Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “NF”

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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Lattice calculation of light meson radiative leptonic decays

In this work, we perform a lattice QCD calculation of the branching ratios and the form factors\r\nof radiative leptonic decays P →ℓνℓγ (P= π,K) using Nf = 2+1 domain wall fermion ensembles\r\ngenerated by the RBC and UKQCD collaborations at the physical pion mass. We adopt the\r\ninfinite-volume reconstruction (IVR) method, which extends lattice data to infinite volume and\r\neffectively controls the finite-volume effects. This study represents a first step toward a complete\r\ncalculation of radiative corrections to leptonic decays using the IVR method, including both real\r\nphoton emissions and virtual photon loops. For decays involving a final-state electron, collinear\r\nradiative corrections, enhanced by the large logarithmic factors such as ln(m2\r\nπ/m2e) and ln(m2K/m2e), can reach the level of O(10%) and are essential at the current level of theoretical and experimental precision. After including these corrections, our result for π →eνeγ agrees with the PIBETA measurement; for K →eνeγ, our results are consistent with the KLOE data and exhibit a 1.7σtension with E36; and for K →µνµγ, where radiative corrections are negligible, our results confirm the previously observed discrepancies between lattice results and the ISTRA/OKA measurements at large photon energies, and with the E787 results at large muon–photon angles.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Parametric Study of the Influence of Support Type, Presence of Platinum on Support, and Ionomer Content on the Microstructure of Polymer Electrolyte Fuel Cell Catalyst Layers

We report Ultra-small angle X-ray scattering (USAXS) was employed to investigate the effects of carbon support type, the presence of platinum on carbon, and ionomer loading on the microstructure of polymer electrolyte fuel cell (PEFC) catalyst layers (CLs). Particle size distributions (PSDs), obtained from fitting the measured scattering data were used to interpret the size of carbon aggregates (40–300 nm) and agglomerates (>400 nm) from two-component carbon/ionomer and three-component platinum/carbon/ionomer CLs. Two types of carbon supports were investigated: high surface area carbon (HSC) and Vulcan XC-72. CLs with a range of perfluorosulfonic acid (PFSA) ionomer to carbon (I/C) ratios (0.2–1.2) and also with perfluoroimide acid (PFIA) ionomer were studied to evaluate the effect of ionomer on CL microstructure. The carbon type, the presence of platinum, and ionomer loading were all found to significantly impact carbon agglomeration. The extent of Pt/C agglomeration in the CL was found to increase with increasing ionomer and platinum concentration and to decrease with increasing carbon surface area. Platinum electrochemically-active surface area (ECSA) and local oxygen transport resistance (R nF ) were correlated to the CL microstructure to yield relationships affecting electrode performance.

25 ENERGY STORAGE↗
DOE OSTI2023

Data for Chemical-Free Production of Multiple High-Value Bioproducts from Metabolically Engineered Transgenic Sugarcane ‘Oilcane’ Bagasse and Their Recovery Using Nanofiltration

Bioenergy crops have potential for being a sustainable and renewable feedstock for biofuels and various value-added bioproducts. The study utilizes recently developed transgenic sugarcane (“oilcane”) bagasse for chemical-free coproduction of high-value bioproducts, i.e., furfurals, HMF, acetic acid, cellulosic sugars, and vegetative lipids. Hydrothermal pretreatment was optimized at 210 °C for 5 min to coproduce 6.91%, 2.67%, 5.07%, 2.42% and 37.82% (w/w) furfurals, HMF, acetic acid, vegetative lipids, and cellulosic sugars, respectively from lignocellulosic biomass. Additionally, nanofiltration system in-series was successfully established to recover sugars, furfurals, HMF, and acetic acid from the pretreatment liquor. 1st nanofiltration with Duracid NF membrane rejected ∼99% sugars. Concentrated sugars with significantly reduced inhibitory products were obtained in retentate for fermentation. 2nd nanofiltration with NF90 membrane used permeate of 1st nanofiltration as feed and rejected ∼ 86% furfurals. The work demonstrates the feasibility of coproducing and recovering multiple biochemicals from lignocellulosic biomass.

