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A method for measuring the resistive characteristics of channels in the blanks of microchannel plates was developed. Two probes were used for measurements, which minimized leakage currents through adjacent channels. The resistive properties of single channels of the microchannel insert in the reduced blank of MCP 18-10 were studied. It was established that the resistance of the channels depends on their position in the microchannel honeycomb. It was shown that the channels located in close proximity to the monolithic frame have less resistance compared to those located in the middle of a multicore glass honeycomb. [ABSTRACT FROM AUTHOR]

We report the experimental observation of second-order corner states in a two-dimensional breathing honeycomb topolectrical circuit with sixfold rotational symmetry C 6 through voltage measurements. The topological corner states originate from the nontrivial bulk topology, which can be characterized by the topological invariant associated with the rotation eigenspectrum. We confirm two types of corner states, both originate from the C 6 symmetry, while one of them is specially pinned to zero admittance because of the emerging chiral symmetry protection. We then examine the robustness of zero modes in the presence of next-nearest-neighbor hopping terms that destroy chiral symmetry but still preserve C 6 symmetry. Our work provides a paradigm in circuit systems to study the exotic topological physics. [ABSTRACT FROM AUTHOR]

A detailed high-pressure investigation is carried out on F e 4 N b 2 O 9 using angle resolved x-ray diffraction and Raman spectroscopy measurements. We find a structural transition from the ambient trigonal phase to a monoclinic phase above 8.8 GPa. The structural transition is assumed to be driven by a large distortion of Nb – O 6 octahedra as seen from x-ray diffraction analysis and a large pressure dependence of an Nb – O 6 octahedra breathing Raman mode. Anomalous behavior of Raman modes and an increase in the phonon lifetime at the phase transition pressure indicate a possible change in the magnetic property of the sample above 8.8 GPa. A decrease in the diffusive scattering rate of a low-frequency electronic contribution contradicts the results of a decrease in the intensity of a high-frequency electronic response and excludes the phenomenon of an insulator to metal transition. On the contrary, the enhancement of the intensity of the Raman modes up to about 8.8 GPa indicates a large change in ferroelectric polarization of the sample, indicating a possible pressure induced re-entrant multiferroic behavior in F e 4 N b 2 O 9 . [ABSTRACT FROM AUTHOR]

We theoretically proposed a feasible way to design multi-topological states in one two-dimensional photonic crystal (PC). By sliding and rotating the meta-atoms of its unit cell, the topological phase of the PC can be continuously tuned, but without a closing of bandgap; it is similar to the Kekulé modulation in honeycomb lattices. We first show the existence of helical topological edge states in conventional topological insulator, which intersect together and form a Dirac cone in the two-dimensional synthetic space of the PC. Then, in full synthetic space, the PC behaves high-order topological insulator, and the corner state is then constructed in a heterostructure that consists of three different PCs. Furthermore, we demonstrate the photonic crystal with non-uniform modulation can behaves as a splitter and a rainbow trapper. Our proposal may provide interesting insight for designing of multiple topological states, which have potential in photonic on-chip devices. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to synthesizing honeycomb carbon quantum dots (CQDs) from cigarette smoke by a hydrothermal process. A comprehensive characterization of these CQDs, conducted through high-resolution transmission electron microscopy (HRTEM), showcases their unique honeycomb structure, with an average particle size of 6.3 nm. Photoluminescence (PL) in CQDs is a captivating phenomenon where these nanoscale carbon structures emit strong blue luminescence at 461 nm upon exposure to ultraviolet light, with their excitation peak occurring at 380 nm. Fourier Transform Infrared (FTIR) analysis also identifies specific functional groups within the CQDs, offering valuable insights into the mechanisms governing their photoluminescence. Analysis of excitation spectra indicates the presence of both aromatic C=C bonds at 254 nm and C–O bonds from 280 to 420 nm. [ABSTRACT FROM AUTHOR]

Rod-like bolapolyphiles with highly branched carbosilane-based side-chains self-assemble into several honeycomb structures if the oligo(p-phenylene ethynylene) core is polyfluorinated, whereas for the non-fluorinated series an A15 type cubic network of rod-bundles was observed instead, suggesting a brand new pathway for the transition between triangular and square honeycomb phases. [ABSTRACT FROM AUTHOR]

Honeycomb composite with excellent mechanical–physical properties had attracted extensive attention. To achieve outstanding sound insulation while maximizing the high‐performance of honeycomb composite, this article reported a honeycomb composite structure filled with glass fiber (HFG) based on a paper‐making process and the corresponding sandwich structure. Pulping parameters, mechanical property, air permeability and sound insulation of HFG were analyzed. The results showed that the hanging index and settling height of glass fiber slurry were inversely proportional to the beating degree, which was beneficial for reducing the coefficient of variation (CV) of HFG with value of 4%–6%. The maximum improvement in tensile strength and bursting strength of HFG were 70% and 53%, respectively. In addition, sound transmission loss (STL) of HFG was proportional to cell size, density, filling amount and thickness of the honeycomb. Compared to HFG, sandwich structure consisting of HFG and glass fiber/hot melt fiber panels effectively improved STL, especially at low‐mid frequencies. It was also found that designing holes on the surface of sandwich structure could further improve STL in certain frequency bands. The structure offered a lightweight and high‐performance response for construction, transportation and infrastructure. Highlights: This article designs a new type of honeycomb filled glass fiber via paper‐making process, aiming to improve the comprehensive performance of honeycomb.By the design of embedded structure, the maximum improvement in tensile strength and bursting strength of honeycomb were 70% and 53%, respectively.By designing perforated, embedded and laminated structures, sound insulation has been improved, while reducing material quality. [ABSTRACT FROM AUTHOR]

