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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

Analyses Made to Order: Using Transformation to Rapidly Configure a Multidisciplinary Environment

Aerospace problems are highly multidisciplinary. Four or more major disciplines are involved in analyzing any particular vehicle. Moreover, the choice of implementation technology of various subsystems can lead to a change of leading domain or reformation of the driving equations. An excellent example is the change of expertise required to consider aircraft built from composite or metallic structures, or those propelled by chemical or electrical thrusters. Another example is in the major reconfiguration of handling and stability equations with different control surface configuration (e.g., canards, t-tail v four-post tail). Combinatorial problems are also commonplace anytime that a major system is to be designed. If there are only 5 attributes of a design to consider with 4 different options, this is already 1024 options. Adding just 5 more dimensions to the study explodes the space to over one million. Even generous assumptions like the idea that only 10% of the combinations are physically feasible can only contain the problem for so long. To make matters worse, the simple number of combinations is only the beginning. Combining the issue of trade space size with the need to reformulate the design problem for many of the possibilities makes life exponentially more difficult. Advances in software modeling approaches have led to the development of model-driven architecture. This approach uses the transformation of models into inferred models (e.g. inferred execution traces from state machines) or the skeletons for code generation. When the emphasis on transformation is applied to aerospace, it becomes possible to exploit redundancy in the information specified in multiple domain models into a unified system model. F1urther, it becomes possible to overcome the combinatorial nature of specifying integrated system behavior by manually combining the equations governing a given component technology. Transformations from a system specification combined with a system-analysis mapping specification enable one-click combination of domain analyses. This is a flexibility that has been missing from many engineering codes, which often entangle design specification and physical examination much more than is required to conduct the analysis. This capability has been investigated and cultivated within the DARPA F6 program by a team of JPL and Phoenix Integration engineers building the Adapatable Systems Design and Analysis (ASDA) framework. By embracing system modeling with SysML and the Query-View-Transformation (QVT) language, the ASDA team has been able to build a flexible, easily reconfigurable framework for building up and solving large tradespaces. Examples of application and lessons learned in building the framework will be described in this paper. In addition, the motivation will be laid for various tool vendors to develop open model description standards while being able to maintain competitive advantage through proprietary algorithms and approaches. These standards will also be compared to the underpinnings of model-driven architecture and the OMG standards of the Meta-Object Facility (MOF), SysML, and QVT.

Cole, Bjorn↗
NASA NTRSDate not supplied

NASA’s Global Change Master Directory (GCMD) Keyword Viewer Beta

The Global Change Master Directory (GCMD) Keyword Viewer is a web-based client that allows metadata curators and ontologists to search for and navigate the GCMD keywords in a user-friendly and human-readable tree structure. The Keyword Viewer is built on top of the Keyword Management Systems (KMS) API, which provides machine-to-machine access to the keywords.

Tyler B Stevens↗
NASA NTRS1990

Coupled BE/FE/BE approach for scattering from fluid-filled structures

NASHUA is a coupled finite element/boundary element capability built around NASTRAN for calculating the low frequency far-field acoustic pressure field radiated or scattered by an arbitrary, submerged, three-dimensional, elastic structure subjected to either internal time-harmonic mechanical loads or external time-harmonic incident loadings. Described here are the formulation and use of NASHUA for solving such structural acoustics problems when the structure is fluid-filled. NASTRAN is used to generate the structural finite element model and to perform most of the required matrix operations. Both fluid domains are modeled using the boundary element capability in NASHUA, whose matrix formulation (and the associated NASTRAN DMAP) for evacuated structures can be used with suitable interpretation of the matrix definitions. After computing surface pressures and normal velocities, far-field pressures are evaluated using an asymptotic form of the Helmholtz exterior integral equation. The proposed numerical approach is validated by comparing the acoustic field scattered from a submerged fluid-filled spherical thin shell to that obtained with a series solution, which is also derived here.

Everstine, Gordon C.↗
DOE OSTI2018

Improved Models for Metallic Nanoparticle Cores from Atomic Pair Distribution Function (PDF) Analysis

X-ray atomic pair distribution functions (PDFs) were collected from a range of canonical metallic nanomaterials, both elemental and alloyed, prepared using different synthesis methods and exhibiting drastically different morphological properties. Widely applied shape-tuned attenuated crystal (AC) fcc models proved inadequate, yielding structured, coherent, and correlated fit residuals. However, equally simple discrete cluster models could account for the largest amplitude features in these difference signals. A hypothesis testing based approach to nanoparticle structure modeling systematically ruled out effects from crystallite size, composition, shape, and surface faceting as primary factors contributing to the AC misfit. On the other hand, decahedrally twinned cluster cores were found to be the origin of the AC structure misfits for a majority of the nanomaterials reported here. It is further motivated that the PDF can readily differentiate between the arrangement of domains in these multiply twinned motifs. Most of the nanomaterials surveyed also fall within the sub-5 nm size regime where traditional electron microscopy cannot easily detect and quantify domain structures, with sampling representative of the average nanocrystal synthesized. Here, the results demonstrate that PDF analysis is a powerful method for understanding internal atomic interfaces in small noble metallic nanomaterials. Such core cluster models, easily built algorithmically, should serve as starting structures for more advanced models able to capture atomic positional disorder, ligand induced or otherwise, near nanocrystal surfaces.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

