Material Parameters Research Articles

Synergistic effect of ZnO-ZnFe2O4 heterostructures for enhanced surface catalytic activity in Cr(VI) reduction, green H2 generation and CO sensing: an experimental study supported by DFT.

Increasing energy demand is an indication of progress, but it necessitates careful management of environmental pollution for maintaining a healthy life and ensuring a better planet for future generations. Heterostructure material-based catalysts have emerged as a comprehensive solution to combat the diverse challenges related to energy and environment. Herein, an n-n-type ZnO-ZnFe2O4 heterostructure was synthesized via a simple reflux followed by a co-precipitation technique for the same. Detailed photocatalytic and gas sensing studies revealed that a 50% ZnO-50% ZnFe2O4-based sample (ZZF-11) showed the highest Cr(VI) degradation with a rate constant of ∼159 × 10-4 s-1, which was ∼23 times higher than that of pristine ZnO and 6.4 times higher than that of pristine ZnFe2O4. Additionally, the ZZF-11 sample produced ∼550 μmol g-1 of H2 within a 300 minute interval via a photocatalytic water-splitting reaction. The ZZF-11 sensor also showed a significantly high response to 1 ppm CO gas (S = 29.4%) compared to all other pure and composite samples. The formation of the heterostructure and transfer of charges through the interface played an important role here. The most possible mechanism for the enhanced surface catalytic performance of ZZF-11 was critically analysed by corroborating the experimental results with DFT results. This study demonstrates a unified pathway to enhance the various surface catalytic processes by tuning different parameters of the heterostructure material to simultaneously overcome environment- and energy-related issues.

Dynamic modeling method and parameter calibration of subarea thin-layer elements in bolted connection area of diaphragm coupling

Abstract Aiming at the finite element modeling problem on the dynamic characteristics of multi-layer elastic diaphragm bolted joints, and adopting the equivalent modeling method of subarea thin-layer elements, a parameter identification method that can accurately and efficiently identify the material parameters of each area of subarea thin-layer elements is proposed. Taking the diaphragm coupling in the marine propulsion shaft system as an example, the accuracy of the simplified model is verified by comparing the dynamics characteristics of the vibrational mode, driving point mechanical impedance, and vibration level drop between test and simulation. The variation of material parameters in each region under different bolt preloads was studied, and the effects of different material parameters on the dynamic properties were analyzed, in which the elastic modulus had a greater effect on the model dynamic characteristics, while Poisson's ratio and density had a smaller effect. The research results show that the subarea thin-layer element modeling method can effectively simplify the dynamic modeling method of the diaphragm coupling under the consideration of bolt preload, and the parameter identification based on the multi-objective genetic algorithm can accurately identify the material parameters of each area of the subarea thin-layer element, which can be used to analyze the dynamic characteristics of the multilayered elastic diaphragm bolted couplings.

Performance analysis of metallo-dielectric optical filters designed using dispersion relations

We present an experimental validation of an analytical approach to predict the spectral response of multilayer metallo-dielectric structures, with applications in the efficient design of bandpass optical filters. Instead of relying on trial-and-error methods, our approach—referred to as the dispersion relation method—is based on intrinsic physical relations, potentially resulting in a significant reduction in time and resources during the design and optimization process. In our previous work, we illustrated that characteristics of the band structure revealed by the dispersion relation can serve as reasonable estimates for the center wavelengths and bandwidths for finite multilayer structures, as obtained from numerical simulations. In this work, we verify those conclusions with experimental results from metallo-dielectric optical filters prepared via magnetron sputtering. Structures using different metals including Ag, Au, and Al are investigated. We show good agreement between spectral response predictions derived from dispersion relations, numerical simulations using the transfer matrix method, and experimental transmittance spectra of the fabricated structures. Considering this experimental validation, the analytical approach based on dispersion relations can offer an accurate and efficient method for designing metallo-dielectric filter structures. Our approach facilitates the selection of geometric parameters for fabrication and provides valuable insight into the optical characteristics of such structures.