To realize the one‐dimensional deformation of morphing wings, zero Poisson's ratio (ZPR) honeycomb metamaterials have become a popular research topic due to their lightweight, low in‐plane modulus, and high out‐of‐plane strength. A ZPR honeycomb metamaterial is designed and prepared from short‐cut carbon fiber‐reinforced polyetheretherketone (CF/PEEK) by a 3D printer. The mechanical properties of ZPR honeycomb metamaterials were tested to determine their tensile and bending stiffness. The results show that the metamaterial can achieve 62.3% ± 3.3% in‐plane elastic deformation after optimized structure design. At the same time, metamaterial has a certain bending resistance to keep the airfoil from normal buckling deformation. Moreover, a new test method for evaluating the cycle deformation behavior of flexible morphing wings is proposed. The high‐speed cyclic tension‐compression test showed that H22‐t0.6‐CT has the best stability, which may be related to its lower porosity (2.15% ± 0.12%). These results indicate that ZPR honeycomb metamaterials have great application prospects in the field of morphing wings. Highlights: The printed CF/PEEK wire is treated as a transversely isotropic material.ZPR honeycomb metamaterial allows for more than 50% in‐plane deformation.A new test method to evaluate the cyclic deformation behavior. [ABSTRACT FROM AUTHOR]

Complex structural configuration design is necessary for dielectric‐magnetic lossy composites to achieved broadband microwave absorption in civil and defense applications. Based on the unique space filling characteristic of fractal structure, the honeycomb metastructure can possess microwave absorption and mechanical resistance. However, traditional molding technique was difficult to realize complex shape of metastructure. Herein, the dielectric‐magnetic filament with different concentration of carbonyl iron particles was fabricated by high‐temperature extrusion process. The multi‐physical honeycomb metastructure with gradient layers was printed by fused deposition modeling (FDM) in a large size. The printed dielectric‐magnetic samples exhibited strong dielectric‐magnetic loss with high printing quality. The honeycomb metastructure achieved broadband microwave absorption in the −10 dB bandwidth of 9.6–18 GHz with tensile strength of 31 MPa. The results indicate that FDM is useful to fabricate metastructure with complex shape for broadband microwave absorption. The dielectric‐magnetic properties of filament are magnified by metastructure design. The proposed design‐fabrication process is promising for functional structure realization with complex shape in the future. Highlights: 1. Magnetic filament was fabricated for functional 3D printing. 2. Structural magnetic dissipation mechanism for microwave was presented. 3. Magnetic metastructure was designed and printed for broadband absorption. 4. Integrated design of mechanical and electromagnetic function was presented. 5. Structural absorption effect of honeycomb metastructure was revealed. [ABSTRACT FROM AUTHOR]

This study presents a novel approach inspired by the hexagonal honeycomb structure found in nature, leveraging image processing algorithms to precisely define complex geometries in thermal systems. Hexagonal phase change material containers and thermally conductive fins were meticulously delineated, mirroring the intricate real-world designs of honeycombs. This innovative methodology not only streamlines setup processes but also enhances our understanding of melting dynamics within enclosures, highlighting the potential benefits of biomimetic design principles in engineering applications. Two distinct honeycomb structures were employed to investigate their impact on the melting process within cavities subject to heating from the left wall, with the remaining walls treated as adiabatic surfaces. The incorporation of a thermally conductive fin system within the enclosure significantly reduced the time required for a complete phase change, emphasizing the profound influence of fin systems on thermal design and performance. This enhancement in heat transfer dynamics makes fin systems advantageous for applications prioritizing precise temperature control and expedited phase change processes. Furthermore, the critical role of the fin system design was emphasized, influencing both the onset and location of the final point of melting. This underscores the importance of tailoring fin systems to specific applications to optimize their performance. Our study highlights the significant impact of the Rayleigh (Ra) number on the melting time in a cavity without fins, revealing a decrease from 6 to 0.4 as the Ra increased from 102 to 105; the introduction of a fin system uniformly reduced the melting time to Ste.Fo = 0.5, indicating fins' universal effectiveness in optimizing thermal dynamics and expediting the melting process. Moreover, the cavity angle was found to significantly affect the fluid fraction diagram in unfanned cavities but had minimal impact when fins were present, highlighting the stabilizing role of fins in mitigating gravitational effects during melting processes. These insights expand our understanding of cavity geometry and fin interactions in heat transfer, offering potential for enhanced thermal system designs in various engineering applications. Decreasing thermal conductivity (λ) by increasing the fin thickness can halve the melting time, but the accompanying disadvantages include a heavier system and reduced energy storage due to less phase change material, necessitating a careful balance in decision-making. [ABSTRACT FROM AUTHOR]

This paper presents an innovative method of constructing energy absorbers, whose primary function is to effectively transform kinetic energy into strain energy in events with high deformation rates. Hybrid specimens are proposed considering thin-walled windowed metallic tubes filled with 3D-printed hexagonal honeycombs made of PET-G and ABS thermoplastic. The patterned windows dimensions vary from 20 × 20, 20 × 30, 15 × 20 and 15 × 30 mm2. Although using polymers in engineering and thin-walled sections is not new, their combination has not been explored in this type of structure designed to withstand impacts. Specimens resist out-of-plane quasi-static axial loading, and test results are analyzed, demonstrating that polymer core gives the samples better performance parameters than unfilled samples regarding energy absorption (Ea), load rate (LR), and structural effectiveness (η). An optimization procedure using specialized software was applied to evaluate experimental results, which led to identifying the optimal window geometry (16.4 × 20 mm2, in case) and polymer to be used (ABS). The optimized sample was constructed and tested for axial compression to validate the optimization outcomes. The results reveal that the optimal sample performed similarly to the estimated parameters, making this geometry the best choice under the test conditions. [ABSTRACT FROM AUTHOR]

