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Portevin–Le Chatelier effect, associated with dynamic strain aging, is widely found in various alloys, and the maximum serration magnitude from the tensile stress–strain curve can be considered as the point closest to the failure threshold. Due to the difficulty to define solute and solvent atoms in multicomponent alloys, it is a great challenge to explore the serration mechanism. In this study, the atoms that play the role of pinning are defined as solute atoms. Aided by mean-field theory, an in situ pinning model coupled with the twinning effect in a CoNiV alloy with low stacking fault energies is successfully established, which can well predict the failure threshold, i.e., the maximum serration magnitude. The present study paves a new way to correlate the serration dynamics and in situ pinning, and further predicts the failure threshold upon loading for multicomponent high- and medium-entropy alloys. [ABSTRACT FROM AUTHOR]

When measuring maximum strength, a high accuracy and precision is required to monitor the training adaptations. Based on available reliability parameters, the literature suggests the replacement of the one repetition maximum (1RM) by isometric testing to save testing time. However, from a statistical point of view, correlation coefficients do not provide the required information when aiming to replace one test by another. Therefore, the literature suggests the inclusion of the mean absolute error (MAE), the mean absolute percentage error (MAPE) for agreement analysis. Consequently, to check the replaceability of 1RM testing methods, the current study examined the agreement of isometric and dynamic testing methods in the squat and the isometric mid-thigh pull. While in accordance with the literature, correlations were classified high r = 0.638–0.828 and ICC = 0.630–0.828, the agreement analysis provided MAEs of 175.75–444.17 N and MAPEs of 16.16–57.71% indicating an intolerable high measurement error between isometric and dynamic testing conditions in the squat and isometric mid-thigh pull. In contrast to previous studies, using MAE, MAPE supplemented by CCC and BA analysis highlights the poor agreement between the included strength tests. The recommendation to replace 1RM testing with isometric testing routines in the squat does not provide suitable concordance and is not recommended. [ABSTRACT FROM AUTHOR]

Glass curtain walls, while broadly used as a building facade, are vulnerable to extreme winds. Curtain-wall failures in major wind events lead to substantial economic losses, and wind-induced vibration is often a major contributing factor to such failures. The main objectives of this study are to (i) present high-fidelity numerical modeling techniques to reproduce the wind-induced dynamic behavior of building facades, specifically focusing on a single-skin curtain-wall system, and (ii) highlight the impact of the interaction between facade and building structure on the wind-induced dynamic behavior of the curtain-wall system. The developed finite-element model is calibrated for a particular wind scenario tested at the Natural Hazards Engineering Research Infrastructure (NHERI) Wall of Wind Experimental Facility (WOW EF) at Florida International University (FIU), and subsequently validated to assess whether it can realistically reproduce the dynamic behavior in different scenarios involving various wind speeds and directions. This study also uncovers that the interaction between the facade and the building structure plays an important role in governing the wind-induced dynamic behavior of the curtain wall. In addition, this study finds that the presence of a vertical protrusion, attached to the facade for architectural reasons, may negatively impact the wind-induced dynamic response of the curtain wall, with this impact being influenced by the interaction between facade and structure. This study reports the significant discoveries, contributing new insights to facade design and the engineering industry. [ABSTRACT FROM AUTHOR]

Evaluations of public service collaborations tend to ignore time and timing as potential explanatory variables. Drawing on theories of environmental dynamism, organizational inertia, accountability 'drift', and isomorphism, we test whether the timing of inter-municipal cooperation, and its duration, affect financial performance for solid waste collection inter-municipal partnerships in the Spanish region of Catalonia over the period 2000–2019. Though still present and significant, the cost advantages of cooperation declined over this period due to population growth and reduced interdependence between municipalities. Timing of cooperation has no effect on savings; although early-adopter and follower groups differ in policy objectives. [ABSTRACT FROM AUTHOR]

The Chongwen Pagoda is the tallest masonry pagoda in China, with numerous openings inside the pagoda body. It is prone to damage during earthquakes, and the patterns of damage are complex. In order to scientifically analyze the dynamic performance, earthquake damage patterns, and mechanisms of the pagoda structure, on‐site dynamic testing was conducted to obtain the dynamic characteristics of the structure. A numerical model was established using Abaqus finite element software to calculate the dynamic characteristics of the structure. The results were compared with the testing results and showed a close agreement. El‐Centro earthquake wave, Taft earthquake wave, and Lanzhou artificial earthquake wave were selected as earthquake inputs based on site conditions, simulating frequent earthquakes, fortification earthquakes, and rare earthquakes with a magnitude of 9. The dynamic response of the pagoda structure was calculated, and the relationship between acceleration amplification factor, interstorey displacement, and interstorey displacement angle with floor height was analyzed. The seismic damage to the structure and the distribution of primary tensile stresses were studied, revealing the seismic damage mechanisms and the distribution characteristics of vulnerable areas in the Chongwen Pagoda. The research results provide references for the seismic assessment of this ancient pagoda. [ABSTRACT FROM AUTHOR]

Dynamic tests performed on masonry cross vaults provide important information to improve the knowledge under seismic actions of these particular structural elements. Under seismic actions, curved masonry elements show a behaviour strongly influenced by several parameters (both physical and mechanical). Their structural behaviour is hard to predict due to the significant variability of the input parameters and the strong heterogeneity of these elements. Refined nonlinear models often require specific numerical calibrations of nonlinear parameters in order to assess the structural capacity of tested element. Conversely, simplified Finite Element models represent useful tools to develop a basic knowledge on the expected structural behaviour. Initial knowledge level in SERA TA blind competition favoured simple assumptions. Therefore, the main goal was to evaluate key information of a masonry vault under dynamic action: triggering and the type of damage, the most stressed areas and the threshold at which evident damage is expected. The results obtained by these preliminary analyses have been compared with the experimental tests. [ABSTRACT FROM AUTHOR]

This paper presents the numerical evaluation of the seismic response of a masonry cross vault using the Discrete Macro-Element Method (DMEM). The case study corresponded to a full-scale unstrengthened cross vault that was experimentally investigated within the scope of the SERA Project — Seismic Response of Masonry Cross Vaults: Shaking table tests and numerical validations. The cross vault was subjected to repeated shaking table and dynamic identification tests until reaching significant damage. The numerical simulations involved the calibration of the Young's modulus of the masonry material aiming at reproducing the cross vault's experimental natural frequencies and mode shapes. The comparison of frequencies was carried out by estimating the difference between experimental and numerical results, whereas the correspondence between mode shapes was studied using the Modal Assurance Criterion. Subsequently, a sensitivity analysis was performed to identify the influence of nonlinear properties on the seismic response of the cross vault (displacement and acceleration time histories and failure mechanism). The accuracy of the numerical time histories was evaluated by estimating magnitude and phase discrepancies. The results aimed at demonstrating the applicability of the DMEM for assessing the seismic response of masonry cross vaults with an acceptable degree of accuracy and low computational cost. [ABSTRACT FROM AUTHOR]

