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Compared to traditional partial differential equation modeling methods, Markov switching models can accurately capture the abrupt changes or jumps that complex systems often experience in the real world. In this paper, we propose a novel wave equation model with Markovian switching to represent complex systems with state‐jumping phenomena better, and the well‐posedness of the model is proved. In addition, a numerical method with non‐uniform grids is also proposed for the proposed model to simulate the data in realistic situations, which is based on the use of finite element discretization in space and central difference discretization in time. Finally, we conduct several experiments to analyze the errors and stability of the proposed model and the traditional model. The results show that the Markov switching model proposed in this paper has a smaller error than the traditional models while ensuring stability and can more accurately simulate the state jump phenomena of real‐world systems. [ABSTRACT FROM AUTHOR]

Background: Traditional electrocardiography (ECG)-derived heart rate variability (HRV) and photoplethysmography (PPG)-derived "HRV" (termed PRV) have been reported interchangeably. Any potential dissociation between HRV and PRV could be due to the variability in pulse arrival time (PAT; time between heartbeat and peripheral pulse). Objective: This study examined if PRV is equivalent to ECG-derived HRV and if PRV's innate error makes it a high-quality measurement separate from HRV. Methods: ECG data from 1084 subjects were obtained from the PhysioNet Autonomic Aging dataset, and individual PAT dispersions for both the wrist (n = 42) and finger (n = 49) were derived from Mol et al. (Exp Gerontol. 2020; 135: 110938). A Bayesian simulation was constructed whereby the individual arrival times of the PPG wave were calculated by placing a Gaussian prior on the individual QRS-wave timings of each ECG series. The standard deviation (σ) of the prior corresponds to the PAT dispersion from Mol et al. This was simulated 10,000 times for each PAT σ. The root mean square of successive differences (RMSSD) and standard deviation of N–N intervals (SDNN) were calculated for both HRV and PRV. The Region of Practical Equivalence bounds (ROPE) were set a priori at ± 0.2% of true HRV. The highest density interval (HDI) width, encompassing 95% of the posterior distribution, was calculated for each PAT σ. Results: The lowest PAT σ (2.0 SD) corresponded to 88.4% within ROPE for SDNN and 21.4% for RMSSD. As the σ of PAT increases, the equivalence of PRV and HRV decreases for both SDNN and RMSSD. The HDI interval width increases with increasing PAT σ, with the HDI width increasing at a higher rate for RMSSD than SDNN. Conclusions: For individuals with greater PAT variability, PRV is not a surrogate for HRV. When considering PRV as a unique biometric measure, SDNN may have more favorable measurement properties than RMSSD, though both exhibit a non-uniform measurement error. [ABSTRACT FROM AUTHOR]

Background: Patient–ventilator asynchrony (PVA) is a condition that commonly affects patients who are mechanically ventilated. PVA happens when the patient's own breathing effort and the ventilator preset settings are out of sync. Ventilator waveform monitoring is viewed as a difficult undertaking, even for experienced practitioners, despite being a non‐invasive and reliable tool for diagnosing PVA. Aim: To assess the knowledge levels and attitudes of critical care nurses (CCNs) regarding the use of ventilator waveform monitoring to detect PVA. Study Design: A cross‐sectional online survey was conducted in three intensive care units (ICUs) in Alexandria, Egypt. The questionnaire consisted of four parts to evaluate CCNs' level of knowledge and attitude regarding ventilator waveform monitoring and assess their ability to detect PVA. Results: Of the 137 CCNs approached, 101 CCNs completed the survey, resulting in a 73.7% response rate. Most nurses (88.1%) demonstrated poor knowledge levels and negative attitudes (93.1%) towards using waveform monitoring to detect PVA. A significant relationship was found between nurses' knowledge of ventilator waveform monitoring and their participation in previous training programmes on mechanical ventilation (MV; p =.031). Additionally, nurses' attitudes towards ventilator waveform monitoring were significantly associated with their level of education (p =.002) and attendance in previous courses on waveform analysis (p =.020). Conclusions: A majority of CCNs have poor knowledge and negative attitudes regarding ventilator waveform monitoring. Previous training in MV and attendance courses on ventilator waveform analysis showed a significant correlation between nurses' level of knowledge and attitudes regarding ventilator waveform monitoring. Relevance to Clinical Practice: Assessment of CCNs' knowledge and attitudes regarding ventilator waveform monitoring for detecting patient–ventilator asynchrony (PVA) informs the development of future educational programmes, ultimately aiding in the delivery of prompt and high‐quality care. [ABSTRACT FROM AUTHOR]

Understanding the crustal seismic characteristics of tectonically active regions is crucial for seismic hazard assessment. The study conducted in NW Iran utilized surface wave tomography, radial anisotropy and density information to analyse the complex crustal structure of the region, which is outstanding because of diverse tectonic features, sedimentary basins and volcanic formations. By selecting a data set of 1243 events out of over 3500 earthquakes with M  > 4, and employing strict data selection criteria (such as SNR, M and Δ), the researchers calculated Rayleigh and Love wave group velocity dispersion curves using Gaussian multiple filters and phase-matched filtering. The tomographic procedure was initiated by excluding data with residuals > 2σ for enhanced stability. Individual inversions were then carried out for local Rayleigh and Love wave dispersion measurements to obtain 1-D VSV and VSH models. Radial anisotropy and VSiso were determined through a discrepancy and averaging of the obtained VSH and VSV , respectively. Gravity modelling was also employed alongside surface wave analysis to understand the region's complex geology, revealing insights into upper-middle-lower crust boundaries, subsurface structures and Moho depths. The study's velocity maps reveal significant findings related to geological units and tectonic features in various regions based on the provided results. Low velocities in the South Caspian Basin (SCB) and Kura Depression (KD) regions are attributed to substantial sedimentary layers, while low velocities, and depth of VS in NW Iran and Eastern Anatolian Accretionary Complex (EAAC) regions suggest the presence of partially molten materials in the upper and middle crust. The Sanandaj–Sirjan Zone (SSZ) region shows a low-velocity anomaly in longer periods and greater depths of VS , surrounded by normal to high velocities, indicating a thick middle crust. Analysing radial anisotropy and VSiso profiles offers insights into upper-middle-lower crust boundaries, subsurface structures and Moho depths, highlighting middle crust thickening and lower crust thinning beneath the SSZ. The study confirms the gentle subduction of the SCB oceanic-like lower crust beneath NW Iran in the Talesh (TAL) region, with a rigid middle crust. Additionally, cross-sections reveal igneous laccoliths underplate with a VSiso of 3.7 km s−1 in the volcanic region. The difference observed by subtracting the velocity models at two adjacent depths, combined with parametric test results, indicates that the Sahand volcanic system is clearly identifiable, while the influence of subtle subduction on the Sabalan volcano at depths up to 30 km remains less distinct. The magma chamber beneath Sahand is situated at depths ranging from 18 to 25 km. [ABSTRACT FROM AUTHOR]