Novel CO2- and H3PO4-modified biochars were successfully synthesized from raw honeycomb biomass. They were characterized via several instrumental techniques. The optimal Pt(II) and Pt(IV) adsorption onto the studied biochars was reached for the initial pH of 1.5 and a contact time of 5 min (Pt(II)) and 24–48 h (Pt(IV)). The highest static adsorption capacities for Pt(II) and Pt(IV) were obtained for the H3PO4-modified biochar: 47 mg g−1 and 35 mg g−1, respectively. The Freundlich model described the Pt(II) adsorption isotherms onto both materials and the Pt(IV) adsorption isotherm onto the CO2-activated material, and the Langmuir model was the best fitted to the Pt(IV) adsorption isotherm onto the H3PO4-activated biochar. The best medium for the quantitative desorption of the Pt form from the H3PO4-modified biochar was 1 mol L−1 thiourea in 1 mol L−1 HCl. The adsorption mechanism of both the studied ions onto the synthesized H3PO4-modified biochar was complex and should be further investigated. The H3PO4-modified biochar was successfully applied for the first time for Pt(IV) removal from a spent automotive catalyst leaching solution. [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]

An infill pattern can be implemented in manufacturing a porous component using 3D Printing technology to reduce the mass of the printed part. The use of an infill pattern and infill angle affects the structure of the printed part. This research aims to investigate the effect of various infill patterns and angles on the compressive strength-to-mass ratio of components manufactured by 3D Printing. This research implements a General Linear Model analysis with two replications. Seventy-two compressive test specimens, according to ASTM D695, are printed and tested for compression. The experiment results show that the type of infill pattern has a significant effect on the mass. However, the mass is not significantly influenced by the infill angle. In addition, the infill pattern type and the infill angle significantly influence the compressive strength of the specimen. Then, the compressive strength-to-mass ratio is significantly affected by the infill patterns and angles. The results indicate that a part using the Honeycomb infill pattern type gains the highest compressive strength-to-mass ratio compared to other infill patterns. On the opposite, the infill pattern that creates the lowest compressive strength-to-mass ratio compared to other infill patterns is the Archimedean chords type. The use of a 45° infill angle causes the lowest compressive strength-to-mass ratio compared to other infill angles. Using a 90° infill angle causes the highest compressive strength-to-mass ratio compared to other infill angles. [ABSTRACT FROM AUTHOR]

Honeycomb materials as reinforcements for shape memory polymers have been considered for their commercial availability, ease of geometric tailoring, and high in-plane stiffnesses. The design optimization of these honeycomb cells remains an open field of research, with many approaches taken in formulating the structural optimization problems. This investigation focuses on implementing a shape variable parametrization of the honeycomb to study the possible value of both cell asymmetry and spatially varying cell geometries in multicell networks. A unit cell finite element model framework was developed to predict the in-plane elastic properties of these composites, and two design objectives were selected to be optimized. Pareto fronts were estimated for multiple loading cases and cell wall material models, and experimental results were collected for model validation. The optimization results find that these composites can achieve a large range of performances, with maximum moduli as high as 17.2 GPa. Large asymmetry is found in the optimized cell geometries, and relationships are identified between loading cases and for different wall materials. Furthermore, the experimental results validate the finite element model predictions, with relative errors as low as 20% for the predicted maximum modulus and 2% for the modulus ratio. [ABSTRACT FROM AUTHOR]

The co-integration of antennas with lighting sources appears as an effective way to distribute broadband networks closer to users, lowering interference and transmitted power, as well as to reduce energy consumption in future lighting systems. We here present an original contribution to the implementation of transparent and invisible antennas with OLED light sources. To validate the proposed approach, the honeycomb mesh technique was used, and an optical transparency of 75.4% was reached. The transparent mesh antenna was compared with the non-transparent full-metal antenna in terms of radio-electrical parameters. Our prototype was designed using copper films deposited on a glass substrate. The simulation results of the S-parameters and the radiation patterns were validated against measurements performed in an anechoic chamber. The directivity and gain obtained were 6.67 dBi and 4.86 dBi at 5.16 G Hz , respectively. To study the effect of antenna integration with OLEDs, optical and photometric characterizations with and without the antenna were measured, and the colorimetric parameters were then treated using the IES TM-30-18 standard. [ABSTRACT FROM AUTHOR]

In this article, the non‐linear free vibration behavior of sandwich composite panels with sinusoidal corrugations is examined. These panels consist of a top and bottom skin made of a graphene‐reinforced composite, with an auxetic honeycomb core having negative Poisson's ratio. The non‐linear kinematic field is based on Kant's higher‐order shear‐deformation theory and the Green‐strain, which incorporates all the higher‐order terms. By implementing the Hamilton principle, the non‐linear governing equations are affirmed and solved further through 2D‐isoparametric finite element approximations via Lagrangian elements in conjunction with Picard's successive iterative scheme. The comparison and validation tests demonstrate the correctness of the present model. The established sandwich model is further employed for various parametric conditions by varying the core‐to‐face sheet thickness, auxetic honeycomb properties, graphene volume fraction, shell configurations, temperature, and support conditions. These numerous results exemplify the non‐linear frequencies at small‐to‐large amplitudes for the sandwich shell structures and are discussed in detail. In addition, a multi‐objective parametric optimization is conducted using the response surface method to investigate the optimal values of the corrugated auxetic honeycomb shell panel's parameters, resulting maximum frequency. Highlights: Non‐linear vibration of corrugated sandwich shell panel.Graphene reinforced skins and honeycomb auxetic core.Kant's higher‐order shear‐deformation theory and Green‐Lagrange non‐linearity.Hamilton principle and Picard's successive iterative scheme.Multi‐objective parametric optimization and prediction using response surface methodology. [ABSTRACT FROM AUTHOR]