In this research, blends are prepared of thermoplastic polyurethane (TPU), ground tire rubber (GTR) and its devulcanized version (dGTR). The primary objective is to produce thermoplastic elastomers wherein TPU is partially substituted by GTR or dGTR obtained from used tires, thereby forming a blend with a favorable cost/value ratio and a smaller environmental footprint. Throughout the experiment, the rubber content of the blends is varied between 0 and 50 wt% and the effect on mechanical properties is investigated. The blends are compounded with a twin‐screw extruder, after which sheet samples are produced by injection molding. With a view to a possible future industrial application, it is important that both the compounding and the injection molding of the specimens are easy to perform, even with a 50 wt% filler content. Increasing the amount of rubber phase reduce the tensile strength and elongation at break of the blends. Unfortunately, devulcanization did not significantly improve the properties of the blends. Overall, even at a (d)GTR content of 50 wt%, an elongation at break of 300% is achieved, which allows the use of the blends as thermoplastic elastomers. In addition, dynamic tests show that the rubber phase increases the damping capacity of the samples. [ABSTRACT FROM AUTHOR]

This research aims at systematically evaluating the properties of SMA-13 asphalt mixture reinforced by several fiber additives including flocculent lignin fiber (FLF), granular lignin fiber (GLF), chopped basalt fiber (CBF), and flocculent basalt fiber (FBF). Firstly, the thermal stability, moisture absorption, and oil absorption property of these fiber additives were analyzed. Secondly, the property of SMA-13 reinforced using four types of single fibers and two kinds of composite fibers (FLF + CBF and FLF + FBF) was comprehensively analyzed. Specifically, the high-temperature performance was evaluated using the uniaxial penetration test and the rutting test, the medium-temperature anticracking property was evaluated using the IDEAL-CT test, the low-temperature property was analyzed using the beam bending test, and the water stability was studied by the freeze–thaw splitting test. Thirdly, the dynamic mechanical response of different-fibers-modified SMA-13 was evaluated using the uniaxial compression dynamic modulus test. Finally, correlation analysis between the results of dynamic modulus and the high-, medium-, and low-temperature mechanical performance was carried out. The research results reveal that the stability of CBF and FBF under thermal action is better than that of GLF and FLF, and FBF shows the best thermal stability. The oil absorption property of FLF is better than that of GLF, followed by FBF and CBF. The comprehensive mechanical properties of CBF- and FBF-reinforced SMA-13 are better than those of FLF- and GLF-modified SMA-13. CBF can better reinforce the mechanical property of SMA-13 under low and medium temperature, while FBF can better reinforce the performance of SMA-13 at high temperature. FLF/CBF- and FLF/FBF-composite-modified SMA-13 show better high-temperature mechanical performance than that of the single-fiber-reinforced mixture, and FLF has some negative impact on the properties of FLF/FBF-composite-modified SMA-13 at low temperature. Fibers have no significant influence on the water stability of the mixtures. Meanwhile, the linear correlation between the mechanical performance of all the fiber-reinforced SMA-13 and the dynamic modulus result is good. [ABSTRACT FROM AUTHOR]

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Background: Differentiation between isolated hypogonadotropic hypogonadism (IHH) and constitutional delay in puberty (CDP) throughout adolescence can be challenging for doctors. This study examines the withdrawal effects of short-term, low-dose testosterone treatment (testosterone priming) on the ability of dynamic testing to distinguish between CDP and IHH based on activation of the hypothalamo-pituitary–testicular axis. Methods: A case–control study included 20 boys with delayed puberty (group A) and 20 patients with IHH (group B). Both groups underwent Triptorelin and human chorionic gonadotropin (hCG) stimulation tests before and 2 months after testosterone injections (100 mg) intramuscularly every 4 weekly for 3 months. Results: The triptorelin-stimulated 4-h LH with a cutoff of 2.4 IU/L and the hCG-stimulated testosterone with a cutoff of 1.160 ng/mL had sensitivities of 65% each, and specificities of 90% and 95%, respectively, to diagnose CDP. After testosterone withdrawal, the cut-off values for 4-h LH were 8.850 IU/L and 3.190 ng/mL for hCG-stimulated testosterone. Basal inhibin B > 88.25 pg/ml was found to be a differentiating factor in diagnosing CDP after testosterone withdrawal. Conclusions: following the withdrawal of testosterone therapy, Inhibin B levels or 4-h stimulated LH are the most effective discriminant assays to distinguish CDP from IHH. [ABSTRACT FROM AUTHOR]

Long-term cyclic loading can have a significant effect on the modulus of sand, and the influence on saturated coral sand has yet to be established. In this paper, the significant influence of non-plastic fines content (FC) and relative density (D r) on dynamic elastic modulus (E) of saturated coral sand has been evaluated by a series of cyclic triaxial drainage tests. The results show that the dynamic elastic modulus increases rapidly at the beginning of loading; then the growth slows down and finally stabilizes. In general, the development of E is influenced collectively by FC, D r and cyclic stress ratio (CSR). The initial dynamic elastic modulus E d-1 and steady-state dynamic elastic modulus E d-s increase with the increase of D r, and decrease as FC increases. The linear fitting equations are given by introducing the equivalent skeleton void ratio esk*. Furthermore, the relative dynamic elastic modulus E r is defined as the ratio of E d-N to E d-s, and the prediction equation for E r was developed to provide a basis for the engineering mechanical parameters of coral sands under long-term loads. [ABSTRACT FROM AUTHOR]

Background: PhenoMetaboDiff is a novel R package for computational analysis and visualization of data generated by Biolog Phenotype Mammalian Microarrays (PM-Ms). These arrays measure the energy production of mammalian cells in different metabolic environments, assess the metabolic activity of cells exposed to various drugs or energy sources, and compare the metabolic profiles of cells from individuals affected by specific disorders versus healthy controls. Methods: PhenoMetaboDiff has several modules that facilitate statistical analysis by sample comparisons using non-parametric Mann–Whitney U-test, the integration of the OPM package (an R package for analysing OmniLog® phenotype microarray data) for robust file conversion, and calculation of slope and area under the curve (AUC). In addition, the built-in visualization allows specific wells to be visualized in selected pathways for a particular time slice. Results: Compared to the standard OPM package, the features developed in PhenoMetaboDiff assess metabolic profiles by employing statistical tests and visualize the dynamic nature of the energy production in several conditions. Examples of how this package can be used are demonstrated for several rare disease conditions. The incorporation of a graphical user interface expands the utility of this program to both expert and novice users of R. Conclusions: PhenoMetaboDiff makes the deployment of the cutting-edge Biolog system available to any researcher. [ABSTRACT FROM AUTHOR]

This study presents a method for generating synthetic electroencephalography (EEG) signals to test dynamic directed brain connectivity estimation methods. Current methods for evaluating dynamic brain connectivity estimation techniques face challenges due to the lack of ground truth in real EEG signals. To address this, we propose a framework for generating synthetic EEG signals with predefined dynamic connectivity changes. Our approach allows for evaluating and optimizing dynamic connectivity estimation methods, particularly Granger causality (GC). We demonstrate the framework's utility by identifying optimal window sizes and regression orders for GC analysis. The findings could guide the development of more accurate dynamic connectivity techniques. [ABSTRACT FROM AUTHOR]

