Search NASA⌕ Search

SEARCH · Search NASA

Results for “N square clusters”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Extracting galactic structure parameters from multivariated density estimation

Multivariate statistical analysis, including includes cluster analysis (unsupervised classification), discriminant analysis (supervised classification) and principle component analysis (dimensionlity reduction method), and nonparameter density estimation have been successfully used to search for meaningful associations in the 5-dimensional space of observables between observed points and the sets of simulated points generated from a synthetic approach of galaxy modelling. These methodologies can be applied as the new tools to obtain information about hidden structure otherwise unrecognizable, and place important constraints on the space distribution of various stellar populations in the Milky Way. In this paper, we concentrate on illustrating how to use nonparameter density estimation to substitute for the true densities in both of the simulating sample and real sample in the five-dimensional space. In order to fit model predicted densities to reality, we derive a set of equations which include n lines (where n is the total number of observed points) and m (where m: the numbers of predefined groups) unknown parameters. A least-square estimation will allow us to determine the density law of different groups and components in the Galaxy. The output from our software, which can be used in many research fields, will also give out the systematic error between the model and the observation by a Bayes rule.

Chen, B.↗
DOE OSTI2020

Materials Data on NiP4N2O19 by Materials Project

NiO6NiP8(NO13)2(NO)2(O2)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two nitroxyl molecules, two oxygen molecules, one NiO6 cluster, and one NiP8(NO13)2 cluster. In the NiO6 cluster, Ni is bonded in a linear geometry to two equivalent O atoms. Both Ni–O bond lengths are 1.81 Å. There are three inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to one Ni and one O atom. The O–O bond length is 1.49 Å. In the second O site, O is bonded in a bent 120 degrees geometry to two O atoms. The O–O bond length is 1.24 Å. In the third O site, O is bonded in a single-bond geometry to one O atom. In the NiP8(NO13)2 cluster, Ni is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.92 Å) and two longer (2.00 Å) Ni–O bond length. There are four inequivalent P sites. In the first P site, P is bonded to four O atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.47–1.63 Å. In the second P site, P is bonded to four O atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.48–1.63 Å. In the third P site, P is bonded to four O atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.47–1.61 Å. In the fourth P site, P is bonded to four O atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. N is bonded in a water-like geometry to two O atoms. There is one shorter (1.15 Å) and one longer (1.66 Å) N–O bond length. There are thirteen inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one P atom. In the second O site, O is bonded in a bent 120 degrees geometry to one P and one N atom. In the third O site, O is bonded in a bent 120 degrees geometry to two P atoms. In the fourth O site, O is bonded in a single-bond geometry to one N atom. In the fifth O site, O is bonded in a 2-coordinate geometry to one Ni and one P atom. In the sixth O site, O is bonded in a single-bond geometry to one P atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to two P atoms. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to one Ni and one P atom. In the ninth O site, O is bonded in a single-bond geometry to one P atom. In the tenth O site, O is bonded in a bent 150 degrees geometry to two P atoms. In the eleventh O site, O is bonded in a single-bond geometry to one P atom. In the twelfth O site, O is bonded in a single-bond geometry to one P atom. In the thirteenth O site, O is bonded in a bent 120 degrees geometry to two P atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbS4N4Cl5 by Materials Project

(NS)4SbCl5 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 1,3,5,7,2,4,6,8-tetrathiatetrazocane molecules and four SbCl5 clusters. In each SbCl5 cluster, Sb3+ is bonded in a square pyramidal geometry to five Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.39–2.42 Å. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AsS4N4F5 by Materials Project

(NS)4AsF5 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 1,3,5,7,2,4,6,8-tetrathiatetrazocane molecules and four AsF5 clusters. In each AsF5 cluster, As5+ is bonded in a square pyramidal geometry to five F1- atoms. There are a spread of As–F bond distances ranging from 1.77–1.79 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb2H24C6(NCl3)3 by Materials Project