Over the past decades, surface wave methods have been routinely employed to retrieve the physical characteristics of the first tens of meters of the subsurface, particularly the shear wave velocity profiles. Traditional methods rely on the application of the multichannel analysis of surface waves to invert the fundamental and higher modes of Rayleigh waves. However, the limitations affecting this approach, such as the 1D model assumption and the high degree of subjectivity when extracting the dispersion curve, motivate us to apply the elastic full‐waveform inversion, which, despite its higher computational cost, enables leveraging the complete information embedded in the recorded seismograms. Standard approaches solve the full‐waveform inversion using gradient‐based algorithms minimizing an error function, commonly measuring the misfit between observed and predicted waveforms. However, these deterministic approaches lack proper uncertainty quantification and are susceptible to get trapped in some local minima of the error function. An alternative lies in a probabilistic framework, but, in this case, we need to deal with the huge computational effort characterizing the Bayesian approach when applied to non‐linear problems associated with expensive forward modelling and large model spaces. In this work, we present a gradient‐based Markov chain Monte Carlo full‐waveform inversion where we accelerate the sampling of the posterior distribution by compressing data and model spaces through the discrete cosine transform. Additionally, a proposal is defined as a local, Gaussian approximation of the target density, constructed using the local Hessian and gradient information of the log posterior. We first validate our method through a synthetic test where the velocity model features lateral and vertical velocity variations. Then we invert a real dataset from the InterPACIFIC project. The obtained results prove the efficiency of our proposed algorithm, which demonstrates to be robust against cycle‐skipping issues and able to provide reasonable uncertainty evaluations with an affordable computational cost. [ABSTRACT FROM AUTHOR]

Traditional free vibration-based forward models generate theoretical dispersion curves under the assumption of planar waves, neglecting the influence of the actual source-receiver configuration. The 2D/3D discretization-based numerical wavefield modeling approaches can mimic real field scenarios considering active source-receiver information. However, numerical methods are computationally inefficient. This study introduces an active sourced semianalytical wavefield modeling approach for laterally homogeneous horizontally stratified media, incorporating source-receiver data acquisition layouts. The method considers a cylindrically spreading wavefield described by the Hankel function instead of the planar wave assumption. The approach considers both propagating waves characterized by real wavenumbers and decaying waves with complex wavenumbers, allowing for the calculation of surface displacements in both the far and near fields. The proposed model captures the complete wavefield, including source-offset effects and leaky waves, while maintaining computational efficiency comparable to any free vibration-based approaches. The method entails solving the eigenvalue problem constructed through the higher-order thin-layer method. Subsequently, it calculates the frequency domain vertical and radial surface responses at any desired location in space generated by a vertically positioned active source. The proposed method's overall performance is investigated on diverse subsurface profiles, including regularly dispersive media, low-velocity layer models, and a field cross-hole model. The Rayleigh wave's vertical and radial component dispersion images obtained from the proposed method are validated against the numerical approach. The proposed method is at least two orders of magnitude faster than the numerical approach. Notably, it addresses mode misidentification issues arising from modal osculation at low frequencies and effectively captures the smooth transition of modal energy from fundamental modes to higher modes. Note that the present method is limited to laterally homogeneous media. However, this method provides a valuable tool for advancing the accuracy and efficiency of active surface wave methods in various engineering applications. [ABSTRACT FROM AUTHOR]

This paper investigates the application of linking as a feature of connected speech by Jordanian English Language senior university students at the Hashemite University. The paper specifically examines Consonant-Vowel (CV) and Vowel-Vowel (VV) environments using audio-recordings of students reading a controlled set of sentences. The recordings were converted into waveforms to facilitate their analysis and comparison with those of a native speaker. The main results show that students applied linking in the CV environments in percentages that exceeded those in the VV environments. Furthermore, when collectively analyzed, data showed that students in the sample failed to apply linking in more than half of the environments of the instrument. The research recommended that EFL teachers should be trained on methods of teaching pronunciation as students could benefit from receiving instruction regarding the application of linking. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate cortical activation and functional connectivity in the cortex during working memory (WM) tasks in patients with Alzheimer’s disease (AD) using functional near-infrared spectroscopy (fNIRS). Methods: A total of 17 older adults with AD and 17 cognitively normal (CN) participants were recruited. fNIRS was utilized to monitor oxygenated hemoglobin (HbO) concentrations in the frontotemporal lobe, while participants performed WM tasks to examine WM impairments in subjects with AD. Student’s t-test for continuous variables and the chi-square test for categorical variables were used to compare the clinical and HbO variables between the AD and CN groups. Functional connectivity was analyzed using Pearson’s correlation coefficient between the time series of each channel-to-channel pair. Results: The changes in HbO concentrations and cortical activations during the WM task showed that the HbO concentration curve of the CN group was higher than that of the AD group during the encoding and maintenance phases of the WM task. Although in the brain region scale, there were no significant differences in average HbO concentrations between the two groups, many channels located in the frontal and temporal lobes showed significant differences (p  <  0.05) in the average HbO (channels 7 and 32) and slope HbO values (channels 7, 8, 9, 23, 30, 34, and 38) during the WM task. The average functional connectivity of the AD group was significantly lower than that of the CN group (p  <  0.05). The functional connectivity was stronger in the frontopolar (FP) region than in other areas in both groups. Conclusion: This study revealed there were significant differences in HbO concentration in older adult patients with AD compared to CN during the WM task. The characteristics of HbO measured by the fNIRS technique can be valuable for distinguishing between AD and CN in older adults. [ABSTRACT FROM AUTHOR]

Introduction: Extraction of Doppler-based measurements from feto-placental Doppler images is crucial in identifying vulnerable new-borns prenatally. However, this process is time-consuming, operator dependent, and prone to errors. Methods: To address this, our study introduces an artificial intelligence (AI) enabled workflow for automating feto-placental Doppler measurements from four sites (i.e., Umbilical Artery (UA), Middle Cerebral Artery (MCA), Aortic Isthmus (AoI) and Left Ventricular Inflow and Outflow (LVIO)), involving classification and waveform delineation tasks. Derived from data from a low-and middle-income country, our approach's versatility was tested and validated using a dataset from a high-income country, showcasing its potential for standardized and accurate analysis across varied healthcare settings. Results: The classification of Doppler views was approached through three distinct blocks: (i) a Doppler velocity amplitude-based model with an accuracy of 94%, (ii) two Convolutional Neural Networks (CNN) with accuracies of 89.2% and 67.3%, and (iii) Doppler view- and dataset-dependent confidence models to detect misclassifications with an accuracy higher than 85%. The extraction of Doppler indices utilized Doppler-view dependent CNNs coupled with post-processing techniques. Results yielded a mean absolute percentage error of 6.1 ± 4.9% (n = 682), 1.8 ± 1.5% (n = 1,480), 4.7 ± 4.0% (n = 717), 3.5 ± 3.1% (n = 1,318) for the magnitude location of the systolic peak in LVIO, UA, AoI and MCA views, respectively. Conclusions: The developed models proved to be highly accurate in classifying Doppler views and extracting essential measurements from Doppler images. The integration of this AI-enabled workflow holds significant promise in reducing the manual workload and enhancing the efficiency of feto-placental Doppler image analysis, even for non-trained readers. [ABSTRACT FROM AUTHOR]

This study aims to investigate the modified nonlinear time fractional Harry Dym equation using analytical and numerical techniques. The modified nonlinear time fractional Harry Dym equation is a generalization of the classical Harry Dym equation, which describes the propagation of nonlinear waves in a variety of physical systems. The conformable fractional derivative is used to define the time fractional derivative in the equation, which provides a natural and straightforward approach. The Khater II method, a powerful analytical technique, is employed to obtain approximate solutions for the equation. Additionally, three numerical schemes, namely, Cubic-B-spline, Quantic-B-spline and Septic-B-spline schemes, are developed and implemented to solve the equation numerically. The numerical results are compared with other numerical solutions to assess the accuracy and efficiency of the proposed schemes. The physical meaning of the modified nonlinear time fractional Harry Dym equation is discussed in detail, and its relation to other nonlinear evolution equations is highlighted. The results of this study provide new insights into the behavior of nonlinear waves in physical systems and contribute to a better understanding of the physical characterizations of the modified nonlinear time fractional Harry Dym equation. [ABSTRACT FROM AUTHOR]

