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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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Mapping reactive flow patterns in monolithic nanoporous catalysts
The development of high-efficiency porous catalyst membranes critically depends on our understanding of where the majority of the chemical conversions occur within the porous structure. This then requires mapping of chemical reactions and mass transport inside the complex nanoscale architecture of porous catalyst membranes which is a multiscale problem in both the temporal and spatial domains. In order to address this problem, we developed a multiscale mass transport computational framework based on the lattice Boltzmann method that allows us to account for catalytic reactions at the gas–solid interface by introducing a new boundary condition. In good agreement with experiments, the simulations reveal that most catalytic reactions occur near the gas-flow facing side of the catalyst membrane if chemical reactions are fast compared to mass transport within the porous catalyst membrane.
Mapping Cation Disorder in Irradiated Gd2Ti2O7 Pyrochlore by 4D-STEM
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Photodissociation Dynamics of Astrophysically Relevant Propyl Derivatives (C 3 H 7 X; X = CN, OH, HCO) at 157 nm Exploiting an Ultracompact Velocity Map Imaging Spectrometer: The (Iso)Propyl Channel
The photodissociation dynamics of astrophysically relevant propyl derivatives (C 3 H 7 X; X = CN, OH, HCO) at 157 nm exploiting an ultracompact velocity map imaging (UVMIS) setup has been reported. The successful operation of UVMIS allowed the exploration of the 157 nm photo dissociation of six (iso)propyl systems - n/i-propyl cyanide (C 3 H 7 CN), n/i-propyl alcohol (C 3 H 7 OH), and (iso)butanal (C 3 H 7 CHO) – to explore the C 3 H 7 loss channel. The distinct center-of-mass translational energy distributions for the i-C 3 H 7 X (X= CN, OH, HCO) could be explained through preferential excitation of the low frequency C-H bending modes of the formyl moiety compared to the higher frequency stretchings of the cyano and hydroxy moieties. Although the ionization energy of the n-C 3 H 7 radical exceeds the energy of a 157 nm photon, C 3 H 7 + was observed in the n-C 3 H 7 X (X= CN, OH, HCO) systems as a result of photoionization of vibrationally "hot" n-C 3 H 7 fragments, photoionization of i-C 3 H 7 after a hydrogen shift in vibrationally "hot" n-C 3 H 7 radicals, and/or two-photon ionization. Our experiments reveal that at least the isopropyl radical (i-C 3 H 7 ) and possibly the normal propyl radical (n-C 3 H 7 ) should be present in the interstellar medium and hence searched for by radio telescopes.
Mapping gas around massive galaxies: cross-correlation of DES Y3 galaxies and Compton- y maps from SPT and Planck
ABSTRACT We cross-correlate positions of galaxies measured in data from the first three years of the Dark Energy Survey with Compton-y maps generated using data from the South Pole Telescope (SPT) and the Planck mission. We model this cross-correlation measurement together with the galaxy autocorrelation to constrain the distribution of gas in the Universe. We measure the hydrostatic mass bias or, equivalently, the mean halo bias-weighted electron pressure 〈bhPe 〉, using large-scale information. We find 〈bhPe 〉 to be $[0.16^{+0.03}_{-0.04},0.28^{+0.04}_{-0.05},0.45^{+0.06}_{-0.10},0.54^{+0.08}_{-0.07},0.61^{+0.08}_{-0.06},0.63^{+0.07}_{-0.08}]$ meV cm−3 at redshifts z ∼ [0.30, 0.46, 0.62, 0.77, 0.89, 0.97]. These values are consistent with previous work where measurements exist in the redshift range. We also constrain the mean gas profile using small-scale information, enabled by the high-resolution of the SPT data. We compare our measurements to different parametrized profiles based on the cosmo-OWLS hydrodynamical simulations. We find that our data are consistent with the simulation that assumes an AGN heating temperature of 108.5 K but are incompatible with the model that assumes an AGN heating temperature of 108.0 K. These comparisons indicate that the data prefer a higher value of electron pressure than the simulations within r500c of the galaxies’ haloes.
Beyond MAP: A guide to dimensions of rainfall variability for tropical ecology
Not provided.
Mapping of exhaust gas recirculation and combustion-residual backflow in the intake ports of a heavy-duty diesel engine using a multiplexed multi-species absorption spectroscopy sensor [Mapping of EGR and combustion residual backflow in the intake ports of a heavy duty diesel engine using a multiplexed multi-species absorption spectroscopy sensor]
Here, the combustion-residual backflow into the intake ports of a commercial diesel engine (Cummins ISX series) was spatiotemporally mapped using a multiplexed multi-species absorption spectroscopy sensor system; the resulting cycle- and cylinder-resolved measurements are applicable for assessing cylinder charge uniformity, control strategies, and computational fluid dynamics tools. On-engine measurements were made using four compact (3/8 in Outside Diameter) stainless steel probes which enabled simultaneous multi-point measurements, required minimal engine hardware modification, and featured a novel tip design for measurement of gas flows parallel to the probe axis. Three sensor probes were used to perform simultaneous backflow measurements in intake runners corresponding to three of the six engine cylinders, and a fourth probe was installed in the intake manifold plenum for tracking dynamics introduced by an external exhaust gas recirculation mixer. Near-crank-angle resolved measurements (5 kHz, that is, 1.2 crank angle resolution at 1000 RPM) were performed during steady-state engine operation at various levels of external exhaust gas recirculation to measure the gas properties and penetration distance of the backflow into the intake runners on a cylinder- and cycle-basis. Validation of computational fluid dynamics model results is also presented to demonstrate the utility of such measurements in advancing engine research.
