Leu-M

Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas.

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Plasma-liquid interactions: A review and roadmap

This paper studies the impact of ambiguity and ambiguity aversion on equilibrium asset prices and portfolio holdings in competitive financial markets. It argues that attitudes toward ambiguity are heterogeneous across the population, just as attitudes toward risk are heterogeneous across the population, but that heterogeneity of attitudes toward ambiguity has different implications than heterogeneity of attitudes toward risk. In particular, when some state probabilities are not known, agents who are sufficiently ambiguity averse find open sets of prices for which they refuse to hold an ambiguous portfolio. This suggests a different cross-section of portfolio choices, a wider range of state price/probability ratios and different rankings of state price/probability ratios than would be predicted if state probabilities were known. Experiments confirm all of these suggestions. Our findings contradict the claim that investors who have cognitive biases do not affect prices because they are infra-marginal: ambiguity averse investors have an indirect effect on prices because they change the per-capita amount of risk that is to be shared among the marginal investors. Our experimental data also suggest a positive correlation between risk aversion and ambiguity aversion that might explain the “value effect” in historical data.

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Theory and Experiment

▪ Abstract The synthesis of nanocrystalline diamond films from carbon-containing noble gas plasmas is described. The nanocrystallinity is the result of new growth and nucleation mechanisms, which involve the insertion of C2, carbon dimer, into carbon-carbon and carbon-hydrogen bonds, resulting in hetereogeneous nucleation rates on the order 1010 cm−2 s−1. Extensive characterization studies led to the conclusion that phase-pure diamond is produced with a microstructure consisting of randomly oriented 3–15-nm crystallites. By adjusting the noble gas/hydrogen ratio in the gas mixture, a continuous transition from micro- to nanocrystallinity is achieved. Up to 10% of the total carbon in the nanocrystalline films is located at 2 to 4 atom-wide grain boundaries. Because the grain boundary carbon is π-bonded, the mechanical, electrical, and optical properties of nanocrystalline diamond are profoundly altered. Nanocrystalline diamond films are unique new materials with applications in fields as diverse as tribolo...

Nanocrystalline diamond films1

Non-thermal plasmas for non-catalytic and catalytic VOC abatement.

N2(A3Σ), the lowest electronically excited state of N2, has a long and distinguished history due to its role in nitrogen discharges and the nitrogen afterglow. Recently, the production of N2(A) via photolysis and chemiluminescent reactions has been newly explored, and new facets of its reactivity have been uncovered. N2(A) is unusual, in that its deactivation probability in collision with small molecules spans many orders of magnitude, and is frequently strongly dependent on the vibrational content of N2(A). This behavior and the observed product channels can be understood in terms of a simple model for the energy transfer process. Brief comparison with reactions of related species is made.

Reactions of N2(A3Σ u

Quenching of electronically excited Ar, Kr, and Xe(3P0,2) atoms by diatomic and triatomic oxygen‐containing compounds has been studied by atomic resonance fluorescence in a discharge‐flow system at room temperature. Absolute branching ratios for molecular fragmentation in the quenching reactions have been obtained, showing that this channel is dominant in many cases. While single R–O bond cleavage is usually the favored process, cleavage of both bonds of H2O occurs in nearly 50% of quenching collisions with Ar*, and evidence is obtained for analogous atomization of NO2 and SO2 by Ar*. Emission by electronically excited fragment species has been found to be mostly weak; thus, dissociative excitation is a minor channel except for the reactions of Ar* with N2O and H2O.

Quenching of metastable Ar, Kr, and Xe atoms by oxygen‐containing compounds: A resonance fluorescence study of reaction products

The Peer-Led Teaching and Learning (Workshop) model has been applied since 1998 to a subset of all General Chemistry laboratory sections at the University of Pittsburgh. In the workshop model, the ...

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Peer Instruction in the General Chemistry Laboratory: Assessment of Student Learning

The products of the reactions of electronically excited Ar(3P0, 3P2), Kr(3P2), and Xe(3P2) atoms with the chloromethanes, chlorofluoromethanes, CF3H, CF2HCl, CFHCl2, CF2Cl⋅CF2Cl, CF3⋅CCl3, and HCl have been investigated by the discharge‐flow technique, using atomic resonance fluorescence to probe dissociation channels and emission spectroscopy. Energy transfer leading to cleavage of C–H or C–Cl bonds is extremely efficient, particularly in the reactions of Xe(3P2) with CF2Cl2 and CFCl3 and of Ar(3P0, 2) with CFCl3, in which more than two Cl atoms are released per primary reactive event. The observation of contrasting behavior in the reactions of Xe(3P2) with CF3H and CF4 has led to the discovery of a qualitative correlation between the rate constants, the products of the energy transfer process, and the accessibility of dissociative or ionizing states of the reagent molecule, as revealed by its vacuum UV absorption spectrum.

Product distributions in the reactions of excited noble‐gas atoms with hydrogen‐containing compounds

https://ntrs.nasa.gov/api/citations/19980027707/downloads/19980027707.pdf

Michael F. Golde

Papers

Reactions of N2(A3Σ u

Quenching of metastable Ar, Kr, and Xe atoms by oxygen‐containing compounds: A resonance fluorescence study of reaction products

Peer Instruction in the General Chemistry Laboratory: Assessment of Student Learning

Product distributions in the reactions of excited noble‐gas atoms with hydrogen‐containing compounds

Electron-Ion Recombination Rate Coefficient Measurements in a Flowing Afterglow Plasma