Foldy v1

We created a cloud-based application for running AlphaFold2 and related structural programs called Foldy. Foldy is built on Helm / Kubernetes, which enables a facile production deployment and a scalable backend. Once set up by an institution, Foldy requires no software expertise from its users. It can be used to predict the structure of large proteins (up to 3000 amino acids), to visualize Pfam and antiSMASH annotations, and to perform ligand docking with Autodock Vina.

Roberts, Jacob↗
DOE OSTI2016

Characterization of electronic structures from CdS/Si nanoheterostructure array based on silicon nanoporous pillar array

Highlights: • CdS/Si nanoheterostructure array has been fabricated through a CBD method. • The electronic properties have been investigated by the I–V and C–V techniques. • The onset voltages, characteristic frequency and built-in potential are investigated. • The electronic structures can be tuned through the annealing treatments. - Abstract: The electronic properties of heterostructures are very important to its applications in the field of optoelectronic devices. Understanding and control of electronic properties are very necessary. CdS/Si nanoheterostructure array have been fabricated through growing CdS nanocrystals on the silicon nanoporous pillar array using a chemical bath deposition method. The electronic properties of CdS nanoheterostructure array have been investigated by the current–voltage, complex impedance spectroscopy and capacitance–voltage techniques. The onset voltages, characteristic frequency and built-in potential are gradually increased with increasing the annealing temperature. It is indicated that the electronic structures of CdS/Si nanoheterostructure array can be tuned through the annealing treatments.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Design of a high power TM01 mode launcher optimized for manufacturing by milling

Recent research on high-gradient rf acceleration found that hard metals, such as hard copper and hard copper-silver, have lower breakdown rate than soft metals. Traditional high-gradient accelerating structures are manufactured with parts joined by high-temperature brazing. The high temperature used in brazing makes the metal soft; therefore, this process cannot be used to manufacture structures out of hard metal alloys. In order to build the structure with hard metals, the components must be designed for joining without high-temperature brazing. One method is to build the accelerating structures out of two halves, and join them by using a low-temperature technique, at the symmetry plane along the beam axis. The structure has input and output rf power couplers. We use a TM01 mode launcher as a rf power coupler, which was introduced during the Next Linear Collider (NLC) work. The part of the mode launcher will be built in each half of the structure. This paper presents a novel geometry of a mode launcher, optimized for manufacturing by milling. The coupler was designed for the CERN CLIC working frequency f = 11.9942 GHz; the same geometry can be scaled to any other frequency.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Advanced Reaction System Program: Materials for ARS Reaction Chambers (FY18 Milestone, Subtask 3.3)

The objective of this effort is to identify materials and manufacturing technology that will allow the rapid construction and evaluation of computer modeled advanced reactor system designs to process specific carbon feedstock materials. Before full scale reaction systems can be built, prototypes need to be constructed and operated to validate the proposed new system performance against target criteria. The first steps, however, are to understand what type of materials are needed that can withstand the targeted process environments and determine how structures using those materials can be built. A wide range of reaction vessel conditions may exist in the processes being considered that could involve temperatures up to 1200°C, abrasive materials (high velocity coal and coal ash), different carbon feedstock materials (coal, biomass, and process wastes such as petcoke), corrosive and oxidizing/reducing gases, different material phases (solid, liquid, and gas), cyclic temperatures, microwave energy, customized vessel construction material needs (process stability, cost, weight, and compatibility with other materials), along with other known/unknown variables – all of which must be considered in selecting materials and considering manufacturing processes. The current focus of the research is to develop a reaction vessel sidewall structure consisting of a metal outer support and an inner ceramic (or cermet) protective surface. Ceramic coatings are desired because of their good corrosion and wear resistance, and because they are the material of choice to reduce metal shell temperature in high temperature processes. However significant property mismatches between metals and ceramics have been a roadblock to the joining of metals and ceramics.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2025

PDB-IHM: A System for Deposition, Curation, Validation, and Dissemination of Integrative Structures

Structures of many large biomolecular assemblies are now being determined using integrative approaches. In these approaches, information derived from multiple experimental and computational methods is combined to compute three-dimensional structures of multi-protein complexes and other macromolecular machines. A standalone prototype data resource for integrative structures called PDB-Dev was built, based on recommendations of the Integrative and Hybrid Methods (IHM) Task Force of the Worldwide Protein Data Bank (wwPDB). This effort included developing data standards and software tools for collecting, curating, validating, visualizing, archiving, and disseminating integrative structures that span diverse spatiotemporal scales and conformational states. Mechanisms have been created to validate integrative structures based on the experimental data underpinning them. Building upon this foundational framework, PDB-Dev has been further expanded to handle large dynamic macromolecular systems and integrative structures that combine, for example, experimental restraints with atomic coordinates computed by machine learning algorithms. Data standards and supporting tools have also been extended to capture information about biomolecular dynamics, such as conformational transitions and related kinetic data derived from biophysical methods. Recently, PDB-Dev was unified with the PDB archive and rebranded as PDB-IHM (pdb-ihm.org), further promoting FAIR (Findable, Accessible, Interoperable, and Reusable) principles of data stewardship for integrative structural biology.