This article investigates the construction of new traveling wave solutions for the conformable fractional Klein–Gordon equation, which is a well‐known mathematical and physical model that can be used to explain spinless pion and de Broglie waves. In order to accomplish this task, a classic and effective analysis method, namely, the extended tanh–coth method, was utilized. By introducing appropriate transformations, the conformable fractional Klein–Gordon equations are reduced to ordinary differential equations, and then the solutions with hyperbolic function form are obtained. In addition, the effect of fractional parameters on waveform is analyzed by drawing two‐ and three‐dimensional graphics. These results contribute to a deeper understanding of the dynamics of the conformable fractional Klein–Gordon equation. The research in this article also indicates that the extended tanh–coth method is a straightforward and concise technique that has the potential to be applicable to many other conformable fractional partial differential equations that appear in mathematical physics. [ABSTRACT FROM AUTHOR]

The seismicity rate markedly increased in the northeastern Noto Peninsula of Ishikawa Prefecture around the end of 2020, with an Mw6.2 event on 5 May, 2023, followed by many aftershocks. Previous earthquake relocation studies have detected upward migration of microearthquakes via multiple faults and clusters, suggesting the involvement of crustal fluids in this sequence. Since some active faults exist near the source region, there was concern that this sequence could lead to a larger earthquake; it became a reality with the Mw7.5 earthquake on 1 January 2024. This study aims to develop an algorithm to precisely relocate microearthquake hypocenters in quasi-real time for better monitoring. A fine view of seismicity requires relative relocation methods such as the double-difference (DD) method with numerous arrival time difference data precisely measured by the waveform correlation analysis. However, the standard DD method has the disadvantage of huge computational costs when data increase, making it unsuitable for real-time monitoring in such situations. We developed a quasi-real-time algorithm that relocates only new earthquakes using the DD method each time a new time window of data is added. The major improvement is that our method incorporates a traditional simple relative relocation and preserves constraints between different time windows; the relative locations of new events are constrained from reference events that were already relocated in the previous time windows. We tested a daily relocation algorithm on 11,546 events from 19 June, 2022, to 31 May, 2023, in the Noto Peninsula earthquake sequence. We found that our modification substantially reduced artificial hypocenter offsets between different time windows and succeeded in resolving the fine fault structures from the cloud-like distribution of initial hypocenters. If we do not impose constraints between different windows, the relocated hypocenters are scattered and do not show fine planar structures. Our algorithm greatly reduces the computational cost, allowing for quasi-real-time earthquake relocation and monitoring. We hope this algorithm will help monitor the spatio-temporal distribution of future earthquake sequences. [ABSTRACT FROM AUTHOR]

The commonly used baseline-free Lamb wave damage identification methods often require a large amount of sensor data to eliminate the dependence on baseline signals. To improve the efficiency of damage localization, this paper proposes a new Lamb wave damage location method, namely the probabilistic exchanging-element time-reversal method (PEX-TRM), which is based on the exchanging-element time-reversal method (EX-TRM) and the probabilistic damage identification method. In this method, the influence of the damage wave packet migration on the correlation coefficient between the reconstructed signals of each sensing path and the initial excitation signal is analyzed, and the structure is divided into multiple regional units corresponding to the damage to locate damage. In addition, the influence of the number of sensing paths on the location accuracy is also analyzed. A method of damage probability imaging based on structural symmetry is proposed to enhance location accuracy in the case of sparse sensing paths. The experimental and simulation results verify that the method can achieve damage location with fewer excitation times. Moreover, this method can avoid the problem that the damage wave packet is difficult to extract, improve the efficiency of damage location, and promote the engineering application of the Lamb wave damage location method. [ABSTRACT FROM AUTHOR]

The antibacterial activity of ZnO nanorods (NRs) has been tested for its ability to inhibit the cells of pathogenic bacteria such as Staphylococcus aureus and Salmonella sp. This study aims to increase the antibacterial activity through modification of Mg2+ doped ZnO morphology under sol-gel-hydrothermal synthesis conditions at pH 10. The mechanism of biosynthetic reactions was using enzymatic grooves of the cell phyllosphere isolate of gambir (Uncaria) leaves as a reducing compound and capping agent. The X-ray diffraction (XRD) analysis showed that ZnO and Mg doped ZnO products were wurtzite structures based on intensities 2θ = 31.78°, 34.43°, 36.27° correlated to hkl (100), (002), (101), respectively (ICSD standard −157724). Mg doped ZnO has the same intensity as the control and no impurity intensity was obtained. Scanning electron microscope (SEM) analysis showed nanospheric morphological patterns, while nanorods have a more dominant size distribution in the range of 125–175 nm. Infrared (FT-IR) analysis at wave numbers 401–584 cm−1 showed a Zn-O stretch. Furthermore, powder ultraviolet (UV-DRS) analysis indicated optical properties based on the uptake on blue-shift regions with λmax ≤ 400 nm and had a change in the bandgap (Eg) of 3.37 eV after conversion using Tauc-plot. The results also showed that the greater the concentration of Mg+2 ions, the smaller the bandgap will be, i.e., of 3.13, eV, 3.10, eV, 3.11 eV, and 3.12 eV for 0, 1, 2, and 3%, respectively. On the antibacterial activity against bacteria Gram (+) Staphylococcus aureus and Gram (–) Salmonella typhi., the largest inhibitory zone was found on Gram (–) bacteria at 24 mm. [ABSTRACT FROM AUTHOR]

The truncated M-fractional Kuralay (TMFK)-II equation is prevalent in the exploration of specific complex nonlinear wave phenomena. Such types of wave phenomena are more applicable in science and engineering. These equations could potentially provide insights into understanding the intricate dynamics of optical phenomena, encompassing solitons, nonlinear effects, and wave interactions. This study aims to uncover a diverse range of soliton solutions to the model, spanning trigonometric, hyperbolic, exponential, and rational expressions. These solutions are unveiled through the application of extended hyperbolic functions and improved F-expansion techniques, representing the primary objective of this research. The three-dimensional (3D) and two-dimensional (2D) combined charts are plotted for some of these solutions. The impact of the fractional parameters and time variations is also illustrated. Moreover, the models are converted into a planar dynamical system using a Galilean transformation, and the analysis of bifurcation is examined. This research underscores the versatility of the aforementioned techniques for exploring complex nonlinear phenomena across various engineering and scientific disciplines. Finally, the findings of this study hold significant implications for advancing our understanding and analysis of nonlinear wave dynamics in diverse physical systems. [ABSTRACT FROM AUTHOR]

Career maturity reflects an individual's readiness to make age-appropriate career decisions. Previous studies on career maturity mainly focus on specific groups and occupations, such as nurses and students, and on the career maturity that has been gradually improved by individuals due to physiological development. This paper believes that the increase of career maturity is accompanied by the whole career of individuals. Therefore, it is imperative to explore the development of career maturity from the psychological perspective in more work scenarios. Based on the Conservation of Resource Theory and the Job Demands-Resources Model, the present study explores the relationship between career maturity and job satisfaction and the underlying mechanisms involved. Analysis of two waves of time-lagged data (N = 443) showed that there was a significant positive correlation between employees' career maturity and job satisfaction; Job crafting mediated the relationship between career maturity and job satisfaction; Openness personality trait moderated both of the effect of career maturity on job crafting and the indirect effect of career maturity on job satisfaction through job crafting, such that both of the effects were stronger for employees with higher levels of openness. Theoretical and practical implications are also discussed. [ABSTRACT FROM AUTHOR]

