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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ca3(GaNi)4 by Materials Project

Ca3(NiGa)4 crystallizes in the cubic I-43m space group. The structure is three-dimensional. Ca is bonded in a 12-coordinate geometry to four equivalent Ni and eight equivalent Ga atoms. All Ca–Ni bond lengths are 3.07 Å. There are four shorter (3.04 Å) and four longer (3.50 Å) Ca–Ga bond lengths. Ni is bonded in a 10-coordinate geometry to three equivalent Ca, three equivalent Ni, and four equivalent Ga atoms. All Ni–Ni bond lengths are 2.57 Å. There are one shorter (2.34 Å) and three longer (2.47 Å) Ni–Ga bond lengths. Ga is bonded in a 7-coordinate geometry to six equivalent Ca and four equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaNi by Materials Project

NiGa is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ni is bonded in a body-centered cubic geometry to eight equivalent Ga atoms. All Ni–Ga bond lengths are 2.52 Å. Ga is bonded in a body-centered cubic geometry to eight equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La3(GaNi)2 by Materials Project

La3Ni2Ga2 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 9-coordinate geometry to four equivalent Ni and five Ga atoms. All La–Ni bond lengths are 3.20 Å. There are a spread of La–Ga bond distances ranging from 3.07–3.30 Å. In the second La site, La is bonded in a 4-coordinate geometry to four equivalent Ni and five Ga atoms. There are a spread of La–Ni bond distances ranging from 2.82–3.35 Å. There are a spread of La–Ga bond distances ranging from 3.19–3.43 Å. Ni is bonded in a 10-coordinate geometry to six La, one Ni, and three Ga atoms. The Ni–Ni bond length is 2.70 Å. There are a spread of Ni–Ga bond distances ranging from 2.54–2.64 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 9-coordinate geometry to seven La and two equivalent Ni atoms. In the second Ga site, Ga is bonded to eight La and four equivalent Ni atoms to form a mixture of distorted corner, edge, and face-sharing GaLa8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr3(GaNi)2 by Materials Project

Pr3(NiGa)2 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are two inequivalent Pr sites. In the first Pr site, Pr is bonded in a 4-coordinate geometry to four equivalent Ni and five Ga atoms. There are a spread of Pr–Ni bond distances ranging from 2.83–3.32 Å. There are a spread of Pr–Ga bond distances ranging from 3.12–3.45 Å. In the second Pr site, Pr is bonded in a 9-coordinate geometry to four equivalent Ni and five Ga atoms. There are two shorter (3.14 Å) and two longer (3.16 Å) Pr–Ni bond lengths. There are a spread of Pr–Ga bond distances ranging from 3.08–3.21 Å. Ni is bonded in a 10-coordinate geometry to six Pr, one Ni, and three Ga atoms. The Ni–Ni bond length is 2.70 Å. There are one shorter (2.52 Å) and two longer (2.60 Å) Ni–Ga bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 9-coordinate geometry to seven Pr and two equivalent Ni atoms. In the second Ga site, Ga is bonded to eight Pr and four equivalent Ni atoms to form a mixture of distorted face, edge, and corner-sharing GaPr8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La2(GaNi)5 by Materials Project

La2(NiGa)5 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 7-coordinate geometry to eight Ni and five Ga atoms. There are a spread of La–Ni bond distances ranging from 3.07–3.27 Å. There are one shorter (3.22 Å) and four longer (3.40 Å) La–Ga bond lengths. In the second La site, La is bonded in a 1-coordinate geometry to seven Ni and six Ga atoms. There are a spread of La–Ni bond distances ranging from 3.01–3.22 Å. There are two shorter (3.15 Å) and four longer (3.35 Å) La–Ga bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 11-coordinate geometry to three La, two equivalent Ni, and six Ga atoms. Both Ni–Ni bond lengths are 2.47 Å. There are four shorter (2.56 Å) and two longer (2.87 Å) Ni–Ga bond lengths. In the second Ni site, Ni is bonded in a 11-coordinate geometry to three La and five Ga atoms. There are a spread of Ni–Ga bond distances ranging from 2.37–2.57 Å. In the third Ni site, Ni is bonded in a 11-coordinate geometry to three La, one Ni, and four equivalent Ga atoms. There are two shorter (2.42 Å) and two longer (2.54 Å) Ni–Ga bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 12-coordinate geometry to two La, five Ni, and three Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.54–2.65 Å. In the second Ga site, Ga is bonded in a 2-coordinate geometry to three La, four Ni, and four equivalent Ga atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

FuelLib (Fuel Library) [SWR-25-26]

FuelLib is a library that utilizes the group contribution method (GCM) for calculating thermodynamic properties of hydro-carbon jet fuels. FuelLib utilizes the tables and functions of the GCM as proposed by Constantinou and Gani (1994) and Constantinou, Gani and O'Connel (1995), with additional physical properties discussed in Govindaraju & Ihme (2016). The code is based on Pavan B. Govindaraju's Matlab implementation of the GCM, and has been expanded to include additional thermodynamic properties and mixture properties. The fuel library contains gas chromatography (GC x GC) data for a variety of fuels ranging from simple single component fuels to complex jet fuels. The GC x GC data for POSF jet fuels comes from Edwards (2020).

