Structural Configuration Research Articles

The "CUPCAKE" technique (coiled underlying pseudoaneurysm contained by a woven endobridge device) for treating intracranial aneurysms with atypical morphology.

Intrasaccular flow diversion using the woven endobridge device (WEB; MicroVention, Aliso Viejo, CA, USA) for the treatment of intracranial aneurysms has demonstrated large scale safety and efficacy. However, limitations arise from its structural configuration, restricting its application to specific aneurysm sizes and shapes. We introduce the CUPCAKE technique, a combination of conventional coiling followed by WEB intrasaccular flow disruption in select cases of atypical aneurysms with technically challenging morphology not typically treatable by WEB alone. A retrospective analysis of a prospectively-maintained dataset from three Australian neurovascular tertiary referral centers, identifying patients treated with the CUPCAKE technique between April 2018 and September 2023. Evaluation of patient and aneurysm characteristics, procedure parameters, complications, radiological and clinical outcomes at follow-up was performed. The CUPCAKE technique was used for the treatment of 22 intracranial aneurysms of total 169 treated with WEB. Overall successful immediate flow stagnation was observed in 95.5% (n = 21) of aneurysms with no cases of perforation or intraoperative hemorrhage. Imaging confirmed thromboembolic complications occurred in two patients, one patient had persistent flow requiring re-treatment during initial admission. Follow-up imaging demonstrated 88.2% complete aneurysm conclusion with no delayed aneurysm expansion or rupture. Synergistic use of conventional coiling with WEB intrasaccular flow disruption presents a viable solution for technically difficult aneurysm treatment. In our series, 13% of all patients treated with WEB received CUPCAKE treatment, resulting in high technical success and no increase in thromboembolic complications with the union of two methods.

Ultimate Strength Analysis of Aluminium Honeycomb Sandwich Panels Subjected to Uniaxial Compressive Loads and Lateral Pressure

Ultimate strength is critical for hull structures because it determines the maximum load the structure can withstand before catastrophic failure. Aluminium honeycomb sandwich panels provide excellent energy absorption and a high strength-to-weight ratio. However, further investigation of honeycomb sandwich panel structural performance is needed in typical marine conditions. This study focuses on the numerical analysis of honeycomb sandwich panels employing the nonlinear finite element method through the commercial software ANSYS. It investigates their performance under uniaxial compression and varying lateral pressure conditions while considering different cell edge lengths and core height configurations. Several structural configurations are compared to the experimental work published in the literature. Enhanced by experimental accuracy, the present study is a further step in expanding the application of honeycomb sandwich panels for ship hull applications that may lead to light and energy-efficient structures.

The Interaction Mechanisms of Swimming Biomimetic Fish Aligned in Parallel Using the Immersed Boundary Method

In natural environments, fish almost always swim in groups. Investigating the coupled mechanism of biomimetic fish exhibiting autonomous swimming capabilities advances our understanding of fish schooling phenomena and simultaneously aids in refining the structural and formation configurations of underwater robotic vehicles. This work innovatively develops an algorithm based on the Direct-Forcing Immersed Boundary Method (DF-IBM) and implements it in an efficient, modular software program written in C++. The program accelerates the calculation process by using a multigrid method. Validation against a benchmark case of flow around a cylinder, with comparison to data from the existing literature, verifies the program’s precision with discrepancies of less than 3.6%. Based on this algorithm, the paper analyzes the incompressible viscous flow during the movement of parallel-aligned biomimetic fish. It uncovers the interaction between the fish’s motion and the surrounding flow field and also reveals the hydrodynamic mechanisms of the group motion of the parallel-aligned biomimetic fish. The flow field under varying spacing and phases between the parallel-aligned biomimetic fish proves that the interaction between the flow fields induced by the two fish bodies becomes increasingly significant when decreasing the lateral spacing from 1.4L to 0.6L. Notably, an initial lateral convergence of the fish bodies is observed, followed by a sideways swimming pattern at a particular pitch angle, accompanied by a decrement in their forward swimming velocity as they approach each other. Additionally, this study compares flow field alterations in parallel-aligned biomimetic fish with identical lateral spacing but opposing flapping phases. The findings indicate that, irrespective of the phase, the fish exhibit an initial convergence followed by a sideways motion at a specific pitch angle. However, due to disparities in the tail’s flow field, a larger pitch angle is generated when the fish swim in unison. All the findings above will provide a solid theoretical foundation for the design and optimization of underwater robotic vehicles.