Balance control, a complex sensorimotor skill, declines with age. Assessing balance is crucial for identifying fall risk and implementing interventions in the older population. This study aimed to measure age-dependent changes in static and dynamic balance using inertial measurement units in a clinical setting. This study included 82 healthy participants aged 20–85 years. For the dynamic balance test, participants stood on a horizontally swaying balance board. For the static balance test, they stood on one leg. Inertial measurement units attached to their bodies recorded kinematic data, with average absolute angular velocities assessing balance capabilities. In the dynamic test, the younger participants had smaller average absolute angular velocities in most body parts than those of the middle-aged and older groups, with no significant differences between the middle-aged and older groups. Conversely, in the single-leg stance tests, the young and middle-aged groups outperformed the older group, with no significant differences between the young and middle-aged groups. Thus, dynamic and static balance decline at different stages with age. These results highlight the complementary role of inertial measurement unit-based evaluation in understanding the effect of age on postural control mechanisms, offering valuable insights for tailoring rehabilitation protocols in clinical settings. [ABSTRACT FROM AUTHOR]

Penetration testing, a critical component of cybersecurity, typically requires extensive time and effort to find vulnerabilities. Beginners in this field often benefit from collaborative approaches with the community or experts. To address this, we develop Cybersecurity Intelligent Penetration-testing Helper for Ethical Researchers (CIPHER), a large language model specifically trained to assist in penetration testing tasks as a chatbot. Unlike software development, penetration testing involves domain-specific knowledge that is not widely documented or easily accessible, necessitating a specialized training approach for AI language models. CIPHER was trained using over 300 high-quality write-ups of vulnerable machines, hacking techniques, and documentation of open-source penetration testing tools augmented in an expert response structure. Additionally, we introduced the Findings, Action, Reasoning, and Results (FARR) Flow augmentation, a novel method to augment penetration testing write-ups to establish a fully automated pentesting simulation benchmark tailored for large language models. This approach fills a significant gap in traditional cybersecurity Q&A benchmarks and provides a realistic and rigorous standard for evaluating LLM's technical knowledge, reasoning capabilities, and practical utility in dynamic penetration testing scenarios. In our assessments, CIPHER achieved the best overall performance in providing accurate suggestion responses compared to other open-source penetration testing models of similar size and even larger state-of-the-art models like Llama 3 70B and Qwen1.5 72B Chat, particularly on insane difficulty machine setups. This demonstrates that the current capabilities of general large language models (LLMs) are insufficient for effectively guiding users through the penetration testing process. We also discuss the potential for improvement through scaling and the development of better benchmarks using FARR Flow augmentation results. [ABSTRACT FROM AUTHOR]

The field load test is a direct and effective method for evaluating the performance of bridge structures. However, existing bridge field static load tests are costly and inefficient; moreover, they obstruct traffic and cause unavoidable damage to the bridge structure. As an alternative the the static load test, a random model update method based on bridge dynamic load tests and the Bayesian inference is proposed in this paper. The bridge static load test results were predicted with a high accuracy. To speed up the Bayesian method to infer the posterior probability density of the updated parameters, the Gaussian process was used in place of the finite element model, and the Bayesian inference used the Markov chain Monte Carlo method based on the delayed rejection adaptive Metropolis algorithm. First, the parameters to be modified for the bridge structure analysis model were determined based on the global sensitivity analysis method. Second, a uniform design sampling method was used to establish the Gaussian process optimization model to update the random model of the bridge structure. Finally, a reinforced concrete truss arch bridge was used to verify the correctness of the static load results of the bridge predicted by the random model update method based on dynamic load testing and Bayesian inference. The research results reveal that the prediction results of the bridge static load test based on the dynamic load test and Bayesian inference method agree with the actual test results. [ABSTRACT FROM AUTHOR]

Broad-spectrum veterinary antibiotic tylosin (TYL) is utilized in livestock and poultry. Due of its extensive usage and animal excretion in urine and feces, it affects the environment and human health. For determining the equilibrium time, the adsorption maximum capacity and the optimal isotherm model, adsorption batch tests have been conducted. Sips and Pseudo-second order models had R2 values of 0.9937 and 0.9764, respectively, and best matched experimental isotherm and kinetic data. The maximum TYL uptake onto soil was 2355.08 mg.kg−1. Using fixed bed adsorption experiments, the current study clarifies the issue of soil contamination in conditions that are close to natural phenomena. Fixed bed adsorption tests demonstrated that the inlet TYL concentration, soil bed height, and flow rate, influenced saturation and breakthrough times. Bohart-Adams, Thomas, and Yoon-Nelson models matched the experimental findings well in a variety of conditions. With 100 mg.L−1 concentration, 4 cm bed height, and 5 mL.min−1 flow rate, the maximal bed capacity of 1277.06 mg.kg−1 was achieved with R2 value of 0.9797. Experimental findings also indicated that the adsorption capacity in batch and dynamic tests are of the same range of magnitude. Based on this, tylosin is a probable soil contaminant. [ABSTRACT FROM AUTHOR]

Scientific and technical developments toward improving bio-oil are under investigation, with an emphasis on research into upgrading bio-oil bitumen. The current study presents a new development of eco-friendly bio-oil bitumen produced using some local materials as well as studying its physical and rheological properties. Two bitumen sources with penetration grade of 40/50 were used, Dora and Nasiriyah, which were locally obtained from Dora and Nasiriyah refineries in Iraq. Biobitumen was prepared by vacuum distillation after esterification of waste cooking oil, which was freely collected from local households and cafeterias. Methanol, sulfuric acid (as a catalyst agent), and zeolite were used in the biobitumen preparation process. Physical and rheological properties were tested in evaluating the performance. The physical tests included viscosity, softening point, and penetration, and the rheological properties involved sweep frequency and creep tests using a dynamic shear rheometer (DSR). Three percentages (10%, 20%, and 30%) of biobitumen were blended with aged petroleum bitumen, which was obtained from excessive aging of the virgin bitumen by thin-film oven test (TFOT). It was found that a ratio of 1∶5 of biobitumen and aged petroleum bitumen exhibited the best performance. Results also highlighted that the new modified bitumen with biobitumen showed superior performance compared with that of traditional bitumen, taking into consideration the influence of biobitumen percentage and level of the age of the virgin bitumen. The current development and outcomes of the study can be considered as promising and encouraging for further investigations into sustainable and environmentally friendly production. [ABSTRACT FROM AUTHOR]

This research investigated dynamic vibration control in a monopile-supported wind turbine system through strategically placed resonators along its length. Four configurations were analyzed: Case 1 (conventional wind turbine model), Case 2 (resonators in the turbine tower), Case 3 (resonators in the monopile), and Case 4 (resonators in both tower and monopile). Utilizing spectral element formulations, the dynamic stiffness matrix was derived for the wind turbine system, embedded in cohesionless soil with frequency-dependent viscoelastic springs. Analytical responses at the tower top and monopile head under dynamic harmonic excitation were computed, and transmittance was determined as the logarithmic ratio of responses to input excitation. Experimental dynamic tests were conducted on a 3D-printed wind turbine scaled model, yielding displacement responses at the tower top and monopile head. Comparison with analytically determined transmittance values reveals consistent agreement across four configurations. Case 4 demonstrates substantial response reductions, highlighting the efficacy of resonators in both tower and monopile. Transmittance plots indicate notable response reduction near resonant frequencies, showcasing local resonance phenomena. Furthermore, the tower and monopile head responses are substantially reduced when the excitation frequency surpasses the resonator's natural frequencies. This underscores the dynamic vibration control capabilities of periodically positioned resonators within the wind turbine scaled model. The research also explores the influence of parameters such as resonator mass ratio, soil shear modulus, and pile and tower slenderness ratio on transmittance plots. [ABSTRACT FROM AUTHOR]

