Groundwater Throughflow and Seawater Intrusion in High Quality Coastal Aquifers.

High quality coastal aquifer systems provide vast quantities of potable groundwater for millions of people worldwide. Managing this setting has economic and environmental consequences. Specific knowledge of the dynamic relationship between fresh terrestrial groundwater discharging to the ocean and seawater intrusion is necessary.

Acid mine drainage formation and arsenic mobility under strongly acidic conditions: Importance of soluble phases, iron oxyhydroxides/oxides and nature of oxidation layer on pyrite.

Acid mine drainage (AMD) formation and toxic arsenic (As) pollution are serious environmental problems encountered worldwide. In this study, we investigated the crucial roles played by common secondary mineral phases formed during the natural weathering of pyrite-bearing wastes-soluble salts (melanterite, FeSO·7HO) and metal oxides (hematite, FeO)-on AMD formation and As mobility under acidic conditions (pH 1.5-4) prevalent in historic tailings storage facilities, pyrite-bearing rock dumps and AMD-contaminated soils and sediments.

Influence of Mineral Composition of Chars Derived by Hydrothermal Carbonization on Sorption Behavior of CO, CH, and O.

The doping of SiO and FeO into hydrochars that were produced by the hydrothermal carbonization of cellulose was studied with respect to its impact on the resulting surface characteristics and sorption behavior of CO, CH, and O. During pyrolysis, the structural order of the Fe-doped char changed, as the fraction of highly ordered domains increased, which was not observed for the undoped and Si-doped chars. The Si doping had no apparent influence on the oxidation temperature of the hydrochar in contrast to the Fe-doped char where the oxidation temperature was reduced because of the catalytic effect of Fe.

Bulk and Surface Properties Regulation of Single/Double Perovskites to Realize Enhanced Oxygen Evolution Reactivity.

Perovskite-based oxides have emerged as promising oxygen evolution reaction (OER) electrocatalysts. The performance is closely related to the lattice, electronic, and defect structure of the oxides, which determine surface and bulk properties and consequent catalytic activity and durability. Further, interfacial interactions between phases in a nanocomposite may affect bulk transportation and surface adsorption properties in a similar manner to phase doping except without solubility limits.

Identifying the Intrinsic Relationship between the Restructured Oxide Layer and Oxygen Evolution Reaction Performance on the Cobalt Pnictide Catalyst.

Cobalt pnictides show good catalytic activity and stability on oxygen evolution reaction (OER) behaviors in a strong alkaline solution. Identifying the intrinsic composition/structure-property relationship of the oxide layer on the cobalt pnictides is critical to design better and cheaper electrocatalysts for the commercial viability of OER technologies. In this work, the restructured oxide layer on the cobalt pnictides and its effect on the activity and mechanism for OER is systematically analyzed.

Cu/ZnO Catalysts Derived from Bimetallic Metal-Organic Framework for Dimethyl Ether Synthesis from Syngas with Enhanced Selectivity and Stability.

Direct conversion of syngas to dimethyl ether (DME) through the intermediate of methanol allows more efficient DME production in a simpler reactor design relative to the conventional indirect route. Although Cu/ZnO-based multicomponent catalysts are highly active for methanol synthesis in this process, the sintering issue of Cu during the prolonged reaction generally deteriorates their performance. In this work, Cu/ZnO catalysts in a novel octahedron structure are prepared by a two-step pyrolysis of Zn-doped Cu-BTC metal-organic framework (MOF) in N and air.

Wettability effect on wave propagation in saturated porous medium.

Micro-fluid mechanics studies have revealed that fluid slip on the boundary of a flow channel is a quite common phenomenon. In the context of a fluid-saturated porous medium, this implies that the fluid slippage increases with the increase of the hydrophobicity, which is the non-wetting degree. Previous studies find that wettability of the pore surface is strongly related to the slippage, which is characterized by slip length.

