Attenuation Pattern Research Articles

The high-temperature gas soft measurement method based on the temperature attenuation patterns of flowing argon gas inside a cavity

The device for generating the airflow temperature signal is employed in aircraft ground simulation. This process involves heating the argon gas by the arc discharge to generate high-temperature gas, which subsequently flows into the cavity and mixes with cold gas to produce the temperature signal. However, the temperature of argon gas at the entrance of the cavity is excessively high, and sensor installation is challenging, making direct measurement difficult. This paper introduces a high-temperature gas soft measurement method based on the temperature attenuation patterns of flowing argon gas inside the cavity, and establishes a mathematical model for the flow and temperature distribution of argon gas within the cavity. The method calculates the target temperature at the entrance of the cavity by measuring the lower-temperature argon gas at the outlet of the cavity. Furthermore, a simulation and experimental platform were set up to validate the proposed method. The experimental results indicate that there is a 7.9% deviation between the soft measurement values and the directly measured values of argon gas temperature in the middle of the cavity. At the outlet of the cavity, the maximum deviation between the directly measured argon gas temperature and the simulation calculation results based on the soft measurement values at the entrance temperature is 5.2%. The paper rigorously validates the accuracy of the soft measurement method from various perspectives. Notably, this method offers the advantage of remote indirect measurement, and indirectly expanding the upper limit of the temperature sensor.

Energy attenuation patterns of microseismic signals in the "three zones" of goaf based on variational mode decomposition

Energy attenuation patterns of microseismic signals in the "three zones" of goaf based on variational mode decomposition

Imaging and characterization of optical emission from ex vivo tissue during conventional and UHDR PBS proton therapy

Objective. Imaging of optical photons emitted from tissue during radiotherapy is a promising technique for real-time visualization of treatment delivery, offering applications in dose verification, treatment monitoring, and retrospective treatment plan comparison. This research aims to explore the feasibility of intensified imaging of tissue luminescence during proton therapy (PT), under both conventional and ultra-high dose rate (UHDR) conditions. Approach. Conventional and UHDR pencil beam scanning (PBS) PT irradiation of fresh ex vivo porcine tissue and tissue-mimicking plastic phantom was imaged using intensified complementary metal-oxide-semiconductor(CMOS) cameras. The optical emission from tissue was characterized during conventional irradiation using both blue and red-sensitive intensifiers to ensure adequate spectral coverage. Spectral characterization was performed using bandpass filters between the lens and sensor. Imaging of conventional proton fields (240 MeV, 10 nA) was performed at 100 Hz frame rate, while UHDR PBS proton delivery (250 MeV, 99 nA) was recorded at 1 kHz frame rate. Dependence of optical emission yield on proton energy was studied using an optical tissue-mimicking plastic phantom and a range shifter. Finally, we demonstrated fast beam tracking capability of fast camera towards in vivo monitoring of FLASH PT. Main results. Under conventional treatment dose rates optical emission was imaged with single spot resolution. Spot profiles were found to agree with the treatment planning system calculation within >90% for all spectral bands and spot intensity was found to vary with spectral filtration. The resultant polychromatic emission presented a maximum intensity at 650 nm and decreasing signal at lower wavelengths, which is consistent with expected attenuation patterns of high fat and muscle tissue. For UHDR beam imaging, optical yield increased with higher proton energy. Imaging at 1 kHz allowed continuous monitoring of delivery during porcine tissue irradiation, with clear identification of individual dwell positions. The number of dwell positions matched the treatment plan in total and per row showing adequate temporal capability of iCMOS imaging. Significance. For the first time, this study characterizes optical emission from tissue during PT and demonstrates our capability of fast optical tracking of pencil proton beam on the tissue anatomy in both conventional and UHDR setting. Similar to the Cherenkov imaging in radiotherapy, this imaging modality could enable a seamless, independent validation of PT treatments.