((CH3)2NH2)3SbCl5SbCl4 is Silicon tetrafluoride-derived structured and crystallizes in the monoclinic Pc space group. The structure is zero-dimensional and consists of six dimethylazanium molecules, two SbCl4 clusters, and two SbCl5 clusters. In each SbCl4 cluster, Sb3- is bonded in a rectangular see-saw-like geometry to four Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.43–2.67 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In each SbCl5 cluster, Sb3- is bonded in a square pyramidal geometry to five Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.44–2.91 Å. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3- atom. In the fifth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to one Sb3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbCNCl5 by Materials Project

CNSbCl5 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four hydrogen cyanide molecules and four SbCl5 clusters. In each SbCl5 cluster, Sb5+ is bonded in a distorted square pyramidal geometry to five Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.32–2.38 Å. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4N5F21 by Materials Project

(N2)5(TeF5)8F2 crystallizes in the tetragonal P-42_1c space group. The structure is zero-dimensional and consists of ten ammonia molecules, two hydrofluoric acid molecules, and eight TeF5 clusters. In each TeF5 cluster, Te5+ is bonded in a square pyramidal geometry to five F1- atoms. There are a spread of Te–F bond distances ranging from 1.85–1.95 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Te5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Te5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Te5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Te5+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Te5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on IN2O4F5 by Materials Project

NONO3IF5 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two nitric acid molecules, two nitroxyl molecules, and two IF5 clusters. In each IF5 cluster, I5+ is bonded in a square pyramidal geometry to five F1- atoms. There are a spread of I–F bond distances ranging from 1.86–1.95 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one I5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one I5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one I5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one I5+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one I5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbN2F5 by Materials Project

N2SbF5 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight ammonia molecules and four SbF5 clusters. In each SbF5 cluster, Sb3+ is bonded in a distorted square pyramidal geometry to five F1- atoms. There are a spread of Sb–F bond distances ranging from 1.88–1.90 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Accurate prediction of core-level spectra of radicals at density functional theory cost via square gradient minimization and recoupling of mixed configurations

State-specific orbital optimized approaches are more accurate at predicting core-level spectra than traditional linear-response protocols, but their utility had been restricted due to the risk of "variational collapse" down to the ground state. We employ the recently developed square gradient minimization algorithm to reliably avoid variational collapse and study the effectiveness of orbital optimized density functional theory (DFT) at predicting second period element 1s core-level spectra of open-shell systems. Several density functionals (including SCAN, B3LYP, and ωB97X-D3) are found to predict excitation energies from the core to singly occupied levels with high accuracy (≤0.3 eV RMS error) against available experimental data. Higher excited states are, however, more challenging by virtue of being intrinsically multiconfigurational. We thus present a configuration interaction inspired route to self-consistently recouple single determinant mixed configurations obtained from DFT, in order to obtain approximate doublet states. This recoupling scheme is used to predict the C K-edge spectra of the allyl radical, the O K-edge spectra of CO + , and the N K-edge of NO 2 with high accuracy relative to experiment, indicating substantial promise in using this approach for the computation of core-level spectra for doublet species [vs more traditional time dependent DFT, equation of motion coupled cluster singles and doubles (EOM-CCSD), or using unrecoupled mixed configurations]. Finally, we also present general guidelines for computing core-excited states from orbital optimized DFT.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1996

Infrared laser spectroscopy of jet-cooled carbon clusters: the nu 5 band of linear C9

The nu 5 antisymmetric stretching vibration of 1 sigma+g C9 has been observed using direct infrared diode laser absorption spectroscopy of a pulsed supersonic cluster beam. Twenty-eight rovibrational transitions measured in the region of 2079-2081 cm-1 were assigned to this band. A combined least squares fit of these transitions with previously reported nu 6 transitions yielded the following molecular constants for the nu 5 band: nu 0 = 2 079.673 58(17) cm-1, B"= 0.014 321 4(10) cm-1, and B'=0.014 288 9(10) cm-1. The IR intensity of the nu 5 band relative to nu 6 was found to be 0.108 +/- 0.006. Theoretical predictions for the relative intensities vary widely depending upon the level of theory employed, and the experimental value reported here is in reasonable agreement only with the result obtained from the most sophisticated ab initio calculation considered (CCSD).

