative value, which depends on an angle parameter of the unit cell of the auxetic honeycomb core. The equations of motion for the viscoelastic FGM sandwich shell with tunable auxetic honeycomb core are derived using Hamilton's principle. Analytical solution for simply supported shell is obtained using Navier's solution procedure. The effects of the geometry parameters, temperature rise, parameters of the tunable auxetic honeycomb core are studied. [ABSTRACT FROM AUTHOR]

A copper-iron mixed oxide was deposited by the washcoating procedure over cordierite honeycomb monoliths for its use as a heterogeneous catalyst in organic synthesis processes. In particular, the prepared catalyst, characterized by techniques such as X-ray fluorescence, X-ray diffraction, SEM-EDS, laser granulometry, adherence tests, Temperature-Programmed Oxidation and Temperature-Programmed Reduction, showed an excellent yield and stability in the selective production of the allylic ester derived from the Kharasch-Sosnovsky oxidation of cyclohexene with benzoic acid. The use of a structured catalyst here proposed opens up an interesting alternative to homogeneous catalysis in the field of synthetic chemistry. [Display omitted] • Copper-iron mixed oxide as structured heterogeneous catalyst for organic synthesis. • High yield in Kharasch-Sosnovsky oxidation of cyclohexene with benzoic acid. • Cordierite honeycomb monolith as support provides excellent catalyst stability. • Proposed formulation for the active phase is more active than separate pure oxides. • Applicable to other benzoic acid derivatives and with potential to reaction scaling. [ABSTRACT FROM AUTHOR]

κ-Carrageenan (κ-Car) is an important material for preparing food gels and hydrogels. However, κ-Car gel has issues with high hardness and low water-holding capacity. Modification strategy of micronization is proposed for the first time to explore its influence on texture properties and gelling process of κ-Car gel, and to investigate the feasibility of κ-Car as a food matrix with low strength. κ-Car undergoing 60 min of micronization, the d (0.9) decreased by 79.33 %, S BET and V total increased by 89.23 % and 95.27 %. The swelling rate and degree of gelling process increased significantly, and the microstructure changed from loose large pores to dense small pores resembling a "honeycomb". Importantly, the hardness of gel-60, Milk-60 and PNS-60 decreased by 72.52 %, 49.25 % and 81.37 %. In addition, WHC of gel-60, Milk-60 and PNS-60 was improved. IDDSI tests showed that κ-Car gels, milk gels and PNS gels can be categorized as level 6 (soft and bite-sized), except for PNS-60, which belongs to level 5 (crumbly and moist). Furthermore, the texture and bitter masking effect of milk gels and PNS gels were improved. In conclusion, this study demonstrated that micronization can be a novel approach to improve the gel properties of κ-Car, laying the groundwork for developing dysphagia foods. [Display omitted] • Micronization is a new way to change the textural properties of κ-carrageenan gel. • The problem of high hardness of κ-carrageenan gel was solved by micronization. • The bitter masking effect of κ-carrageenan gel is improved after micronization. • Micronized κ-carrageenan gel can be as a dysphagia food with good texture and taste. [ABSTRACT FROM AUTHOR]

The aim of this research is to prepare and identify functionalized carboxymethylcellulose/mesoporous silica nanohydrogels (CMC/NH 2 -MCM-41) for obtaining a pH-sensitive system for the controlled release of drugs. The beads of CMC/NH 2 -MCM-41 nanocomposites were prepared by dispersing NH 2 -MCM-41 in a CMC polymer matrix and crosslinking with ferric ions (Fe3+). The SEM analysis of samples revealed enhancement in surface porosity of the functionalized nanohydrogel beads compared to the conventional beads. Swelling of the prepared functionalized nanohydrogels was evaluated at various pH values including pH = 7.35–7.45 (simulated body fluid or healthy cells), pH = 6 (simulated intestinal fluid), and pH = 1.5–3.5 (simulated gastric fluid). The swelling of CMC/MCM-41 and CMC/NH 2 -MCM-41 nanohydrogels at the pH values of simulated body fluid and simulated intestinal fluid is much higher than that of simulated gastric fluid, indicating successful synthesis of pH-sensitive nanohydrogels for drug delivery. The drug loading results showed that drug release in the CMC/NH 2 -MCM-41 system is much slower than that in the CMC/MCM-41 system. The results of the survival studies for the manufactured systems showed a very good biocompatibility of the designed drug delivery systems for biological applications. By coating the surface of functionalized mesopores with CMC hydrogel, we were able to develop a pH-sensitive intelligent drug delivery system. [ABSTRACT FROM AUTHOR]