Aging degradation of the geomembrane (GMB) significantly influences the dynamic shear characteristics of the composite liner interface, which comprises the GMB and the compacted clay liner (CCL), potentially jeopardizing the dynamic stability of landfills. In this study, cyclic shear tests were performed on two types of aging GMB/CCL interfaces, concurrently with shear tests on the nonaging GMB/CCL interface for comparison. The results suggest that the impact of aging on the dynamic shear characteristics of the GMB/CCL interface is essentially governed by the surface roughness and brittleness of the GMB, with the effect degree of brittleness influenced by the normal stress. Under low normal stress, aging increased the vertical displacement, dynamic shear strength, and shear stiffness of the GMB/CCL interface. However, under high normal stress, the dynamic shear strength and shear stiffness of the aging GMB/CCL interface were more likely to be lower than those of the nonaging interface. As the displacement amplitude increased, the influence of aging on the shear stiffness of the GMB/CCL interface gradually diminished. Aging also reduced the damping ratio of the GMB/CCL interface. The difference in vertical displacement between the exposed GMB/CCL interface and the in soil GMB/CCL interface caused by brittleness was not significant. In practical engineering, when the overlying load on the GMB/CCL composite liner is relatively small, aging makes the GMB more susceptible to tearing under seismic loads, whereas with larger overlying loads, aging is more likely to increase the shear displacement, thereby increasing the likelihood of instability in landfill. Finally, based on classic models of soil, fitting models for the normalized shear stiffness and damping ratio of the GMB/CCL interface were established and validated. This study can provide reference for analyzing the dynamic stability of landfills during long-term use. [ABSTRACT FROM AUTHOR]

Several ground improvement techniques, which have been proven to be effective and economical solutions for increasing the lateral stiffness and strength of weak soils around piles, can often result in unnecessarily conservative large volumes of soil improvement. Additionally, there are no rigorous techniques available to analyze the seismic behavior of piles in improved soils that can be utilized in day-to-day engineering practice. In this study, a stand-alone one-dimensional finite element computer code called DYPAC (Dynamic Piles Analysis Code), which uses the beams on nonlinear Winkler foundation (BNWF) approach, was developed to analyze the seismic response of a single pile in both improved and unimproved soils. The computer code models the pile as a beam element and the nonlinear soil behavior as springs and viscous dashpots using a nonlinear p-y element, where y = displacement; and p = soil reaction per unit length of the pile. This study proposes and validates a method for modifying the p-y curves to consider the limited lateral extent of ground improvement. The p-y curves were inputted into DYPAC to analyze a series of dynamic centrifuge tests of single piles in soft clay improved using cement deep soil mixing (CDSM). Free-field site response analyses were performed using the DEEPSOIL computer program and the soil displacement-time histories were inputted into the free-field ends of the nonlinear p-y elements. The predictions made by DYPAC were validated using the centrifuge data and the results show that the DYPAC predictions are reasonable. Furthermore, the proposed method for modifying p-y curves to characterize CDSM-improved soil appears to be appropriate and practical. Moreover, the benefits of nonlinear DEEPSOIL free-field site response analyses during large earthquakes, as compared to equivalent linear analyses, were also demonstrated. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to develop and validate finite element (FE) models of commercial manual and power wheelchairs, as well as related test fixtures and tiedown hardware, to provide tools for designing integrated wheelchair seating stations for automated and other vehicles. Methods: The manual wheelchair model is based on a Ki Mobility Catalyst 5, and the power wheelchair is based on a Quantum Rehab Q6 Edge 2.0 with Synergy Seating. A 3D Sense scanner was used to capture wheelchair geometry. Wheelchairs were disassembled into components to collect masses and additional dimensions. These geometric data were used to construct computer-aided design (CAD) models of each product. Additional fixture models were generated from available drawings for the surrogate wheelchair base (SWCB), surrogate wheelchair 4-point strap tiedowns, traditional docking hardware, and hardware meeting Universal Docking Interface Geometry (UDIG). Models were constructed in LS-DYNA. For each wheelchair, between 1 and 3 dynamic sled tests in front, lateral, and rear directions were conducted for a total of 13 tests with varying wheelchair securement methods to obtain validation data. Frontal and rear impact tests used a Hybrid III midsized male, whereas the side impact tests used the ES-2re. Validation sled pulses were nominally 20 g–48 km/h for frontal tests, 10 g–22 km/h for lateral tests, and 14 g–30 km/h for rear impact tests. CORrelation and Analysis (CORA) scores were calculated for head and chest resultant accelerations. Results: Validation results include comparison of component masses, overall wheelchair and anthropomorphic test device (ATD) kinematics, ATD head and chest signals, and calculation of CORA scores for head and chest resultant accelerations. For the 2 wheelchairs and SWCB, total model mass was within 1% to 4% of physical mass. Across the 13 test conditions, head acceleration CORA scores ranged from 0.71 to 0.92 in 8 conditions and from 0.52 to 0.67 in 5 conditions. For chest acceleration, CORA scores ranged from 0.73 to 0.96 in 8 conditions and from 0.51 to 0.67 in 5 conditions. In addition, residual deformation was similar between test and model in conditions where it occurred. Conclusions: These publicly available tools will allow vehicle safety engineers to design equitable occupant protection systems for occupants who travel while seated in their wheelchairs. They will also be the baseline for ongoing research to develop parametric wheelchair models for additional occupant sizes. [ABSTRACT FROM AUTHOR]

The article focuses on studying the impact-driven penetration of multi-strength fibroconcrete pyramid-prismatic piles. The research object includes multi-strength pyramid-prismatic piles with varying types of reinforcement and different levels of concrete compressive strength. The aim of the study is to experimentally investigate the enhancement of pile impact resistance through the differentiated selection of concrete strength based on the dynamic stresses in the pile shaft caused by impact forces. As a result of the experimental studies on the piles, it was found that the difference in energy costs for driving them does not exceed 3.7–4.1%, proving the insignificant influence of the type of reinforcement and fiber concrete strength on the energy expenditure during driving. At the same time, it was established that the type of reinforcement and the type of fiber significantly affect the strength and impact-resistant properties of the pile shaft, ensuring defect-free driving. For example, the defectiveness (e.g., chips, cracks, potholes, spalling) of the head of the steel fiber concrete (SFC) pile reaches 57.5%, while for the polypropylene fiber concrete (PFC) pile it does not exceed 5.2%, demonstrating the advantages of using polypropylene fiber under impact conditions. [ABSTRACT FROM AUTHOR]