Surface water resource attenuation attribution and patterns in Hai River Basin

Surface water resource attenuation attribution and patterns in Hai River Basin

Importance of the receiver's height for transmission studies in acoustic ecology.

In animal communication, the sound pressure level (SPL) of the acoustic signals has been studied in relation to various biological functions. Previous research reported that senders and receivers benefit from being at elevated positions. However, sometimes, researchers find contradictory results. Using a transmission experiment, we measured SPL of two acoustic stimuli: (i) white noise, and (ii) advertisement calls of the Iberian tree frog (Hyla molleri) at two different heights above ground level (0.05 and 0.75 m) and from six distances (1, 2, 4, 8, 16, and 32 m) from a loudspeaker. Calls of the Iberian tree frog have two spectral peaks centred at the frequencies of ca. 1 and 2 kHz. As expected, SPL decreased with distance, but following a distinct attenuation pattern across height above the ground and frequency. Our findings show that the ground effect may critically alter frequency attenuation and, therefore, signal composition and discrimination at the listener's location, even at low heights above the ground. We suggest that recording devices should be positioned at the same height that natural listeners are usually located in nature, to facilitate the replication and comparison of experiments in the field of acoustic ecology and, also, bioacoustics.

Development of a Laboratory Test Apparatus for Simulating Core Drilling under High In Situ Stress

Abstract Rock cores drilled under high in situ stress environments are inevitably permanently damaged due to the stress relief, which significantly affects the evaluation of the physical and mechanical properties of deep rocks. Quantitatively correlating this sampling damage with in situ stress distribution is challenging because of the complexity of the geological environment and the diversity of rock materials. To address this challenge, a laboratory test apparatus has been developed that can apply specific pressure to shallow rock materials to simulate high in situ stress environments and drilling–coring to simulate the sampling process of deep rock masses. The results of verification tests demonstrate that the integrity of cores gradually deteriorated as the sampling confining pressure increased. Moreover, simultaneous increases in the density and size of microcracks were observed within the cores, where these microcracks propagate through grain boundaries, generate intragrain and transgranular microcracks, extend outwardly to form macroscopic cracks, and enhance porosity. These findings confirm the applicability of the apparatus for conducting quantitative sampling damage studies. In the future, further investigations using the apparatus will be conducted to explore the mechanical attenuation patterns of rock cores, thereby providing a reference to evaluate rock mechanics parameters for engineering practices.

Induced seismic activity and source parameter characteristics in the Datong coal mine, China

To clarify the activity patterns and source characteristics of coal mining–induced microseismicity, this study analyzed the spatial distribution characteristics of microseismic events in the Datong coal mining area based on records from the regional digital seismic network. We conducted a detailed characterization of the depth distribution characteristics of microseismic events using the double-difference localization method. Additionally, the source parameters, including corner frequency ( fc), source rupture radius ( r), seismic moment ( M0), source radiated energy ( Es), and stress drop (Δσ), were calculated for 136 mine-induced earthquakes with magnitudes ranging from ML1.3 to ML3.2. The results show that ML ≥ 2.0 mining-induced seismic events occur mainly within numerous microfractures in the Datong mining area. The depth of the seismic sources in the mining area is concentrated at 200∼500 m, with significant north–south differences and a close correlation with the mining depth. The displacement spectra of microseismic sources show agreement with the Brune source model [Formula: see text] attenuation pattern. As M0 gradually increases, r, Δσ, and Es show an increasing trend, while fc gradually decreases, exhibiting characteristics similar to those of tectonic earthquakes. Compared to tectonic earthquakes, coal mining-induced earthquakes have lower corner frequencies and stress drop levels mainly because mining activities alter the originally stable geological structure and stress state, leading to weakened rock strength, decreased elastic modulus, and shallower source depths. These factors contribute to the reduction in corner frequencies. As mining operations continue, microfracturing occurs in the coal and surrounding rock mass, intensifying the dynamic instability of the rock mass that was already under high stress conditions. This situation triggers larger-magnitude, mining-induced seismic events under lower stress conditions.

