Non-Fickian transport processes accelerate the movement of PFOS in unsaturated media: An experimental and modelling study.

The transport of per- and polyfluoroalkyl substances (PFASs) through unsaturated source-zone soils is a critical yet poorly understood aspect of their environmental behavior. To date, most experimental studies have only focused on the equilibrium or non-equilibrium partitioning of PFASs to the air-water interface, or solid-phase based equilibrium or non-equilibrium transport. Currently, there are discrepancies between air-water interfacial partitioning (K) results measured using a drainage-based column method (which supports a Langmuir isotherm) when compared to measurements from alternative experimental methods (which support a Freundlich isotherm).

Predicting Concentration- and Ionic-Strength-Dependent Air-Water Interfacial Partitioning Parameters of PFASs Using Quantitative Structure-Property Relationships (QSPRs).

Air-water interfacial retention of poly- and perfluoroalkyl substances (PFASs) is increasingly recognized as an important environmental process. Herein, column transport experiments were used to measure air-water interfacial partitioning values for several perfluoroalkyl ethers and for PFASs derived from aqueous film-forming foam, while batch experiments were used to determine equilibrium data for compounds exhibiting evidence of rate-limited partitioning. Experimental results suggest a Freundlich isotherm best describes PFAS air-water partitioning at environmentally relevant concentrations (10-10 ng/L).

Protecting reproductive health information in the post-Roe era: interoperability strategies for healthcare institutions.

On June 24, 2022, the US Supreme Court ended constitutional protections for abortion, resulting in wide variability in access from severe restrictions in many states and fewer restrictions in others. Healthcare institutions capture information about patients' pregnancy and abortion care and, due to interoperability, may share it in ways that expose their providers and patients to social stigma and potential legal jeopardy in states with severe restrictions. In this article, we describe sources of risk to patients and providers that arise from interoperability and specify actions that institutions can take to reduce that risk.

Using Simulation to Teach Learners in Health Care Behavioral Skills Related to Diversity, Equity, and Inclusion: A Scoping Review.

Bias is commonplace in the health care environment and can negatively impact patients and their health outcomes. Simulation has long been shown to be an effective teaching tool for communication skills in health care, but it has rarely been used to deliver concrete behavioral skills that address issues of diversity, equity, and inclusion (DEI). This scoping review examines 23 published articles surrounding the use of simulation in health care education to impart behavioral skills that reduce bias and promote DEI.

Pore-Scale Mechanisms of Solid Phase Emergence During DNAPL Remediation by Chemical Oxidation.

In situ chemical oxidation (ISCO) has proven successful in the remediation of aquifers contaminated with dense nonaqueous phase liquids (DNAPLs). However, the treatment efficiency can often be hampered by the formation of solids or gas, reducing the contact between remediation agents and residual DNAPLs. To further improve the efficiency of ISCO, fundamental knowledge is needed about the complex multiphase flow and reactive transport processes as new solid and fluid phases emerge at the microscale.

An overlooked mechanism underlying the attenuated temperature response of soil heterotrophic respiration.

Biogeochemical reactions occurring in soil pore space underpin gaseous emissions measured at macroscopic scales but are difficult to quantify due to their complexity and heterogeneity. We develop a volumetric-average method to calculate aerobic respiration rates analytically from soil with microscopic soil structure represented explicitly. Soil water content in the model is the result of the volumetric-average of the microscopic processes, and it is nonlinearly coupled with temperature and other factors.

Estimation of Transport Parameters of Perfluoroalkyl Acids (PFAAs) in Unsaturated Porous Media: Critical Experimental and Modeling Improvements.

Predicting the transport of perfluoroalkyl acids (PFAAs) in the vadose zone is critically important for PFAA site cleanup and risk mitigation. PFAAs exhibit several unusual and poorly understood transport behaviors, including partitioning to the air-water interface, which is currently the subject of debate. This study develops a novel use of quasi-saturated (residual air saturation) column experiments to estimate chemical partitioning parameters of both linear and branched perfluorooctane sulfonate (PFOS) in unsaturated soils.

The Mass Transfer Index (MTI): A semi-empirical approach for quantifying transport of solutes in variably saturated porous media.

