Pandemic-induced shifts in urban noise perception: A spatial-temporal analysis in a Chinese megacity.

The COVID-19 pandemic has significantly altered urban noise perception, with prolonged lockdowns in China producing lasting effects on residents' noise experiences. This study examines the spatiotemporal evolution of noise perception and its relationship with green space distribution in Hangzhou, China, using six years of noise complaint data from 2018 to 2023. Findings reveal a dynamic trajectory of noise complaints: initial diffusion, intensified agglomeration in core areas during lockdowns, followed by re-diffusion post-restriction.

Understanding the association between urban noise and nighttime light in China.

Nighttime light data partially reflects the process of urban modernization and its reaction to urban scale, but its correlation with noise remains unclear, especially over a long-term time series, remains unclear. To address this gap, we examine 31 provincial capital cities and municipalities in China as the study area, utilizing noise monitoring data and nighttime light data to explore their relationship in urban areas from 2012 to 2021. The results show that: (1) During the study period, the regional environmental noise and night light index of 31 major cities exhibited a consistent upward trend, with the average equivalent sound level of environmental noise in most urban areas fluctuating between 50.

Analytical model for the mitigation of VOC vapor with horizontal permeable reactive barrier in the contaminated site considering non-uniform source.

Volatile organic compounds (VOCs) contamination at the groundwater may cause vapor intrusion and pose significant threats to human health. As a novel low-carbon mitigation technology, a horizontal permeable reactive barrier (HPRB) is proposed to remove the VOC vapor in the vadose zone and mitigate the vapor intrusion risk. To estimate the performance of HPRB in the contaminated site with a non-uniform source, a transient two-dimensional analytical model is developed in this study to simulate the VOC vapor migration and oxidation processes in the layered soil.

Modeling the spreading and remediation efficiency of slow-release oxidants in a fractured and contaminated low-permeability stratum.

Traditional remediation technologies cannot well remediate the low permeability contaminated stratums due to the limitation in the transport capacity of solute. The technology that integrates the fracturing and/or slow-released oxidants can be a new alternative, and its remediation efficiency remains unknown. In this study, an explicit dissolution-diffusion solution for the oxidants in control release beads (CRBs) was developed to describe the time-varying release of oxidants.

Applications of functional nanoparticle-stabilized surfactant foam in petroleum-contaminated soil remediation.

Surfactant foam (SF) can be used to remediate petroleum-contaminated soil because of its easy transfer to inhomogeneous and low-permeability formations. Nanoparticles (NPs) not only stabilize SF under extreme conditions but also impart various functions, aiding the removal of petroleum contaminants. This review discusses the stabilization mechanisms of nanoparticle-stabilized SF (NP-SF) as well as the effects of NP size, chargeability, wettability, and NP-to-surfactant ratio on foam stability.

Approximate analytical model for transient transport and oxygen-limited biodegradation of vapor-phase petroleum hydrocarbon compound in soil.

Volatile organic compounds (VOCs) contamination may occur in subsurface soil due to various reasons and pose great threat to people. Petroleum hydrocarbon compound (PHC) is a typical kind of VOC, which can readily biodegrade in an aerobic environment. The biodegradation of vapor-phase PHC in the vadose zone consumes oxygen in the soil, which leads to the change in aerobic and anaerobic zones but has not been studied by the existing analytical models.

Enhanced delivery of amendments in fractured clay sites based on multi-point injection: An analytical study.

Fracturing technology that can enhance the delivery of amendments has attracted attention in the remediation of low-permeability contaminated sites. However, there are few works on the enhanced delivery of amendments based on multi-point injection in a fracture-matrix system. This study develops a two-dimensional analytical model for enhanced delivery of amendments in a finite-domain low-permeability matrix through multi-point injection in a natural, hydraulic or pneumatic fracture.

Effects of lower body positive pressure treadmill on functional improvement in knee osteoarthritis: A randomized clinical trial study.

Background: Knee joint pain and stiffness are the two main symptoms of knee osteoarthritis (OA) and thus restrict a patient's activities, such as walking and walking up and downstairs. The lower body positive pressure (LBPP) treadmill as one of the emerging body weight support system devices brings new hope for exercise-related rehabilitation for knee OA patients.

Aim: To investigate the biomechanical effects and the subjective clinical assessment of LBPP treadmill walking exercise when compared with conventional therapy in mild to moderate knee OA patients.