Influence of Structural Configurations, Boundary Conditions, and Atomic Number on the Curie Transition Temperature of Bulk Cobalt: A Monte Carlo Simulation Study

This study investigates the impact of structural configurations, boundary conditions, and atomic number on the Curie transition temperature ([Formula: see text] of bulk cobalt (Co) utilizing Monte Carlo simulations. The analysis reveals that the Curie temperature increases as the structure transitions from a simple cubic (SC) to a body-centered cubic (BCC), hexagonal close-packed (HCP), and face-centered cubic (FCC) configuration. The SC structure, exhibiting the lowest [Formula: see text], serves as the reference for evaluating these influencing factors. The study also demonstrates that nonperiodic boundary conditions yield the lowest [Formula: see text] compared to periodic ones. Additionally, an increase in the number of atoms from 4000 to 108,000 under nonperiodic boundary conditions correlates with an increase in [Formula: see text]. These findings are consistent with experimental data and provide a foundational basis for researchers involved in the synthesis and application of bulk Co in devices, biomedical applications at room temperature, and emerging technologies.

1.5D Chiral Perovskites Mediated by Hydrogen-Bonding Network with Remarkable Spin-Polarized Property.

In this study, we developed new chiral hybrid perovskites, (R/S-MBA)(GA)PbI4, by incorporating achiral guanidinium (GA+) and chiral R/S-methylbenzylammonium (R/S-MBA+) into the perovskite framework. The resulting materials possess a distinctive structural configuration, positioned between 1D and 2D perovskites, which we describe as 1.5D. This structure is featured by a hydrogen-bonding-network-induced arrangement of zigzag inorganic chains, further forming an organized layered architecture. The structural dimensionality affects both electronic and spin-related properties. Density functional theory (DFT) calculations reveal Rashba splitting induced by the inversion asymmetry of the crystal structure, while circularly polarized transient absorption spectroscopy confirms spin lifetime on the nanosecond timescale. Magnetic conductive-probe atomic force microscopy (mCP-AFM) measurements demonstrate exceptional chiral-induced spin selectivity (CISS) with maximum spin polarization degrees of (92 ± 1)% and (-94 ± 2)% for (R-MBA)(GA)PbI4 and (S-MBA)(GA)PbI4, respectively. These findings underscore the potential of (R/S-MBA)(GA)PbI4 as promising candidates for next-generation spintronic devices, also highlight the critical role of chemical environment in sculpturing the structural dimension and spin-polarized property of chiral perovskites.

1.5D Chiral Perovskites Mediated by Hydrogen‐Bonding Network with Remarkable Spin‐Polarized Property

In this study, we developed new chiral hybrid perovskites, (R/S‐MBA)(GA)PbI4, by incorporating achiral guanidinium (GA+) and chiral R/S‐methylbenzylammonium (R/S‐MBA+) into the perovskite framework. The resulting materials possess a distinctive structural configuration, positioned between 1D and 2D perovskites, which we describe as 1.5D. This structure is featured by a hydrogen‐bonding‐network‐induced arrangement of zigzag inorganic chains, further forming an organized layered architecture. The structural dimensionality affects both electronic and spin‐related properties. Density functional theory (DFT) calculations reveal Rashba splitting induced by the inversion asymmetry of the crystal structure, while circularly polarized transient absorption spectroscopy confirms spin lifetime on the nanosecond timescale. Magnetic conductive‐probe atomic force microscopy (mCP‐AFM) measurements demonstrate exceptional chiral‐induced spin selectivity (CISS) with maximum spin polarization degrees of (92 ± 1)% and (‐94 ± 2)% for (R‐MBA)(GA)PbI4 and (S‐MBA)(GA)PbI4, respectively. These findings underscore the potential of (R/S‐MBA)(GA)PbI4 as promising candidates for next‐generation spintronic devices, also highlight the critical role of chemical environment in sculpturing the structural dimension and spin‐polarized property of chiral perovskites.