Background: Honeycomb cysts (HC) within the alveolar region are distinct histopathological features in the lungs of idiopathic pulmonary fibrosis (IPF) patients. HC are lined with a single-or stratified layer of basal cells (BC), or with a bronchiolar-like epithelium composed of basal-, ciliated- and secretory epithelial cells. By using cultured IPF patient-derived alveolar BC, we aimed to establish an in vitro- and in vivo model to mimic HC formation in IPF. We (1) optimized conditions to culture and propagate IPF patient-derived alveolar BC, (2) cultured the cells on an air liquid interface (ALI) or in a three dimensional (3D) organoid model, and (3) investigated the cells' behavior after instillation into bleomycin-challenged mice. Methods: Alveolar BC were cultured from peripheral IPF lung tissue and grown on tissue-culture treated plastic, an ALI, or in a 3D organoid model. Furthermore, cells were instilled into bleomycin-challenged NRG mice. Samples were analyzed by TaqMan RT-PCR, immunoblotting, immunocytochemistry/immunofluorescence (ICC/IF), or immunohistochemistry (IHC)/IF. Mann–Whitney tests were performed using GraphPad Prism software. Results: Cultured alveolar BC showed high expression of canonical basal cell markers (TP63, keratin (KRT)5, KRT14, KRT17), robust proliferation, and wound closure capacity. The cells could be cryopreserved and propagated for up to four passages without a significant loss of basal cell markers. When cultured on an ALI or in a 3D organoid model, alveolar BC differentiated to ciliated- and secretory epithelial cells. When instilled into bleomycin-challenged mice, human alveolar BC cells formed HC-like structures composed of human basal-, and secretory epithelial cells within the mouse parenchyma. Conclusion: IPF patient-derived alveolar BC on an ALI, in 3D organoids or after instillation into bleomycin-challenged mice form HC-like structures that closely resemble HC within the IPF lung. These models therefore represent powerful tools to study honeycomb formation, and its potential therapeutic inhibition in IPF. [ABSTRACT FROM AUTHOR]

This research delves into the influence of intrinsic decoherence on the behavior of quantum correlations and coherence between two interacting qubits in a graphene-based system. To evaluate the amount of nonclassical correlations in the system, we employ local quantum uncertainty (LQU), and to assess quantum coherence we use the relative entropy of coherence (C r) and l 1 -norm (C l 1 ). We assume that the system is initially prepared in an extended-Werner-like (EWL) state, and we investigate how these quantifiers evolve over time and examine their sensitivity to various graphene layer system parameters, mixture parameter of the initial state and the intrinsic decoherence rate. Our results indicate that by adjusting the wave number operators, decreasing the intrinsic decoherence rate, and increasing the initial state mixing parameter, it is possible to enhance both quantum correlations and coherence within the two-dimensional honeycomb lattice system. In addition, we found that quantum coherence is more resilient to intrinsic decoherence than LQU, moreover, the l 1 -norm is more robust than the relative entropy of coherence. [ABSTRACT FROM AUTHOR]

The key to obtain supercapacitors with high energy density is rational design and synthesis of negative electrode materials. Herein, a new type of polyoxometalate‐based coordination polymer was prepared by one‐step hydrothermal method. Polymer 1 with honeycomb two‐dimensional network structure is beneficial to improve electrical conductivity and storage capacity because of its π‐π stacking interaction. Ti3C2Tx, an MXene material with excellent electrical conductivity, was mixed with compound 1, which has rich redox reactions. As expected, 1@Ti3C2Tx exhibited outstanding specific capacitance (768.7 F g−1 at 8 A g−1), which is superior to many materials. In addition, the hybrid material also showed good cycle stability (88.1 % capacity retention after 1000 cycles). This work provides an effective way to develop hybrid electrode materials based on polyoxometalate‐based coordination polymers as supercapacitors. In addition, using 1@Ti3C2Tx as the negative electrode material and celery leaf carbon paper as the positive electrode material, the asymmetric supercapacitor device is fabricated. When the power density is 629.7 W kg−1, the energy density is 9.2 Wh kg−1, which indicates that it has a good application prospect. [ABSTRACT FROM AUTHOR]

Lattice structures nowadays have gained a peak in research. Inspired by the honeycomb structure and fishbone, this study investigated lattice structures that can provide auxetic behavior and store maximum energy absorption during deformation mode. From that, the study involved designing and producing different modified lattices based on the honeycomb's structure and the fishbone's perspective. The specimens were 3D printed within fused filament fabrication techniques within the additive manufacturing platform of Euromed University of Fes. The conception, production, mechanical testing, and simulation have been employed to get optimum data analysis of the mechanical properties of the designed structures. The results observed under quasi-dynamic compression did not show significant densification behavior; but, the auxetic behavior was seen in all structures, while some suddenly collapsed. The experimental and numerical analysis demonstrated similar deformation behavior and strong agreement in their respective results. Nevertheless, some discrepancies in mechanical values were observed, with a relative percentage error of approximately 1% for both methods. Consequently, owing to the enhanced energy absorption observed in the V2 and V3 structures, it is evident that these modifications hold promise for optimizing the performance of these metamaterials in various practical applications. [ABSTRACT FROM AUTHOR]