Computational Challenges and Experimental Validation of the Flexural Behaviour of RC Beams Using the Nonlinear 3D Finite Element Analysis by the Damage Plasticity Model in Abaqus: a Guidance Study

Statement of the problem. Due to the remarkable development of the reinforced concrete (RC), there is a growing need to rely on the finite element analysis (FEA) and numerical analysis, specifically with complicated phenomena (as nonlinearity and failure) that are hard to clarify experimentally. Results. This study tackles both the finite element analysis and the numerical one to extend a valuable supplement to the behavioral laboratory study besides approving the theoretical calculations. Thus, the 3D finite element simulation was conducted with the suitable modeling elements types, size, and the corresponding constitutive model using the well-known structural analysis package ABAQUS. The material parameters of the concrete damage plasticity (CDP) model in ABAQUS were validated based on the test results of simply supported two beams tested under four-point loading taken from the open literature and the numerical results were compared with the experimental values. In terms of a load-deflection response, the results of both the experimental and the numerical studies show good agreement. In terms of crack patterns, a good agreement between the two models was also observed. The concrete damaged plasticity model is capable of predicting the ultimate load capacity and the formation of the concrete cracks in RC beams against any kind of loads. Conclusions. Therefore, the CDP model is a versatile tool for modeling RC structures and meticulous choice of solution procedures in order to obtain an accurate modeling using a few routine laboratory test results of the materials. While analyzing the beams structurally, it was proved that the suggested model exhibited an excellent approximation to the projects of reinforced concrete beams.

Revisiting airflow resistivity measurement of fibrous porous materials via impedance and transmission loss tubes in the mid-frequency region

Abstract Airflow resistivity (AFR) is one of the most significant parameters of any given fibrous porous material for predicting the corresponding acoustical performance. In this experimental research, the AFR is first measured via the ISO 9053 method and then the results are compared with indirect measurements via an impedance tube (IT) and transmission loss (TL) tube following ASTM E1050 and ASTM E2611, respectively. The indirect measurements are carried out up to the duct cut-off frequencies, i.e. 300–4500 Hz, to demonstrate that AFR can be evaluated within an error of ⩽ 2.5% even in the mid-frequency ( ∼ 1–2 kHz) region, superseding the limits of the ultra-low-frequency (2–100 Hz) region as mentioned in the previous literature. From the present experimental studies, it is also revealed that the AFR calculated via IT measurement is somewhat ambiguous since there are periodic peaks and valleys due to the resonance of the air cavity used in the measurement. In contrast, the AFR calculated via the TL tube is even, particularly in the mid-frequency ( ∼ 1–2 kHz) regime, making it more reliable for AFR estimations.

On‐aim generation of monodisperse droplets from piezoelectric pulsation‐driven glass nozzles

AbstractPiezoelectric pulsation‐driven glass nozzles are capable of generating monodisperse droplets through liquid jet breakup. Due to the lack of fundamental understanding of this process, how to ensure uniform droplet generation with a specified size for liquids with specific rheological properties remains unknown. In this work, the complete atomization process including phenomena in and outside of the nozzle has been described by a new multi‐physics model, where the expensive in‐nozzle simulation can be rigorously replaced by a semi‐empirical relationship. This computationally efficient model allowed us to systematically and quantitatively explore the influence of different material and operating parameters on jet breakup. It was found unintuitively that the surface tension has negligible influence on droplet size and its distribution. The droplet size can be independent of the nozzle radius under the condition of a constant inflow rate. Moreover, a detailed guideline was established to achieve on‐aim size control of the atomized droplets.