Regulating Lithium-Ion Transport in PEO-Based Solid-State Electrolytes through Microstructures of Clay Minerals.

Clay minerals show significant potential as fillers in polymer composite solid electrolytes (CSEs), whereas the influence of their microstructures on lithium-ion (Li+) transport properties remains insufficiently understood. Herein, we design advanced poly(ethylene oxide) (PEO)-based CSEs incorporating clay minerals with diverse microstructures including 1D halloysite nanotubes, 2D Laponite (Lap) nanosheets, and 3D porous diatomite. These minerals form distinct Li+ transport pathways at the clay-PEO interfaces due to their varied structural configurations. Among them, 2D Lap nanosheets exhibit the most significant improvements in Li+ conductivity (1.67 × 10-4 ± 0.02 × 10-4 S cm-1 at 30 °C), Li+ transference number (0.72), and oxidative stability (4.7 V). Consequently, a solid-state Li|LiFePO4 battery with the PEO/Lap CSE exhibits high reversible capacity and superior cycling stability (with 90.2% capacity retention after 250 cycles at 1.0 and 30 °C). Furthermore, pouch batteries with an integrated LiFePO4 cathode and PEO/Lap CSE show superior safety performance, even under extreme damage. This work provides valuable theoretical insights for the design and application of clay mineral fillers in CSEs.

Effect of curvature angle and structural configurations on dynamic performance of honeycomb sandwich structures

The aim of this study is to investigate the effects of curve angle and structural parameters on ballistic performance of honeycomb sandwich structures. In the study, high-velocity impact simulations were performed in LS DYNA finite element program to investigate the effects of honeycomb structural parameters, curve angle, residual velocity, specific energy absorption (SEA) and damage mechanism. Progressive damage analysis based on the combination of cohesive zone model (CZM) and bilinear traction-separation law was performed. The ballistic limit value increased by 41.9% when the facesheet thickness increased by two times. When the cell wall thickness increased by five times, the ballistic limit value increased by 13.3%. When the core height was two times increased, the ballistic limit velocity value increased by 2.076 times. Although the ballistic limit velocity value of the CFRP Facesheet and Aluminum (Al) core sandwich structure is 7.14% lower than the all Al specimen, the SEA value is 9.47% higher. When the curve angle increases from 0˚ to 180˚, the ballistic limit value decreases by 22.8%. In general, this study provides useful information about the design of ballistic structures, parameters affecting their performance and their effects.

Platinum-Nickel@High-Entropy Alloy Core@Satellite Nanowires as Efficient Bifunctional Electrocatalysts for PEMFC.

The optimized composition and precisely tailored structure configuration play critical roles in enhancing the catalytic reaction kinetics. Here we report a distinctive core@satellite strategy for designing the advanced platinum-nickel@platinum-nickel-copper-cobalt-indium high-entropy alloy nanowires (Pt3Ni@HEA NWs) as efficient bifunctional catalysts in the proton exchange membrane fuel cell. Impressively, the Pt3Ni@HEA NWs/C shows 19.4/15.3 times higher mass/specific activity than that of commercial Pt/C for the oxygen reduction reaction. More importantly, synchronously as the cathodic and anodic catalysts, it can achieve a high membrane electrode assembly power density of 1653.5 mW cm-2 and long-term stability (only 3.9% voltage loss) for 280 h, largely outperforming those of commercial Pt/C. The weakened Pt-CO binding strength, quick removal of CO with linear adsorption, and favorable CO adsorption form contribute to the high performance of Pt3Ni@HEA NWs/C. This core@satellite strategy provides a new paradigm to develop the comprehensively efficient Pt-based functional catalysts for fuel cells and beyond.

