Transport Modeling - Science topic

Open biomass burning (OBB) is a significant source of air pollutants, profoundly impacting regional air quality and global climate change. However, due to the lack of high-resolution burned area products, limited biomass data resolution, and inappropriate emission factors (EFs), current OBB emission inventories have significant uncertainties. In th...

Rheological experiments and measurements of particle settling velocity under static conditions were conducted for two types of polyacrylamide (PAA-based) fluids. The flow behavior of the viscoelastic fluids is described by a simplified, three-parameter model that integrates a constant viscosity at low shear rates with a power-law viscosity dependen...

Making ultra-short gate-length transistors significantly contributes to scaling the contacted gate pitch. This, in turn, plays a vital role in achieving smaller standard logic cells for enhanced logic density scaling. As we push the boundaries of miniaturization, it is intriguing to consider that the ultimate limit of contacted gate pitch could be...

The chapter “ Setting the Scene for Automated Mobility: A Comparative Introduction to the Mobility Systems in Germany and Japan ” provides an overview of the framework conditions characterizing the transport systems in Germany and Japan. Following two chapters investigate relation of the governance style to regulatory changes and resource allocatio...

Studying hyper-nuclei yields and their collectivity can shed light on their production mechanism as well as the hyperon-nucleon interactions. Heavy-ion collisions from the RHIC beam energy scan phase II (BES-II) provide an unique opportunity to understand these at high baryon densities. In these proceedings, we present a systematic study on energy...

Reactive Transport Models (RTMs) are essential tools for understanding and predicting intertwined ecohydrological and biogeochemical processes on land and in rivers. While traditional RTMs have focused primarily on subsurface processes, recent watershed‐scale RTMs have integrated ecohydrological and biogeochemical interactions between surface and s...

Although long-distance international travel contributes significantly to global emissions from the transport sector, disaggregated travel demand forecasting models on long-distance international travel are scarce. Large infrastructure investments such as high-speed rail may have a profound impact on long-distance international travel demand and thu...

Currently, there are two primary issues with CFD simulations of local scour around bridge foundations using the RANS method. Firstly, the self-sustaining characteristics of turbulent boundary conditions at the inlet require special attention. Secondly, the simulated location of the maximum scour depth does not align with experimental observations....

Given the potential risks of unknown and emerging infectious respiratory diseases, prioritizing an appropriate ventilation strategy is crucial for controlling aerosol droplet dispersion and mitigating cross-infection in hospital wards during post-epidemic periods. This study optimizes the layout of supply diffusers and exhaust outlets in a typical...

Anguilla marmorata, A. megastoma, and A. obscura live in the freshwater habitats of tropical islands spread across the western half of the South Pacific from New Caledonia to French Polynesia, but little is known about their early life histories or spawning areas in the eastern region. Otolith microstructure examinations of 455 glass eels from Moor...

Routine observations of the vertical distribution of tropospheric nitrogen oxides (NOx≡ NO + NO2) are severely lacking, despite the large influence of NOx on climate, air quality, and atmospheric oxidants. Here, we derive vertical profiles of global seasonal mean tropospheric NO2 by applying the cloud-slicing method to TROPOspheric Monitoring Instr...

Methane (CH4) fluxes emitted by wetlands at high latitudes remain one of the largest sources of uncertainties in global methane budgets. At these latitudes, flux estimation approaches, such as atmospheric inversions, are impacted by improper characterisation of atmospheric transport due to challenging meteorological conditions and a lack of measure...

Accurately modeling geochemical reactions in subsurface flow is essential for understanding processes such as CO2 sequestration and contaminant transport. This paper presents a new numerical subsurface simulator (MF3D-GC) that combines flow, geomechanics, and geochemistry in an integrated and fully coupled manner. The simulator's capabilities were...

We used WRF-Chem to simulate ash transport from eruptions of Chile’s Calbuco volcano on 22–23 April 2015. Massive ash and SO2 ejections reached the upper troposphere, and particulates transported over South America were observed over Argentina, Uruguay, and Brazil via satellite and surface data. Numerical simulations with the coupled Weather Resear...

Air pollution is a risk to human health, especially in urban areas. While exhaust emissions from road traffic have decreased over the last decades, non-exhaust emissions remain and tend to increase. In this study, tyre and brake wear emissions are quantified applying a bottom-up model for the city of Hamburg in 2018. Their dispersion and contributi...