Changes in the surrounding environment, if transmitted to the electron microscope, are frequently perceived as noise that diminishes the quality of the images. However, in fact, ‘noises’ contain rich information about the environment. This work reports a very rare event where aberration‐corrected HAADF‐STEM images were acquired during the impact of seismic waves, resulted from a mild earthquake. By analysing these images, we found that the drift and vibration of the sample are detectable and quantifiable. Despite many potential challenges, this work demonstrates the utilisation of electron microscopes in detecting and monitoring seismic waves with high spatial resolution, which may lead to unique applications in the low‐frequency regime. [ABSTRACT FROM AUTHOR]

ABSTRACT The on‐board DC/DC converter proposed in this research consists of a Buck converter and a three‐phase interleaved LLC resonant converter. This paper analyzes the average current and output current ripple characteristics of the rear‐stage converter in addition to explaining the topology and working principles of the front‐stage Buck converter and the rear‐stage three‐phase interleaved LLC resonant converter. To establish a single‐phase fundamental equivalent circuit for the rear‐stage converter, apply the fundamental wave analysis method, and it is essential for comprehending the impact of relevant system parameters on voltage gain characteristics and resonant operating regions. Conducting research on the two‐stage on‐board DC/DC converter's control strategy involves establishing small‐signal circuit models for both front and rear stage converters, derivation of parameters for double closed‐loop control, and determination of the control strategy employing phase‐shifted current sharing for the rear‐stage converter in cases where significant tolerance exists in resonant components. The simulation for a two‐stage on‐board DC/DC converter results indicates that under various conditions of resonant component tolerance, the converter is capable of achieving balanced phase currents and demonstrates minimal output current ripple prior to capacitor filtering. A 1.5‐kW experimental prototype has been fabricated, and the experimental findings indicate that the output voltage remains stable at 13.8 V despite fluctuations in input voltage. The highest efficiency of the prototype is about 96.27%, and the utilization of phase‐shifting current balancing control results in a notable reduction in output current ripple. This provides more evidence that the design of a two‐stage on‐board DC/DC converter is correct. [ABSTRACT FROM AUTHOR]

The article focuses on a study on the use of compression therapy in the assessment and management of the venous and arterial aetiologies underlying leg ulceration as part of a holistic care plan, which was presented in an expert panel discussion held in October 2023.

Bright light impacts the human circadian system such that exposure to bright light at night can suppress melatonin secretion, and exposure to bright light in the morning prevents light-induced melatonin suppression at night. The preventive effect of morning light may attenuate the prior history of light sensitivity of intrinsically photosensitive retinal ganglion cells (ipRGCs) that regulate the circadian system. In this study, we evaluated electroretinogram (ERG) responses to red and blue flickering lights following dim and bright daylight conditions. Eleven healthy females underwent ERG measurements during exposure to 33 Hz flickering red or blue light under dim and bright daytime conditions. We averaged ERG waves for 50 flickering light pulses of the trigger signal data. We obtained the amplitude of the signal-averaged ERG by calculating the difference between the waves' peaks and bottoms. Although there was no significant dim and bright light difference in the amplitude of ERG waves, the ERG amplitude to flickering blue light under the bright light condition was significantly lower than to flickering blue light under the dim light condition. In this study, blue light stimulated mainly ipRGCs and S-cones. Since S-cones may contribute minimally to the light-adapted 33 Hz flicker ERG results, our findings suggest that bright light during the daytime attenuates the sensitivity of human ipRGCs. [ABSTRACT FROM AUTHOR]

The design of waveforms plays a critical role in integrated sensing and communication (ISAC) systems. An ISAC waveform with a 0dB peak‐to‐average power ratio (PAPR) is designed by combining a Golay complementary sequence with a constant envelope orthogonal frequency‐division multiplexing. By adjusting the phase modulation parameters, this waveform allows for a trade‐offs between communication and sensing capabilities. The authors focus on several key performance metrics for the proposed ISAC waveform, notably using mutual information as a holistic performance indicator to assess both sensing and communication effectiveness. Through extensive numerical simulations, the authors demonstrate that the ISAC waveform significantly enhances detection probability compared to traditional phase‐modulated waveforms. The findings suggest that this approach is beneficial for designing low PAPR phase‐modulated ISAC waveforms, enhancing both the functionality and efficiency of ISAC systems. [ABSTRACT FROM AUTHOR]

The wave dynamics play a crucial role in the operation characteristics of the rotating detonation engine. We conducted numerical simulations of a rotating detonation combustor (RDC) using multicomponent reactive Navier–Stokes equations coupled with a discrete phases model. The RDC in this research employs a configuration with multiple coaxial injectors supplying oxygen-enriched air and kerosene spray at room temperature. To accurately identify and analyze waves within the RDC, we proposed a three-dimensional transient detonation wave detection method based on the combined parameters of normal Mach number and heat release rate in the flow field. Two typical wave modes, referred to as single-wave mode and counter-waves mode, are identified and then selected to conduct a detailed wave dynamics analysis. The general wave behavior is discussed, and velocity deficit is compared for these two wave modes. For the single-wave mode, intermittent micro-explosions are observed generating retonation waves periodically in the unburnt pockets behind the rotating detonation shock front. For the counter-waves mode, we analyzed the collision process of the two waves and the coupling/decoupling of the shock front with the detonative heat release zone, revealing the reason for significant velocity deficits in this wave mode. This research demonstrates that micro-explosions intermittently occur in the multiphase RDC in both single-wave and counter-waves modes and generate micro explosion shock waves periodically, which influence the complicated wave dynamics behavior. [ABSTRACT FROM AUTHOR]

In order to detect the presence of melanoma cells in two cells under the condition of cell photoacoustic wave interference, this paper conducted a finite element analysis of the photoacoustic wave interference field of two cells. First, the wavelength corresponding to the dominant frequency of the signal from a single red blood cell (mean diameter) was calculated. Then, the distance between two identical red blood cells (mean diameter) was set as a multiple of the wavelength to identify the optimal interference distance and the position of the enhanced zone detection point. Next, under the optimal distance, the signal curves of two cells as red blood cells and when melanoma cells exist in two cells were calculated in sequence. Finally, the frequency domain sound pressure level curve of the detection point under the two states was compared with the single-cell signal to obtain the Frechet distance. The results show that when both cells are red blood cells, the Frechet value is less than 48; when melanoma cells exist in both cells, the Frechet value is greater than 52. This study shows that the presence of melanoma cells in two cells can be determined by adjusting the distance between the cells, arranging the positions of the detection points, and employing the Frechet distance metric curve difference under the condition that the two-cell photoacoustic waves interfere with each other. [ABSTRACT FROM AUTHOR]

In this paper, a novel low‐cost, double‐node upset (DNU) tolerant latch aiming at nourishing the lack of these devices in the state of the art was presented, especially featuring high reliability while maintaining a low‐cost profile. The proposed latch is based on a low‐cost single event double‐node upset tolerant latch and also provides self‐recoverability against double‐node‐upsets. The latch uses clock‐controlled DICE (Dual‐interlocked storage cell) cell and CE(C‐Elements) cell to tolerate double‐node‐upsets fully. The Simulation waveforms and analysis results show that the proposed latch can maintain the correct output in any case of DNU. In addition, under the premise of high radiation tolerance, the minimum improvement of the area‐power‐delay product (APDP) of the proposed low‐power double‐node‐upsets hardened latch (LPDHL) is 16.60%, compared with the latest DNU tolerant latch on the literature. [ABSTRACT FROM AUTHOR]