Structural vibration characteristics of the historical building in a nearby blasting test

The tunnel construction by the drill-and-blast method can have a significant impact on the adjacent buildings, especially the historical buildings with poor structural performances. Based on a special explosive case of Nanjing Metro Line 4, an in-situ blasting test for vibration safety evaluation on the Nanjing Drum Tower was carried out. According to the site geological investigation, the location of the blasting test was selected near the planned tunnel. 6 blasting was carried out in terms of sing-hole blasting and millisecond-delay blasting. The attenuation of the ground vibration and the structural vibration responses of the historical Drum Tower were analyzed. The test results also showed that the Nanjing Drum Tower was not damaged by this blasting test. For single-hole blasting tests, the peak particle velocity increased with the increasing of the explosive charge, but decreased remarkably when using the millisecond-delay blasting technology. The horizontal and vertical ground vibration attenuation patterns were consistent, which can be described by the Sadowski formula. The ground vibration response was dominated by the horizontal vibration, and the velocity amplification factor in the case of the single-hole test with a charge quantity of 400 g reached 2.4, which was observed the most remarkable amplification effect.

Selective Organ-Targeting Hafnium Oxide Nanoparticles with Multienzyme-Mimetic Activities Attenuate Radiation-Induced Tissue Damage.

Radioprotective agents hold clinical promises to counteract off-target adverse effects of radiation and benefit radiotherapeutic outcomes, yet the inability to control drug transport in human organs poses a leading limitation. Based upon a validated rank-based multigene signature model, radiosensitivity indices are evaluated of diverse normal organs as a genomic predictor of radiation susceptibility. Selective ORgan-Targeting (SORT) hafnium oxide nanoparticles (HfO2 NPs) are rationally designed via modulated synthesis by α-lactalbumin, homing to top vulnerable organs. HfO2 NPs like Hensify are commonly radioenhancers, but SORT HfO2 NPs exhibit surprising radioprotective effects dictated by unfolded ligands and Hf(0)/Hf(IV) redox couples. Still, the X-ray attenuation patterns allow radiological confirmation in target organs by dual-beam spectral computed tomography. SORT HfO2 NPs present potent antioxidant activities, catalytically scavenge reactive oxygen species, and mimic multienzyme catalytic activities. Consequently, SORT NPs rescue radiation-induced DNA damage in mouse and rabbit models and provide survival benefits upon lethal exposures. In addition to inhibiting radiation-induced mitochondrial apoptosis, SORT NPs impede DNA damage and inflammation by attenuating activated FoxO, Hippo, TNF, and MAPK interactive cascades. A universal methodology is proposed to reverse radioenhancers into radioprotectors. SORT radioprotective agents with image guidance are envisioned as compelling in personalized shielding from radiation deposition.

Shear Waves in an Elastic Plate with a Hole Resting on a Rough Base

The article is devoted to the analytical and numerical study of the pattern of propagation and attenuation, due to Coulomb friction, of shear waves in an infinite elastic thin plate with a circular orifice of radius r0 lying on a rough base. Considering the friction forces and their influence on the sample of wave propagation in extended rods or thin plates is important for calculating the stress–strain state in them and the size of the area of motion. An exact analytical solution of a nonlinear boundary value problem for tangential stresses and velocities is obtained in quadratures by the Laplace transform, with respect to time. It turned out that the complete exhaustion of the wave front of a strong rupture occurs at a finite distance r* from the center of the orifice, and an elementary formula is given for this distance (the case of tangential shock stresses suddenly applied to the orifice boundary is considered). For various ratios of the magnitude of the limiting friction force to the amplitude of the applied load, the stopping (trailing) wave fronts are calculated. After passing them, a state of static equilibrium between the elastic and friction forces with a nonlinear distribution of residual stresses is established in the region r0≤r≤r*. For the first time, a precise analytical solution was obtained for the boundary value problem of the propagation of elastic shear waves in an infinite isotropic space with a cylindrical cavity, when a tangential shock load is set on its surface.