Biomass Analytics↗
DOE OSTI2023

Tree damage and mortality measurements across seven ForestGEO plots in the tropics between Oct 2016 and Mar 2023

Annual records (raw data) on tree survival and structural completeness of 36,524 trees (2,467 species) collected across 29 censuses in seven tropical forests distributed across the Neotropics (Amacayacu, Colombia; Barro Colorado Island (BCI), Panamá; Yasuní, Ecuador) and Asia (Fushan, Taiwan; Huai Kha Khaeng (HKK), Thailand; Khao Chong (KC), Thailand; Pasoh, Malaysia). This dataset was used to compare aboveground biomass loss via damage to living trees relative to total AGB loss (mortality + damage). Variable definitions: site: name of the ForestGEO plot stemID.ams: Unique ID for the stem in the annual mortality surveys (ams) treeID.ams: Unique ID for the tree in the ams date.full.census: date of the previous full census of the plot, format: YYYY-MM-DD dbh.full.census: diameter at the breast height (dbh in mm) measured during the previous full census of the plot home: height of measurement of dbh (in m) meanWD: species-level wood density (g cm-3) date.ams: date of the ams, format: YYYY-MM-DD status: survival status of the tree (A: alive; D: dead; NF: not found; "?": unknown) H_considering_damage: living length of the main axis in meters; provides an estimate of the amount of remaining living tissues along the main axis of the stem (e.g., the height of breakage or the height discounting wood decay) b: the remaining proportion of branch volume within the living length (b∈[0,1]). weights.ind: frequency of the [size class x species] bins within the forest plot relative to their frequency in the sample. Necessary to extrapolate estimates to the whole plot.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on Be(NF2)2 by Materials Project

(BeNF4)2(BeNF3)2N2(NF)2 crystallizes in the orthorhombic Pna2_1 space group. The structure is zero-dimensional and consists of four ammonia molecules, four monofluoroamine molecules, four BeNF3 clusters, and four BeNF4 clusters. In each BeNF3 cluster, Be2+ is bonded in a distorted linear geometry to three F1- atoms. There are a spread of Be–F bond distances ranging from 1.38–2.42 Å. N1+ is bonded in a single-bond geometry to one F1- atom. The N–F bond length is 1.36 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Be2+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one Be2+ and one N1+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Be2+ atom. In each BeNF4 cluster, Be2+ is bonded in a distorted trigonal non-coplanar geometry to three F1- atoms. There are a spread of Be–F bond distances ranging from 1.41–1.76 Å. N1+ is bonded in a water-like geometry to two F1- atoms. There is one shorter (1.33 Å) and one longer (1.51 Å) N–F bond length. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one N1+ atom. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to one Be2+ and one N1+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Be2+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Be2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr(NF3)2 by Materials Project

ZrF4(NF)2 crystallizes in the orthorhombic Pca2_1 space group. The structure is one-dimensional and consists of sixteen monofluoroamine molecules and four ZrF4 ribbons oriented in the (1, 0, 0) direction. In each ZrF4 ribbon, there are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six F1- atoms to form a mixture of distorted corner and face-sharing ZrF6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Zr–F bond distances ranging from 1.92–2.20 Å. In the second Zr4+ site, Zr4+ is bonded to six F1- atoms to form a mixture of distorted corner and face-sharing ZrF6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Zr–F bond distances ranging from 1.92–2.24 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Zr4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Zr4+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Zr4+ atom. In the fourth F1- site, F1- is bonded in an L-shaped geometry to two Zr4+ atoms. In the fifth F1- site, F1- is bonded in an L-shaped geometry to two Zr4+ atoms. In the sixth F1- site, F1- is bonded in an L-shaped geometry to two Zr4+ atoms. In the seventh F1- site, F1- is bonded in a bent 150 degrees geometry to two Zr4+ atoms. In the eighth F1- site, F1- is bonded in a single-bond geometry to one Zr4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeN2F5 by Materials Project

(Fe2NF8)2N2(NF)4 crystallizes in the orthorhombic Pbcn space group. The structure is two-dimensional and consists of four ammonia molecules; eight monofluoroamine molecules; and two Fe2NF8 sheets oriented in the (0, 0, 1) direction. In each Fe2NF8 sheet, Fe3+ is bonded to five F1- atoms to form corner-sharing FeF5 trigonal bipyramids. There are a spread of Fe–F bond distances ranging from 1.80–2.10 Å. N1+ is bonded in a linear geometry to two equivalent F1- atoms. Both N–F bond lengths are 1.77 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to one Fe3+ and one N1+ atom. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Fe3+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Fe3+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Fe3+ atom. In the fifth F1- site, F1- is bonded in a linear geometry to two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ce(NF3)2 by Materials Project

CeF4(NF)2 crystallizes in the triclinic P1 space group. The structure is one-dimensional and consists of eight monofluoroamine molecules and two CeF4 ribbons oriented in the (1, 0, 0) direction. In each CeF4 ribbon, there are two inequivalent Ce4+ sites. In the first Ce4+ site, Ce4+ is bonded to six F1- atoms to form edge-sharing CeF6 octahedra. There are a spread of Ce–F bond distances ranging from 2.03–2.30 Å. In the second Ce4+ site, Ce4+ is bonded to six F1- atoms to form edge-sharing CeF6 octahedra. There are a spread of Ce–F bond distances ranging from 2.03–2.30 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a water-like geometry to two Ce4+ atoms. In the second F1- site, F1- is bonded in a water-like geometry to two Ce4+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Ce4+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Ce4+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Ce4+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Ce4+ atom. In the seventh F1- site, F1- is bonded in a water-like geometry to two Ce4+ atoms. In the eighth F1- site, F1- is bonded in a water-like geometry to two Ce4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Be(NF2)2 by Materials Project