United States (US) background ozone (O3) is the counterfactual O3 that would exist with zero US anthropogenic emissions. Estimates of US background O3 typically come from chemical transport models (CTMs), but different models vary in their estimates of both background and total O3. Here, a measurement–model data fusion approach is used to estimate...

Thermoelectric properties of organic semiconductors have been intensively studied over the last 15 years for their application in converting waste heat into electricity. Optimism in the field of organic thermoelectrics points at the possibility of achieving figures of merit (ZT) approaching or exceeding one. Despite tremendous research effort over...

Background To link the treatment of radiation injury with angiogenesis, and to design and seek a new therapeutic technique for the prevention and treatment of radiation injury. Methods The transverse bone transport device for rabbit mandible was designed and manufactured. Eighteen New Zealand white rabbits were randomly divided into a radiotherapy...

Measurements collected from ground monitoring stations have gained popularity as a valuable data source for evaluating numerical models and correcting model errors through data assimilation. The penalty quantified by simulation minus observations drives both model evaluation and assimilation. However, the penal forces are challenged by the existenc...

Changes in tropospheric ozone over the Tibetan Plateau (TP) profoundly affect the local ecosystems and human health. Yet previous studies on the TP ozone have focused on the background regions, with much less attention on the urban ozone. Here we quantify the ozone trends over the whole TP from 2015 to 2019 in the context of its long-term trends, w...

Forest fires in the Western Himalaya region pose significant environmental and health challenges. The present communication examines the impact of these fires on air quality, focusing on elevated levels of carbon monoxide, formaldehyde and aerosols. Utilizing satellite inputs and chemistry transport models such as Hybrid Single Particle Lagrangian...

Aerosol chemical components are critical parameters that influence the atmospheric environment, climate effects, and human health. Retrieving global columnar atmospheric aerosol components from satellite observations provides foundational data and practical value. This study develops a method for retrieving aerosol component composition from polari...

The Mississippi Sound and Bight is a complex coastal system with shallow estuarine waters that are highly vulnerable to the effects of climate change and anthropogenic influences. In order to further our understanding of the system and provide natural resource managers and decision-makers with science-based guidance, a pre-operational coastal ocean...

In this work, we present a fundamental mathematical model for proton transport, tailored to capture the key physical processes underpinning Proton Beam Therapy (PBT). The model provides a robust and computationally efficient framework for exploring various aspects of PBT, including dose delivery, linear energy transfer, treatment planning and the e...

Autogenous self-healing can close cracks in water-retaining concrete structures. However, its inconsistent efficiency in building practice indicates that the underlying processes are not fully understood. Therefore, this study characterizes reactive transport through cracked concrete and models it using PHREEQC to develop a comprehensive understand...

Despite substantial reductions in anthropogenic emissions, ozone (O3) pollution remains a severe environmental problem in urban China. These reductions affect ozone formation by altering levels of O3 precursors, intermediates, and the oxidation capacity of the atmosphere. However, the underlying mechanisms driving O3 changes are still not fully und...

Modeling transition-continuum hypersonic flows poses significant challenges due to thermodynamic nonequilibrium and the associated breakdown of the continuum assumption. Standard continuum models such as the Navier-Stokes equations are inaccurate for these flows, and molecular models can be inefficient due to the large number of computational parti...

Chemical transport models (CTM) have wide and profound applications in air quality simulations and managements. However, its applications are often constrained by high computational burdens. In this study, we developed a neural network based CTM model (FastCTM) to efficiently simulate ten air pollutant composition variables, including major PM2.5 s...

We propose a new method to measure the evolution of the neutron skin thickness between different isotopes with small statistical and systematic uncertainties. We consider antiproton--nucleus interactions close to the production threshold of $\Lambda \overline{\Lambda }$ and $\Sigma^-\overline{\Lambda }$ pairs. At low energies, $\Lambda \overline{\L...

Radio halos of edge-on galaxies are crucial for investigating cosmic ray propagation and magnetic field structures in galactic environments. We present VLA C-configuration S-band (2--4 GHz) observations of the spiral galaxy NGC 3556, a target from the Continuum Halos in Nearby Galaxies - an EVLA Survey (CHANG-ES). We estimate the thermal contributi...

Purpose Understanding trends in residual sediment transport is of great interest to target a sustainable morphological management of estuaries, addressing natural sediment transport, anthropogenic interference and climate change. To provide managers with additional information to optimize their sediment management strategy, a sand and mud budget ha...

