Prairie Horizon Carbon Management Hub (DE-FE0032371) Closeout Meeting
Conference presentation at U.S. Department of Energy NETL Carbon Management Research Project Review Meeting, virtual, November 20, 2025.
03 NATURAL GAS↗
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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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Fast and sensitive measurements of sub-3 nm particles using Condensation Particle Counters For Atmospheric Rapid Measurements (CPC FARM)
New particle formation (NPF) is the atmospheric process whereby gas molecules react and nucleate to form detectable particles. NPF has a strong impact on Earth's radiative balance as it produces roughly half of global cloud condensation nuclei. However, the time resolution and sensitivity of current instrumentation are inadequate in measuring the size distribution of sub-3 nm particles, the particles critical for understanding NPF. Here we present the Condensation Particle Counters For Atmospheric Rapid Measurements (CPC FARM), a method to measure the concentrations of freshly nucleated particles. The CPC FARM consists of five CPCs operating in parallel, each configured to operate at different detectable particle sizes between 1–3 nm. This study explores two methods to calculate the size distribution from the differential measurements across the CPC channels. The performance of both inversion methods was tested against the size distribution measured by a pair of stepping particle mobility sizers (SMPSs) during an ambient air sampling study in Pittsburgh, PA. Observational results indicate that the CPC FARM is more accurate with higher time resolution and sensitivity in the sub-3 nm range compared to the SMPS.
Cheng, Darren [Carnegie Mellon Univ., Pittsburgh, ↗
SIGNIFICANCE OF DETONATION STUDY TO PROPULSION DYNAMICS
Utilization of detonation wave to investigate transient processes in gas wave dynamics of rocket propulsion systems
DETONATION WAVE↗
Inelastic molecular collisions
Collision cross sections direct measurement for determining macroscopic reaction rates in inelastic molecular collision processes in gas dynamics
Utterback, N. G.↗
Development of propulsion for high atmospheric pressure or dense environments
The development of a propulsion system that employs a detonating propellant is described, and the need for such a system and its use in certain planetary atmospheres are demonstrated. A theoretical formulation of the relevant gas-dynamic processes was developed, and a related series of experimental tests were pursued.
Varsi, G.↗
Photochemistry chemical kinetics in the interstellar medium.
Gas phase processes involving interstellar molecules are considered. The primary process is photodissociation in the ambient radiation field. In obscured regions, a combination of Johnson's (1965) and Stecher's (1969) Perseus extinction curves was used to obtain the radiation field as a function of the extinction at 5,500 A. On the basis of laboratory measurements, it is concluded that the molecules of water, ammonia, methane, and formaldehyde have lifetimes less than one hundred years.
Donn, B.↗
Chemical depletion of the ionosphere
A theoretical study of the chemical and gas dynamical processes resulting from the release of reactive gases into the daytime ionosphere is discussed. Only point releases, such as from an explosion or a pulsed jet, are considered. Some scientific uses of the artificial reduction of the ionospheric plasma are considered.
Bernhardt, P. A.↗
Development and testing of a wet oxidation waste processing system
The wet oxidation process is considered as a potential treatment method for wastes aboard manned spacecraft for these reasons: (1) Fecal and urine wastes are processed to sterile water and CO2 gas. However, the water requires post-treatment to remove salts and odor; (2) the residual ash is negligible in quantity, sterile and easily collected; and (3) the product CO2 gas can be processed through a reduction step to aid in material balance if needed. Reaction of waste materials with oxygen at elevated temperature and pressure also produces some nitrous oxide, as well as trace amounts of a few other gases.
Weitzmann, A. L.↗
Hydrogen production by water decomposition using a combined electrolytic-thermochemical cycle
A proposed dual-purpose power plant generating nuclear power to provide energy for driving a water decomposition system is described. The entire system, dubbed Sulfur Cycle Water Decomposition System, works on sulfur compounds (sulfuric acid feedstock, sulfur oxides) in a hybrid electrolytic-thermochemical cycle; performance superior to either all-electrolysis systems or presently known all-thermochemical systems is claimed. The 3345 MW(th) graphite-moderated helium-cooled reactor (VHTR - Very High Temperature Reactor) generates both high-temperature heat and electric power for the process; the gas stream at core exit is heated to 1850 F. Reactor operation is described and reactor innards are illustrated. A cost assessment for on-stream performance in the 1990's is optimistic.
Farbman, G. H.↗
Role of condensed phase details in the oscillatory combustion of composite propellants
The response functions of composite propellants are theoretically derived, including explicitly the pressure-dependent degradation term in the condensed phase, hypothesizing that the overall rate-limiting reactions are in the relatively low temperature condensed phase. The method of 'inner' and 'outer' expansions with the reduced activation energy as the singular perturbation parameter has been employed. The results cover subsurface reactions with and without surface reactions, adiabatic and uniform-combustion models for the quasi-steady gas phase processes. The response functions display several experimentally observed features like dependence on mean pressure and the instability behavior of some 'zero-n' propellants.
Kumar, R. N.↗
Purging means and method for Xenon arc lamps
High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.
Miller, C. G.↗
Nuclear track and compositional studies of olivines in CI and CM chondrites
The CI and CM chondrites, with bulk chemical compositions closely resembling solar values, are important for the study of early solar system processes. Noble gas and particle track studies have revealed that a majority of the CI and CM chondrites contain precompaction solar wind and solar flare irradiation records. A quantitative understanding of these records is important because it would allow constraints to be placed on the environment in which the irradiation occurred, and, therefore, on the mode of evolution of the CI and CM chondrites. The present investigation is concerned primarily with fossil track evidence, taking into account selected specimens of several CI and CM chondrites. In addition, the results are presented of extensive studies of the angular distributions of tracks in irradiated grains from four CM chondrites. The results provide information on the exposure geometry of the grains.