BeF2(NF)2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four beryllium fluoride molecules and eight monofluoroamine molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe(NF2)3 by Materials Project

FeF3(NF)3 is alpha bismuth trifluoride structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ferric fluoride molecule and three monofluoroamine molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U(NF2)4 by Materials Project

UF6N2(NF)2 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight ammonia molecules, eight monofluoroamine molecules, and four uranium hexafluoride molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2N7OF15 by Materials Project

(Th2F9)2N2(NF)6(N3OF3)2 crystallizes in the cubic P2_13 space group. The structure is zero-dimensional and consists of four ammonia molecules, twelve monofluoroamine molecules, four N3OF3 clusters, and four Th2F9 clusters. In each N3OF3 cluster, N+1.29+ is bonded in a water-like geometry to one O2- and one F1- atom. The N–O bond length is 1.48 Å. The N–F bond length is 1.38 Å. O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent N+1.29+ atoms. F1- is bonded in a single-bond geometry to one N+1.29+ atom. In each Th2F9 cluster, Th4+ is bonded in a 6-coordinate geometry to six F1- atoms. There are three shorter (2.15 Å) and three longer (2.40 Å) Th–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Th4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Th4+ atom. The F–Th bond length is 2.15 Å. In the third F1- site, F1- is bonded in a water-like geometry to two equivalent Th4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaBe2N3F8 by Materials Project

(NaBe2F6)2N2(NF)4 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one ammonia molecule; two monofluoroamine molecules; and one NaBe2F6 sheet oriented in the (0, 0, 1) direction. In the NaBe2F6 sheet, Na1+ is bonded in an octahedral geometry to six equivalent F1- atoms. All Na–F bond lengths are 2.31 Å. Be2+ is bonded in a trigonal planar geometry to three equivalent F1- atoms. All Be–F bond lengths are 1.47 Å. F1- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Be2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th(NF2)4 by Materials Project

ThF4(NF)4 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of eight monofluoroamine molecules and one ThF4 ribbon oriented in the (1, 0, 0) direction. In the ThF4 ribbon, Th4+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Th–F bond distances ranging from 2.11–2.40 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Th4+ atom. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to two equivalent Th4+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Th4+ atom. In the fourth F1- site, F1- is bonded in a water-like geometry to two equivalent Th4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(NF2)3 by Materials Project

(ScF3)2N2(NF)4F2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ammonia molecule, one hydrofluoric acid molecule, two monofluoroamine molecules, and one scandium fluoride molecule.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GeN3F7 by Materials Project

N2Ge(NF4)2GeF4(NF)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four ammonia molecules, four monofluoroamine molecules, two tetrafluorogermane molecules, and two Ge(NF4)2 clusters. In each Ge(NF4)2 cluster, Ge4+ is bonded in a distorted octahedral geometry to six F1- atoms. There are four shorter (1.75 Å) and two longer (2.44 Å) Ge–F bond lengths. N1+ is bonded in a water-like geometry to two F1- atoms. There is one shorter (1.34 Å) and one longer (1.45 Å) N–F bond length. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Ge4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one N1+ atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to one Ge4+ and one N1+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Ge4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Thermal Neutron Scattering Law Evaluations for Zirconium Carbide and Critical Mass Calculations [Slides]

Zirconium Carbide (ZrC) is a refractory material currently being investigated for high temperature reactor applications. ZrC was studied as a base of (U,Zr)C solid solution and UC 2 composite fuels for NERVA-type cores during the Rover program. Testing of the material was performed at Nuclear Furnace 1 (NF-1) located at Los Alamos. Thermal Scattering Law (TSL) evaluations generated with FLASSH are a new contribution to ENDF/B-VIII.1.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Nucleon valence quark distribution functions from Lattice QCD

We present results on the nucleon valence quark distribution extracted from Lattice QCD simulations, using a gauge ensemble of Nf=2+1 Wilson-Clover fermions with a pion mass of m?=350 MeV and lattice spacing of a=0.091 fm. We obtain reduced Ioffe Time Distributions (rITDs) by computing appropriate matrix elements on the lattice, and elaborate on the extraction of the desired quark distributions from the rITDs following the pseudo-PDF approach. A set of techniques are considered in order to ensure ground state dominance. Theoretical and experimental implications of our calculation are discussed.

Kallidonis, Christos↗