The Sporadic E layer or Es is an ionospheric phenomenon characterized by enhancements in electron density within 90–120 km above the Earth's surface. Based on the wind shear theory, the formation of Es layers is associated with vertical shears in the horizontal wind, in the presence of the Earth's magnetic field. This study explores the role of planetary waves on inducing these vertical shears and subsequently shaping Es layers. Our investigations benefit from a large amount of data facilitated by the FORMOSAT‐7/COSMIC2 and Spire missions, which offer extensive global coverage. A wave analysis is applied to the Es intensity as represented by the S4 index derived from radio occultation measurements, in search of potential planetary wave signatures. Additionally, measurements from Aura/MLS are used to analyze corresponding spectra for the geopotential height, enabling a comparative examination of planetary wave signatures in the Es layer and geopotential height variations. The findings reveal westward and eastward wave components with specific wavenumbers and periods, suggesting the involvement of westward propagating quasi 6‐day, quasi 4‐day planetary waves, and eastward propagating Kelvin waves with a period of around 3 days in Es layer formation at low latitudes. Key Points: Spatial‐temporal analysis of FORMOSAT‐7/COSMIC2 & Spire radio occultation data shows influence of planetary waves on Es layer formationWestward propagating planetary waves, particularly the 6‐day and 4‐day wave (wavenumber 1 and 2), impact Es layer intensity at low latitudesThe study reveals the involvement of eastward propagating ultrafast Kelvin waves also play a role for low‐latitude Es [ABSTRACT FROM AUTHOR]

In the past, satellite climatologies of gravity waves (GWs) have initiated progress in their representation in global models. However, these could not provide the phase speed and direction distributions needed for a better understanding of the interaction between GWs and the large-scale winds directly. The ESA Earth Explorer 11 candidate CAIRT could provide such observations. CAIRT would use a limb-imaging Michelson interferometer resolving a wide spectral range, allowing temperature and trace gas mixing ratio measurements. With the proposed instrument design, a vertical resolution of 1 km, along-track sampling of 50 km, and across-track sampling of 25 km in a 400 km wide swath will be achieved. In particular, this allows for the observation of three-dimensional (3D), GW-resolving temperature fields throughout the middle atmosphere. In this work, we present the methodology for the GW analysis of CAIRT observations using a limited-volume 3D sinusoidal fit (S3D) wave analysis technique. We assess the capability of CAIRT to provide high-quality GW fields by the generation of synthetic satellite observations from high-resolution model data and comparison of the synthetic observations to the original model fields. For the assessment, wavelength spectra, phase speed spectra, horizontal distributions, and zonal means of GW momentum flux (GWMF) are considered. The atmospheric events we use to exemplify the capabilities of CAIRT are the 2006 sudden stratospheric warming (SSW) event, the quasi-biennial oscillation (QBO) in the tropics, and the mesospheric preconditioning phase of the 2019 SSW event. Our findings indicate that CAIRT would provide highly reliable observations not only of global-scale GW distributions and drag patterns but also of specific wave events and their associated wave parameters. Even under worse-than-expected noise levels of the instrument, the resulting GW measurements are highly consistent with the original model data. Furthermore, we demonstrate that the estimated GW parameters can be used for ray tracing, which physically extends the horizontal coverage of the observations beyond the orbit tracks. [ABSTRACT FROM AUTHOR]

The triply twisted Möbius carbon nanobelt (TMCNB) possesses an extremely distinctive geometric and electronic structure and therefore is anticipated to demonstrate outstanding optical properties. In this paper, through integrating quantum chemical calculations and wave function analysis approaches, in-depth studies are conducted on the one-photon absorption (OPA) and two-photon absorption (TPA) characteristics, aromaticity, and circular dichroism of the TMCNB. Inspired by this structure, we further deform it to construct a novel structure, MCNB2, and verify the stability of this structure, thereby confirming its rationality. Since variations in structure will result in dissimilar optical properties, we also undertake theoretical analyses on the absorption properties and circular dichroism of MCNB2. The outcomes of this study offer a significant theoretical foundation for the design and construction of chiral optoelectronic materials. [ABSTRACT FROM AUTHOR]

A review of the S‐velocity structure beneath South America, for the crust and upper mantle, is performed using a recent methodology based on Rayleigh wave analysis, and a new 3D S‐velocity model (from 0 to 400 km depth) is achieved for this study area. The precise location and structure of the asthenosphere have been both determined from this new model, which have not been obtained in other previous studies, allowing to know how the different geological units that compose South America are delimited in terms of S‐velocity and lithosphere thickness. For example, the highest S‐velocities and the thickest lithosphere of the cratonic areas, are determined at the east of the Amazonian Craton and the São Francisco Craton. The lithosphere beneath the Guyana Shield is thinner than beneath the Central Brazil Shield, and the lithospheric root of the Amazonian Craton is determined deeper than the São Francisco Craton. The lithosphere at the east of the Central Brazil Shield is the thickest (~200‐km thick). Another interesting feature depicted in terms of S‐velocity and lithosphere thickness is the Transbrasiliano Lineament, which is determined in the crust and the upper mantle, confirming that it is not just a surface feature but a deep feature. [ABSTRACT FROM AUTHOR]

Studying the source characteristics of doublet or multiple earthquake sequences presents significant challenges in seismology, especially with short time intervals between events. On November 14, 2021, a doublet earthquake (Mw 6.0 and Mw 6.1) occurred near Fin city, southern Iran, within a span of less than two minutes and 10 km apart. We employed the Kinematic Waveform Inversion (KIWI) procedure to determine the point and extended source parameters of these events, using a multistep inversion approach for stable solutions. Our analysis highlighted the directivity of the earthquakes: the first event exhibited bilateral directivity, causing a rupture area that reached the surface, while the second event showed unilateral westward directivity, supported by waveform amplitude differences observed at various stations. This directivity analysis plays an essential role in seismic hazard studies. Our findings regarding the source parameters of these recent doublet earthquakes in the Fin region align well with regional geological trends and fault patterns. However, retrieving the main fault plane for the second earthquake was challenging due to the complexities of the waveform. Moment tensor decomposition revealed significant non-double-couple components for the second event, indicating the complexity inherent in analyzing doublet events. This study underscores the critical role of precise waveform analysis and robust inversion techniques in understanding complex seismic events. [ABSTRACT FROM AUTHOR]

Internal waves in two-dimensional aquaria can develop singular profiles, called internal wave attractors, in the long time evolution. We review the microlocal analysis of internal wave attractors, connecting the evolution of internal waves with classical dynamical systems on domain boundaries. [ABSTRACT FROM AUTHOR]

A semi-analytical modeling approach is introduced for investigating the traveling wave vibration characteristics of spinning functionally graded porous graphene platelet-reinforced composite (FGP-GPLRC) stepped cylindrical shells under discontinuous boundary conditions. The equivalent material properties of the stepped shell are generated based on the open cell body theory and the Halpin–Tsai micromechanical model. Then, the arc connection approach is introduced, and the artificial spring method is used to model the continuous coupling relationship between the shell segments and discontinuous boundary conditions at the ends of the shell. Based on the first-order shear deformation theory (FSDT), the traveling wave frequency of the shell under discontinuous boundary conditions is solved by the Gegenbauer–Ritz method and the state space method. Finally, the correctness of the semi-analytical modeling approach is confirmed by comparison of the results with the literature and the finite element method. In addition, the effects of various parameters on the frequency of spinning FGP-GPLRC stepped cylindrical shells under discontinuous boundary conditions are discussed. [ABSTRACT FROM AUTHOR]