Shear Thickening Fluid (STF) is a specialized high-concentration particle suspension capable of rapidly and reversibly altering its viscosity when exposed to sudden impacts. Consequently, STF-based dampers deliver a self-adaptive damping force and demonstrate significant potential for applications in structural vibration control. This study presents both a modeling and experimental investigation of a novel double-rod structured STF damper. Initially, a compound STF is formulated using silica particles as the dispersed phase and polyethylene glycol solution as the dispersing medium. The rheological properties of the STF are then experimentally evaluated. The STF's constitutive rheological behavior is described using the G-R model. Following this, the flow behavior of the STF within the damper's annular gap is explored, leading to the development of a two-dimensional axisymmetric fluid simulation model for the damper. Based on this model, the dynamic mechanism of the proposed STF damper is analyzed. Subsequently, the STF damper is optimally designed and subjected to experimental investigation using a dynamic testing platform under different working conditions. The experimental results reveal that the proposed STF damper, whose equivalent stiffness can achieve a nearly threefold change with excitation frequency and amplitude, exhibits good self-adaptive capabilities. By dividing the damper force into two parts: the frictional damping pressure drop, and the osmotic pressure drop generated by the "Jamming effect". A fitting model is proposed, and it aligns closely with the nonlinear performance of the STF damper. [ABSTRACT FROM AUTHOR]

The dynamic properties of high-temperature sandstone quickly deteriorate with different cooling methods, which leads to the instability of underground engineering rock structures. Therefore, it is of great significance to quantify the changes in the dynamic characteristics of high-temperature cooled sandstone under impact loads. Therefore, the sandstone is heated to different temperatures and cooled using three methods. A dynamic tensile test is performed using the Splitting Hopkinson Pressure Bar (SHPB) test set for high-temperature cooled sandstone. At the same time, the transient process of rock failure was examined using high-speed cameras. The influence of different temperatures and cooling methods on the thermal damage value of sandstone was analyzed, and the prediction equation was formed. The change in rock energy during rock failure under impact load was calculated. [ABSTRACT FROM AUTHOR]

In situ dynamic testing is conducted to study the dynamic characteristics of the wooden structure of the North House main hall. The velocity response signals on the measurement points are obtained and analyzed using the self-interaction spectral method and stochastic subspace method, yielding natural frequencies, mode shapes, and damping ratios. This study reveals that the natural frequencies and damping ratios are highly consistent between the two methods. Therefore, to eliminate errors, the average of the results from both modal identification methods is taken as the final measured modal parameters of the structure. The natural frequencies of the first and second order in the X direction were 2.097 Hz and 3.845 Hz and in the Y direction were 3.955 Hz and 5.701 Hz. The modal frequency in the Y direction of the structure exceeds that in the X direction. Concurrently, a three-dimensional finite element model was established using ANSYS 2021R1, considering the semi-rigid properties of mortise–tenon connections, and validated based on in situ dynamic testing. The sensitivity analysis indicates adjustments to parameters such as beam–column elastic modulus, tenon–mortise joint stiffness, and roof mass for finite element model refinement. Modal parameter calculations from the corrected finite element model closely approximate the measured modal results, with maximum errors of 9.41% for the first two frequencies, both within 10% of the measured resonant frequencies. The adjusted finite element model closely matches the experimental results, serving as a benchmark model for the wooden structure of North House main hall. The validation confirms the rationality of the benchmark finite element model, providing valuable insights into ancient timber structures along transportation routes. [ABSTRACT FROM AUTHOR]

This paper presents a study on aircraft engine identification using real-time 3D LiDAR point cloud segmentation technology, a key element for the development of automated docking systems in airport boarding facilities, known as jetbridges. To achieve this, 3D LiDAR sensors utilizing a spinning method were employed to gather surrounding environmental 3D point cloud data. The raw 3D environmental data were then filtered using the 3D RANSAC technique, excluding ground data and irrelevant apron areas. Segmentation was subsequently conducted based on the filtered data, focusing on aircraft sections. For the segmented aircraft engine parts, the centroid of the grouped data was computed to determine the 3D position of the aircraft engine. Additionally, PointNet was applied to identify aircraft engines from the segmented data. Dynamic tests were conducted in various weather and environmental conditions, evaluating the detection performance across different jetbridge movement speeds and object-to-object distances. The study achieved a mean intersection over union (mIoU) of 81.25% in detecting aircraft engines, despite experiencing challenging conditions such as low-frequency vibrations and changes in the field of view during jetbridge maneuvers. This research provides a strong foundation for enhancing the robustness of jetbridge autonomous docking systems by reducing the sensor noise and distortion in real-time applications. Our future research will focus on optimizing sensor configurations, especially in environments where sea fog, snow, and rain are frequent, by combining RGB image data with 3D LiDAR information. The ultimate goal is to further improve the system's reliability and efficiency, not only in jetbridge operations but also in broader autonomous vehicle and robotics applications, where precision and reliability are critical. The methodologies and findings of this study hold the potential to significantly advance the development of autonomous technologies across various industrial sectors. [ABSTRACT FROM AUTHOR]

The harsh ocean environment and complex operating conditions require high dynamic positioning (DP) capability of offshore vessel. The design, development, and performance evaluation of DP systems are generally carried out through numerical simulations or scale-model experiments. Simulations are a convenient and inexpensive alternative to experiments, but may not be practical due to the simplicity of the model. Thus, this paper presents a hybrid simulation and experiment test platform for DP vessels. For realistic calculating environmental loads and kinematic responses in hydrodynamic simulations, the 6DoF model is used to describe the dynamic response of DP vessels, considering fluid-memory effects and frequency-dependent hydrodynamic parameters. In the experiments, similarity theory based on the same Froude number is used to ensure consistency of the control parameters with the simulations, reducing the time for experimental tuning. Finally, a case study of a DP shuttle tanker is used to verify the credibility of the test platform. [ABSTRACT FROM AUTHOR]