In this paper, sorghum and reed, which possess light stem structures in nature, were selected as biomimetic prototypes. Based on their mechanical stability characteristics—the porous structure at the node feature and the porous feature in the outer skin— biomimetic optimization design, simulation, and experimental research on both the traditional hexagonal structure and a hexagonal honeycomb structure were carried out. According to the two types of straw microcell and chamber structure characteristics, as well as the cellular energy absorption structure for the bionic optimization design, 22 honeycomb structures in 6 categories were considered, including a corrugated cell wall bionic design, a modular cell design, a reinforcement plate structure, and a self-similar structure, as well as a porous cell wall structure and gradient structures of variable wall thickness. Among them, HTPC-3 (a combined honeycomb structure), HSHT (a self-similar honeycomb structure), and HBCT-257 (a radial gradient variable wall thickness honeycomb structure) had the best performance: their energy absorption was 41.06%, 17.84%, and 83.59% higher than that of HHT (the traditional hexagonal honeycomb decoupling unit), respectively. Compared with HHT (a traditional hexagon honeycomb decoupling unit), the specific energy absorption was increased by 39.98%, 17.24%, and 26.61%, respectively. Verification test analysis revealed that the combined honeycomb structure performed the best and that its specific energy absorption was 22.82% higher than that of the traditional hexagonal structure. [ABSTRACT FROM AUTHOR]

Purpose: The primary objective of this study is characterizing the anisotropic mechanical properties of corrugated cardboard and simultaneously simulating its drop cushioning dynamic effects under various drop conditions. Design/methodology/approach: Static and dynamic tests were conducted on corrugated cardboard to obtain adequate experimental data in different directions. An effective anisotropic constitutive model is introduced by developing the honeycomb materials model in ANSYS LS-Dyna, and an effective approach is established toward effectively determining the material parameters from the test data obtained. The model is validated by comparing simulation results with experimental data from five drop conditions, including bottom drop, front drop, side drop, 30° side drop and edge drop. Additionally, simulations are conducted to study the cushioning performance of the packaging by dropping the corrugated cardboard at different heights. Findings: The study establishes a fast and effective approach to simulating the drop cushioning performance of corrugated cardboard under various drop conditions, which demonstrates good agreement with experimental data. Originality/value: This approach is of value for packaging protection and provides guidance for stacking of packaging during transportation. [ABSTRACT FROM AUTHOR]

This analysis investigated the impact wave response and propagation on a composite sandwich shell when subjected to a low-velocity external shock, considering hygrothermal effects. The sandwich shell was crafted using face layers composed of functional gradient metal–ceramic matrix material and a core layer reinforced with negative Poisson's honeycomb. The honeycomb layer consisted of a combination of viscoelastic polymer material and elastic material. The equivalent parameters for the functional gradient material in the face layers were determined using the Mori–Tanaka and Voigt models, and the parameters for the negative Poisson's ratio honeycomb reinforcement core layer were obtained through Gibson's unit cell model. Parameters relevant to a low-velocity impact were derived using a modified Hertz contact law. The internal deformations, strains, and stress of the composite sandwich shell were described based on the higher-order shear deformation theory. The dynamic equilibrium equations were established using Hamilton's principle, and the Galerkin method along with the Newmark direct integration scheme was employed to calculate the shell's response to impact. The validity of the analysis was confirmed through a comparison with published literature. This investigation showed that a multilayer negative Poisson's ratio viscoelastic polymer material honeycomb-cored structure can dissipate impact wave energy swiftly and suppress shock effectively. [ABSTRACT FROM AUTHOR]

Regarding two-dimensional (2D) nanomaterials as gas sensors, we have studied the adsorption of gas molecules (NH3, NO2, NO) on the graphitic GaN sheet (PL-GaN) using density functional theory calculations. "Langmuir" adsorption of gas molecules of NH3, NO2, and NO on the graphitic GaN sheet has been accomplished using density functional theory. The changes in charge density have shown a more important charge transfer on the hexagonal honeycomb nanosheet of gallium nitride (GaN) which acts as the electron acceptor while gas molecules act as the stronger electron donors through adsorption on the graphitic-like GaN surface. The adsorption of NH3, NO 2 , and NO, respectively, on GaN nanosheet has more contribution with high expansion curves of hydrogen, nitrogen and oxygen. The results extracted from PDOS curves after optimization show the electron transferring from nitrogen and oxygen of gas molecules (adsorbate/donor) towards gallium in the active site of GaN surface (adsorbent/acceptor). GaN nanosheet represents enough capability for adsorbing gases of NH3, NO2, and NO through charge transfer from nitrogen and oxygen atoms to the gallium atom regarding the intra-atomic and interatomic interactions. Concerning the change of physicochemical properties of the PL-GaN sheet before and after molecule adsorption, the PL-GaN nanosheet can be applied as an appropriate selective gas sensor for NH3, NO2 and NO detection. [ABSTRACT FROM AUTHOR]

The cuttlebone is known for its ability to possess high specific stiffness, progressive failure and lightweight from the porous chambered structure. Inspired by the microstructural characteristics of cuttlebone and incorporating the wall gradient design, a series of double-asymmetric honeycombs were designed and processed by LPBF. Results indicated that bionic structural units with the junction design can maintain the integrity of the residual parts after local buckling and failure, improving the load-bearing capacity. The double-asymmetric honeycomb with gradation parameter a = 2/3 achieved a maximum specific compressive strength of 70.64 MPa cm3/g. As a decreases, there is an increase in specific energy absorption and a narrowing of the hysteresis loop. The as-build honeycomb had undergone stress-induced martensite transformation during compression. The dissipated mechanical energy (ME) decreased with the increasing cycle number and the decreasing a. The results provide design guidelines and process strategies for developing high-performance honeycombs. [ABSTRACT FROM AUTHOR]