A flight controller formulation based on incremental nonlinear dynamics inversion (INDI) control with nonlinear disturbance observer (NDO) is proposed. INDI control is a nonlinear controller based on incremental dynamics. Aimed to attain robustness for nonlinear dynamics inversion (NDI)-based controller, incremental dynamics are derived using the f...

Purpose Cadmium (Cd), as a common heavy metal pollutant, has attracted considerable attention due to its ecotoxicity in aquatic and terrestrial ecosystems. However, the impact of humic acid (HA) on the transport of Cd²⁺ in biochar-amended soils remains unclear. Methods The transport behavior of Cd²⁺ in saturated porous media amended with pomelo pe...

The significance of groundwater is largely shaped by the quality of wastewater from industrial, agricultural, and municipal sources. Understanding the controlling factors is essential to prevent the spread of contamination in groundwater. These factors could be divided into physical defenses, such as grouting and slurry walls, and hydrodynamic fact...

Nitrous acid (HONO) is a main precursor of hydroxyl radicals (OH), which contribute to the formation of numerous secondary air pollutants in the troposphere. Despite its importance in atmospheric chemistry, HONO chemistry has not been fully incorporated into many chemical transport models (CTMs). Due to the lack of atmospheric HONO processes, CTM s...

Inspired by various studies on extracting the density distributions of nuclei from their collisions at ultrarelativistic energies, in the present work we investigate the possibility of extracting the neutron-skin thickness $\Delta r_{np}$ in nuclei by their collisions at intermediate energies. We have analyzed the free neutron-to-proton yield ratio...

We introduce NitroNet, a deep learning model for the prediction of tropospheric NO2 profiles from satellite column measurements. NitroNet is a neural network trained on synthetic NO2 profiles from the regional chemistry and transport model WRF-Chem, which was operated on a European domain for the month of May 2019. This WRF-Chem simulation was cons...

This study investigates the correlation between dairy farm characteristics and methane concentrations as derived from satellite observations in Eastern Canada. Utilizing data from 11 dairy farms collected between January 2020 and December 2022, we integrated Sentinel-5P satellite methane data with critical farm-level attributes, including herd gene...

The collisional and transport properties of hypersonic plasmas have been simulated by an air plasma chemistry model, which includes collisions with electrons, ions and neutral species, elastic scattering, vibrational relaxation and a transport model. Species and thermal fluxes at the surface of the vehicle have been investigated as a function of po...

Within the framework of Lanzhou quantum molecular dynamics transport model, the neutron-skin thickness and its impact on the nuclear dynamics induced by low-energy antiprotons are investigated thoroughly. The correlation of the neutron-skin thickness and stiffness of symmetry energy is implemented into the transport model via the Fermi distribution...

We use an integrated modeling workflow with the transport code ASTRA coupled with the quasi-linear transport model TGLF-SAT2, the neoclassical model NCLASS, the FACIT model for the neoclassical impurity transport and the IMEP routines for the pedestal calculations, in order to predict the evolution of the plasma profiles for the Divertor Tokamak Te...

The strange baryon production in Bi + Bi collisions at sNN=9.0 GeV is studied using the PHSD transport model. Hyperon and anti-hyperon yields, transverse momentum spectra, and rapidity spectra are calculated, and their centrality dependence and the effect of rapidity and transverse momentum cuts are studied. The rapidity distributions for Λ¯, Ξ, Ξ¯...

Recently the transportation sector has witnessed several new technologically driven disruptions that have amplified the complexity of city planning and policymaking. Traditional well-established processes of decision-making in urban planning and transportation are proving insufficient to deal with this degree of complexity and uncertainty. This pap...

Squealer tip has a significant influence on both aerodynamic and heat transfer characteristics of the high-pressure turbine. Among the geometric parameters of the squealer, squealer height is one of the essential parameters in the tip design. However, due to the complexity of parameterization and meshing of the squealer, the related research is usu...

API Phonons is a Python software package to predict the transport dynamics of heat-carrying phonons. Using the powerful syntax of Python, this package provides modules and functions interfacing between different packages for atomistic simulations, lattice dynamics, and phonon-phonon interaction calculations including LAMMPS, Quippy, Phonopy, and Sh...

Environmental exposures are ubiquitous and play a significant, and sometimes understated, role in public health as they can lead to the development of various chronic and infectious diseases. In an ideal world, there would be sufficient experimental data to determine the health effects of exposure to priority environmental contaminants. However, th...