Theoretical Calculation Guided Design of Single-Atom Catalysts toward Fast Kinetic and Long-Life Li-S Batteries.

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage technologies due to their high theoretical energy density, environmental friendliness, and low cost. However, low conductivity of sulfur species, dissolution of polysulfides, poor conversion from sulfur reduction, and lithium sulfide (LiS) oxidation reactions during discharge-charge processes hinder their practical applications. Herein, under the guidance of density functional theory calculations, we have successfully synthesized large-scale single atom vanadium catalysts seeded on graphene to achieve high sulfur content (80 wt % sulfur), fast kinetic (a capacity of 645 mAh g at 3 C rate), and long-life Li-S batteries.

Pore scale investigation of low salinity surfactant nanofluid injection into oil saturated sandstone via X-ray micro-tomography.

Hypothesis: Low salinity surfactant nanofluids have recently shown promising characteristics in wettability alteration of the silicate-based rock representative substrate and interfacial tension reduction of oil/aqueous phase interface. Pore level understanding of the physical processes entailed in this new class of low salinity injection fluids in oil-phase saturated real rock porous media is required, which has not been conceived yet.

Experiments: Thus, we investigate the oil recovery performance and possible mechanisms of oil recovery by the injection of low salinity surfactant (SDBS, 1.

New perspectives on Solid Earth Geology from Seismic Texture to Cooperative Inversion.

Seismic and electromagnetic methods are fundamental to Solid Earth research and subsurface exploration. Acquisition cost reduction is making dense 3D application of these methods accessible to a broad range of geo-scientists. However, the challenge of extracting geological meaning remains.

Tuning the Electron Localization of Gold Enables the Control of Nitrogen-to-Ammonia Fixation.

The (photo)electrochemical N reduction reaction (NRR) provides a favorable avenue for the production of NH using renewable energy in mild operating conditions. Understanding and building an efficient catalyst with high NH selectivity represents an area of intense interest for the early stages of development for NRR. Herein, we introduce a CoO layer to tune the local electronic structure of Au nanoparticles with positive valence sites for boosting conversion of N to NH .

Iron Single Atoms on Graphene as Nonprecious Metal Catalysts for High-Temperature Polymer Electrolyte Membrane Fuel Cells.

Iron single atom catalysts (Fe SACs) are the best-known nonprecious metal (NPM) catalysts for the oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells (PEMFCs), but their practical application has been constrained by the low Fe SACs loading (<2 wt%). Here, a one-pot pyrolysis method is reported for the synthesis of iron single atoms on graphene (FeSA-G) with a high Fe SAC loading of ≈7.7 ± 1.

Importance of lignin removal in enhancing biomass hydrolysis in hot-compressed water.

Beech wood was pretreated by ethanol/water mixture or sodium chlorite/acetic acid mixture to prepare two representative samples rich in cellulose/lignin and cellulose/hemicellulose, respectively. These samples were then hydrolysed in hot-compressed water (HCW) using a semi-continuous reactor under optimal conditions where the secondary reactions in the liquid products were minimised. The glucose recovery in the primary liquid products from hydrolysis in HCW is enhanced to ∼80% for the cellulose/hemicellulose rich sample from ∼56% for the raw sample, while that for the cellulose/lignin rich sample only increases slightly to ∼64%.

Patient-specific 3D printed model of biliary ducts with congenital cyst.

Background: 3D printing has shown great promise in medical applications, with increasing reports in liver diseases. However, research on 3D printing in biliary disease is limited with lack of studies on validation of model accuracy. In this study, we presented our experience of creating a realistic 3D printed model of biliary ducts with congenital cyst.

Synchrotron radiation computed tomography assessment of calcified plaques and coronary stenosis with different slice thicknesses and beam energies on 3D printed coronary models.

Background: To investigate the effect of different slice thicknesses and beam energies on the visualization and assessment of coronary artery stenosis caused by calcified plaques using synchrotron radiation computed tomography (CT) based on 3D printed coronary artery models.

