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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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To grow films of Cu 2 O, bis-(dimethylamino-2-propoxide)Cu( ii ), or Cu(dmap), is used as an atomic layer deposition precursor using only water vapor as a co-reactant.
Transmission resistance for selective water vapor permeation through hydrophobic conduits with a varying degree of surface wettability is estimated inside a nanofluidic device.
Ultra-rapid biohydrogen production from water splitting energized by a natural energy storage compound starch with an artificial enzymatic biosystem.
Bipolar membranes maintain a steady pH in electrolytic cells through water autodissociation at the interface between their cation- and anion-exchange layers. We analyze the balance of electric field and catalysis in accelerating this reaction.
HG 2 ·KCl hydrogel assemblies non-covalently bind anionic dyes and covalently bind an aldehyde in water.
Perovskite oxides are promising materials for photoabsorbers and electrocatalysts for solar-driven water oxidation.
Testing the ability of molecular dynamics simulations using non-polarizable water models to reproduce dielectric spectra of bulk liquid water we show that the Debye relaxation is determined by the dynamics of the hydrogen-bond network.
Aliovalently Al 3+ doped strontium titanate enables overall water splitting in type 1 baggie particle suspension reactors in direct sunlight.
Water–NaCl–organic ternary mixtures evaluated with hydrates salt concentrations to reveal general phenomenon of the one-for-one molar displacement of NaCl by organic solutes as well as implications on solvent driven water treatments.
Thin films of nickel oxide (NiO x ), cobalt oxide (CoO x ) and nickel–cobalt oxide (NiCoO x ) produced integrated, protected Si (111) photoanodes integrated, protected Si photoanodes that did not require deposition of a separate heterogeneous electrocatalyst for water oxidation.
Decoupled electrochemical water splitting systems separate the hydrogen- and oxygen-evolution reactions spatially, temporally, or both, resulting in modular, flexible, and intrinsically safe electrolysis.
PEO restructures water near the polymer, reducing free volume and slowing local water.
We analyze the recent temperature dependent oxygen-oxygen pair-distribution functions from experimental high-precision x-ray diffraction data of bulk water by Skinner et al. [J. Chem. Phys. 141, 214507 (2014)] with particular focus on the intermediate range where small, but significant, correlations are found out to 17 Å. The second peak in the pair-distribution function at 4.5 Å is connected to tetrahedral coordination and was shown by Skinner et al. to change behavior with temperature below the temperature of minimum isothermal compressibility. Here we show that this is associated also with a peak growing at 11 Å which strongly indicates a collective character of fluctuations leading to the enhanced compressibility at lower temperatures. We note that the peak at ∼13.2 Å exhibits a temperature dependence similar to that of the density with a maximum close to 277 K or 4 °C. We analyze simulations of the TIP4P/2005 water model in the same manner and find excellent agreement between simulations and experiment albeit with a temperature shift of ∼20 K.
The growth rate of crystalline ice (CI) in amorphous solid water (ASW) films was investigated using reflection absorption infrared spectroscopy. Two different experiments were set up to measure rates of the crystallization front propagation from the underlying crystalline template upward and from the vacuum interface downward. In one set of experiments, layers of ASW (5% D 2 O in H 2 O) were grown on a CI template and capped with a decane layer. In isothermal experiments from 140 to 150 K, crystallization was observed from the onset (no induction time) and the extent of crystallization increased linearly with time. In a second set of experiments, uncapped ASW films without a CI template were studied. The films were created by placing a 100 ML isotopic layer (5% D 2 O in H 2 O) at various positions in a 1000 ML ASW (H 2 O) film. The CI growth rates obtained from the two configurations (capped films with a CI template and uncapped films without a CI template) are in quantitative agreement. The results support the idea that for ASW films in a vacuum, a crystalline layer forms at the surface that then acts as a CI template for a growth front that moves downward into the film.
Newly developed coupled-cluster (CC) methods enable simulations of ionization potentials and spectral functions of molecular systems in a wide range of energy scales ranging from core-binding to valence. This paper discusses the results obtained with the real-time equation-of-motion CC cumulant (RT-EOM-CC) approach and CC Green’s function (CCGF) approaches in applications to the water and water dimer molecules. Here, we compare the ionization potentials obtained with these methods for the valence region with the results obtained with the coupled-cluster with singles, doubles, and perturbative triples formulation as a difference of energies for N and N – 1 electron systems. All methods show good agreement with each other. They also agree well with the experiment with errors usually below 0.1 eV for the ionization potentials. We also analyze unique features of the spectral functions, associated with the position of satellite peaks, obtained with the RT-EOM-CC and CCGF methods employing single and double excitations, as a function of the monomer OH bond length and the proton transfer coordinate in the dimer. Finally, we analyze the impact of the basis set effects on the quality of calculated ionization potentials and find that the basis set effects are less pronounced for the augmented-type sets.
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Abstract The rapid depletion of US groundwater resources and rising number of dying wells in the Western US brings attention to the significance of groundwater governance and sustainability restrictions. However, such restrictions on groundwater withdrawals are likely to generate spillover effects causing further environmental stresses in other locations and adding to the complexity of sustainability challenges. The goal of this paper is to improve our understanding of the implications of growing global food demand for local sustainability stresses and the implications of local sustainability policies for local, regional, and global food production, land use, and prices. We employ SIMPLE-G-US (Simplified International Model of agricultural Prices, Land use, and the Environment—Gridded version for the United States) to distangle the significance or remote changes in population and income for irrigation and water resources in the US. Then we examine the local-to-global impacts of potential US groundwater sustainability policies. We find that developments in international markets are significant, as more than half of US sustainability stresses by 2050 are caused by increased commodity demand from abroad. Furthermore, a US sustainable groundwater policy can cause overseas spillovers of US production, thereby potentially contributing to environmental stresses elsewhere, even as groundwater stress in the US is alleviated. These unintended consequences could include deforestation due to cropland expansion, as well as degradation in water quality due to intensification of production in non-targeted areas.