The ability to quickly and accurately estimate the state of charge (SOC) of lithium batteries is a key function of the battery management system (BMS). To enhance the accuracy of SOC estimation for lithium batteries, we propose a method that combines the dynamic factor recursive least squares (DFFRLS) algorithm and the strong tracking H-infinity filtering (STF-HIF) algorithm. To address the issue of fixed forgetting factors in recursive least squares (RLS) that struggle to maintain both fast convergence and stability in battery parameter identification, we introduce dynamic forgetting factors. This approach adjusts the forgetting factor based on the residuals between the model's estimated and actual values. To improve the H-infinity filtering (HIF) algorithm's poor performance in tracking sudden state changes, we propose a combined STF-HIF algorithm, integrating HIF with strong tracking filtering (STF). Simulation experiments indicate that, compared to the HIF algorithm, the STF-HIF algorithm achieves a maximum absolute SOC estimation error (MaxAE) of 0.69%, 0.72%, and 1.22%, with mean absolute errors (MAE) of 0.27%, 0.25%, and 0.38%, and root mean square errors (RMSE) of 0.33%, 0.30%, and 0.46% under dynamic stress testing (DST), federal urban driving schedules (FUDS), and Beijing dynamic stress testing (BJDST) conditions, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Earthquake Sciences is the property of China Earthquake Administration, Institute of Geophysics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Progress in Earthquake Sciences is the property of China Earthquake Administration, Institute of Geophysics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Efficient separation of liner alkanes from branched alkanes is of prime importance in the petrochemical industry. Herein an adaptive metal‐organic framework FJI‐H38 is reported with 1D channel which can vary delicately ≈4.0 Å. The activated FJI‐H38 displays extremely large butane (n‐C4H10) capacity, especially at low pressure (44.15 cm3 g−1 at 298 K and 0.1 bar), but barely adsorbs isobutane (iso‐C4H10). Remarkably, FJI‐H38 possesses a high n‐C4H10/iso‐C4H10 selectivity of 246.75. Gas‐loaded single crystal X‐ray analysis and modeling calculation reveal that the synergetic effect of pore confinement and surfaces decorated with uncoordinated carboxyl group plays a critical role in the capture of the relatively smaller n‐C4H10 while the exclusion of the larger iso‐C4H10. In addition, dynamic breakthrough tests explicitly prove FJI‐H38 displays prominent separation performance for n/iso‐C4H10 under various conditions with ultra‐high productivity of high‐purity n‐C4H10 (42.48 L/kg, ≥99.0%) and iso‐C4H10 (42.35 L/kg, ≥99.95%). [ABSTRACT FROM AUTHOR]

The implementation of hydrogen fuel cell vehicle (HFCV) policies represents a crucial strategy in addressing global warming within the transportation sector. This study assesses the impact of these policies on HFCV-related stock returns from 2019 to 2023, utilizing static and dynamic contagion tests to construct a contagion network. The results indicate several key findings: (1) both fuel cell (FC)- and hydrogen-oriented policies exhibit significant contagion effects across the HFCV supply chain, particularly between FC/hydrogen sectors and their upstream, midstream, and downstream counterparts, with stronger contagion pre-2021 and a modest decline post-2022; (2) in 2020, FC-oriented policies dominated contagion dynamics, with a notable shift towards hydrogen-oriented policies after 2021; (3) prior to 2021, contagion rates reached as high as 80%, largely driven by higher-order co-moments rather than linear correlations, but declined to below 25% after 2021; (4) upstream sectors within the HFCV supply chain are more sensitive to policy contagion compared to midstream and downstream sectors; and (5) among the 10 policies analyzed, the 2021–2023 New Energy Vehicle Industry Development Plan had the most substantial impact, both driving and receiving policy shocks within the HFCV network. These findings offer critical insights into the energy-economic interactions shaping the HFCV market, providing valuable guidance for policymakers and industry stakeholders aiming to promote sustainable transport strategies. • To study policy impact on HFCV industrial chain stock returns. • Use the contagion test to judge the impact of policy shocks on related sectors. • Upstream HFCV sectors are more receptive to policy contagion. • New Energy Vehicle Industry Development Plan wields the strongest influence. [ABSTRACT FROM AUTHOR]

Recently B←N organic frameworks (BNFs) have gained substantial attention owing to their unique dative bond energy, which imparts them with specialized functionalities across a broad spectrum of applications. Despite previous reports on BNFs with permanent porosity, research endeavors towards three‐dimensional (3D) BNFs with similar properties are scarce, with no report of robust 3D BNFs featuring permanent porosity to date. Herein, electrostatic complementary strategy is proposed to construct the first example of 3D robust and microporous BNF, BNF‐100, featuring a reo topology with 8‐connected sandwich nodes assembled via dative B←N bonds. The activated form BNF‐100 a exhibits excellent chemical stability and permanent porosity with Langmuir surface area of 645.9 m2 g−1 and pore volume of 0.23 cm3 g−1. BNF‐100 a can efficiently separate hexane isomers through sieving mechanisms, as confirmed by vapor adsorption experiments and dynamic breakthrough tests, surpassing the performance of most MOF materials. Finally, we achieved the purification of different branched hexane isomers using a single breakthrough column in a combined breakthrough and purging experiment, which is the first reported instance in the literature on hexane isomer separation. [ABSTRACT FROM AUTHOR]

Objectives: Patients with intermediate or advanced hepatocellular carcinoma (HCC) require repeated disease monitoring, prognosis assessment and treatment planning. In 2018, a novel machine learning methodology "survival path" (SP) was developed to facilitate dynamic prognosis prediction and treatment planning. One year after, a deep learning approach called Dynamic Deephit was developed. The performance of the two state-of-art models in dynamic prognostication have not been compared. Methods: We trained and tested the SP and Dynamic DeepHit models in a large cohort of 2511 HCC patients using time-series data. The time-series data were converted into data of time slices, with an interval of three months. The time-dependent c-index for OS at given prediction time (t = 1, 6, 12, 18 months) and evaluation time (∆ t = 3, 6, 9, 12, 18, 24, 36, 48 months) were compared. Results: The comparison between SP model and Dynamic DeepHit-HCC model showed the latter had significant better performance at the time of initial admission. The time-dependent c-index of Dynamic DeepHit-HCC model gradually decreased with the extension of time (from 0.756 to 0.639 in the training set; from 0.787 to 0.661 in internal testing set; from 0.725 to 0.668 in multicenter testing set); while the time-dependent c-index of SP model displayed an increased trend (from 0.665 to 0.748 in the training set; from 0.608 to 0.743 in internal testing set; from 0.643 to 0.720 in multicenter testing set). When the prediction time comes to 6 months or later since initial treatment, the survival path model outperformed the dynamic DeepHit model at late evaluation times (∆ t > 12 months). Conclusions: This research highlighted the unique strengths of both models. The SP model had advantage in long term prediction while the Dynamic DeepHit-HCC model had advantages in prediction at near time points. Fine selection of models is needed in dealing with different scenarios. [ABSTRACT FROM AUTHOR]

This paper investigates the inherent nonlinear damping characteristics of a rotary eddy-current damper (RECD) and evaluates its vibration control performance on a single-degree-of-freedom (SDOF) system subjected to harmonic and seismic excitations. First, a RECD prototype was manufactured to experimentally identify its intrinsic nonlinear eddy-current damping characteristics. A magic formula model is then proposed to characterize the relationship between the eddy-current damping force and the velocity of the RECD, and its applicability in depicting the nonlinear damping characteristics of the RECD is evaluated by comparing with the electromagnetic finite-element (FE) model and the commonly used Wouterse's model. Moreover, by comparing the experimental and analytical frequency–domain responses of an SDOF structure equipped with a RECD, the applicability of the magic formula model in evaluating the structural vibration control performance of the RECD is further verified. Finally, the control performance of the RECD for an SDOF structure subjected to earthquake ground motions is numerically evaluated and compared. Results show that the eddy-current damping force of the RECD presents obvious nonlinear characteristics with increasing velocity, and the proposed magic formula model can adequately depict the nonlinear eddy-current damping characteristics of the RECD. Moreover, the RECD exhibits superior structural control performance under harmonic and seismic excitations. [ABSTRACT FROM AUTHOR]