Methods: Patient-specific 3D coronary models were created based on 3 sample coronary CT angiographic cases with calcified plaques in the left coronary arteries. In addition to the original significant coronary stenosis (>70%) shown on these CT images, stenoses of <50% and >90% were created in the segmented coronary models for simulation of different degrees of stenosis.

In Situ Formation of ErBiO Protective Layer at Cobaltite Cathode/YO-ZrO Electrolyte Interface under Solid Oxide Fuel Cell Operation Conditions.

Bismuth-based oxides exhibit outstanding oxygen ionic conductivity and fast oxygen surface kinetics and have shown great potential as a highly active component for electrode materials in solid oxide fuel cells (SOFCs). Herein, a Nb-doped LaSrCoFeNbO (LSCFNb) electrode with 40% ErBiO (ESB) composite electrode was successfully fabricated by decoration method and directly assembled on barrier-layer-free yttrium-stabilized zirconia (YSZ) electrolyte cells, achieving a peak power density of 1.32 W cm and excellent stability at 750 °C and 250 mA cm for 100 h.

Unusual synergetic effect of nickel single atoms on the electrocatalytic activity of palladium for alcohol oxidation reactions in alkaline media.

Palladium nanoparticles (Pd NPs) supported on Ni single atoms encapsulated in carbon nanotubes (NiSA) show a significantly enhanced electrocatalytic activity for the oxidation reactions of methanol, ethanol and glycerol in alkaline media due to an unusual electron withdrawal effect of NiSA on Pd NPs.

Acid Pretreatment to Enhance Proton Transport of a Polysulfone-Polyvinylpyrrolidone Membrane for Application in Vanadium Redox Flow Batteries.

An acid pretreatment strategy is developed to enhance the proton transport of polysulfone-polyvinylpyrrolidone (PSF-PVP) membranes for application in vanadium redox flow batteries (VRFB). The acid pretreatment leads to the formation of ionic conducting clusters with a size of around d=15.41 nm in the membrane (p-PSF-PVP).

Crystalline TiO protective layer with graded oxygen defects for efficient and stable silicon-based photocathode.

The trade-offs between photoelectrode efficiency and stability significantly hinder the practical application of silicon-based photoelectrochemical devices. Here, we report a facile approach to decouple the trade-offs of silicon-based photocathodes by employing crystalline TiO with graded oxygen defects as protection layer. The crystalline protection layer provides high-density structure and enhances stability, and at the same time oxygen defects allow the carrier transport with low resistance as required for high efficiency.

Absorption of foliar-applied Zn in sunflower (Helianthus annuus): importance of the cuticle, stomata and trichomes.

Background And Aims: The pathways whereby foliar-applied nutrients move across the leaf surface remain unclear. The aim of the present study was to examine the pathways by which foliar-applied Zn moves across the sunflower (Helianthus annuus) leaf surface, considering the potential importance of the cuticle, stomata and trichomes.

Methods: Using synchrotron-based X-ray florescence microscopy and nanoscale secondary ion mass spectrometry (NanoSIMS), the absorption of foliar-applied ZnSO4 and nano-ZnO were studied in sunflower.

Ejection of Droplets from a Bursting Bubble on a Free Liquid Surface-A Dimensionless Criterion for "Jet" Droplets.

This work examines the ejection of droplets from a bursting gas bubble on a free liquid surface, both experimentally and numerically. We explore the physical processes which govern the bursting of bubbles and the subsequent formation of "jet" droplets. We present new relationships regarding the dependence of jet drop formation on bubble diameter.

All-age hospitalization rates in coal seam gas areas in Queensland, Australia, 1995-2011.

Background: Unconventional natural gas development (UNGD) is expanding globally, with Australia expanding development in the form of coal seam gas (CSG). Residents and other interest groups have voiced concerns about the potential environmental and health impacts related to CSG. This paper compares objective health outcomes from three study areas in Queensland, Australia to examine potential environmentally-related health impacts.