MCOCT: an experimentally and numerically validated, open-source Monte Carlo simulator for optical coherence tomography.

Here, we present MCOCT, a Monte Carlo simulator for optical coherence tomography (OCT), incorporating a Gaussian illumination scheme and bias to increase backscattered event collection. MCOCT optical fluence was numerically compared and validated to an established simulator (MCX) and showed concordance at the focus while diverging slightly with distance to it. MCOCT OCT signals were experimentally compared and validated to OCT signals acquired in tissue-mimicking phantoms with known optical properties and showed a similar attenuation pattern with increasing depth while diverging beyond 1.5 mm and proximal to layer interfaces. MCOCT may help in the design of OCT systems for a wide range of applications.

Urban Sewage Pollution Dynamics: Reviewing Deposition, Attenuation Patterns, and Environmental Implications

Domestic sewage is prone to deposit in the sewer system due to its complex composition and lengthy collection and transportation route. The migration and transformation of pollutants between deposits and sewage during the deposition process play a vital role in the sound and stable operation of the sewer system, the enhancement of the centralized collection rate of domestic sewage, and the safeguarding of urban water environments. Built on research findings worldwide, this paper summarizes the generation pattern and composition characteristics of the deposition and attenuation of pollutants in domestic sewage within the sewer system. The leading factors influencing sewage pollutant deposition are explored, and the harm engendered by the migration and transformation of pollutants between deposits and sewage is analyzed. Finally, we express hopes for addressing the issue of sewage pollutant deposition and attenuation, aiming to enhance the quality and efficiency of sewage treatment and foster the green and healthy development of sewer systems.

Analysis of computerized tomography characteristics in gastrointestinal subepithelial lesions diagnosed through endoscopy or endovascular ultrasound

Aim: Subepithelial lesions (SEL) of the gastrointestinal tract are lesions arising from the mucosa, submucosa or muscularis propria. This study is aimed to asses diagnostic characteristics of SELs on computerized tomography (CT) and to present the localization, size, CT attenuation and contrast enhancement patterns of the lesions that may aid in making correct diagnosis. Materials and Methods: Between December 2022 and March 2024, patients with a preliminary diagnosis of SEL on endoscopy or EUS and who underwent abdominal CT were retrospectively screened from the hospital database. Localization, size, pre-contrast and post-contrast Hounsfield Unit (HU) values of the lesions, and pathologic diagnoses were recorded and compared in patients with SEL. Results: Pathologic diagnosis was available in 25 (23.4%) patients with SEL detected on CT. Among these, the most common lesion was gastrointestinal stromal tumors (GIST, 52%). In 22 (20.6%) patients, the lesion was not detected on CT. The lesions that could not be seen on CT were less than 2 cm in size. Gastrointestinal distension was insufficient in the majority of patients in whom the lesion could not be visualized on CT. While the HU values increased by approximately 3 times in patients diagnosed with neuroendocrine tumors (median [interquartile ranges] 36.5 [32 – 40] vs. 101.5 [81.5 – 127.5]; p = 0.068), the increase was approximately 2 times in those with GIST (30 [29 – 38] vs. 70 [57 – 77]; p=0.003). Conclusion: This study presents several CT characteristics and pitfalls that may aid correct diagnosis of SELs with CT. SELs smaller than 2 cm in size and located in cardia are more likely to be missed with CT. Adequate gastric distention is crucial in correct diagnosis.