SYNTHESIS, CRYSTAL STRUCTURE, AND HIRSHFELD SURFACE ANALYSIS OF 4,4A,5,6,7,8-HEXAHYDRO-4A-METHYL-2,5,7-TRIPHENYL-2H-PYRIDO[4,3-D][1,3]OXAZINE

The synthesis of the 2,6-diphenyldpiperidin-4-one derivative of the title compound, 4,4a,5,6,7,8-hexahydro-4a-methyl-2,5,7-triphenyl-2H-pyrido[4,3-d][1,3]oxazine (HMTPO), was developed using the reaction of 4-hydroxy-3-methyl-2-butanone, benzaldehyde, and ammonium acetate in ethanol as a solvent. The molecular structure of HMTPO was determined by single-crystal X-ray diffraction. The chemical structure was confirmed by employing IR, 1H NMR, 13C NMR, and mass spectral data. To gain deeper insight into the bonding interactions within the compound, Hirshfeld surface analysis and two-dimensional fingerprint plots were conducted. The findings reveal that the Hirshfeld surfaces are predominantly influenced by H···H and C···H contacts, highlighting the significant role these interactions play in the compound’s overall stability and structural configuration.

A Review on Structural Configuration and Constitutive Material Behavior of Rail Tracks in Finite Element Modeling

A Review on Structural Configuration and Constitutive Material Behavior of Rail Tracks in Finite Element Modeling

Comprehensive determination of highly symmetric transition metal dichalcogenide multilayers.

This study expands the JAM notation to systematically explore stacking configurations of transition metal dichalcogenide (TMDC) multilayers, covering both conventional and Janus structures. We extended JAM to represent four TMDC types: 1H, 1T, Janus 1H, and Janus 1T, adding characters to describe these structures. Additionally, we updated the JAM algorithm to generate stacking configurations and produce VASP-compatible POSCAR files. Using bilayer MoSSe as a model system, we analyzed stability, band gap, and interlayer interactions across all stackings. This expanded JAM approach enables detailed exploration of TMDC multilayers and supports further research into 2D materials.

A low-frequency broadband ring transducer driven by the flextensional structure.

The flextensional transducer (FT) is a typical low-frequency transmitting transducer that is capable of high-power operation due to its capacity for displacement amplification. This article uses the structural configuration of the class IV FT as the basis for designing a ring transducer, which is a circular structure comprising a multitude of class IV flextensional structures as well as circular acoustic radiation structures. The flextensional structure drives the circular acoustic radiation structure, which in turn generates sound waves at low frequencies. It concurrently enhances the intensity of the sound source. Moreover, the acoustic radiation structure is designed to operate with two resonances that can be coupled with each other to extend the bandwidth of the transducer. A finite element model of the low-frequency broadband ring transducer was developed, and its structural parameters were optimized to achieve the optimal bandwidth. The optimization of the transducer was followed by the fabrication of its prototype, which was then used to evaluate its underwater acoustic performance. The results of measurements showed that the proposed transducer could successfully couple two modes of vibrations to yield an in-band fluctuation of approximately 12 dB in the range of frequencies of 540 to 1580 Hz.

A Deep Learning-Based Watershed Feature Fusion Approach for Tunnel Crack Segmentation in Complex Backgrounds.