AbstractSeismic uplift of a high-speed rail (HSR) cable-stayed bridge’s bearing affects train safety. Existing technique lacks improved seismic isolation in the vertical direction due to the bearing’s vertical stiffness. Based on the on-site dynamic test and train derailment table experiments and different software, the train running safety of the semi-floating system of the cable-stayed bridge-rail-train system was analyzed using different damping and isolation control strategies. The larger vertical seismic component increases the danger of flange climb derailment when subjected to near-fault earthquakes. After installing lateral/or viscous fluid dampers (VFDs) and magnetorheological (MR) bearing (A = 3.0), the bridge has an obvious bearing uplift response. Still, it is not enough to threaten the structure, and the seismic damping capacity of the bridge structure is improved, making the train ride safe. This research presents discoveries on the impact of bearing uplift on train operational safety. Specifically, it reveals that the lifting of the end bearings on both sides of the main girder is not synchronized. This investigation presents a technical reference for comparable initiatives. [ABSTRACT FROM AUTHOR]

ABSTRACT The construction history and subsequent usage of burial mounds are an important testimony for socio‐economic transformation in prehistoric societies. The Baalberge–Schneiderberg burial mound, subject of the presented study, falls in this category as it is considered as an important monument that indicates the emergence of early social stratification during the Chalcolithic period in central Europe. This hypothesis relies on the chronological development of the burial mound, which is not fully understood until now. Therefore, a reconstruction of the complex stratigraphy of the burial mound including construction phases and later alterations is highly relevant for archaeological research, but the required excavations would be onerous and inconsistent with preservation efforts. In this paper, we demonstrate that non‐invasive geophysical prospection, especially seismic sounding with shear and Love waves, is suitable to obtain the required stratigraphic information, if seismic full waveform inversion (FWI) and reflection imaging are applied. Complementary information on the preservation state of the mound is obtained through Electrical Resistivity Tomography (ERT) and Electromagnetic Induction (EMI) measurements. To support the seismic and geoelectric results, we utilize Dynamic Testing (DynP), geoarchaeological corings, 14C‐Dating and archaeological records. Our investigations reveal two construction phases of the Baalberge–Schneiderberg mound. The 14C‐Dating yields dates for the older burial mound that are contemporary to the Chalcolithic Baalberge group (4000–3400 bc). During the Early Bronze Age (EBA), the mound was enlarged to its final size by people of the Aunjetitz/Únětice society (2300–1600 bc). However, both seismic and geoelectric depth sections show an extensive disturbance of the original stratigraphy due to former excavations. For this reason, the exact shape of the older burial mound cannot be determined exactly. Based on our data, we estimate that its height was below 2 m. In consequence, the original Baalberge burial mound was less monumental as until now assumed, which potentially prompting a revision of its significance as indicator for social differentiation. [ABSTRACT FROM AUTHOR]

Binder morphology is a critical factor determining the electrode microstructures and properties, which fundamentally controls the charge transport and mechanical performance of the resultant battery. In this case, polytetrafluoroethylene (PTFE) binder is of great interest as it exhibits unique nanofibration capability and mechanical flexibility, which has been broadly applied for dry processing of battery electrodes. However, there is a lack of fundamental study on how binder nanofibration affects the electrochemomechanical properties of electrodes. Here, similar to the fibrous structures of the cell microenvironment, the attempt is to answer this question from the viewpoint of active‐material microenvironment (ME@AM). First, the PTFE nanofibration degree is adjusted by electrode calendering treatment and binder loading. Second, the microstructures, mechanical relaxation behavior, bending capability, and liquid–electrolyte wetting capability of the fibrous ME@AM are comparatively investigated in detail by dynamic mechanical testing. Finally, the superiority of highly fibrous ME@AM in electrochemical performance is confirmed by the C‐rate and cycling stability testing of half‐cells. This study indicates that a highly fibrous ME@AM can remarkably improve the electrochemomechanical properties of electrodes by enhanced capillary action with liquid electrolyte, good electrode flexibility, and structural stability under compression. [ABSTRACT FROM AUTHOR]

This study presents the validation of a dynamic test system to simulate a high‐speed train passing bridges under seismic excitation. The system comprises scaled models of a CRH380A high‐speed train and an 11‐span simply supported bridge on a shake table array. This innovative apparatus combines seismic loading with the moving train load to replicate train‐track‐bridge interaction (TTBI) during earthquakes. It allows investigation of various train speeds and seismic excitations, providing invaluable insights into TTBI. First, the detailed similarity design principle based on the equations of motion was discussed, and its applicability to the wheel‐rail contact relationship was verified. Then, the dynamic characteristics of the scaled model were identified, and the impact of the error between the scaled model and the theoretical model on the TTBI response was assessed. Furthermore, the comparison of the dynamic test model and the numerical simulation in acceleration responses validated the accuracy of the rigid‐flexible coupling model method for the actual TTBI system. Test cases without external excitation, with simple harmonic excitation and with seismic excitation were conducted on the dynamic test system. Results showed that the influence of track irregularity and running speed on train response aligns with the classical train‐bridge interaction theory. The successful implementation of this test system marks a significant advance in understanding TTBI mechanics and has significant implications for seismic safety enhancement of railway infrastructure. [ABSTRACT FROM AUTHOR]

The strain rate effect significantly influences the dynamic mechanical behavior of reinforcing steel under impact loads. To investigate the effect of strain rate on the dynamic mechanical behavior of reinforcing steel, this study conducts dynamic compression tests on four types of reinforcing steel using a Split Hopkinson pressure bar. The results show that there is a significant strain rate effect on the reinforcing steel when the strain rate reaches 103–104 s−1. The experimental results are analyzed using the Johnson–Cook model (J–C model), and the original model is modified based on the error between the model predictions and the experimental results. The results indicate that the modified J–C model, which includes an enhanced strain rate effect term, better predicts the dynamic mechanical behavior of reinforcing steel at ultrahigh strain rates. [ABSTRACT FROM AUTHOR]

Previous studies have implied that stress is a risk factor for depression, but relatively little is known about how healthy individuals' stress dynamically affects depression as a mood in daily life. Therefore, an ecological momentary assessment study was conducted among 141 college students to test the temporal dynamic effect of daily perceived stress on depression and the underlying mediating and moderating role of rumination. Perceived stress, state rumination, and depression were measured using self‐compiled questionnaire three times a day over 12 days. Trait rumination was measured with the Nolen‐Hoeksema Ruminative Response Scale. Hierarchical linear models with HLM 7.0 were adopted to examine the mediation and moderation effects. In the mediation model, the greater the daily perceived stress at time t, the higher the state rumination at time t + 1, and state rumination at t + 1 positively predicted college students' depression at t + 2. In the moderation model, trait rumination significantly facilitated perceived stress‐induced depression. These results verified that daily perceived stress could affect college students' depression directly or indirectly through the critical mediating mechanism of state rumination, and this effect would be exacerbated with a higher level of trait rumination. [ABSTRACT FROM AUTHOR]

