Urban flood exposure assessment through citizen science, 2D hydraulic modeling, and artificial intelligence.

Addressing and predicting urban flooding remains a significant challenge. This study combines citizen observations, two-dimensional modelling, and machine learning (ML) to model, calibrate, validate, and forecast flooding in an urban area of central Mexico with limited runoff and rain gauge data. Citizen observations via social media and newspapers identified flood events and locations.

Phase separation and rheology of segregating binary fluid under shear.

We employ molecular dynamics simulation to study the phase separation and rheological properties of a three-dimensional binary liquid mixture with hydrodynamics undergoing simple shear deformation. The impact of shear intensity on domain growth is investigated, with a focus on how shear primarily distorts the domains, leading to the formation of anisotropic structures. The structural anisotropy is quantified by evaluating domain sizes along the flow and shear direction.

Effect of heavy impurities on the plasticity of amorphous solids.

We investigate the effect of heavy impurities on the mechanical properties and plasticity of a modeled amorphous solid by introducing a small fraction of these impurities into the material which resembles real experimental systems. The impurities being mobile, the total degrees of freedom and the potential energy landscape of the pure system are preserved in our model. The mechanical failure and the shear band formation in the amorphous solid in the presence of impurities are studied at the microscopic level by employing the finite shear deformation protocol at nonzero temperature.

Kinetics of vapor-liquid transition of active matter system in confined geometry.

We study the kinetics of vapor-liquid phase separation in a quasi-one-dimensional confined active matter system using molecular dynamics simulations. Activity is invoked via the Vicsek rule, while passive interaction follows the Lennard-Jones potential. With the system density near the vapor branch, the evolution morphology features disconnected liquid clusters.

Kinetics of vapor-liquid and vapor-solid phase separation under gravity.

We study the kinetics of vapor-liquid and vapor-solid phase separation of a hydrodynamics preserving three-dimensional one-component Lennard Jones system in the presence of an external gravitational field using extensive molecular dynamic simulation. A bicontinuous domain structure is formed when the homogeneous system near the critical density is quenched inside the coexistence region. In the absence of gravity, the domain morphology is statistically self-similar and the length scale grows as per the existing laws.

Evaluation of biodegradability, toxicity and ecotoxicity of organic acid-based deep eutectic solvents.

Over the past decade, deep eutectic systems (DES) have become popular, yet their potential toxicity to living organisms is not well understood. This study fills this gap by examining the toxicity, antibacterial activity and biodegradability of p-toluenesulfonic acid monohydrate (PTSA)-based DESs prepared from ammonium or phosphonium salts. Brine shrimp assays revealed varying toxicity levels of PTSA and salts.

Kinetics of phase separation and aging dynamics of segregating fluid mixtures in the presence of quenched disorder.

Quenched or frozen-in structural disorder is ubiquitous in real experimental systems. Much of the progress is achieved in understanding the phase separation of such systems using the diffusion-driven coarsening in an Ising model with quenched disorder. But there is a paucity of research on the phase-separation kinetics in fluids with quenched disorder.

Technological and economic analysis of electrokinetic remediation of contaminated soil: A global perspective and its application in Indian scenario.

Globally million hectares of land annually is getting contaminated by heavy metalloids like As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with current concentrations in soil above geo-baseline or regulatory standards. The heavy metals are highly toxic, mobile, and persistent and hence require immediate and effective mitigation. There are many available remediation techniques like surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation which have been evolved to clean up heavy metal-contaminated sites.

Surface-directed spinodal decomposition of fluids confined in a cylindrical pore.

The surface-directed spinodal decomposition of a binary liquid confined inside a cylindrical pore is investigated using molecular dynamics simulations. One component of the liquid wets the pore surface while the other remains neutral. A variety of wetting conditions are studied.

Integrating multiple spheres to identify the provenance and risk of urban dust and potentially toxic elements: Case study from central Mexico.

This study aims to improve the current method of studying potentially toxic elements (PTEs) in urban dust using direct chemical evidence (from dust, rock, and emission source samples) and robust geochemical methods. The provenance of urban dust was determined using rare earth elements (REEs) and geochemical diagrams (V-Ni-Th*10, TiO vs. Zr, and Zr/Ti vs.

Characteristics and correlations of nonaffine particle displacements in the plastic deformation of athermal amorphous materials.

When an amorphous solid is deformed homogeneously, it exhibits heterogeneous plastic instabilities with a localized cooperative rearrangement of a cluster of particles in response. The heterogeneous behavior plays an important role in deciding the mechanical properties of amorphous solids. In this paper, we employ computer simulations to study the characteristics and the spatial correlations of these clusters characterized by their non-affine displacements in amorphous solids under simple shear deformation in the athermal quasistatic limit.

Silicon nanoparticles decrease arsenic translocation and mitigate phytotoxicity in tomato plants.

In this study, we simulate the irrigation of tomato plants with arsenic (As)-contaminated water (from 0 to 3.2 mg L) and investigate the effect of the application of silicon nanoparticle (Si NPs) in the form of silicon dioxide (0, 250, and 1000 mg L) on As uptake and stress. Arsenic concentrations were determined in substrate and plant tissue at three different stratums.