As highway tunnel operations continue over time, structural defects, particularly cracks, have been observed to increase annually. Coupled with the rapid expansion of tunnel networks, traditional manual inspection methods have proven inadequate to meet current demands. In recent years, machine vision and deep learning technologies have gained significant attention in civil engineering for the detection and analysis of structural defects. However, rapid and accurate defect identification in highway tunnels presents challenges due to complex background conditions, numerous interfering factors, and the relatively low proportion of cracks within the structure. Additionally, the intensive labor requirements and limited efficiency in labeling training datasets for deep learning pose significant constraints on the deployment of intelligent crack segmentation algorithms. To address these limitations, this study proposes an automatic labeling and optimization algorithm for crack sample sets, utilizing crack features and the watershed algorithm to enable efficient automated segmentation with minimal human input. Furthermore, the deep learning-based crack segmentation network was optimized through comparative analysis of various network depths and residual structure configurations to achieve the best possible model performance. Enhanced accuracy was attained by incorporating axis extraction and watershed filling algorithms to refine segmentation outcomes. Under diverse lining surface conditions and multiple interference factors, the proposed approach achieved a crack segmentation accuracy of 98.78%, with an Intersection over Union (IoU) of 72.41%, providing a robust solution for crack segmentation in tunnels with complex backgrounds.

Experimental study on the heat transfer performance of heat pipe radiators with Diverse structural configurations for laser pump sources

Experimental study on the heat transfer performance of heat pipe radiators with Diverse structural configurations for laser pump sources

Picrotoxane-type sesquiterpenoids from Dendrobium improve insulin resistance and increase glucose-stimulated insulin secretion.

Twelve picrotoxane-type sesquiterpenoids were isolated from Dendrobium wardianum, of which dendrowardins K-N (1-4) are new compounds and dendrowardins O and P (9, 10) are new natural products. Notably, the structure of dendrowardin K contains the rarely observed 10,11-γ-lactone ring. The structural configurations of these compounds were determined through comprehensive 1D and 2D nuclear magnetic resonance (NMR), single-crystal X-ray diffraction, and other spectroscopic analyses. Additionally, the hypoglycaemic activities of the picrotoxane-type sesquiterpenes and their analogues were systematically evaluated by determining the antidiabetic activities of these compounds and six others (13-18) obtained from genus Dendrobium. Twelve compounds (1, 2, 4-6, 8, 12, 13- 15, 17, and 18) significantly improved insulin resistance. Further experiments revealed that compound 6 improved insulin resistance by increasing GLUT-4 expression. The possible mechanism is related to AKT-related pathways, and the effects of treatment with 50μM compound 6 were comparable to those of the positive control drug metformin. Compounds 4-6 and 13-15, 17 displayed great increases in the secretion of insulin from β-TC-6 cells. On the basis of these findings, the structure-activity relationships (SARs) of picrotoxane-type sesquiterpenoids were discussed for the first time.

Tunable magnetic and electronic properties of CrS2/VS2 lateral superlattices.

Two-dimensional (2D) lateral heterostructures and superlattices, especially those based on transition metal dichalcogenides, boast exceptional properties for electronics, optoelectronics, and photovoltaics. Our study delves into the intricate superlattice architecture of CrS2/VS2, as well as its magnetic and electronic attributes, utilizing the framework of density functional theory. The CrS2/VS2 superlattice, crafted by seamlessly stitching together CrS2 and VS2 monolayers along their armchair interfaces, demonstrates remarkable stability and magnetism. Notably, the magnetic phase transitions exhibited by this superlattice are intricately linked to its overall size and sublattice width. Furthermore, the electronic structures of these CrS2/VS2 superlattices exhibit a strong dependence on the widths of the CrS2 and VS2 ribbons. In smaller superlattices, spin-down electrons establish semiconductor-semiconductor contacts with a distinct type II band alignment. Conversely, spin-up electrons forge metal-metal contacts, facilitating spin-dependent 2D electron segregation. However, in larger superlattices, the electronic states are more constrained, leading to metal-semiconductor contacts that exhibit ohmic conductivity within a single spin channel. This versatility in integrating various magnetic and contact modes fosters multiple structural configurations, ushering in an exciting new paradigm characterized by significant tunability. This advancement holds immense promise for the development and application of multifunctional spintronic devices, offering a wide range of possibilities for future technological innovations.