The processes impacting solute transport through unsaturated porous media have been receiving renewed attention due to their relevance to the transport of emerging contaminants. A set of well-monitored and highly controlled experiments in sand columns were conducted to determine the effect of partial saturation on conservative solute breakthrough in porous media. The results suggest traditional transport parameter estimation methods inadequately account for the pore-scale processes of mass transfer to the immobile zones and the effects of partial saturation on advective transport, even for conservative tracers.

Obstetrics and Gynecology and Reparations: The Debt We Owe (and Continue to Accumulate).

Obstetrics and gynecology (OBGYN) is rife with exploitation and oppression of Black individuals and disparate health outcomes. We posit that racial disparities in OBGYN are fueled by racism and the racial wealth gap stemming from slavery, legal segregation, and institutionalized discrimination against Black Americans. We believe reparations are not only morally requisite, but would also improve health outcomes for our patients.

Effects of large-scale heterogeneity and temporally varying hydrologic processes on estimating immobile pore space: A mesoscale-laboratory experimental and numerical modeling investigation.

The advection-dispersion equation (ADE) often fails to predict solute transport, in part due to incomplete mixing in the subsurface, which the development of non-local models has attempted to deal with. One such model is dual-domain mass transfer (DDMT); one parameter that exists within this model type is called immobile porosity. Here, we explore the complexity of estimating immobile porosity under varying flow rates and density dependencies in a large-scale heterogeneous system.

Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments.

Plant performance (i.e., fecundity, growth, survival) depends on an individual's access to space and resources.

Massive ovarian edema, due to adjacent appendicitis.

Massive ovarian edema is a benign clinical entity, the imaging findings of which can mimic an adnexal mass or ovarian torsion. In the setting of acute abdominal pain, identifying massive ovarian edema is a key in avoiding potential fertility-threatening surgery in young women. In addition, it is important to consider other contributing pathology when ovarian edema is secondary to another process.

Effect of NAPL Source Morphology on Mass Transfer in the Vadose Zone.

The generation of vapor-phase contaminant plumes within the vadose zone is of interest for contaminated site management. Therefore, it is important to understand vapor sources such as non-aqueous-phase liquids (NAPLs) and processes that govern their volatilization. The distribution of NAPL, gas, and water phases within a source zone is expected to influence the rate of volatilization.

Study of the effect of wind speed on evaporation from soil through integrated modeling of the atmospheric boundary layer and shallow subsurface.

In an effort to develop methods based on integrating the subsurface to the atmospheric boundary layer to estimate evaporation, we developed a model based on the coupling of Navier-Stokes free flow and Darcy flow in porous medium. The model was tested using experimental data to study the effect of wind speed on evaporation. The model consists of the coupled equations of mass conservation for two-phase flow in porous medium with single-phase flow in the free-flow domain under nonisothermal, nonequilibrium phase change conditions.

Same-day synthetic osmotic dilators compared with overnight laminaria before abortion at 14-18 weeks of gestation: a randomized controlled trial.

Objective: To increase access to early second-trimester surgical abortion by determining noninferiority of same-day synthetic osmotic dilators compared with overnight Laminaria for cervical preparation before early second-trimester dilation and evacuation.

Methods: We enrolled women between 14 and 18 weeks of gestation and randomized them to same-day synthetic osmotic dilators or overnight Laminaria. Study participants and clinicians were blinded to group assignment.

Long-term mass transfer and mixing-controlled reactions of a DNAPL plume from persistent residuals.

Understanding and being able to predict the long-term behavior of DNAPL (i.e., PCE and TCE) residuals after active remediation has ceased have become increasingly important as attention at many sites turns from aggressive remediation to monitored natural attenuation and long-term stewardship.

Dissolution of dense non-aqueous phase liquids in vertical fractures: effect of finger residuals and dead-end pools.

Understanding the dissolution behavior of dense non-aqueous phase liquids (DNAPLs) in rock fractures under different entrapment conditions is important for remediation activities and any related predictive modeling. This study investigates DNAPL dissolution in variable aperture fractures under two important entrapment configurations, namely, entrapped residual blobs from gravity fingering and pooling in a dead-end fracture. We performed a physical dissolution experiment of residual DNAPL blobs in a vertical analog fracture using light transmission techniques.

Experimental study of the effects of DNAPL distribution on mass rebound.