Goswami, J. N.↗
Numerical simulations of loops heated to solar flare temperatures. I - Gasdynamics. II - X-ray and UV spectroscopy
The NRL's Dynamic Flux Tube Model is used to numerically simulate the dynamic response of a coronal magnetic loop to an energy input of the order encountered in solar flares. The coronal plasma is heated by the deposition of flare energy at the top of the loop to more than 10 million K, yielding a conduction front that moves toward the chromosphere, where the plasma is heated by the large downward conductive flux and ablates upward to the coronal part of the loop at velocities of a few hundred km/sec. The conduction front simultaneously produces chromospheric ablation and compresses the material ahead of it. With the aid of compressional instabilities, the compressed plasma grows throughout the flare heating phase, presenting a possible source of the flare optical continuum emission which is correlated with soft X-ray radiation. The observational consequences of rapidly heated loop gas dynamic processes are discussed. In the second part of this presentation, the dynamical calculation results previously obtained are used to predict the spectral line intensities, profiles and wavelengths of several X-ray lines and the UV line of Fe XXI at 1354.1 A. Three different viewing orientations of the loop are considered.
Cheng, C.-C.↗
Liquid fuel spray processes in high-pressure gas flow
Atomization of single liquid jets injected downstream in high pressure and high velocity airflow was investigated to determine the effect of airstream pressure on mean drop size as measured with a scanning radiometer. For aerodynamic - wave breakup of liquid jets, the ratio of orifice diameter D sub o to measured mean drop diameter D sub m which is assumed equal to D sub 32 or Sauter mean diameter, was correlated with the product of the Weber and Reynolds numbers WeRe and the dimensionless group G1/square root of c, where G is the gravitational acceleration, 1 the mean free molecular path, and square root of C the root mean square velocity, as follows; D sub o/D sub 32 = 1.2 (WeRe) to the 0.4 (G1/square root of c) to the 0.15 for values of WeRe 1 million and an airstream pressure range of 0.10 to 2.10 MPa.
Ingebo, R. D.↗
Local interstellar gasdynamical stability in spiral arm flow
The stability of two-dimensional interstellar gas flow passing through a spiral potential has been investigated. The background flow is assumed to move in a tightly wound potential, which may be regarded as external or self-generated. The unperturbed flow, which may be time dependent, is self-gravitating and satisfies the Roberts equations of motion. A polytropic, single-fluid assumption has been used. Magnetic effects are not considered. The motivation behind this work is to try to understand how much of the diversity of spiral arm morphology can be understood by large scale gas dynamical processes alone. To this end, it is suggested that spurring and feathering, and forming molecular cloud complexes may be closely related in the sense of having dynamically similar origins.
Balbus, S. A.↗
Combustion/particle sizing experiments at the Naval Postgraduate School Combustion Research Laboratory
Particle behavior in combustion processes is an active research area at NPS. Currently, four research efforts are being conducted: (1) There is a long standing need to better understand the soot production and combustion processes in gas turbine combustors, both from a concern for improved engine life and to minimize exhaust particulates. Soot emissions are strongly effected by fuel composition and additives; (2) A more recent need for particle sizing/behavior measurements is in the combustor of a solid fuel ramjet which uses a metallized fuel. High speed motion pictures are being used to study rather large burning particles; (3) In solid propellant rocket motors, metals are used to improve specific impulse and/or to provide damping for combustion pressure oscillations. Particle sizing experiments are being conducted using diode arrays to measure the light intensity as a function of scattering angle; (4) Once a good quality hologram is attained, a need exists for obtaining the particle distributions from hologram in a short period of time. A Quantimet 720 Image Analyzer is being used to reconstruct images.
Powers, John↗
Liquid fuel spray processes in high-pressure gas flow
Atomization of single liquid jets injected downstream in high pressure and high velocity airflow was investigated to determine the effect of airstream pressure on mean drop size as measured with a scanning radiometer. For aerodynamic - wave breakup of liquid jets, the ratio of orifice diameter D sub o to measured mean drop diameter D sub m which is assumed equal to D sub 32 or Sauter mean diameter, was correlated with the product of the Weber and Reynolds numbers WeRe and the dimensionless group G1/square root of c, where G is the gravitational acceleration, 1 the mean free molecular path, and square root of C the root mean square velocity, as follows; D sub o/D sub 32 = 1.2 (WeRe) to the 0.4 (G1/square root of c) to the 0.15 for values of WeRe 1 million and an airstream pressure range of 0.10 to 2.10 MPa.
Ingebo, R. D.↗
Making Smaller Microshells From Refractory Metals
Tendency toward gas porosity exploited. Falling through drop tube, fine drops of molten metal lose heat to surroundings, forming hard shells around precipitated gas. Second heating/cooling cycle in drop tube of lower pressure lets gas expand. Process produces smaller shells in greater variety of materials than possible with such current processes as based on hollow-jet instability, dry-chemical blowing or fluid-droplet drying. Shell aspect ratio (ratio of radius to wall thickness) controllable. New process makes shells having diameters smaller than 100 micrometer. There are several candidate shell materials including refractory metals.
Lee, Mark C.↗