The International Monitoring System, the primary means of verification of the Comprehensive Nuclear-Test-Ban Treaty, monitors the planet for any sign of a nuclear explosion. Regarding the International Monitoring System radionuclide stations, it is known that radioxenon released from nuclear facilities such as medical isotope production facilities...

We investigate the pre-equilibrium dipole response in the charge-asymmetric reaction $^{40}$Ca+$^{152}$Sm, of recent experimental interest, at several beam energies within the range $[5, 11]$ AMeV and different collision centralities. By employing Skyrme-like effective interactions for the nuclear mean field, we probe the role of the different ingr...

Atmospheric inverse modeling is the process of estimating emissions from atmospheric observations by minimizing a cost function, which includes a term describing the difference between simulated and observed concentrations. The minimization of this difference is typically limited by uncertainties in the atmospheric transport model rather than by un...

The problem of cross-infection between patients and surgeons in the operating room had been widely concerned by the international community. The purpose of this study had been to explore the potential of a Dual-loop Different Velocity Air Curtain System (DDVACS) being applied in the operating room to reduce cross-infection. In this study, the perfo...

The collective flow is crucial for understanding the anisotropic expansion of particles produced in heavy-ion collisions and is sensitive to the equation of state of nuclear matter in high baryon density regions. In this paper, we use the hadronic transport model SMASH to study the elliptic flow ($v_2$), quadrangular flow ($v_4$), and their ratio (...

A reactive transport model was employed to investigate the influence of multiple hydrate phases during acetic acid attack on Portland cement paste. The simulation accounted for the dissolution of primary cement hydrates like Ettringite, Portlandite and C-S-H, along with the formation of silica gel products impacting diffusivity. The simulations pri...

The SMall Aspect Ratio Tokamak (SMART) is currently being commissioned at the University of Seville and will be able to compare the performance of positive and negative triangularity plasmas at low aspect ratio. Predictive simulations have been performed for different machine scenarios and heating schemes using the TRANSP code. The objectives of th...

Diterpenes (C 20 H 32 ) are commonly found in trees, but their emissions into the atmosphere were previously considered unlikely due to their low volatility. Consequently, they have been disregarded in atmospheric chemistry processes. Recent improvements in sampling and analytical instrumentation have enabled the detection and quantification of dit...

Studying the magnetic field properties on the solar surface is crucial for understanding the solar and heliospheric activities, which in turn shape space weather in the solar system. Surface flux transport (SFT) modeling helps us to simulate and analyze the transport and evolution of magnetic flux on the solar surface, providing valuable insights i...

Biomarkers such as functional gene mRNA (transcripts) and proteins (enzymes) provide direct proof of metabolic regulation during the reductive dechlorination (RD) of chlorinated ethenes (CEs). Yet, current models to simulate their spatiotemporal variability are not flexible enough to mimic the homologous behavior of RDase functional genes. To this...

Validation of groundwater models is relatively challenging due to the need to reserve scarce water level data for calibration targets. In addition, traditional statistical validation metrics are unintuitive for non-technical audiences and do not directly identify model behaviors that require further refinement. We developed a novel model validation...

There is a growing interest in the health impacts of PM2.5 originating from landscape fires. We conducted a time-series study to investigate the association between daily exposure to landscape fire PM2.5 and hospital admissions for cardiovascular events in 184 major Chinese cities. We developed a machine learning model combining outputs from chemic...

Modeling the transport of low-energy (1−10 MeV) cosmic-ray electrons can lead to valuable insights as to the behavior of the heliospheric magnetic field (HMF), due to the fact that the mean free path (MFP) of these particles parallel to the HMF is significantly larger than their perpendicular MFP, and that these particles experience little in the w...

The strange baryon production in Bi+Bi collisions at $\sqrt{s_{NN}}=9.0$\,GeV is studied using the PHSD transport model. Hyperon and anti-hyperon yields, transverse momentum spectra, and rapidity spectra are calculated, their centrality dependence and the effect of rapidity and transverse momentum cuts are studied. The rapidity distributions for $\...

Increased concentrations of greenhouse gases in the atmosphere are known to be the main cause of global warming. Among the various decarbonisation strategies proposed, geological storage of CO2 is one of the most interesting options for reducing net carbon emissions to the atmosphere. The safe long-term storage of CO2 in spatially confined undergro...