In quantum mechanics, the exchange symmetry of wave functions for identical particles has observable effects, including the widely studied Hong–Ou–Mandel (HOM) effect. A theoretical description using second quantization is elegant but abstract. In contrast, this paper describes a simple model of two-particle interference using a one-dimensional delta potential well as a beam splitter. The conditions for the HOM effect are derived from the perspective of wave packet evolution. Furthermore, the interference processes of bosons, fermions, and distinguishable particles are demonstrated and compared in detail. The method presented here is concrete, easy to visualize, and can help students to better understand the effects arising from the exchange symmetry of wave functions. The main results can be animated for classroom teaching or developed into an undergraduate seminar topic. Editor's Note: In this article, the authors explore the role of particle statistics in the scattering of noninteracting particles. They illustrate how a one-dimensional delta-function well can play the role of a beam splitter in a Hong–Ou–Mandel experiment and then compare and contrast the scattering of pairs of bosons, fermions, and distinguishable particles. The authors introduce graphical methods for visualizing the scattering process alongside a comprehensive analysis of the evolution of the wave function. The model is accessible to students in an introductory quantum mechanics course and connects one-dimensional scattering theory to contemporary experiments with photons and cold atoms. [ABSTRACT FROM AUTHOR]

The correction map method means extended phase-space algorithm with correction map. In our research, we have developed a correction map method, specifically the dissipated correction map method with trapezoidal rule, for numerical simulations of gravitational waves from spinning compact binary systems. This new correction map method, denoted as |$CM3$|⁠ , has shown remarkable performance in various simulation results, such as phase-space distance, dissipated energy error, and gravitational waveform, closely resembling the high-order precision implicit Gaussian algorithm. When compared with the previously used mid-point map which is denoted as |$C_2$|⁠ , the |$CM3$| consistently exhibits a closer alignment with the highly accurate Gaussian algorithm in waveform evolution and orbital trajectory analysis. Through detailed comparisons and analyses, it is evident that |$CM3$| outperforms other algorithms, including |$CM2$| and |$C_2$| mentioned in this paper, in terms of accuracy and precision in simulating spinning compact binary systems. The incorporation of the trapezoidal rule and the optimization with a scale factor |$\gamma$| have significantly enhanced the performance of |$CM3$|⁠ , making it a promising method for future numerical simulations in astrophysics. With the groundbreaking detection of gravitational waves by the LIGO/VIRGO collaboration, interest in this research domain has soared. Our work contributes valuable insights for the application of matched filtering techniques in the analysis of gravitational wave signals, enhancing the precision and reliability of these detection. [ABSTRACT FROM AUTHOR]

In this work, a theoretical analysis of bulk wave interaction with a sliding layer has been considered. The layer is assumed to be sliding with a constant velocity. The effect of the sliding velocity on the reflection and transmission behaviors has been studied. A low loss viscoelastic property is considered for the layer, which is held between two identical grounded elastic half-spaces. The governing equations for the dilatoric and deviatoric wave components in the viscoelastic layer are derived. The problem is solved using a coordinate transform based on an appropriate change in the wave velocities. The solutions are then used to calculate the reflection and transmission coefficients by solving the system of linear equations. The coefficients are observed to be affected remarkably by the sliding velocity of the layer. The effects of incidence angle and frequency of an incoming wave on the reflection and transmission characteristics are studied. The conditions for the existence of critical incidence are also discussed. This work gives some theoretical understanding of the wave characteristics in a sliding medium, which is expected to be useful in applications related to wave-based actuation and manipulation. [ABSTRACT FROM AUTHOR]

There are controversial findings on how projectile penetration into the human tissue can induce tissue damage. The evidence from recent experimental investigations has explained the related underlying mechanisms. To understand and simulate the exact biomechanical mechanisms of projectile penetration-induced tissue damage, we evaluated effects of two-dimensional (2D) transient stress wave propagation of 2D-functionally graded material (FGM, radial and circumferential inhomogeneity) in an infinite hollow cylinder. A periodic radial and circumferential material gradation fluctuating a constant value has been considered as the effective material properties, across the cylinder wall and the problem has been solved by implementing the graded finite element method with nonlinear Lagrangian shape functions. In contrast with other researches, the stress wave propagation for $ r $ r and $ \theta $ θ -inhomogeneity is different compared to the case in which the $ r $ r or $ \theta $ θ -inhomogeneity has been considered, separately. Moreover, this example resembles the bullet penetration in human tissue that produces stress wave propagation, resulting in unintentional trauma in human organs. For the case of 1D-FGM ( $ r $ r – inhomogeneity), the responses are pulse-like and symmetric. Finally, due to shear waves, the $ \theta $ θ -inhomogeneity has more visible effect on the stress wave propagation than $ r $ r – inhomogeneity due to shear waves, especially when the pulse collapses. [ABSTRACT FROM AUTHOR]

Originally developed for application in dissimilar joints, the dynamic feeding technology applied to the GMAW process is gaining popularity with applications in wire arc additive manufacturing (WAAM). Given the growing importance of additive manufacturing (AM) in industrial production, it is essential to better understand the main tool of WAAM technology. Acknowledging the limitations imposed on current waveform parameterization in commercial welding sources, this work used a proprietary welding source, named MIG-AD, which allows full control of parameters through dedicated hardware and open-source software. This study focuses on the impact of arc phase parameters on metal transfer, namely arc pulse time, arc pulse current level, and arc base current level. The results show the impact of altering each parameter on droplet formation, wire retraction, detachment frequency, and metal bridge elongation, as well as the stability and quality of the weld bead. This research offers valuable insights for optimizing welding parameters, aiming for greater control and process customization, making it a viable alternative for advanced research in WAAM, cladding, computational simulation, and artificial intelligence applied to welding. [ABSTRACT FROM AUTHOR]

In this article, wave propagation in a one-dimensional (1-D) composite periodic frame structure is analyzed using spectral finite elements (SFE) method together with Bloch's theorem. Each element in the periodic frame structure is modeled as a first-order shear deformation theory (FSDT) beam element and wave equations for the beam elements are derived using FSDT considering axial, flexural, and shear deformations. Next, these equations are solved using the frequency domain SFE method to obtain an elemental dynamic stiffness matrix which on assembly gives the dynamic stiffness matrix for the unit cell of the periodic structure. A polynomial eigenvalue problem is formulated thereafter using Bloch's theorem to evaluate the dispersion coefficients and wave amplitude ratios. Finally, the entire periodic frame is modeled as homogenized two-noded elements capturing the wave response of the PS with a drastic reduction in computational cost. The results obtained using the present method are validated with finite element simulation using ANSYS mechanical Ansys Parametric Design Language (APDL). The frequency band gaps observed in the frequency domain responses are investigated and corroborated with those predicted by the dispersion relations. This is followed by a detailed parametric study on the influence of different parameters on the band gap characteristics. The present method provides a scheme of wave propagation analysis of composite periodic frames with substantial computational efficiency. [ABSTRACT FROM AUTHOR]

Wave propagation in elastic solids is analyzed by a space-time discontinuous Galerkin quadrature element method. First, the space-time quadrature element is conveniently formulated based on the space-time discontinuous Galerkin formulation. This method treats both the spatial and temporal domains in a unified manner, enabling it to handle not only structured space-time meshes but also unstructured ones. It effectively captures discontinuities or sharp gradients in the solution. To transform the formulation into a system of algebraic equations, the Gauss-Lobatto quadrature rule and the differential quadrature analog are utilized. High-order elements are constructed simply by increasing the order of integration and differentiation without the laborious construction of shape functions. Then, dispersion analysis is conducted for one- and two-dimensional elements. The analysis reveals that as the Courant number decreases, the total dispersion error monotonically converges to the spatial dispersion error, which can be reduced by increasing the element order. Additionally, high-order elements nearly eliminate numerical anisotropy in different directions. Finally, several numerical examples of elastic wave propagation validate the method's effectiveness and high accuracy. [ABSTRACT FROM AUTHOR]