A comprehensive review of yttrium aluminum nitride: crystal structure, growth techniques, properties, and applications

YAlN has emerged as a wide band gap semiconductor with high potential to compete with ScAlN in industrial applications. Theoretical predictions about YAlN’s material properties have been the main motivation for conducting experimental investigations and verify simulated results. However, several challenges have been faced in experimental studies on YAlN that contradict theoretical data, especially when trying to reach higher alloy concentrations. This work presents a systematic review analyzing different material properties including structural characterization, elastic properties, and thermal features. It combines all available experimental data on the growth and reported material parameters, such as band gap, lattice parameters, and electrical properties with the aim of introducing a new motivation to further study YAlN’s potential in various fields of device applications. The review provides a comprehensive overview on the current state of knowledge on YAlN, highlighting the discrepancies between theoretical predictions and experimental results. By providing information from multiple studies, this work offers valuable insights into the challenges and opportunities associated with YAlN development, paving the way for future research directions and potential industrial applications of this promising wide band gap semiconductor.

Theoretical method and experimental verification for solving two/three component phononic crystals based on comsol partial differential equation module

Abstract In order to reduce the low frequency vibration and noise of ships, the phononic crystal structure is used to control the vibration and noise of ships. Based on three-dimensional spatial elastic wave theory and plane wave expansion method, combined with the differential equation module of finite element software, the band structure and transport characteristics of phononic crystal structure can be accurately solved. The correctness and feasibility of this method are verified by comparison with the simulation results of solid mechanics module of finite element software, which provides a new idea for solving phononic crystal structure. It lays a solid foundation for further study of phononic crystal structure. At the same time, this paper studies a new phononic crystal sandwich plate structure, which is applied to the vibration and noise reduction of ships. The theoretical method and experiment are used to study the structure, which proves that the structure has good vibration and noise reduction performance, and further explains the correctness and feasibility of the theoretical method. Based on this calculation method, it can be used to study the effect of the geometrical parameters and material parameters of phononic crystal structure on the band gap. By adjusting these parameters reasonably, the ship can achieve a good effect of vibration and noise reduction.

Outlier-resistant guided wave dispersion curve recovery and measurement placement optimization base on multitask complex hierarchical sparse Bayesian learning

Outlier-resistant guided wave dispersion curve recovery and measurement placement optimization base on multitask complex hierarchical sparse Bayesian learning

A new method to determine cohesive parameters of elastic-plastic materials based on elastic component of J-integral

A new method to determine cohesive parameters of elastic-plastic materials based on elastic component of J-integral

Analytical solution for the structural strain parameter of power-law hardening materials to evaluate low- and high-cycle fatigue life of welded components

Analytical solution for the structural strain parameter of power-law hardening materials to evaluate low- and high-cycle fatigue life of welded components

Impact of material and geometrical parameters on the aeroelastic tailoring of uni-directional composite plate-wings

Impact of material and geometrical parameters on the aeroelastic tailoring of uni-directional composite plate-wings

Giant Seebeck Effect of Dibenzo[g,p]chrysene and its Derivatives: Deuteration and Substituent Effects and Relationship with Interlayer Distance.

Thermoelectric properties of undoped crystals of dibenzo[g,p]chrysene (DBC), deuterated DBC (DBC-d16), and 2,10-dimethyl-DBC (DBC-Me2) have been studied to obtain some insights into the relationship between the structural parameters of materials and the giant Seebeck effect. X-ray crystallography showed one-dimensional columnar packing with the interlayer distances (d) for DBC-d16, DBC, and DBC-Me2 were 3.78 Å, 3.79 Å, and 3.91 Å, respectively. All three compounds formed one-dimensional carrier transport pathways as suggested by the transfer integral calculations. Their Seebeck coefficients (α) were negative, indicating n-type behavior. DBC-d16 exhibited among the highest peak Seebeck coefficient (αmax=-114 mV/K) compared to DBC and DBC-Me2 (αmax=-31 and -22 mV/K, respectively). The power factors of DBC-d16 and DBC-Me2 were higher than that of DBC, due to an increase in Seebeck coefficient and conductivity, respectively. Notably, a positive correlation was found between the peak temperature of the Seebeck coefficient and interlayer distance d, while |αmax| correlated negatively with d. Deuteration significantly enhanced |αmax|, likely due to reduced molecular vibrations, though further investigation should consider the effect of dynamic structural fluctuation caused by thermal motion.