Geographical and environmental distance differ in shaping biogeographic patterns of microbe diversity and network stability in lakeshore wetlands

Soil microorganisms play a crucial role in wetland ecosystems, but the specific mechanisms underlying their diversity and network stability across lakeshore wetlands, as well as their importance in microbial ecology, are still poorly understood. Here, we analyzed the biogeographical pattern and network stability of lakeshore wetland microbial communities across a regional scale, and identified the primary factors that influence their composition. The results revealed that α-diversity of wetland bacteria decreased linearly with increasing longitude and latitude, whereas the α-diversity of fungal showed an increasing trend in lakeshore wetlands. Species richness was the principal way that the biogeographical pattern of α-diversity was expressed. The β-diversity of soil microbial in lakeshore wetlands has a significant geographical attenuation pattern. Fungal communities were influenced by stochastic spatial diffusion, while bacterial communities were influenced by deterministic environmental filtration as they transition from semi-arid to arid regions. Community network stability was specifically determined by bacterial and fungal diversity. Structural equation modelling revealed that spatial distance and climate indirectly affect bacterial diversity by influencing soil and plant diversity, which in turn affects feedback network stability. These findings show that the geographical pattern of soil microbial diversity in lakeshore wetlands influences network stability at the spatial scale, offering insights into the adaptation of wetland ecosystem diversity and stability at the regional level.

Analysis of noise distributions at heliports and vertiports: A guide for site selection and land use planning

Purpose: The purpose of this study was to examine the noise profiles of helicopters and eVTOLs at heliports and vertiports in order to support site planning and the development of local land-use compatibility guidelines. Design/methodology/approach: This study used existing helicopter and eVTOL sound profiles to develop noise distribution contours for heliports and vertiports. This study collected noise data from available studies on helicopters and eVTOLs. This data was then entered into dBmap noise mapping tool to develop noise maps for helicopters and eVTOLs. Three air transit facility configurations for each aircraft category were analyzed: open (unobstructed), urban, and rooftop. Two additional vertiport configurations were created by overlaying building and noise data with Google Earth imagery. Noise data was entered into dBmap for processing. Noise contours were mapped for three configurations for both aircraft categories.Findings: Key observations from the noise distribution analysis showed that open (unobstructed) facility configurations have even noise distributions for both eVTOLs and helicopters. Noise maps for urban locations showed areas of attenuation and asymmetrical patterns due to the interactions of sound waves with surrounding buildings. An analysis of a rooftop installation of a heliport or vertiport provided some noise mitigation advantages. Noise contour distributions closely matched those outlined in previous research; however, the sound intensities modeled in this study were lower than indicated in exigent research. Assessments were also conducted for real-world sites with potential future use as vertiports in Seattle, Washington, and Chicago, Illinois.Practical Implications: This study suggests that current land use compatibility guidance may be inadequate for rotorcraft and eVTOL operations. Findings suggest the development of symmetrical noise-impact zones centered around heliports and vertiports. Examples of these zones are outlined, and recommendations for future research are provided. Local planners can use the data from this study to make educated choices about the siting of heliports and vertiports. Additionally, the findings can assist planners in the development of zoning and land use compatibility standards.Social Implications: Land use compatibility standards for heliports and vertiports will help ensure a synergistic relationship between local communities and these air transit facilities. The data from this study can also help protect individuals from excessive noise and annoyance.Originality/value: This study is one of the few on this topic and the only known research on noise distributions of helicopters and eVTOLs with a particular focus on land use compatibility