In this study, a subsidence simulator, also known as a trapdoor, is used to evaluate stages of soil arching (a load transfer mechanism), and related failure features are imaged using time-lapse surface-wave analysis in near real time. The trapdoor was reinforced with a nonwoven geotextile to simulate void roof sagging due to increased loading during void development. This soil behavior was uniquely monitored with three methodologies, namely, multiple horizontal layers of earth pressure cells, photography, and time-lapse seismic surface-wave surveys. Pressure measurements were recorded after every 1 mm of trapdoor downward displacement, along with time-lapse photographs, to visually monitor the development of failure features. Time-lapse seismic surface-wave surveys were conducted after every 7 mm of displacement with pseudo-2D shear-wave velocity (Vs) sections generated for each survey using surface-wave inversion techniques. Vs variations were consistent with the progressive development of shear planes that formed an arch above the trapdoor. A simplified ground reaction curve was then derived from pressure measurements with the estimated stages of soil arching supported by each experimental method. Based on this physical model, Vs variations from surface-wave surveys can be used to successfully and noninvasively image and monitor stress-field variations related to progressive void roof collapse and associated deformation features. [ABSTRACT FROM AUTHOR]

Predicting flood wave propagation from reservoir failures is critical to practical flood hazard assessment and risk management. Flood waves are sensitive to topography, channel geometry, structures, and natural features along floodplain paths. Thus, the accuracy of flood wave modelling depends on how precisely those features are represented. This study introduces an enhancing approach to flood wave modelling by accurately representing three-dimensional objects in floodplains using the structure-from-motion (SfM). This method uses an unmanned aerial vehicle to capture topographic complexities and account for ground objects that impact flood propagation. Using the three-dimensional volume of fluid numerical approach significantly improves an enhanced representation of turbulent flow dynamics and computational efficiency, especially in handling large topography datasets. Reproductions from this enhanced three-dimensional approach were validated against recent reservoir failure observations and contrasted with traditional two-dimensional models. The results revealed that the suggested three-dimensional methodology achieved a significant 84.4% reproducibility when juxtaposed with actual inundation traces. It was 35.5%p more accurate than the two-dimensional diffusion wave equation (DWE) and 17.1%p more than the shallow water equation (SWE) methods in predicting flood waves. This suggests that the reproducibility of the DWE and SWE decreases compared to the three-dimensional approach when considering more complex floodplains. These results demonstrate that three-dimensional flood wave analysis with the SfM methodology is optimal for effectively minimising topographic and flood wave reproduction errors across extensive areas. This dual reduction in errors significantly enhances the reliability of flood hazard assessments and improves risk management by providing more precise and realistic predictions of flood waves. [ABSTRACT FROM AUTHOR]

Purpose: The auditory brainstem response (ABR) can be elicited by broadband stimuli such as the click and chirp. Differences in the click- and chirp-evoked ABR have been extensively described using subjective analyses. The aim of the current research is to determine if subjectively observed differences between the click- and chirp-evoked ABR are also represented in objective signal-tonoise ratio (SNR) measurements obtained from these responses at different stimulus intensities and sweep counts. Method: ABRs were collected using click and chirp stimuli on nine adults with normal hearing sensitivity. Three SNR methods (split-sweep average--based SNR [SSA-SNR], F ratio--based single-point [Fsp], and multipoint [Fmp]) were used for the objective analysis of the waveforms at four stimulus intensities (20, 40, 60, and 80 dB nHL) and five sweep counts (100, 200, 300, 400, and 500 sweeps). Results: SSA-SNR measurements were statistically stronger for chirp- as compared to click-evoked ABRs. Additionally, chirp/click SSA-SNR, Fsp, and Fmp ratio measurements were consistently greater than 1. The advantage associated with the chirp was most noticeable at moderate stimulus intensities for all three measurements. Discussion: The advantages for the chirp observed here could have implications for threshold estimation and screening ABR tests. Furthermore, when stimulus intensity and sweep count were varied, general response trends suggest that the three SNR-based methods performed similarly to each other, as well as to traditionally used subjective measures, suggesting that these techniques have the potential to be used effectively in clinic. [ABSTRACT FROM AUTHOR]

Understanding shock wave behavior in supersonic flow environments is critical for optimizing the aerodynamic performance of turbomachinery components. This study introduces a novel transonic linear cascade design, focusing on advanced blade manufacturing and experimental validation. Blades were 3D-printed using Inconel 625, enabling tight control over the geometry and surface quality, which were verified through extensive dimensional accuracy assessments and surface finish quality checks using coordinate measuring machines (CMMs). Numerical simulations were performed using Ansys CFX with an implicit pressure-based solver and high-order numerical schemes to accurately model the shock wave phenomena. To validate the simulations, experimental tests were conducted using Schlieren visualization, ensuring high fidelity in capturing the shock wave dynamics. A custom-designed test rig was commissioned to replicate the specific requirements of the cascade, enabling stable and repeatable testing conditions. Experiments were conducted at three different inlet pressures (0.7-bar, 0.8-bar, and 0.9-bar gauges) at a constant temperature of 21 °C. Results indicated that the shock wave intensity and position are highly sensitive to the inlet pressure, with higher pressures producing more intense and extensive shock waves. While the numerical simulations aligned broadly with the experimental observations, discrepancies at finer flow scales suggest the need for the further refinement of the computational models to capture detailed flow phenomena accurately. [ABSTRACT FROM AUTHOR]

Metasurfaces are opening promising flexibilities to reshape the wavefront of electromagnetic waves. Notable optical phenomena are observed with the tailored surface plasmon, which is excited by metallic components in the visible spectrum. However, metamaterial or metasurface devices utilizing metallic materials encounter the challenge of low transmission efficiency, particularly within the visible spectrum. This study proposes a multilayer design strategy to enhance their transmission efficiency. By incorporating additional metal layers for improvements in the transmission efficiency and dielectric layers as spacers, cavities are formed along the propagation direction, enabling the modulation of transmittance and reflection through a process mimicking destructive interference. An analytical model simplified with the assumption of deep-subwavelength-thick metal layers is proposed to predict the structural parameters with optimized transmittance. Numerical studies employing the rigorous coupled wave analysis method confirmed that the additional metal layers significantly improve the transmittance. The introduction of the extra metal and dielectric layers enhances the transmission efficiency in specific spectral regions, maintaining a controllable passband and transmittance. The results indicate that the precise control over the layers' thicknesses facilitates the modulation of peak-to-valley ratios and the creation of comb-like filters, which can be further refined through controlled random variation in the thickness. Furthermore, when the thickness of the silver layer followed an arithmetic sequence, a multilayer structure with a transmittance of approximately 80% covering the entire visible spectrum could be achieved. Significantly, the polarization extinction ratio and the phase delay of the incident beams could still be modulated by adjusting the geometrical structure and parameters of the multilayer metamaterial for diversified functionalities. [ABSTRACT FROM AUTHOR]