Montgomery, David [National Renewable Energy Labor↗
DOE OSTI2023

Data preservation in high energy physics

Data preservation is a mandatory specification for any present and future experimental facility and it is a cost-effective way of doing fundamental research by exploiting unique data sets in the light of the continuously increasing theoretical understanding. This document summarizes the status of data preservation in high energy physics. The paradigms and the methodological advances are discussed from a perspective of more than ten years of experience with a structured effort at international level. The status and the scientific return related to the preservation of data accumulated at large collider experiments are presented, together with an account of ongoing efforts to ensure long-term analysis capabilities for ongoing and future experiments. Transverse projects aimed at generic solutions, most of which are specifically inspired by open science and FAIR principles, are presented as well. A prospective and an action plan are also indicated.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Kink-antikink collisions and multi-bounce resonance windows in higher-order field theories

In this work, we study collisions of coherent structures in higher-order field-theoretic models, such as the Φ 8 , Φ 10 and Φ 12 ones. The main distinguishing feature, of the example models considered herein, is that the collision arises due to the long-range interacting algebraic tails of these solitary waves. We extend the approach to suitably initialize the relevant kinks, in the additional presence of finite initial velocity, in order to minimize the dispersive wave radiation potentially created by their slow spatial decay. We find that, when suitably initialized, these models still feature the multi-bounce resonance windows earlier found in models in which the kinks bear exponential tails, such as the Φ 4 and Φ 6 field theories among others. Also present is the self-similar structure of the associated windows with three- and more-bounce windows at the edges of two- and lower-bounce ones. Moreover, phenomenological but highly accurate (and predictive), scaling relations are derived for the dependence of the time between consecutive collisions and, e.g., the difference in kinetic energy between the incoming one and the critical one for one-bounces. Such scalings are traced extensively over two-bounce collision windows throughout the three models, hinting at the possibility of an analytical theory in this direction.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Finding a common ground for RCM experiments. Part B: Benchmark study on ethanol ignition

Rapid compression machines (RCMs) are widely used to investigate gas phase reaction kinetics of various kind of fuels at application relevant conditions. In principle, the operation of an RCM is based on the idea of compressing a homogenous pre-mixed fuel-air mixture by a piston. Usually creviced pistons ensure a homogenous adiabatic core in the center of the reaction chamber which permits the assumption of an isentropic relation between the measured pressure and gas temperature. Despite the ideal core gas compression, non-ideal effects such as heat loss, differences in the compression behavior, and ultimately non-standardized design and operation of rapid compression machines lead to different experimental results in different facilities at nominally the same end of compression conditions. In this study ignition delay times of ethanol are investigated at four different conditions in five independent RCMs. As expected, the raw results of the different facilities indeed show notable differences at the same end of compression conditions. However, according to the adiabatic core hypothesis the agreement between kinetic simulations and experiments should be consistent for all facilities provided that the facility effects are correctly accounted for. To elaborate upon this hypothesis, a kinetic mechanism is optimized to reflect the experimental results of all facilities. In the end, the optimized mechanism predicts all experimental data within the expected uncertainty. This confirms the reliability of RCM experiments for kinetic investigations and the validity of the effective volume approach in simulating RCM data.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Atomic-scale investigations of Ti 3 C 2 T x MXene surfaces

The family of two-dimensional (2D) carbides and/or nitrides, also known as MXenes, has generated great excitement within the scientific community and has been proposed for a wide variety of applications since its discovery. Despite this attention, there have been only limited studies of the atomically resolved local electronic and physical structure of MXene surfaces strongly affecting the physicochemical properties of these materials. Here, in this study, we report local structural, spectroscopic, and chemical investigations of the surfaces of Ti 3 C 2 T x flakes using scanning tunneling microscopy and spectroscopy, closely coupled to theoretical studies. Terminal groups are visualized and characterized, along with surface TiO 2 clusters formed upon exposure to air. Fundamental insight into the local electronic and chemical properties associated with different terminal groups on MXenes and their oxidation products is presented.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Experimental and kinetic modeling study of tetralin: A naphtheno-aromatic fuel for gasoline, jet and diesel surrogates

Distillate fuels contain significant proportions of naphtheno-aromatic components and tetralin is a suitable surrogate component to represent this molecular moiety. The presence of aromatic and naphthyl rings makes kinetic modeling of tetralin very challenging. Primary radicals formed during the oxidation of tetralin can be aryl, benzylic or paraffinic in nature. Using available information on reaction paths and rate constants of naphthenes and alkyl-aromatics, in this study a kinetic model of tetralin has been developed with emphasis on low-temperature chemistry and high-pressure conditions. Due to the lack of high-level quantum chemical calculations on reaction pathways of tetralin, analogous rates from ab-initio studies on benzylic and paraffinic radicals have been adopted here. Some modifications to the reaction rate rules are incorporated to account for the unique characteristics of tetralin's molecular structure. Important reaction channels have been identified using reaction path and brute force sensitivity analyses. In order to investigate the model performance at low temperatures, new experiments are carried out in a rapid compression machine on blends of tetralin and 3-methylpentane. Blending of low-reactivity tetralin with a high-reactivity alkane allowed the investigation of tetralin ignition at very low temperatures (665 – 856 K). The kinetic model developed in the current study is found to predict the current experiments and literature data adequately. The new model will aid in high-fidelity surrogate predictions at engine-relevant conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Probing the Chemical Kinetics of Minimalist Functional Group Gasoline Surrogates