Machine learning assisted feature identification and prediction of hemodynamic endpoints using computed tomography in patients with CTEPH.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but potentially curable cause of pulmonary hypertension (PH). Currently PH is diagnosed by right heart catheterisation. Computed tomography (CT) is used for ruling out other causes and operative planning. This study aims to evaluate importance of different quantitative/qualitative imaging features and develop a supervised machine learning (ML) model to predict hemodynamic risk groups. 127 Patients with diagnosed CTEPH who received preoperative right heart catheterization and thoracic CTA examinations (39 ECG-gated; 88 non-ECG gated) were included. 19 qualitative/quantitative imaging features and 3 hemodynamic parameters [mean pulmonary artery pressure, right atrial pressure (RAP), pulmonary artery oxygen saturation (PA SaO2)] were gathered. Diameter-based CT features were measured in axial and adjusted multiplane reconstructions (MPR). Univariate analysis was performed for qualitative and quantitative features. A random forest algorithm was trained on imaging features to predict hemodynamic risk groups. Feature importance was calculated for all models. Qualitative and quantitative parameters showed no significant differences between ECG and non-ECG gated CTs. Depending on reconstruction plane, five quantitative features were significantly different, but mean absolute difference between parameters (MPR vs. axial) was 0.3mm with no difference in correlation with hemodynamic parameters. Univariate analysis showed moderate to strong correlation for multiple imaging features with hemodynamic parameters. The model achieved an AUC score of 0.82 for the mPAP based risk stratification and 0.74 for the PA SaO2 risk stratification. Contrast agent retention in hepatic vein, mosaic attenuation pattern and the ratio right atrium/left ventricle were the most important features among other parameters. Quantitative and qualitative imaging features of reconstructions correlate with hemodynamic parameters in preoperative CTEPH patients-regardless of MPR adaption. Machine learning based analysis of preoperative imaging features can be used for non-invasive risk stratification. Qualitative features seem to be more important than previously anticipated.

“Cumulative effect” of second harmonic Lamb waves in a lossy plate

The second harmonic Lamb waves have high sensitivity to microstructural defects in materials and are therefore promising for incipient damage detection and monitoring of thin-walled structures. Existing studies have shown that the second harmonic Lamb waves can be cumulative with increasing propagation distance under the internal resonance conditions, which is conducive to nonlinear wave measurements in view of structural health monitoring. However, when propagating in a lossy structure with damping, the cumulative properties of the second harmonic Lamb waves are affected by energy dissipation and thus need to be re-examined. In this paper, a method for predicting the cumulative characteristics of second harmonic Lamb waves in damped plates is proposed. Instead of using material damping parameters which are difficult to obtain in practice, the proposed method relies on the attenuation patterns of Lamb waves at fundamental and double frequencies while taking into account the influence of the wave beam divergence. The proposed methodology is validated by finite element simulations and experiments. The results show that the cumulative second harmonic Lamb waves in the damped plate tend to increase and then decrease, and a “sweet” zone of relatively large amplitude can be predicted using the proposed method. The elucidation of the cumulative characteristics of the second harmonic Lamb waves provides guidance for effective system design for structural damage detection and monitoring applications.

Relationships between KLOTHO and APOE4‐associated β‐amyloid and tau alterations across AD continuum

AbstractBackgroundApolipoprotein E ε4 allele (APOE4) is the leading genetic risk factor for Alzheimer’s disease (AD). APOE4 carriers (APOE4+) exhibit greater accumulation of the two AD neuropathological hallmarks, beta‐amyloid (β‐amyloid) and tau. KLOTHO KL‐VS heterozygosity (KL‐VSHET) attenuates APOE4‐related β‐amyloid and age‐related tau burden in cognitively normal individuals. It remains unclear whether this holds true for individuals with mild cognitive impairment (MCI) and AD. Here we investigate whether KL‐VSHET attenuates APOE4‐related cerebrospinal fluid (CSF) AD‐biomarker burden across the AD continuum.MethodMiddle‐aged and older adults (N = 396; MeanAge = 65) from the Wisconsin Registry for Alzheimer’s Prevention and Wisconsin Alzheimer’s Disease Research Center who were genotyped for KLOTHO and APOE and underwent CSF sampling were included in analyses. General linear models, covarying for sex, age, and AD family history, examined whether APOE4 yielded expected outcomes on β‐amyloid and tau burden. Follow‐up regression analyses, stratified by KL‐VS genotype [non‐carriers(KL‐VSNC,N = 293); KL‐VSHET (N = 103)], evaluated whether the APOE4 associations with β‐amyloid and tau differed between KL‐VSHET and KL‐VSNC. Analyses were stratified further by diagnosis [cognitively normal (N = 308) or MCI/AD (N = 88)] to investigate whether the relationships between APOE4 and β‐amyloid or tau differed among KL‐VSHET and KL‐VSNC in cognitively normal and MCI/AD participants.ResultResults for the entire sample, as well as stratified by KL‐VS status and diagnosis, are presented in Table 1. When the analysis was stratified by KL‐VS status, the APOE4+ effect on both β‐amyloid and tau burden was seen among KL‐VSNC but not KL‐VSHET. When further stratifying by diagnosis, the same pattern of attenuation among KL‐VSHET was observed for β‐amyloid burden in both cognitively normal individuals and MCI/AD whereas for tau burden, we only observed a non‐significant trend among cognitively normal persons (KL‐VSNC: p = 0.10; KL‐VSHET: p = 0.74).ConclusionKL‐VSHET attenuates both APOE4‐related CSF β‐amyloid and tau burden in cognitively normal individuals. This attenuation extends to CSF β‐amyloid but not tau accumulation in MCI/AD. These results add to the literature suggesting that KL‐VS heterozygosity is protective against APOE‐related biomolecular alterations that confer AD risk.

