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7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on LuTh by Materials Project

ThLu is alpha La-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded to six equivalent Th and six Lu atoms to form ThLu6Th6 cuboctahedra that share corners with twelve ThLu6Th6 cuboctahedra, edges with twelve ThLu6Th6 cuboctahedra, edges with twelve LuLu6Th6 cuboctahedra, faces with six equivalent ThLu6Th6 cuboctahedra, and faces with twelve LuLu6Th6 cuboctahedra. All Th–Th bond lengths are 3.52 Å. All Th–Lu bond lengths are 3.50 Å. In the second Th site, Th is bonded to ten equivalent Th and six Lu atoms to form ThLu6Th10 cuboctahedra that share corners with ten LuLu6Th6 cuboctahedra, corners with twelve ThLu6Th6 cuboctahedra, edges with eight LuLu6Th6 cuboctahedra, edges with sixteen ThLu6Th6 cuboctahedra, faces with sixteen equivalent ThLu6Th10 cuboctahedra, and faces with eighteen LuLu6Th6 cuboctahedra. There are a spread of Th–Th bond distances ranging from 3.52–7.04 Å. All Th–Lu bond lengths are 3.50 Å. There are three inequivalent Lu sites. In the first Lu site, Lu is bonded to six equivalent Th and six equivalent Lu atoms to form LuLu6Th6 cuboctahedra that share corners with twelve LuLu6Th6 cuboctahedra, edges with twelve equivalent ThLu6Th6 cuboctahedra, edges with twelve LuLu6Th6 cuboctahedra, faces with six equivalent LuLu6Th6 cuboctahedra, and faces with twelve equivalent ThLu6Th6 cuboctahedra. All Lu–Lu bond lengths are 3.52 Å. In the second Lu site, Lu is bonded to six Th and six equivalent Lu atoms to form LuLu6Th6 cuboctahedra that share corners with five equivalent ThLu6Th10 cuboctahedra, corners with twelve LuLu6Th6 cuboctahedra, edges with ten ThLu6Th6 cuboctahedra, edges with twelve LuLu6Th6 cuboctahedra, faces with six equivalent LuLu6Th6 cuboctahedra, and faces with fifteen ThLu6Th6 cuboctahedra. All Lu–Th bond lengths are 3.50 Å. All Lu–Lu bond lengths are 3.52 Å. In the third Lu site, Lu is bonded to six Th and six equivalent Lu atoms to form LuLu6Th6 cuboctahedra that share corners with five equivalent ThLu6Th10 cuboctahedra, corners with twelve LuLu6Th6 cuboctahedra, edges with ten ThLu6Th6 cuboctahedra, edges with twelve LuLu6Th6 cuboctahedra, faces with six equivalent LuLu6Th6 cuboctahedra, and faces with fifteen ThLu6Th6 cuboctahedra. All Lu–Lu bond lengths are 3.52 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LuTh(BRh)8 by Materials Project

ThLu(RhB)8 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Th is bonded in a 12-coordinate geometry to twelve Rh and twelve B atoms. There are four shorter (3.01 Å) and eight longer (3.20 Å) Th–Rh bond lengths. There are eight shorter (3.04 Å) and four longer (3.18 Å) Th–B bond lengths. Lu is bonded in a 12-coordinate geometry to twelve Rh and twelve B atoms. There are four shorter (2.95 Å) and eight longer (3.17 Å) Lu–Rh bond lengths. There are eight shorter (3.04 Å) and four longer (3.18 Å) Lu–B bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 5-coordinate geometry to one Th, two equivalent Lu, and five B atoms. There are a spread of Rh–B bond distances ranging from 2.22–2.24 Å. In the second Rh site, Rh is bonded in a 5-coordinate geometry to two equivalent Th, one Lu, and five B atoms. There are a spread of Rh–B bond distances ranging from 2.22–2.31 Å. There are two inequivalent B sites. In the first B site, B is bonded in a 6-coordinate geometry to one Th, two equivalent Lu, five Rh, and one B atom. The B–B bond length is 1.81 Å. In the second B site, B is bonded in a 6-coordinate geometry to two equivalent Th, one Lu, five Rh, and one B atom. The B–B bond length is 1.78 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Plant Nutrition Influences Resistant Maize Defense Responses to the Fall Armyworm ( Spodoptera frugiperda )