With the global widespread preference for low-floor trams, the expectation for tram riding comfort has been increasingly heightened. This paper identifies an abnormal riding comfort problem (ARCP, characterized by an excessive and W-shaped distribution of riding comfort) during dynamic field tests on a low-floor tram. To address ARCP, a multi-body dynamics model of the tram was constructed and validated its accuracy through dynamic field tests. By integrating track irregularities and wheel-rail contact analysis, the riding comfort index was assessed and reproduced the ARCP phenomenon. Linearization and time-domain integration studies were conducted on the mechanisms and measures to resolve the ARCP. The research findings reveal that the primary cause of the deterioration in the mean comfort index is the large amplitude of the track irregularity and the low equivalent conicity of the wheel-rail contact relationship. The main reason for the W-shaped distribution of riding comfort is the weaker inter-vehicle constraints and the lack of lateral energy-absorbing devices. Finally, optimization measures were proposed, including reducing the lateral stiffness of the second suspension, altering the carbody structural parameters, and modifying the inter-vehicle connection devices. This research enriches the study of tram dynamic performance and offers insights that may contribute to the resolution of ARCP. [ABSTRACT FROM AUTHOR]

The decrease in dynamic elastic modulus is a primary indicator of quantitative damage in concrete. To quantitatively assess depth-by-depth damage within a concrete structure, cylindrical specimens obtained through coring can be cut into disk specimens to measure the dynamic elastic modulus of concrete at each depth. To minimize external damage during coring, it is essential to extract cylinders with the smallest possible diameter. In addition, for higher resolution in depth-based damage assessment, creating disk specimens with the smallest possible thickness is necessary. However, there is no information available in the literature on experimental limitation of smallest possible diameter and thickness for dynamic elastic modulus of disk-shaped specimens. This study evaluated whether the dynamic modulus measured from various sizes of concrete disk specimens provided sufficient reliability compared to reference values obtained from cylinders. Moreover, the study examined how the presence of coarse aggregate and variation in the water–cement ratio significantly influenced the dynamic modulus measurement. In addition, test results from impulse excitation technique (IET) and impact resonance (IR) were compared to find a more reliable test method for dynamic elastic modulus of disk specimen. The experimental findings revealed that as the thickness-to-radius ratio of the disk specimens decreased, measured data variation increased. Mortar specimens without coarse aggregates showed less variability compared to concrete specimens, and the variation in dynamic modulus measured by IR was lower than that measured by IET. [ABSTRACT FROM AUTHOR]

To determine the appropriate stiffness coefficient k values for rubber belts used in dynamic testing of the elastic modulus and shear modulus of timber and solid wood composite materials, this study employed three different thicknesses of rubber belts. Dynamic tests were conducted on straw boards, Laminated Veneer Lumber (LVL), and Spruce-Pine-Fir (SPF) materials, and the results were validated and analyzed using static four-point bending tests. The conclusions drawn from this research indicate that the range of stiffness coefficient k values for the rubber belts obtained through dynamic testing fell between 0.05 and 0.28 N/m. The correctness of the dynamic testing method was verified through static fourpoint bending tests. The error levels for elastic modulus E and shear modulus G of the same type of board measured using the three different rubber belts were below 9.5% and 9.8%, respectively. [ABSTRACT FROM AUTHOR]

This is the first of two papers on a wide pile group. The geology and a geotechnical model of the site are presented, along with the design of a single pile, analysis of a static loading test, and some dynamic tests. Response of the piled foundations comprising 399 bored piles supporting three 70-storey towers on a common mat was monitored. Records consist of results of a static loading test, dynamic tests of four piles, the development of load in 15 piles, and settlement of 40 points during construction and nine years following. At end of construction, the perimeter piles received more load from the towers than did the interior piles and the mat settled on average 90 mm. By the end of the monitoring period, due to the general subsidence, the average settlement of the mat had increased by 50 mm. Most of the settlement is considered to originate from the compression of the soil layers below the pile toe level. A subsequent paper will present the analysis and design of the wide pile group, and the numerical analysis of the static loading test on a single pile and of the wide pile group. [ABSTRACT FROM AUTHOR]

In this study, carbon materials with different dimensions, including the typical one-dimensional (1D) carbon nanotube (CNT), two-dimensional (2D) graphene (GF), and three-dimensional (3D) activated carbon (AC), were investigated as a support for Pt catalysts for the selective hydrogenation of 3,4-dichloronitrobenzene (3,4-DCNB) to 3,4-dichloroaniline (3,4-DCAN). Notably, the Pt/CNT catalyst with the lowest dimension exhibited the best conversion of 3,4-DCNB under mild reaction conditions, followed by Pt/GF. Comprehensive characterizations, including XRD, TEM, XPS, and in situ CO DRIFTS, reveal that the dimension of carbon supports plays an important role in the particle size and electronic properties of Pt species, consequently affecting the catalytic performances of Pt catalysts. According to the results, electron-deficient Pt particles with small sizes are more favorable for the hydrogenation of 3,4-DCNB to 3,4-DCAN. In addition, dynamic tests and in situ DRIFTS of 3,4-DCNB indicated that the carbonaceous supports will largely influence the adsorption and activation capacity of the Pt catalysts, so that Pt loaded on CNT and GF are superior to that on the AC. We believe this study will provide good guidance for designing efficient carbon-supported metal catalysts for selective hydrogenation. [ABSTRACT FROM AUTHOR]

Earthquake‐triggered landslides are widely recognized. Despite extensive research on the seismic responses of landslides triggered by single earthquakes, there is a lack of understanding of the seismic responses of landslides due to earthquake sequences and multiple earthquakes, and the mechanisms of dynamic weakening under multiple earthquakes still lack support from experimental results. To explore their seismic response characteristics and triggering mechanism, a series of multi‐period vibrations ring shear tests and dynamic triaxial‐bender tests were conducted with glass spheres. The experimental results show that the co‐vibration slip occurred during the vibration process, and as the vibration periods increased, the sample gradually slipped after vibration, eventually leading to accelerated instability. The sample exhibited a transition from a solid‐semi‐solid state to a liquid state due to the increase in vibration periods. Further results show that the shear modulus progressively weakened with successive vibration periods. The weakening of the shear strength of the sample caused by multi‐periods vibration was affected by the amplitude, the vibration time, and the interval time between two periods of vibration. Our study provided insights into how multiple earthquakes of seismic sequence and seismically active area trigger landslides. Plain Language Summary: Earthquake‐triggered landslides are affected by seismic sequences and multiple earthquakes in the geological history, but how multiple earthquakes trigger landslides is still unclear. In view of the dynamic response characteristics and triggering mechanism of landslides triggered by multi‐stage earthquakes, we carried out dynamic ring shear experiments and dynamic triaxial‐bender experiments. The experimental results show that with an increase in the number of vibration period, the sample initially experienced no deformation after vibration, followed by decelerated deformation, and finally underwent accelerated unstable deformation, showing a phase transition process from solid‐semi solid to liquid. The experimental results further indicate that this was because the shear modulus of the sample decreased with the increase of the vibration period. Our results revealed how multiple earthquakes and seismic sequences trigger landslides. Key Points: Ring shear experiments show the deformation characteristics of granular materials under multi‐period vibrationsPost‐vibration slip controls the accelerated deformation and instability of granular materialsThe shear modulus of granular media decrease under multi‐period vibrations, resulting in phase transitions from solid‐semi solid to liquid [ABSTRACT FROM AUTHOR]