Two-dimensional analytical solution for subsurface volatile organic compounds vapor diffusion from a point source in layered unsaturated zone.

Although migration of subsurface volatile organic compounds (VOCs) from contaminant sources in unsaturated soil widely exists, the related analytical models are quite limited. A two-dimensional analytical solution is hence developed to simulate vapor diffusion from the subsurface contaminant source in the layered unsaturated zone. The contaminant source is simplified as a point source leaking at a constant rate.

An analytical model for one-dimensional diffusion of degradable contaminant through a composite geomembrane cut-off wall.

A one-dimensional analytical model is proposed to analyze contaminant diffusion through a composite geomembrane cut-off wall (CGCW) composed of a geomembrane (GMB) and a bentonite cut-off wall (BCW). The model considers degradation process of contaminant and time-dependent inlet boundary condition which are common in engineering practices. Moreover, two limiting scenarios of the exit boundary condition (EBC) of CGCW for field conditions are taken into account, including the flushing and non-advective semi-infinite aquifer EBCs.

Analytical model for organic contaminant transport through GMB/CCL composite liner with finite thickness considering adsorption, diffusion and thermodiffusion.

A new analytical model for organic contaminant transport through GMB/CCL (geomembrane and compacted clay liner) composite liner is developed, which can consider adsorption, diffusion and thermodiffusion processes and is applicable for typical bottom boundary conditions. The separation of variables method is adopted to derive the solution. The present model is first verified against experimental results and a numerical model.

Two-dimensional analytical solution for VOC vapor migration through layered soil laterally away from the edge of contaminant source.

A two-dimensional analytical solution is developed to simulate vapor migration in layered soil laterally away from the edge of contaminant source and has advantages in considering the vapor concentration profile in a functional form near the source edge. The analytical solution is validated against existing analytical solution, numerical model and experimental results. It has also proved to be an alternative screening tool to evaluate the vapor intrusion (VI) risk by compared with existing VI assessment tools.

Numerical model of aerobic bioreactor landfill considering aerobic-anaerobic condition and bio-stable zone development.

Aeration by airflow technology is a reliable method to accelerate waste biodegradation and stabilization and hence shorten the aftercare period of a landfill. To simulate hydro-biochemical behaviors in this type of landfills, this study develops a model coupling multi-phase flow, multi-component transport and aerobic-anaerobic biodegradation using a computational fluid dynamics (CFD) method. The uniqueness of the model is that it can well describe the evolution of aerobic zone, anaerobic zone, and temperature during aeration and evaluate aeration efficiency considering aerobic and anaerobic biodegradation processes.

Transient analytical solution for one-dimensional transport of organic contaminants through GM/GCL/SL composite liner.

Analytical solution for transport of organic contaminants through composite liner consisting of a geomembrane (GM), a geosynthetic clay liner (GCL), and a soil liner (SL) with finite thickness is presented. The transient diffusion-advection processes in the whole composite liner and adsorption in GCL and SL can be described by the present method. The method is successfully verified against analytical solution to a coupling transient diffusion-advection problem in double-layer porous media.

CFD modeling of hydro-biochemical behavior of MSW subjected to leachate recirculation.

The most commonly used method of operating landfills more sustainably is to promote rapid biodegradation and stabilization of municipal solid waste (MSW) by leachate recirculation. The present study is an application of computational fluid dynamics (CFD) to the 3D modeling of leachate recirculation in bioreactor landfills using vertical wells. The objective is to model and investigate the hydrodynamic and biochemical behavior of MSW subject to leachate recirculation.

[Malaria Epidemic Situation in Rudong County of Jiangsu Province during 1999-2014].

From 1999 to 2014 a total of 23 cases of malaria were reported in Rudong County, Jiangsu Province, comprising one indigenous case of vivax malaria, 9 imported cases of vivax malaria, and 13 imported cases of falciparum malaria. The imported cases accounted for 95.7%(22/23) of all cases.

Ant colony optimization analysis on overall stability of high arch dam basis of field monitoring.

A dam ant colony optimization (D-ACO) analysis of the overall stability of high arch dams on complicated foundations is presented in this paper. A modified ant colony optimization (ACO) model is proposed for obtaining dam concrete and rock mechanical parameters. A typical dam parameter feedback problem is proposed for nonlinear back-analysis numerical model based on field monitoring deformation and ACO.