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Abstract There is not a clear understanding of the extent by which naturally occurring reactions can attenuate trichloroethene (TCE) and its daughter products within low permeability zones (LPZs), and addressing this knowledge gap requires advancement of methods to accurately measure in situ volatile chemical concentrations. In this study, a soil coring method that freezes the soil in‐situ (a.k.a., cryogenic coring) was utilized to measure depth‐discrete distributions of TCE and its volatile reaction products through a TCE‐impacted silty clay aquitard, and results were compared with those from adjacent soil cores taken using a conventional coring approach. Vertical concentration profiles of TCE,cis‐1,2‐dichloroethylene (DCE), vinyl chloride (VC), ethane, and methane were all compared between the two coring methods, and results indicate the two coring methods recovered statistically equivalent concentrations of volatiles across most depths of the fine‐grained cohesive clayey soil at the study site. Biotic reductive dechlorination was the dominant TCE reaction pathway at the site; several reduced gasses that are possible markers for abiotic reduction were detected, but their concentrations and intervals of occurrence were not sufficiently consistent to indicate whether they were from abiotic TCE reduction or unrelated biological processes. Overall, cryogenic coring yielded improved recovery of sand lenses compared to conventional coring, but offered no apparent benefits for improved recovery of TCE and its volatile reaction products in the low permeability aquitard material at the site. 

Abstract An extremely rapid process for self‐assembling well‐ordered, nano, and microparticle monolayers via a novel aerosolized method is presented. The novel technique can reach monolayer self‐assembly rates as high as 268 cm²min⁻¹from a single aerosolizing source and methods to reach faster monolayer self‐assembly rates are outlined. A new physical mechanism describing the self‐assembly process is presented and new insights enabling high‐efficiency nanoparticle monolayer self‐assembly are developed. In addition, well‐ordered monolayer arrays from particles of various sizes, surface functionality, and materials are fabricated. This new technique enables a 93× increase in monolayer self‐assembly rates compared to the current state of the art and has the potential to provide an extremely low‐cost option for submicron nanomanufacturing. 

Electrochemical (EC) and photoelectrochemical (PEC) water treatment systems are gaining popularity, necessitating new electrode materials that offer reliable performance across diverse application platforms. For applications specifically targeting dilute chemical pollutants ( i.e. , parts-per-million concentrations or less), beneficial electrode properties include high surface area to overcome kinetic overpotential losses, low electrode areal electrical resistance, and high water permeability with sufficient mechanical strength for use in electroactive membrane-based treatment systems. Here, we used electrospinning to fabricate (photo)electrodes from carbon nanofibers (CNFs) containing titanium dioxide (TiO 2 ) nanoparticles. Optimal CNF/TiO 2 composites were electrochemically and photochemically active with a surface area of ∼50 m 2 g −1 and electrode areal resistance of 2.66 Ω cm 2 , values comparable to commercial carbon-based electrode materials ( e.g. , Kynol Activated Carbon Cloth). Transformation experiments with carbamazepine (CBZ), a recalcitrant organic contaminant, suggest CNF/TiO 2 electrodes function dually as sorbents, first binding CBZ prior to oxidation at positive applied potentials. Complete CBZ transformation was observed in both EC (dark) and PEC (UV light; 280 mW cm −2 ) systems over 90 minutes, with PEC systems exhibiting 1.5-fold higher transformation rates ( k obs ∼ 0.18 min −1 ) at +1.00 V ( vs. Ag/AgCl). Composite electrodes also exhibited stability across repeated use, yielding consistent current densities over five experimental cycles (120 min each) of CBZ transformation (0.25 ± 0.03 mA cm −2 ). Because of their high surface area, electrical conductivity, photoactivity, and electrochemical stability, these electrospun CNF/TiO 2 composites represent promising (photo)electrode alternatives for diverse EC and PEC applications.