Optimized sustainable procedures in both acidic and basic conditions are considered to meet some of the current environmental challenges of the scientific community. In this paper, the successful syntheses of two classes of indium-based silica nanomaterials are reported. Both procedures were conceived to enhance the sustainability of the synthesis methods and promote their preparations at room temperature while avoiding the hydrothermal treatment under static conditions at 100 °C. A fast, room-temperature synthesis of porous nanospheres was conceived together with an "acid-free" procedure for SBA-15-like materials. Moreover, the isomorphic substitution of silicon with indium was achieved. All the materials were deeply characterized to probe their structural, textural and morphological properties (e.g., transmission electron microscopy, N2 physisorption, ss MAS NMR of 29Si). The high specific surface area and the mesoporosity were always preserved even under the mild reaction conditions employed. The honeycomb structure and the spherical morphology of SBA-15-like materials and nanospheres, respectively, were also observed. The insertion of indium was confirmed via X-ray photoelectron spectroscopy (XPS) investigations. [ABSTRACT FROM AUTHOR]

Layered honeycomb magnets with strong atomic spin–orbit coupling at transition metal sites have been intensively studied for the search of Kitaev magnetism and the resulting non-Abelian braiding statistics. α -RuCl 3 has been the most promising candidate, and there have been several reports on the realization of sibling compounds α -RuBr 3 and α -RuI 3 with the same crystal structure. Here, we investigate correlated electronic structures of α -RuCl 3 and α -RuI 3 by employing first-principles dynamical mean-field theory. Our result provides a valuable insight into the discrepancy between experimental and theoretical reports on transport properties of α -RuI 3 , and suggests a potential realization of correlated flat bands with strong spin–orbit coupling and a quantum spin-Hall insulating phase in α -RuI 3 . [ABSTRACT FROM AUTHOR]

This study reports a modified Haldane model that supports transitions between valley and Chern topological phases in photonic crystals. Berry curvatures of this system can be flexibly diffused, converged, or flipped by endowing different model parameters, thus exhibiting exotic topological interface/edge behaviors, such as topological bound states with ideally zero dispersion. Importantly, the coexistence of chiral and antichiral edge states preserved simultaneously by valley and Chern topological phases is achieved by splicing together two kinds of topological structures as an entirety. It further employs a honeycomb lattice comprising gyromagnetic and ceramic cylinders at microwave frequencies, where inversion and time‐reversal symmetries can be flexibly manipulated. Topological interface transport is demonstrated, including two opposite signs of group velocities jointly protected by topologically distinct regimes. These results bridge the gap between valley and Chern topological physics and shed light on developing reconfigurable integrated device applications for classical (quantum) information processing and photonic computing. [ABSTRACT FROM AUTHOR]

Higher‐order topological insulators hosting topological modes at hinges and corners provide a new avenue for disorder‐immune light transport, which prospects great potential in applications of integrated photonics devices. However, the active control of topological modes in 3D higher‐order topological insulators is not realized yet, and its construction is too complicated and huge to analyze. Here, a method is proposed to construct effective Hamiltonians for higher‐order topological insulators, which provides a correct physical picture of the states and the corresponding energies at the domain walls. A non‐Hermitian 3D honeycomb lattice is constructed, which can generate arbitrary‐located, arbitrary‐shaped, and robust topological hinge states propagating at gain‐loss domain walls. The 3D honeycomb lattice can also appear as non‐Hermitian third‐order TIs exhibiting corner states, which can be dynamically controlled and show new topologically protected confinement rules. This work expands the understanding of the topological properties in non‐Hermitian systems and enables the dynamic control of topological states of different dimensions. [ABSTRACT FROM AUTHOR]

Carbon honeycombs (CHs) are new carbon cellular structures, very promising in many respects, in particular, for high-capacity storage of various materials, especially in gaseous and liquid forms. In this study, we report a strong uptake of carbon dioxide kept inside carbon honeycomb matrices up to temperatures about three times higher as compared with CO2 desorption at ≈ 90 K from flat solid surfaces in vacuum where we conduct our high-energy electron diffraction experiments. Desorption of CO2 from CH matrices upon heating exhibits non-monotone behavior, which is ascribed to carbon dioxide release from CH channels of different sizes. It is shown that modeling of CO2 uptake, storage, and redistribution in the thin CH channels of certain types and orientations upon heating can explain experimental observations. [ABSTRACT FROM AUTHOR]

In this paper, we study the quantum correlations, particularly entanglement, between two qubits in graphene lattices. This study considers the short-range electron–electron Coulomb interactions as introduced by the Hubbard model and examines entanglement and other quantum correlations using the logarithmic negativity E N and the measurement-induced disturbance (MID) quantifiers, respectively. The results show that the on-site repulsion U, the nearest-neighbor interaction V between two qubits can promote entanglement up to a certain limit of U and V, but beyond entanglement, they can destroy other quantum correlations. These parameters can be seen as potentials generated near the two qubits, and they have a significant impact role in determining the amount and nature of quantum correlations in the system. Additionally, we have noted that the temperature T and the hopping parameter t also affect the quantum correlations in the system. Moreover, we found that MID is more robust than E N . That is means that even when there is no entanglement present, quantum correlations are still present in the interacting two-qubit states, which can be detected by MID quantifier. [ABSTRACT FROM AUTHOR]