A novel method of determining the possible shapes of pressure wavefronts in ducts after they have travelled sufficient distances to evolve to asymptotic states is introduced. Although it is possible in principle to achieve the same outcome by simulating complete flow histories from the time of the creation of the wavefronts, this can be impracticable. It is especially unsuitable to use such methods when extremely small grid lengths are needed to represent the final outcome adequately. The new method does not simulate the propagation phase at all. Instead, it explores what final end states are possible, but gives no information about the initiating disturbance or the wavefront evolution towards the assessed asymptotic state. Accordingly, the two methods do not overlap, but instead are complementary to each other. A typical case in which the new capability has high potential is described and used to illustrate the purpose and use of the methodology. However, the primary focus is on the presentation and assessment of the method, not on any particular phenomenon. It is shown that the required computational resources are far smaller than those needed for conventional unsteady flow simulations of propagating wavefronts. The potential numerical limitations of the method are highlighted and, with one exception, are shown to be either of no consequence or easily reduced to acceptable levels. Special attention is paid to the one exception because it cannot be proven to be unimportant and, indeed, it would be unsafe to use it in general analyses of wave propagation. However, strong evidence is presented of its acceptability for the study of asymptotic wavefronts. [ABSTRACT FROM AUTHOR]

Wave erosion of slopes can easily trigger landslides into marine environments and pose severe threats to both the ecological environment and human activities. Therefore, near-shore slope monitoring becomes crucial for preventing and alerting people to these potential disasters. To achieve a comprehensive understanding, it is imperative to conduct a detailed investigation into the dynamics of wave erosion processes acting on slopes. This research is conducted through flume tests, using a wave maker to create waves of various heights and frequencies to erode the slope models. During the tests, seismic signals, acoustic signals, and pore pressure generated by wave erosion and slope failure are recorded. Seismic and acoustic signals are analyzed, and time-frequency spectra are calculated using the Hilbert–Huang Transform to identify the erosion events and signal frequency ranges. Arias Intensity is used to assess seismic energy and explore the relationship between the amount of erosion and energy. The results show that wave height has a more decisive influence on erosion behavior and retreat than wave frequency. Rapid drawdown may potentially cause the slope to slide during cyclic swash and backwash wave action. As wave erosion changes from swash to impact, there is a significant increase in the spectral magnitude and Power Spectral Density (PSD) of both seismic and acoustic signals. An increase in pore pressure is observed due to the rise in the run-up height of waves. The amplitude of pore pressure will increase as the slope undergoes further erosion. Understanding the results of this study can aid in predicting erosion and in planning effective management strategies for slopes subject to wave action. [ABSTRACT FROM AUTHOR]

The integrable Kuralay-Ⅱ system (K-IIS) plays a significant role in discovering unique complex nonlinear wave phenomena that are particularly useful in optics. This system enhances our understanding of the intricate dynamics involved in wave interactions, solitons, and nonlinear effects in optical phenomena. Using the Riccati modified extended simple equation method (RMESEM), the primary objective of this research project was to analytically find and analyze a wide range of new soliton solutions, particularly fractal soliton solutions, in trigonometric, exponential, rational, hyperbolic, and rational-hyperbolic expressions for K-IIS. Some of these solutions displayed a combination of contour, two-dimensional, and three-dimensional visualizations. This clearly demonstrates that the generated solitons solutions are fractals due to the instability produced by periodic-axial perturbation in complex solutions. In contrast, the genuine solutions, within the framework of K-IIS, take the form of hump solitons. This work demonstrates the adaptability of the K-IIS for studying intricate nonlinear phenomena in a wide range of scientific and practical disciplines. The results of this work will eventually significantly influence our comprehension and analysis of nonlinear wave dynamics in related physical systems. [ABSTRACT FROM AUTHOR]

Pier structures in port and fishing harbor facilities require dynamic analyses during the design phase to account for external dynamic forces because of their high flexibility. Dynamic forces are frequently approximated as equivalent static forces for design purposes in practical engineering applications, but the fluctuational effects induced by these dynamic forces can be neglected. As the frequency range of wave forces acting on pier structures (0.05–1.0 Hz) significantly overlaps with the typical natural frequency range of pier structures (0.25–4.0 Hz), the response of a pier structure can be amplified because of the dynamic effects of the waves. In this study, we conducted a dynamic analysis by applying wave forces—a representative dynamic load—to a pier structure. The results were compared with those from a static analysis. A fatigue life assessment, which is often overlooked in static analyses, was also performed. The findings indicated that the concrete at the connection between the upper pier and steel piles exhibited a fatigue life of 27.3 years. The steel piles exhibited fatigue lives of 27.1 and 8.3 years depending on the weld details, falling short of the expected structural durability. Based on these results, recommendations for pier structures are proposed. [ABSTRACT FROM AUTHOR]

Aim: This article seeks to evaluate the shifts in publication rates and the participation of Indian orthodontists in different quartiles of orthodontic journals before, during, and after the pandemic, spanning the years 2017–2023. Methods: The evaluation involved manually searching through archives of 15 journals divided into quartiles, that is, Q1, Q2, and Q3. Articles with at least one author affiliated with an Indian university were collected and tabulated into graphs. Results: In Q1 journals, "Progress in Orthodontics" achieved the highest Indian publication percentage at 4.66%, whereas the European Journal of Orthodontics recorded the lowest at 0.93%. Among Q2 journals, the Journal of Orthodontic Science led with a maximum publication rate of 35.83%, while the Korean Journal of Orthodontics had the least, accounting for only 0.36%. In Q3 journals, the highest contribution of 31.16% was observed in APOS Trends in Orthodontics, while International Orthodontics had the lowest contribution at 8.24%. Conclusion: The examination of 15 orthodontic journals spanning the 7 years from 2017 to 2023 revealed that the publication trends remained largely unchanged in the majority of journals across all three time periods: pre-COVID-19, during the pandemic, and post-COVID-19. Notable exceptions included a slight increase in publications observed during and after the pandemic, specifically in the American Journal of Orthodontics and Dentofacial Orthopedics (Q1 journal), Journal of Orthodontic Science (Q2 journal), APOS Trends in Orthodontics (Q3 journal), and International Orthodontics (Q3 journal). [ABSTRACT FROM AUTHOR]

In this study, the nonlinear two-dimensional Kadomtsev–Petviashvili-modified equal width (KP-MEW) equation is under investigation, which is described as a nonlinear wave model in weakly restoring forces and shallow water waves in the way of ferromagnetic, solitary waves in two dimensions with short amplitude and long wavelength and are also helpful in the investigation of various behaviors in nonlinear sciences. We successfully found the interesting and novel solitary wave results in bright solitons, kink solitons, dark solitons, anti-kink solitons, periodic singular solitons for nonlinear two-dimensional KP-MEW equation on the base of extension of simple equation technique under symbolic computational software Mathematica. The created solitons play an important role in nonlinear engineering and physics such as nonlinear optics, nonlinear dynamics, soliton wave theory, optical fiber and communication system. We are sure that these constructed results are novel and interesting which does not exist in the previous literature works. The graphical representation of constructed results is shown by 2D, 3D and contour graphs. The investigated research work proved that utilized technique is more concise, straightaway and efficient for study of other nonlinear partial differential equations. [ABSTRACT FROM AUTHOR]

Rayleigh waves are crucial in earthquake engineering due to their significant contribution to structural damage. This study aims to accurately synthesize Rayleigh wave fields in both uniform elastic half-spaces and horizontally layered elastic half-spaces. To achieve this, we developed a self-programmed FORTRAN program utilizing the thin layer stiffness matrix method. The accuracy of the synthesized wave fields was validated through numerical examples, demonstrating the program's reliability for both homogeneous and layered half-space scenarios. A comprehensive analysis of Rayleigh wave propagation characteristics was conducted, including elliptical particle motion, depth-dependent decay, and energy concentration near the surface. The computational efficiency of the self-programmed FORTRAN program was also verified. This research contributes to a deeper understanding of Rayleigh wave behavior and lays the foundation for further studies on soil-structure interaction under Rayleigh wave excitation, ultimately improving the safety and resilience of structures in seismic-prone regions. [ABSTRACT FROM AUTHOR]