The release of stored dissolved contaminants from low permeability zones contributes to plume persistence beyond the time when dense nonaqueous phase liquid (DNAPL) has completely dissolved. This is fundamental to successfully meeting acceptable low concentrations in groundwater that are driven by site-specific cleanup goals. The study goals were to assess the role of DNAPL entrapment morphology on mass storage and plume longevity.

Laboratory investigations of the effects of geologic heterogeneity on groundwater salinization and flush-out times from a tsunami-like event.

This intermediate scale laboratory experimental study was designed to improve the conceptual understanding of aquifer flushing time associated with diffuse saltwater contamination of coastal aquifers due to a tsunami-like event. The motivation comes from field observations made after the tsunami in December, 2004 in South Asia. The focus is on the role and effects of heterogeneity on flushing effectiveness.

Effects of single-fracture aperture statistics on entrapment, dissolution and source depletion behavior of dense non-aqueous phase liquids.

Understanding of the entrapment and dissolution behavior of dense non-aqueous phase liquids (DNAPLs) in single fractures is important for modeling contaminant flux generation from fractured sites. Here a systematic numerical study is presented to investigate the effect of fracture aperture statistics on DNAPL migration, entrapment and dissolution within individual, variable-aperture fractures. Both fractures with open and closed bottom boundaries were considered.

PCE dissolution and simultaneous dechlorination by nanoscale zero-valent iron particles in a DNAPL source zone.

While the capability of nanoscale zero-valent iron (NZVI) to dechlorinate organic compounds in aqueous solutions has been demonstrated, the ability of NZVI to remove dense non-aqueous phase liquid (DNAPL) from source zones under flow-through conditions similar to a field scale application has not yet been thoroughly investigated. To gain insight on simultaneous DNAPL dissolution and NZVI-mediated dechlorination reactions after direct placement of NZVI into a DNAPL source zone, a combined experimental and modeling study was performed. First, a DNAPL tetrachloroethene (PCE) source zone with emplaced NZVI was built inside a small custom-made flow cell and the effluent PCE and dechlorination byproducts were monitored over time.

Polymer-modified Fe0 nanoparticles target entrapped NAPL in two dimensional porous media: effect of particle concentration, NAPL saturation, and injection strategy.

Polymer-modified nanoscale zerovalent iron (NZVI) particles are delivered into porous media for in situ remediation of nonaqueous phase liquid (NAPL) source zones. A systematic and quantitative evaluation of NAPL targeting by polymer-modified NZVI in two-dimensional (2-D) porous media under field-relevant conditions has not been reported. This work evaluated the importance of NZVI particle concentration, NAPL saturation, and injection strategy on the ability of polymer-modified NZVI (MRNIP2) to target the NAPL/water interface in situ in a 2-D porous media model.

Transport and deposition of polymer-modified Fe0 nanoparticles in 2-D heterogeneous porous media: effects of particle concentration, Fe0 content, and coatings.

Concentrated suspensions of polymer-modified Fe(0) nanoparticles (NZVI) are injected into heterogeneous porous media for groundwater remediation. This study evaluated the effect of porous media heterogeneity and the dispersion properties including particle concentration, Fe(0) content, and adsorbed polymer mass and layer thickness which are expected to affect the delivery and emplacement of NZVI in heterogeneous porous media in a two-dimensional (2-D) cell. Heterogeneity in hydraulic conductivity had a significant impact on the deposition of NZVI.

Empirical correlations to estimate agglomerate size and deposition during injection of a polyelectrolyte-modified Fe0 nanoparticle at high particle concentration in saturated sand.

Controlled emplacement of polyelectrolyte-modified nanoscale zerovalent iron (NZVI) particles at high particle concentration (1-10 g/L) is needed for effective in situ subsurface remediation using NZVI. Deep bed filtration theory cannot be used to estimate the transport and deposition of concentrated polyelectrolyte-modified NZVI dispersions (>0.03 g/L) because particles agglomerate during transport which violates a fundamental assumption of the theory.

On integrating groundwater transport models with wireless sensor networks.

The emerging technology of wireless sensor networks (WSNs) is an integrated, distributed, wireless network of sensing devices. It has the potential to monitor dynamic hydrological and environmental processes more effectively than traditional monitoring and data acquisition techniques by providing environmental information at greater spatial and temporal resolutions. Furthermore, due to continuing high-performance computing development, these data may be introduced into increasingly robust and complex numerical models; for instance, the parameters of subsurface transport simulators may be automatically updated.