Hydropower Market Report Story Map
This story map complements the fourth complete edition of the U.S. Hydropower Market Report (2024 update) and builds on the 2024 update. This update focuses on data and trends in 2024 and contextualizes this information compared to evolving high-level trends over the past 10–20 years. It contains information on U.S. hydropower (and pumped storage hydropower) development pipeline, relicenses, license surrenders, performance metrics, and supply chain.
U.S. Hydropower Supply Chain Manufacturing Locations Map, 2025
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Computer controlled performance mapping of thermionic converters: effect of collector, guard-ring potential imbalances on the observed collector current-density, voltage characteristics and limited range performance map of an etched-rhenium, niobium planar converter
The effect of collector, guard-ring potential imbalance on the observed collector-current-density J, collector-to-emitter voltage V characteristic was evaluated in a planar, fixed-space, guard-ringed thermionic converter. The J,V characteristic was swept in a period of 15 msec by a variable load. A computerized data acquisition system recorded test parameters. The results indicate minimal distortion of the J,V curve in the power output quadrant for the nominal guard-ring circuit configuration. Considerable distortion, along with a lowering of the ignited-mode striking voltage, was observed for the configuration with the emitter shorted to the guard ring. A limited-range performance map of an etched-rhenium, niobium, planar converter was obtained by using an improved computer program for the data acquisition system.
A methodology for small scale rural land use mapping in semi-arid developing countries using orbital imagery. Part 6: A low-cost method for land use mapping using simple visual techniques of interpretation
The author has identified the following significant results. It was found that color composite transparencies and monocular magnification provided the best base for land use interpretation. New methods for determining optimum sample sizes and analyzing interpretation accuracy levels were developed. All stages of the methodology were assessed, in the operational sense, during the production of a 1:250,000 rural land use map of Murcia Province, Southeast Spain.
Statistical mapping of sheet aiquile SE-20-9 (national map) making use of ERTS images
New possibilities of remote sensing by means of satellites to do research on natural resources are reported. These images make it possible to carry out integrated studies of natural resources in the shortest time possible and with small investments. Various maps and a complete description of each are included. With the use of these satellites, scientists can hopefully plan development projects at the national level.
Heat Capacity Mapping Mission (HCMM) thermal surface water mapping and its correlation to LANDSAT
Graphics are presented which show HCMM mapped water-surface temperature in Lake Anna, a 13,000 dendrically-shaped lake which provides cooling for a nuclear power plant in Virginia. The HCMM digital data, produced by NASA were processed by NOAA/NESS into image and line-printer form. A LANDSAT image of the lake illustrates the relationship between MSS band 7 data and the HCMM data as processed by the NASA image processing facility which transforms the data to the same distortion-free hotline oblique Mercator projection. Spatial correlation of the two images is relatively simple by either digital or analog means and the HCMM image has a potential accuracy approaching the 80 m of the original LANDSAT data. While it is difficult to get readings that are not diluted by radiation from cooler adjacent land areas in narrow portions of the lake, digital data indicated by the line-printer display five different temperatures for open-water areas. Where the water surface response was not diluted by land areas, the temperature difference recorded by HCMM corresponds to in situ readings with rsme on the order of 1 C.
Comparison of Ground-Based 3-Dimensional Lightning Mapping Observations with Satellite-Based LIS Observations in Oklahoma: Comparison of LMS and LIS Lightning Mapping
3-dimensional lightning mapping observations obtained during the MEaPRS program in central Oklahoma during June, 1998 have been compared with observations of the discharges from space, obtained by NASA's Lightning Imaging Sensor (LIS) on the TRMM satellite. Excellent spatial and temporal correlations were observed between the two sets of observations. Most of the detected optical events were associated with intracloud discharges that developed into the upper part of the storm. Cloud-to-ground discharges that were confined to mid- and lower-altitudes tended not to be detected by LIS. Extensive illumination tended to occur in impulsive bursts toward the end or part way through intracloud flashes and appeared to be produced by energetic K-changes that typically occur at these times.
Mapping Rock and Soil Units in the MPF IMP SuperPan Using a Kohonen Self Organizing Map
The 1997 Mars Pathfinder mission provided information on a site in the Ares Vallis floodplain. Initial analysis of multispectral data from the Imager for Mars Pathfinder (IMP) indicated the presence of only a single rock type, the 'gray rock' spectral class and various coated variants thereof (e.g., 'maroon rock'). Continued analysis of the IMP 'SuperPan' mosaic has confirmed multiple examples of a second 'black rock' spectral class existing as small cobbles in the near field and as boulders in the far field. These results are consistent with recent analysis of MGS Thermal Emission Spectrometer (TES) data which indicates that there is likely a mix of both 'Surface Type 1' (ST1) and 'Surface Type 2' (ST2) spectral classes at the MPF landing site. Nominally, the black rock spectral class would correspond to ST1 (basalts) and 'gray rock' would correspond to ST2 (andesites). Orbital remote sensing has also revealed the pervasive presence of layering on Mars. Recently it was suggested that there are extensive outcrops of the black rock spectral class in the SuperPan far field on the flanks of the Twin Peaks and on the rim of Big Crater. These authors suggested that these exposures represented outcrops of black rock from beneath a surficial, flood deposited layer. In this work, we have reexamined the MPF IMP SuperPan mosaic using an artificial neural network self organizing map (SOM) processing architecture in order to classify the distribution of spectral classes within the SuperPan. In this paper, we present initial results from that work and draw specific attention to a subset of the identified spectral classes in order to address questions relating to whether there are extensive exposures of black rock in the IMP far field, what other materials might be exposed in the far field, and what evidence there is for subsurface layering at the MPF landing site.