Non-NASA Center↗
DOE OSTI2020

Materials Data on RuN3(Cl2O)2 by Materials Project

RuOCl4N2NO crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight ammonia molecules, four nitroxyl molecules, and four RuOCl4 clusters. In each RuOCl4 cluster, Ru5+ is bonded in a distorted square pyramidal geometry to one O2- and four Cl1- atoms. The Ru–O bond length is 1.72 Å. There are a spread of Ru–Cl bond distances ranging from 2.32–2.37 Å. O2- is bonded in a single-bond geometry to one Ru5+ atom. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Ru5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Ru5+ atom. In the third Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Ru5+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Ru5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Millimeter-wave observations of Euclid Deep Field South using the South Pole Telescope: A data release of temperature maps and catalogs

Context. The South Pole Telescope third-generation camera (SPT-3G) has observed over 10,000 square degrees of sky at 95, 150, and 220 GHz (3.3, 2.0, 1.4 mm, respectively) and will significantly overlap the ongoing 14,000 square-degree Euclid Wide Survey. The Euclid collaboration recently released Euclid Deep Field South (EDF-S) observations of 23 square degrees at wide field depths in the first quick data release (Q1). Aims. With the goal of releasing complementary millimeter-wave data and encouraging legacy science, we performed dedicated observations of a 57-square-degree field overlapping the EDF-S. Methods. The observing time totaled 20 days, and we reached noise depths of 4.3, 3.8, and 13.2 $μ$K-arcmin at 95, 150, and 220 GHz, respectively. Results. In this work we present the temperature maps and two catalogs constructed from these data. The emissive source catalog contains 601 objects (334 inside EDF-S) with 54% synchrotron-dominated sources and 46% thermal dust emission-dominated sources. The 5$σ$ detection thresholds are 1.7, 2.0, and 6.5 mJy in the three bands. The cluster catalog contains 217 cluster candidates (121 inside EDF-S) with median mass $M_{500c}=2.12 \times 10^{14} M_{\odot}/h_{70}$ and median redshift $z$ = 0.70, corresponding to an order-of-magnitude improvement in cluster density over previous tSZ-selected catalogs in this region (3.81 clusters per square degree). Conclusions. The overlap between SPT and Euclid data will enable a range of multiwavelength studies of the aforementioned source populations. This work serves as the first step toward joint projects between SPT and Euclid and provides a rich dataset containing information on galaxies, clusters, and their environments.

Archipley, M. [Chicago U., Astron. Astrophys. Ctr.↗
DOE OSTI2020

Materials Data on TeC4S4N8(ClO)2 by Materials Project

C4TeS2(N4Cl)2(SO)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four sulfur monoxide molecules and two C4TeS2(N4Cl)2 clusters. In each C4TeS2(N4Cl)2 cluster, there are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a 3-coordinate geometry to two N1- atoms. There is one shorter (1.31 Å) and one longer (1.32 Å) C–N bond length. In the second C4+ site, C4+ is bonded in a linear geometry to two N1- atoms. There is one shorter (1.18 Å) and one longer (1.31 Å) C–N bond length. There are four inequivalent N1- sites. In the first N1- site, N1- is bonded in a bent 120 degrees geometry to one C4+ and one Te6+ atom. The N–Te bond length is 2.05 Å. In the second N1- site, N1- is bonded in a distorted single-bond geometry to one C4+ and one Cl1- atom. The N–Cl bond length is 1.70 Å. In the third N1- site, N1- is bonded in a bent 120 degrees geometry to one C4+ and one S2- atom. The N–S bond length is 1.59 Å. In the fourth N1- site, N1- is bonded in a single-bond geometry to one C4+ atom. Te6+ is bonded in a distorted square co-planar geometry to two equivalent N1- and two equivalent S2- atoms. Both Te–S bond lengths are 2.68 Å. S2- is bonded in a distorted single-bond geometry to one N1- and one Te6+ atom. Cl1- is bonded in a distorted single-bond geometry to one N1- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo3Se(NO6)2 by Materials Project