Carbon-ash separation is a prerequisite for efficiently utilizing coal gasification fine slag (CGFS), but the enrichment characteristics of harmful elements (HEs) in the separation process are not fully understood. This paper uses gravity separation to prepare different samples, and four typical HEs (Se/Cd/ Pb/Cr) in separated products were investigated. The results showed that samples with an ash yield of 28.72%–98.86% and a specific surface area of 12.90 m2 /g-389.51 m2 /g were obtained through gravity separation. The highly volatile element Se was enriched in the C-C/C-H structure of residual carbon under the catalysis of acidic gases. The nonvolatile element Cr was encapsulated by low-melting-point minerals and remained in the minerals. The semi-volatile element Cd/Pb was easily enriched in a particle with a high specific surface area/large pore volume, especially in porous residual carbon, with an enrichment factor as high as 7.0 and 4.0, respectively. The leaching risk analysis of sorted products indicates that the products were not suitable for direct landfill; however, besides honeycomb porous carbon, other highly specific surface area products can be safely used for soil improvement. The results of this study are expected to provide a reference for the classification and utilization of CGFS and the control of HE pollution. [ABSTRACT FROM AUTHOR]

To improve the impact resistance of the honeycomb, a self-similar spider-web hierarchical structure is introduced by adding smaller hexagons to the centers of the primitive cells in the underlying hexagonal network and connecting the vertices of the smaller hexagons to the center points of the cell walls via straight beams. The hierarchical structure is introduced into the regular hexagonal honeycomb (RH) cells, and some novel hierarchical bio-honeycombs are proposed for the development of innovative hierarchical bio-honeycombs. Compression simulation was performed to validate the finite element model. Subsequently, a finite element model of the bio-honeycomb was developed to investigate its out-of-plane crashworthiness. The results show that the introduction of bionic cells and the RH cell walls produces significant interaction effects, with more severe plastic deformation at their intersections and the formation of more folded flaps in the cell walls. The effect of geometric parameters on the crashworthiness of the novel biomimetic bio-honeycomb structures is further discussed. It is shown that smaller bionic honeycomb pore sizes are beneficial for improving the efficiency of material utilization. [ABSTRACT FROM AUTHOR]

Partial shadowing is the primary cause of power degradation in PV systems. There are various methods for harvesting extreme power from a PV array. Proper selection of PV array configuration is one of the strategies to extract maximum power. Cross ties in PV array configurations play a major role in maximizing the power. As the number of cross ties increases, maximum power from PV array increases. But, these cross ties have resistance, which increases the wiring losses, which may result in the decrease of power from the PV array. For the investigation of the impact of wiring resistance (column wiring and cross-ties wiring) under static and dynamic partial shading situations, this paper considers several 9×9 PV array designs such as Series-Parallel, Bridge-Link, Honey-Comb, Total-Cross-Tied, and Triple-Tied-Cross-Linked. The analysis of Total-Cross-Tied and Triple-Tied-Cross-Linked PV array configurations is extended to 18×18 array size. Measures such as global maximum power point, efficiency, fill factor, and mismatch losses were used in the performance analysis. The simulation findings show that, when a large number of panels are shaded statistically, the impact of wiring resistance is significant. [ABSTRACT FROM AUTHOR]

We present the first and deepest Australia Telescope Compact Array radio continuum images of the Honeycomb Nebula at 2000 and 5500 MHz solely from archival data. The resolutions of these images are 3.6 × 2.8 arcsec2 and 1.3 × 1.2 arcsec2 at 2000 and 5500 MHz. We find an average radio spectral index for the remnant of--0.76 ± 0.07. Polarisation maps at 5500 MHz reveal an average fractional polarisation of 25 ± 5% with a maximum value of 95 ± 16. We estimate the equipartition field for Honeycomb Nebula of 48 ± 5 μG, with an estimated minimum energy of jBmjn = 3 × 104δ erg. The estimated surface brightness, ΣiGHz> is 30 × IO-20 W m-2 Hz-1 sr-1; applying the Σ-D relation suggests this supernova remnant is expanding into a low-density environment. Finally, using Hl data, we can support the idea that the Honeycomb Nebula exploded inside a low-density wind cavity. We suggest that this remnant is likely to be between late free expansion stage and early Sedov phase of evolution and expanding into a low-density medium. [ABSTRACT FROM AUTHOR]

The shape memory alloy (SMA) can deform pseudo-plastically under external load, based on which a reusable impact energy absorption structure was designed. According to the classical SMA constitutive model, the finite element model for thin-wall structures was established, and the dynamic characteristics such as deformation modes and energy absorption of different forms of honeycomb structures under different impacting velocities, were analyzed, and the optimal energy absorption performance of the SMA structures was obtained. In addition, through comparison of the energy absorption performance of the SMA honeycomb with that of the aluminum honeycomb, the energy absorption of the SMA honeycomb with different structure configurations was different from that of the aluminum honeycomb under different-velocity impacts, with the optimal structure changes. The work provides a reference for the selection and design of the SMA honeycomb structures. [ABSTRACT FROM AUTHOR]