We report surrogate mixtures are routinely used for understanding gasoline fuel combustion in engine simulations. The general trend in surrogate formulation has been to increase the number of fuel components in a mixture to better emulate real fuel properties. Recently, a new surrogate design strategy based on functional group analysis of real gasolines was proposed using a minimal number of species [minimalist functional group (MFG)-approach]. MFG surrogates (having just one or two components) could experimentally capture the ignition delay time (IDT), threshold sooting index, and smoke point of different gasoline fuels with hundreds of components. However, other combustion characteristics were not explored, and kinetic modeling of MFG surrogates was not reported. These aspects are addressed in this paper, where the combustion behavior of MFG surrogates for various gasolines was assessed by simulating IDT, jet-stirred reactor oxidation, and premixed laminar flame speeds using chemical kinetic modeling. MFG simulations were compared with experimental data of the real gasolines as well as with the more complex multicomponent (five to nine species) surrogates. This study reveals that binary MFG surrogate mixtures are capable of accurately simulating the combustion behavior of more complex gasoline fuels with hundreds of components.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Emergent Magnetism with Continuous Control in the Ultrahigh-Conductivity Layered Oxide PdCoO 2

The current challenge to realizing continuously tunable magnetism lies in our inability to systematically change properties, such as valence, spin, and orbital degrees of freedom, as well as crystallographic geometry. Here, we demonstrate that ferromagnetism can be externally turned on with the application of low-energy helium implantation and can be subsequently erased and returned to the pristine state via annealing. We find that this high level of continuous control is made possible by targeting magnetic metastability in the ultrahigh-conductivity, nonmagnetic layered oxide PdCoO 2 where local lattice distortions generated by helium implantation induce the emergence of a net moment on the surrounding transition metal octahedral sites. These highly localized moments communicate through the itinerant metal states, which trigger the onset of percolated long-range ferromagnetism. The ability to continuously tune competing interactions enables tailoring precise magnetic and magnetotransport responses in an ultrahigh-conductivity film and will be critical to applications across spintronics.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2020

A fully unprivileged CernVM-FS

The CernVM File System provides the software and container distribution backbone for most High Energy and Nuclear Physics experiments. It is implemented as a file system in user-space (Fuse) module, which permits its execution without any elevated privileges. Yet, mounting the file system in the first place is handled by a privileged suid helper program that is installed by the Fuse package on most systems. The privileged nature of the mount system call is a serious hindrance to running CernVM-FS on opportunistic resource and supercomputers. Fortunately, recent developments in the Linux kernel and in the Fuse user-space libraries enabled fully unprivileged mounting for Fuse file systems (as of RHEL 8), or at least outsourcing the privileged mount system call to a custom, external process. This opens the door to several, very appealing new ways to use CernVM-FS, such as a generally usable “super pilot” consisting of the pilot code bundled with Singularity and CernVM-FS, or the on-demand instantiation of unprivileged, ephemeral containers to publish new CernVM-FS content from anywhere. In this contribution, we discuss the integration of these new Linux features with CernVM-FS and show some of its most promising, new applications.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Future Circular Collider Feasibility Study Report

Volume 1 of the FCC Feasibility Report presents an overview of the physics case, experimental programme, and detector concepts for the Future Circular Collider (FCC). This volume outlines how FCC would address some of the most profound open questions in particle physics, from precision studies of the Higgs and EW bosons and of the top quark, to the exploration of physics beyond the Standard Model. The report reviews the experimental opportunities offered by the staged implementation of FCC, beginning with an electron-positron collider (FCC-ee), operating at several centre-of-mass energies, followed by a hadron collider (FCC-hh). Benchmark examples are given of the expected physics performance, in terms of precision and sensitivity to new phenomena, of each collider stage. Detector requirements and conceptual designs for FCC-ee experiments are discussed, as are the specific demands that the physics programme imposes on the accelerator in the domains of the calibration of the collision energy, and the interface region between the accelerator and the detector. The report also highlights advances in detector, software and computing technologies, as well as the theoretical tools/reconstruction techniques that will enable the precision measurements and discovery potential of the FCC experimental programme. The content and structure of this report are guided by the scope and priorities defined in the mandate of the FCC Feasibility Study. It is therefore not intended to serve as an exhaustive review of the full physics potential of FCC. Several topics, already covered in earlier reports such as the FCC CDR, are not reiterated here or are addressed only briefly, in alignment with the study’s focus. This volume reflects the outcome of a global collaborative effort involving hundreds of scientists and institutions, aided by a dedicated community-building coordination, and provides a targeted assessment of the scientific opportunities and experimental foundations of the FCC programme.

Benedikt, M. [European Organization for Nuclear Re↗