Maintaining Task Performance Levels Under Cognitive Load While Walking Requires Widespread Reallocation of Neural Resources.

This study elucidates the neural mechanisms underlying increasing cognitive load while walking by employing 2 versions of a response inhibition task, the '1-back' version and the more cognitively demanding '2-back' version. By using the Mobile Brain/Body Imaging (MoBI) modality, electroencephalographic (EEG) activity, three-dimensional (3D) gait kinematics and task-related behavioral responses were collected while young adults (n=61) performed either the 1-back or 2-back response inhibition task. Interestingly, increasing inhibitory difficulty from 1-back to 2-back during walking was not associated with any detectable costs in response accuracy, response speed, or gait consistency. However, the more difficult cognitive task was associated with distinct EEG component changes during both successful inhibitions (correct rejections) and successful executions (hits) of the motor response. During correct rejections, ERP changes were found over frontal regions, during latencies related to sensory gain control, conflict monitoring and working memory storage and processing. During hits, ERP changes were found over left-parietal regions during latencies related to orienting attention and subsequent selection and execution of the motor plan. The pattern of attenuation in walking-related EEG amplitude changes, during 2-back task performance, is thought to reflect more effortful recalibration of neural processes, a mechanism which might be a key driver of performance maintenance in the face of increased cognitive demands while walking. Overall, the present findings shed light on the extent of the neurocognitive capacity of young adults and may lead to a better understanding of how factors such as aging or neurological disorders could impinge on this capacity.

Measuring and modeling the effects of green barriers on the spatial distribution of fine particulate matter at roadside

Green barriers are regarded as a viable strategy for improving road air quality, and yet there lacks consensus regarding how they can actively regulate air pollution, particularly under dynamic traffic, meteorology and built environments. To address this, field measurements were conducted to assess the levels of fine particulate matter (PM2.5) before and after green barriers along an urban expressway. The measurements revealed distinct spatial attenuation patterns in vegetation-rich and vegetation-sparse areas. Specifically, the first-layer green barriers were found to significantly reduce PM2.5 levels by 8.4–9.3% in the vegetation-rich area. The magnitude of PM2.5 reduction at all locations distant from the motorway varied depending on the wind direction. On average, there are reductions of 7.8% (winter) and 13.0% (summer) in PM2.5 levels under cross-road winds. A validated hybrid model further demonstrated the significant impact of green barriers on pollutant diffusion, showing an unstable spatial variation trend under changing wind conditions. A combination of trees and hedgerows with a tree spacing of 3 m and obovate or spherical tree crowns proved effective in reducing roadside pollution. Simulations also suggested significant pollution reduction when considering appropriate spatial distribution of traffic flow and solid barrier alongside green barriers. These findings underscore the potential of combining green barriers with diverse measures to maximize the reduction of traffic-related pollution at roadside.