Despite the wide growth of additive manufacturing, it is still very expensive to mass produce 3D-printed parts. The costs can be minimized if the quantity of material required to produce a part can be substantially reduced by introducing hollow cavities into the structure, without compromising its properties. This study investigates the effect of the degree of hollowness and different internal cavity structures on the mechanical properties of 3D-printed materials. Test specimens were prepared with four polymeric materials (i.e., acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), carbon fiber-reinforced (CFR) ABS, and CFR PLA) using the fused deposition modeling 3D printing technique. Internal hollow cavities were introduced to the specimens during printing and the specimens were prepared with three different cavity structures (i.e., hexagonal honeycomb, circular drills, and squares), and the degree of hollowness was varied from 0% to 30% in 10% increments. Tensile and flexural properties of the 3D-printed specimens were evaluated and analyzed. The mechanical properties of all specimens were found to decrease with increasing hollowness levels, regardless of the type of material or the internal cavity structure. The hexagonal honeycomb structure showed the best tensile properties out of the three internal cavity structures, while the flexural properties were not significantly affected by the internal cavity structure. The material type had a significant impact on the mechanical properties with PLA exhibiting better tensile and flexural properties than ABS, while their carbon fire reinforced counterparts showed enhanced mechanical properties than pure ABS and PLA. [ABSTRACT FROM AUTHOR]

In this work, the effects of doping with carbon (C) and silicon (Si) on the electronic and magnetic properties of phosphorus nitride (PN) monolayer are investigated. PN monolayer is stable, exhibiting the semiconductor nature with indirect band gap of 1.81(2.89) eV calculated by standard Perdew–Burke–Ernzerhof (hybrid HSE06) functional. C and Si impurities prefer doping at N and P sublattices, respectively. PN monolayer is slightly magnetized by doping with 25% of C with total magnetic moment of 0.20 μB$\mu _{\text{B}}$. The magnetization is stronger in the remaining cases with total magnetic moments of 1.00 μB$\mu _{\text{B}}$. Magnetic properties are produced mainly by C and Si impurities. In addition, C and Si codoping is also investigated, in which the magnetization depends strongly on the interatomic distance between impurities. Specifically, the inter‐dopant interactions preserve the non‐magnetic nature of PN monolayer, but significantly reduce the energy gap. However, further separating these dopants leads to the emergence of magnetism with total magnetic moment of up to 1.97 μB$\mu _{\text{B}}$. Results may introduce doping‐based effective method to induce feature‐rich electronic and magnetic properties in buckled honeycomb PN monolayer. Such that, the C‐ and Si‐doped PN sheets are recommended for spintronic applications considering their magnetic semiconductor nature. [ABSTRACT FROM AUTHOR]

The oxidation of carbon monoxide (CO) and unburnt hydrocarbons (HC) under segmented honeycomb catalysts was investigated using actual exhaust gas mixtures from a gasolinefueled internal combustion engine of a motorcycle. The honeycomb catalysts were prepared through a wet process, resulting in four types coated with transition metals (Cu, Cr, Fe, and Ni) supported on Al2O3. The oxidation of CO and HC was monitored using an exhaust gas analyzer across a range of air-to-fuel ratios (AFR), from lean to rich, under stationary conditions. The results demonstrate that the honeycomb catalysts effectively decreased CO and HC concentrations in the exhaust gas. Among the transition metal oxide honeycomb catalysts, Cr and Ni exhibited high CO and HC conversion rates, surpassing those observed with Cu. The average CO and HC conversion calculations, spanning from lean to rich air-tofuel ratios, were consistent with the actual conversion rates achieved. Furthermore, the study investigated the effect of honeycomb segmentation on CO and HC conversion. Surprisingly, the catalytic performance of Cr and Ni remained high even with longer gaps in the honeycomb. Interestingly, the conversion of CO and HC over the iron oxide honeycomb catalyst increased as the gap in the honeycomb became longer. This is likely due to an increase in the gap size and enhanced re-mixing of reactants (CO, HC, and O2) caused by recirculation. Thus, this study provides valuable elucidation on the potential application of segmented honeycomb catalysts for reducing CO and HC emissions in exhaust gases. [ABSTRACT FROM AUTHOR]

It is widely believed that the phase transition for the four-state ferromagnetic Potts model on the square lattice is of pseudo-first order. Specifically, it is expected that first-order phase transition behavior is found on small lattices and that the true nature of the second-order phase transition only emerges with large system sizes. It is also intuitively expected that, for other geometries, the types of the associated phase transitions should be identical to that of the square lattice. However, after simulating more than 16 million spins for the four-state Potts model, we observe that a feature of the first-order phase transition persists on the square lattice. Additionally, a characteristic of the second-order phase transition already appears on a small honeycomb lattice. Indications of a pseudo-first-order phase transition were not found in our investigation. This suggests that a thorough analytic calculation may be required to develop a better understanding of the presented results. [ABSTRACT FROM AUTHOR]

In the present paper, a semi-analytical solution is presented for the free vibration analysis of a sandwich cylindrical shell with a reentrant auxetic honeycomb (AH) core fabricated from metalceramic functionally graded materials (FGM). It is assumed that the volume fraction of the ceramic phase in the functionally graded auxetic honeycomb (FGAH) core increases from zero at the inner surface of the core to one at the outer one according to various patterns including power-law function (P-FGM), sigmoid function (S-FGM), and exponential function (E-FGM). The FGAH core is covered with an isotropic homogenous inner face layer made of metal and an isotropic homogenous outer one made of ceramic. The sandwich shell is modeled via Murakami’s zig-zag theory, and the governing equations are derived using Hamilton’s principle. An exact solution is presented for a simply supported shell via the Navier method to find the natural frequencies of the shell. The effects of various parameters on the natural frequencies are studied such as material gradation, the thickness-to-radius ratio, the core-to-face layers thickness ratio, and geometric factors of the auxetic cells. It is found that for each vibrational mode, an optimal ratio can be found between the thickness of the FGAH core and the thickness of the shell which leads to the highest natural frequency. [ABSTRACT FROM AUTHOR]