This paper examines the impact of polyurethane foam (PUF) filling on the dynamic response of honeycomb sandwich beams (HSBs) through the blast testing. The HSBs are composed of steel face sheets and an aluminium alloy honeycomb core filled with PUF. A comparative analysis of damage modes is conducted between conventional hexagonal and auxetic HSBs, considering both foam-filled and unfilled configurations. The results reveal that the HSBs with foam filling demonstrate significantly enhanced blast performance compared to their counterparts without foam filling. This superiority is evident in both global deformation and local damage characteristics. Furthermore, a well-validated numerical model is developed to examine the damage mechanisms of PUF-filled HSBs under blast loading. The investigation reveals that appropriate PUF filling methods can effectively enhance bending resistance while minimizing the decline in the energy absorption efficiency. Finally, a multiobjective optimization was conducted using the back-propagation (BP) neural network and the SPEA2 algorithm to identify the optimal position for PUF. By utilizing a reduced foam filling approach as opposed to completely filling the structure, the two optimized configurations show a decrease in deformation of 5.38 % with an equivalent specific energy absorption (SEA) or an increase in the SEA by 5.26 % with an equivalent deformation. [ABSTRACT FROM AUTHOR]

In this study, an inverse design framework was constructed to explore gradient honeycomb structures (HCS) with high impact resistance. By establishing the relationship between the height of the cell and the cell-wall angle, HCS with different gradient modes were designed. The developed machine learning (ML) framework consisted of a forward regression model based on neural network (NN) and an inverse optimization model based on generative adversarial network (GAN). The regression model surrogated finite element analysis (FEA) to rapidly provide corresponding mechanical properties for the generated data of GAN. To ensure that the generated data met the desired design targets, additional physical constraints were incorporated into the generator of the GAN. This ensured that the network output not only consisted of valid data but also exhibited superior impact resistance. The results demonstrated that the trained ML model optimized both specific energy absorption (SEA) and initial peak stress of HCS. It even discovered high-performance gradient designs that outperformed the original data, with a maximum energy absorption 49.5% higher than that of uniform HCS. Moreover, the gradient modes and structural parameters of superior designs were identified, which is of great significance for the gradient design of HCS under impact loading. As a general design approach, this ML framework holds significant potential for the optimization design of metamaterials in other structures or with different mechanical properties. • A inverse design framework for finding high impact resistance HCS is proposed. • Using NN surrogate FEA to accelerate the prediction of structural performance. • The design of desired properties can be obtained by introducing physical constraints. • The multi-layer HCS with different gradient modes is evaluated. [ABSTRACT FROM AUTHOR]