Effect of annealed disorder on phase separation kinetics and aging phenomena in fluid mixtures.

We use state-of-the-art molecular dynamics simulations to study the effects of annealed disorder on the phase-separating kinetics and aging phenomena of a segregating binary fluid mixture. In the presence of disorder, we observe a dramatic slowing down in the phase separation dynamics. The domain growth follows the power law with a disorder-dependent exponent.

Mechanical properties and pore size distribution in athermal porous glasses.

We study the mechanical properties and pore structure in a three-dimensional molecular dynamics model of porous glass under athermal quasistatic shear. The vitreous samples are prepared by rapid thermal quenching from a high-temperature molten state. The pore structures form solid-gas phase separation.

Universality of plastic instability and mechanical yield in metallic glasses.

The generic response of a wide range of amorphous solids is the average increase of stress upon external loading until the yielding transition point, after which elasto-plastic steady state sets in. The stress-strain response comprises of a series of elastic branches interspersed with plastic drops. The ubiquitousness of these phenomena indicates universality, independent of material property, but the literature predominantly deals with specific materials.

Paracyclops chiltoni inhabiting water highly contaminated with arsenic: Water chemistry, population structure, and arsenic distribution within the organism.

We investigated population structure and arsenic bioaccumulation and distribution in zooplankton inhabiting highly contaminated freshwater with arsenic. We collected water and zooplankton samples over a 4 year period, determined environmental temperature as well as water temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), oxidation-reduction potential (ORP), dissolved oxygen (DO), major cations and anions and total arsenic concentration. We identified zooplankton species and determined their abundance, length, sex ratios, and arsenic bioaccumulation and distribution in exposed organisms.

Alluvial and gypsum karst geological transition favors spreading arsenic contamination in Matehuala, Mexico.

Arsenic transport in alluvial aquifers is usually constrained due to arsenic adsorption on iron oxides. In karstic aquifers, however, arsenic contamination may spread to further extensions mainly due to favorable hydrogeochemical conditions. In this study, we i) determined the spatial and temporal behavior of arsenic in water in an alluvial-karstic geological setting using field and literature data, ii) established whether a contaminated aquifer exists using field and literature piezometric data and geophysical analysis, iii) studied the local geology and associated arsenic contaminated water sources to specific aquifers, iv) revealed and modeled subsoil stratigraphy, and v) established the extent of arsenic exposure to the population.

Characterization and Adsorption Behavior of Strontium from Aqueous Solutions onto Chitosan-Fuller's Earth Beads.

Fuller's earth spherical beads using chitosan as a binder were prepared for the removal of strontium ions from aqueous solution. The adsorbents were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which revealed the porous nature of the beads. The Brunauer⁻Emmett⁻Teller (BET) surface area of the beads was found to be 48.

Distribution of Arsenic and Risk Assessment of Activities on Soccer Pitches Irrigated with Arsenic-Contaminated Water.

The aim of this research was to estimate the risk of human exposure to arsenic due to sporting activities in a private soccer club in Mexico, where arsenic-contaminated water was regularly used for irrigation. For this purpose, the total concentration in the topsoil was considered for risk assessment. This was accomplished through three main objectives: (1) measuring arsenic concentrations in irrigation water and irrigated soils, (2) determining arsenic spatial distribution in shallow soils with Geographical Information Systems (GIS) using geostatistical analysis, and (3) collecting field and survey data to develop a risk assessment calculation for soccer activities in the soccer club.

Arsenic and fluoride removal from contaminated drinking water with Haix-Fe-Zr and Haix-Zr resin beads.

The objective of the study was to carry-out batch tests to examine the effectiveness of Haix-Fe-Zr and Haix-Zr resin beads in the removal of As(III), As(V) and F from groundwater with a similar geochemistry to a site where a community-based drinking water plant has been installed in West Bengal, India. The groundwater was spiked separately with ∼200 μg/L As(III) and As(V) and 5 mg/L F. Haix-Zr resin beads were more effective than Haix-Fe-Zr resin beads in removing As(III) and As(V).

Arsenic contamination in irrigation water, agricultural soil and maize crop from an abandoned smelter site in Matehuala, Mexico.

Mobility of Arsenic (As) from metallurgical wastes in Matehuala, Mexico has been accounted for ultra-high concentration of As in water (4.8-158mg/L) that is used for recreational purposes as well as cultivation of maize. In this study, we (i) measured As concentrations in soils irrigated with this water, (ii) investigated the geochemical controls of available As, and (iii) measured bioaccumulation of As in maize.

Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin.

Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.

Remediation of Arsenic Contaminated Soil Using Phosphate and Colloidal Gas Aphron Suspensions Produced from Sapindus mukorossi.

Phosphate and colloidal gas aphrons (CGAs) generated from saponin extracted from Sapindus mukorossi fruit, were evaluated for washing low levels of arsenic from an iron rich soil. Phosphate is one of the most commonly dispersed chemicals that increases arsenic mobility in soil due to their structural similarities, making it an important factor in arsenic removal process. Column washing experiments were performed with CGAs in down flow and up flow modes on soil of pH 5 and 6.