Space–time wave localization in systems of subwavelength resonators

In this article, we study the dynamics of metamaterials composed of high-contrast subwavelength resonators and show the existence of localized modes in such a setting. A crucial assumption in this article is time-modulated material parameters. We prove a so-called capacitance matrix approximation of the wave equation in the form of an ordinary differential equation. These formulas set the ground for the derivation of a first-principle characterization of localized modes in terms of the generalized capacitance matrix. Furthermore, we provide numerical results supporting our analytical results showing for the first time the phenomenon of space–time localized waves in a perturbed time-modulated metamaterial. Such spatio-temporal localization is only possible in the presence of subwavelength resonances in the unperturbed structure. We introduce the time-dependent degree of localization to quantitatively determine the localized modes and provide a variety of numerical experiments to illustrate our formulations and results.

A DeepONets-based resolution independent ABC inverse method for determining material parameters of HAZ

A DeepONets-based resolution independent ABC inverse method for determining material parameters of HAZ

Machine learning-based laser heterodyne photothermal displacement method: simultaneous estimation of silicon thermal diffusivity and carrier lifetime

Abstract The laser heterodyne photothermal displacement (LH-PD) method, a recently developed photothermal technique, enables the measurement of absolute surface displacements, which are otherwise challenging to measure with other photothermal methods. This method offers significant potential for quantifying physical properties that are difficult to achieve with traditional photothermal methods. In this study, we aimed to estimate the thermal diffusivity and carrier lifetime of Si using a machine-learning model based on the time variation of the displacement obtained using the LH-PD method. By leveraging the machine learning model, we generated predictive mappings of thermal diffusivity and carrier lifetime of a pattern-etched Si wafer from the displacement mappings. Furthermore, our findings demonstrated that fine-tuning the model enabled accurate predictions of the carrier lifetime. While traditional simulations require tens of hours to estimate the material parameters, machine learning reduced this process to only a few seconds.

Study on performance improvement of vanadium redox flow batteries focused on electrode fabrication parameters and compression strategies

Study on performance improvement of vanadium redox flow batteries focused on electrode fabrication parameters and compression strategies

Fluorescence Behavior of Cyanine Fluorophore Cy3 Confined in Anodic Porous Alumina: Advanced Surface Analysis

Fluorescence Behavior of Cyanine Fluorophore Cy3 Confined in Anodic Porous Alumina: Advanced Surface Analysis

The Journey of Additive Manufacturing in Prosthodontics from the Early Dawn till the Current State of Art: A Narrative Review.

Additive manufacturing (AM), also known as 3D printing, has become one of the pillars of digital technology in the dental field of prosthodontics. With the burgeoning development in preexisting AM technology and the evolution of new techniques, which are concurrent with the development of printable biomaterials, the application range of the technology has broadened from the construction of diagnostic models to more complex applications such as maxillofacial prosthetics and implant planning. A full understanding of the technology and its related fabrication parameters will enable the maximum benefit from such technology. Therefore, the aim of this review is to represent a range of AM technologies so that prosthodontists and dental technicians can evaluate more closely the advantages and disadvantages of each technique, the application of technology in the field of prosthodontics, areas of current research in the field, and recommendations for areas of future research.

Investigation of damage effects on circular air-backed clamped plates under repeated underwater explosions

ABSTRACT Underwater weapon explosions are a primary cause of structural damage to ships, warranting thorough investigation. Experiments and numerical analysis were conducted on a simplified circular air-backed clamped plate after four repeated damage tests in a water tank. The numerical algorithm and material parameters were verified by comparing simulations with experimental and theoretical data. The plate's damage accumulated with repeated explosions, and central deflection decreased with increased thickness, aligning with Taylor's theory. Deformation under various conditions showed that long-distance explosions after short-range ones, and small-charge explosions after large-charge ones, caused greater damage. Increasing plate yield strength up to 850 MPa didn't further reduce deformation from a single explosion but did so under multiple explosions.