The physical, chemical, and electrocatalytic properties of conventional single-component electrocatalysts developed for the hydrogen evolution reaction (HER) no longer match the needs of many commercial applications. This necessitates for the creation of more sophisticated and effective electrocatalysts for the HER. In this study, MoS 2 -CuCo 2 S 4 was loaded onto NF using a simple two-step hydrothermal method. In the resultant NF/MoS 2 -CuCo 2 S 4 material, CuCo 2 S 4 offers a lot of active sites to support vertically arranged MoS 2 nanosheets, thereby decreasing their agglomeration. Moreover, the heterogeneous structure formed between CuCo 2 S 4 and MoS 2 facilitates charge transfer and exposes the active sites for HER, further improving the electrochemical hydrogen evolution performance of the heterostructured electrocatalyst. In a 1.0 M KOH solution, the synthesized NF/MoS 2 -CuCo 2 S 4 nanosheet catalyst has outstanding electrocatalytic efficacy, with an overpotential as low as 67 mV at a current density of 10 mA·cm−2. • Heterostructured electrocatalysts can enable synergistic effects of the components. • MoS 2 -CuCo 2 S 4 heterostructure formed on Ni foam exhibits superior activity in HER. • Heterostructure formation significantly increases the conductivity of the catalyst. • The Gibbs free energy for hydrogen adsorption to the catalyst approaches zero. [ABSTRACT FROM AUTHOR]

Light-weight structures, such as honeycomb sandwiches, have been demonstrated to have high potential in reducing ship weight and, in turn, fuel consumption and emissions while increasing the load-carrying capacity. In parallel, innovative technologies, such as additive manufacturing (AM), are established as effective solutions for producing light-weight structural components with enhanced performance. The vision driving the study is that the key enabling technology of AM provides disruptive design flexibility to develop and integrate innovative marine structural solutions. However, to achieve such an objective, an in-depth investigation of the structural response of components produced by AM is necessary to exploit their potential fully. Given such a framework, the study aims analysing the flexural response of Additive Manufactured Honeycomb Sandwich structures (AMHS) for marine structural applications. Three-point bending tests were conducted on multi-material and multi-layer composite AMHS specimens produced by an innovative AM technique. A numerical model, which correlates experimental results with ship structural design principles, was developed to predict the AMHS structural response. Moreover, the study provides insight into the failure mechanism of AMHS by de-coupling the progressively occurring compressive failure modes. This research is the first step in creating efficient design and manufacturing procedures for marine structural applications of AMHS. • 3-point bending tests were conducted on multi-material and multi-layer composite AMHSproduced by an innovative AM technique. • A numerical model was developed to predict the AMHS structural response. • The study provides insight into the failure mechanism of AMHS by de-coupling the occurring compressive failure modes. • The study is an initial step towards developing design and manufacturing methods for marine structural applications of AMHS. [ABSTRACT FROM AUTHOR]

In our manuscript, the assembly of micron and nanoscale structures was combined by laser etching hexagonal honeycomb-mounted micropores combined with hydrothermal growth of pine-needle-like ZnO, which relied on the capillary action of the micropores and the stabilizing mechanical properties of the honeycomb structure to achieve the locking of the lubricant and improve its durability. [Display omitted] • A honeycomb-inspired multidimensional lubricant-infused surface was fabricated; • The fabricated surface has a good ability to lock in lubricant; • The surface ensures excellent long-term lubrication performance; • The surface is able to rapidly coalesce and remove water droplets during condensation; • The surface retards the formation of ice. The slippery liquid-infused porous surfaces with nanostructures have emerged as a high-performance multifunctional surface with super-liquid repellency, low contact angle hysteresis and self-healing. However, the amount of lubricant captured by the nanostructures is extremely low, and such oil-filled functional surfaces are susceptible to lubricant loss depletion. In this research, we developed a honeycomb-inspired multidimensional lubricant-infused surface that has a good ability to lock in lubricant while providing excellent mechanical durability. The honeycomb-shaped hexagonal micropores store lubricant to stabilize the smooth oil layer, while the pine-needle shaped nano-needles in the pores retain the lubricant in the pores, making it more difficult to lose the lubricant and increasing durability. Compared to conventional nanostructured slippery liquid-infused porous surfaces, this surface ensures excellent long-term lubrication performance under extreme conditions such as cooling, high shear and water spray impact. Meanwhile the honeycomb mesh lubricant injected into the surface is able to rapidly coalesce and remove water droplets during condensation due to the presence of coarsening effect, and it also retards the formation of ice. This structure provides a new idea for anti-icing and water collection research [ABSTRACT FROM AUTHOR]