(MoO3)3N2SeO3 crystallizes in the hexagonal P6_3 space group. The structure is two-dimensional and consists of four ammonia molecules; two SeO3 clusters; and two MoO3 sheets oriented in the (0, 0, 1) direction. In each SeO3 cluster, Se2- is bonded in a trigonal planar geometry to three equivalent O2- atoms. All Se–O bond lengths are 1.63 Å. O2- is bonded in a single-bond geometry to one Se2- atom. In each MoO3 sheet, Mo6+ is bonded to five O2- atoms to form distorted corner-sharing MoO5 square pyramids. There are a spread of Mo–O bond distances ranging from 1.70–2.02 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Mo6+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Mo6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Mo6+ atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1983

Remote Sensing techniques used to characterize soil erosion in southwestern Sao Paulo state

Within randomly sampled squares of a 1 km x 1 km grid, rill/gullies frequency, land cover/land use type and shape of the slopes were extracted from aerial photographs of the Ribeirao Anhumas drainage basin. Mean slope gradient, stream frequency and slope length were calculated on topographic maps. Ground truth data on fine sand/coarse sand ratio and vegetation cover densities were obtained. The MSS-LANDSAT-2 data (CCTs) were analyzed using single-cell, cluster synthesis and slicer algorithms. Graphical and statistical analyses of the data indicate that different slope gradients and land cover/land use types are the most significant factors related to the soil erosion process. The digital analysis of MSS data allowed the association among gray level classes and vegetation cover classes, which defined seven classes. These gray level classes and slope gradient classes were used to rank erosion risk.

Parada, N. D. J.↗
DOE OSTI2024

Measurement of groomed event shape observables in deep-inelastic electron-proton scattering at HERA

The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s} =319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of 351 pb -1 . Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet measurements in hadronic collisions; this paper presents the first application of grooming to DIS data. The analysis is carried out in the Breit frame, utilizing the novel Centauro jet clustering algorithm that is designed for DIS event topologies. Events are required to have squared momentum-transfer $Q^2 > 150$ GeV 2 and inelasticity $0.2< y < 0.7$. We report measurements of the production cross section of groomed event 1-jettiness and groomed invariant mass for several choices of grooming parameter. Monte Carlo model calculations and analytic calculations based on Soft Collinear Effective Theory are compared to the measurements.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Quantifying rupture characteristics of microearthquakes in the Parkfield Area using a high-resolution borehole network

It is well known that large earthquakes often exhibit significant rupture complexity such as well separated subevents. With improved recording and data processing techniques, small earthquakes have been found to exhibit rupture complexity as well. Studying these small earthquakes offers the opportunity to better understand the possible causes of rupture complexities. Specifically, if they are random or are related to fault properties. We examine microearthquakes (M < 3) in the Parkfield, California, area that are recorded by a high-resolution borehole network. We quantify earthquake complexity by the deviation of source time functions and source spectra from simple circular (omega-square) source models. We establish thresholds to declare complexity, and find that it can be detected in earthquakes larger than magnitude 2, with the best resolution above M2.5. Comparison between the two approaches reveals good agreement (>90 per cent), implying both methods are characterizing the same source complexity. For the two methods, 60–80 per cent (M 2.6–3) of the resolved events are complex depending on the method. The complex events we observe tend to cluster in areas of previously identified structural complexity; a larger fraction of the earthquakes exhibit complexity in the days following the M w 6 2004 Parkfield earthquake. Ignoring the complexity of these small events can introduce artefacts or add uncertainty to stress drop measurements. Focusing only on simple events however could lead to systematic bias, scaling artefacts and the lack of measurements of stress in structurally complex regions.

58 GEOSCIENCES↗