Investigation of a flat-type piezoelectric motor using in-plane vibrations.

This paper presents a flat-type piezoelectric motor utilizing in-plane vibration modes. Two piezoelectric ceramic plates in combination with a brass metal sheet were used to construct the stator. The superposition of two second order in-plane vibration modes can generate a traveling-wave inside the stator. The greatest advantage of the proposed motor lies in its sheet structure configuration, which significantly reduces the overall size of piezoelectric motors exploiting in-plane vibrations, particularly in terms of thickness. Meanwhile, the stator also demonstrates greater vibration displacements when compared to higher-order operating modes. Through discussing the impact of stator structure parameters on the vibration deflection angle θ, the excitation ways of operating modes were investigated. Subsequently, the finite element method was utilized to explore both the static and dynamic vibration properties of the stator. Simulation results suggest that at a steady state, stator driving points achieve vibrations at the micro-meter level, satisfying actual application requirements. Finally, a prototype motor was fabricated. Driven by two-phase alternating voltage with a frequency of 69.4kHz, the no-load speed and stall torque of the prototype motor are 52rpm and 3.2mNm, respectively.

Computational and experimental investigation of thermally auxetic multi-metal lattice structures produced by laser powder bed fusion

ABSTRACT Communication antennas and optical systems of space-borne satellites require highly accurate relative positioning of components despite large variations in ambient temperature. As a potential solution, additive manufacturing technologies, such as laser powder bed fusion, enable the production of metamaterial structures with complex local geometries that can be designed to achieve the desired thermal and mechanical behaviours. Recent advances enable the processing of multiple materials within a single build to achieve composite structural properties that are infeasible using conventional single materials. This study investigates the potential of tailoring the structural thermal expansion properties of several configurations of a multi-metal re-entrant lattice structure made of stainless steel 316L and the copper alloy CuCr1Zr. Unit cells and lattice structure segments with theoretical coefficients of thermal expansion ranging from 1.64 × 10−5 °C−1 to 2.51 × 10−5 °C−1 (16% more than CuCr1Zr) are evaluated by finite element analysis and validated experimentally. Imperfections related to the manufacturing process are shown to have a significant effect on net expansion. The results indicate good agreement despite the imperfections. The study demonstrates the feasibility of designing and fabricating metal lattice structures for a specific thermal expansion within, as well as above and below, the range of thermal expansion of the parent materials.

Optimization on Reasonable Construction State for Cable-Stayed Bridge with Steel Box Girder Based on Multi-Objective Programming Algorithm

The reasonable construction state of a cable-stayed bridge refers to the state achieved after construction is carried out according to a specific sequence of procedures, leading to the reasonable completion status the bridge. The corresponding construction states at each stage are considered as part of the reasonable construction state. For the optimization of the construction state of cable-stayed bridges with steel box girders, a method combining a multi-objective programming algorithm with a forward iteration method is proposed to determine a reasonable construction state based on the structural characteristics and optimization principles of such bridges. First, a multi-objective programming model was established, taking the bending moments of the main girder and pylon, as well as cable forces, as objective functions. The weighted square sum method, a type of evaluation function method, was then employed to convert the multi-objective programming model into an unconstrained single-objective quadratic programming model. Subsequently, the damped Newton method was utilized to solve the quadratic programming problem. By integrating this algorithm with the forward iteration method, the reasonable construction state of a large-span and double-tower steel box girder cable-stayed bridge was optimized. The influence of different objective functions on the optimization results was analyzed. The findings demonstrate that the proposed method produces a smooth structural configuration under the optimized construction state, with internal forces and normal stresses within a reasonable range. In the completed state derived from this construction state, internal forces, normal stresses, and cable forces are uniformly distributed, while the reactions at transition piers and auxiliary piers exhibit sufficient pressure reserves. The structural state under dead load achieved through this method closely aligns with the desired reasonable completed state.