Plants are often confronted by different groups of herbivores, which threaten their growth and reproduction. However, they are capable of mounting defenses against would-be attackers which may be heightened upon attack. Resistance to insects often varies among plant species, with different genotypes exhibiting unique patterns of chemical and physical defenses. Within this framework, plant access to nutrients may be critical for maximal functioning of resistance mechanisms and are likely to differ among plant genotypes. In this study, we aimed to test the hypothesis that access to nutrition would alter the expression of plant resistance to insects and alter insect performance in a manner consistent with fertilization regime. We used two maize (Zea mays) genotypes possessing different levels of resistance and the fall armyworm (Spodoptera frugiperda) as model systems. Plants were subjected to three fertilization regimes prior to assessing insect-mediated responses. Upon reaching V4 stage, maize plants were separated into two groups, one of which was infested with fall armyworm larvae to induce plant defenses. Plant tissue was collected and used in insect bioassays and to measure the expression of defense-related genes and proteins. Insect performance differed between the two plant genotypes substantially. For each genotype, fertilization altered larval performance, where lower fertilization rates hindered larval growth. Induction of plant defenses by prior herbivory substantially reduced naïve fall armyworm growth in both genotypes. The effects between fertilization and induced defenses were complex, with low fertilization reducing induced defenses in the resistant maize. Gene and protein expression patterns differed between the genotypes, with herbivory often increasing expression, but differing between fertilization levels. The soluble protein concentrations did not change across fertilization levels but was higher in the susceptible maize genotype. These results demonstrate the malleability of plant defenses and the cascading effects of plant nutrition on insect herbivory.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1983

CARS temperature measurements in the fuel preburner of the Space Shuttle main engine: A feasibility study

This report discusses the feasibility of making temperature profile measurements in the fuel preburner of the main engine of the space shuttle (SSME) using coherent anti-Stokes Raman spectroscopy (CARS). The principal thrust of the work is to identify problems associated with making CARS measurements in high temperature gas phase hydrogen at very high pressures (approx 400 atmospheres). To this end a theoretical study was made of the characteristics of the CAR spectra of H2 as a function of temperature and pressure and the accuracy with which temperatures can be extracted from this spectra. In addition the experimental problems associated with carrying out these measurements on a SSME at NSTL were identified. A conceptual design of a CARS system suitable for this work is included. Many of the results of the calculations made in this report are plotted as a function of temperature. In the course of presenting these results, it was necessary to decide whether the number of density or the pressure should be treated as a fixed parameter.

Beiting, E. J.↗
NASA NTRS1987

Thermal-infrared spectral observations of geologic materials in emission

The thermal-infrared spectra of geologic materials in emission were studied using the prototype Thermal Emission Spectrometer (TES). A variety of of processes and surface modifications that may influence or alter the spectra of primary rock materials were studied. It was confirmed that thermal emission spectra contain the same absorption features as those observed in transmission and reflection spectra. It was confirmed that the TES instrument can be used to obtain relevant spectra for analysis of rock and mineral composition.

Christensen, Philip R.↗
NASA NTRS2013

A Semantic Basis for Proof Queries and Transformations

We extend the query language PrQL, designed for inspecting machine representations of proofs, to also allow transformation of proofs. PrQL natively supports hiproofs which express proof structure using hierarchically nested labelled trees, which we claim is a natural way of taming the complexity of huge proofs. Query-driven transformations enable manipulation of this structure, in particular, to transform proofs produced by interactive theorem provers into forms that assist their understanding, or that could be consumed by other tools. In this paper we motivate and define basic transformation operations, using an abstract denotational semantics of hiproofs and queries. This extends our previous semantics for queries based on syntactic tree representations.We define update operations that add and remove sub-proofs, and manipulate the hierarchy to group and ungroup nodes. We show that

Proof Queries↗