IHMCIF↗
DOE OSTI2018

Structural Basis for ( S )-3,4-Dicarboxyphenylglycine (DCPG) As a Potent and Subtype Selective Agonist of the mGlu 8 Receptor

(S)-3,4-Dicarboxyphenylglycine (DCPG) was first reported in 2001 as a potent orthosteric agonist with high subtype selectivity for the mGlu8 receptor, but the structural basis for its high selectivity is not well understood. Herein, we have solved a cocrystal structure of recombinant human mGlu8 amino terminal domain (ATD) protein bound to (S)-DCPG, which possesses the largest lobe opening angle observed to date among known agonist-bound mGlu ATD crystal structures. The binding conformation of (S)-DCPG observed in the crystal structure is significantly different from that in the homology model built from an L-glutamate-bound rat mGlu1 ATD crystal structure, which has a smaller lobe opening angle. This highlights the importance of considering various lobe opening angles when modeling mGlu ATD–ligand complex. New homology models of other mGlu receptors based on the (S)-DCPG-bound mGlu8 ATD crystal structure were explored to rationalize (S)-DCPG’s high mGlu8 receptor subtype selectivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

La 1– x Bi 1+ x S 3 ( x ≈ 0.08): An n-Type Semiconductor

The new bismuth chalcogenide LaBiS3 crystallizes in the monoclinic space group C2/m with a = 27.997(5) Å, b = 4.0663(4) Å, c = 14.747(3) Å, and β = 118.55(3)°. The structure of LaBiS3 is built up of NaCl-type Bi2S5 blocks, and BiS4 and LaS5 infinitely long chains forming a compact three-dimensional framework. Optical spectroscopy and resistivity measurements reveal a semiconducting behavior with a direct band gap of 1.08(2) eV and activation energy of 0.36(1) eV. Thermopower measurements suggest the majority carriers of LaBiS3 are electrons. Heat capacity measurement indicates no phase transition from 2 to 300 K. Band structure calculations at the density function level support the presence of a direct band gap in LaBiS3.

Han, Fei↗
NASA NTRS1988

Software reuse environment user's guide

This document describes the services provided by the prototype Software Reuse Environment, which was developed by CTA for NASA Goddard Space Flight Center, Code 520. This is one of three guides delivered by CTA as part of the environment. The other two guides are: Software Generation and Installation Guide; and SEMANTX--Defining the Schema. The Software Generation and Installation Guide describes the software source modules that make up the Reuse Environment, with instructions on how to generate and install an executable system from the source code. SEMANTX--Defining the Schema describes how a reuse database is created. Actually this guide is more general than the reuse database, as it describes how to generate a SEMANTX database. SEMANTX is an off-the-shelf tool that we have used to implement the reuse database. It is a product of Semantyk Systems, Inc. The Software Reuse Environment is built upon SEMANTX as well as on the IDE Structured Analysis Integrated Environment. (IDE is Interactive Development Environments, Inc.) SEMANTX itself is built on top of the Unify Database Management System. To use the Software Reuse Environment you should have the User's Manuals for SEMANTX, for Unify, and for the IDE software. CTA has provided all of these with the environment.

Source record↗
DOE OSTI2015

SU-E-J-93: Development of Pre-Contoured Human Model Library in DICOM-RT Format for the Epidemiological Study of the Radiotherapy Patients

Purpose: Prior to 3D conformal radiation therapy planning, patient anatomy information was mostly limited to 2D beams-eye-view from the conventional simulator. To analyze the outcomes of such treatments for radiation late effects, 3D computational human models are often used in commercial treatment planning systems (TPSs). However, several underlying difficulties such as time-consuming manual delineation procedures of a large number of structures in the model have always limited its applications. Primary objective of this work was to develop a human model library for the epidemiological study by converting 3D-surface model organs to DICOM-RT format (DICOM-RT structure) using an in-house built software. We converted the ICRP reference human models to DICOM-RT models, which can be readily adopted for various dose calculations. Methods: MATLAB based code were utilized to convert the contour drawings extracted in text-format from the 3D graphic-tool, Rhinoceros into DICOM-RT structure format for 50 different organs of each model using a 16GB dual-core processor. The conversion periods were measured for each DICOM-RT models, and the reconstructed structure volumes were validated against the original 3D-surface models in the TPS. Ten reference hybrid whole-body models (8-pediatric and 2-adults) were automatically processed to create DICOM-RT computational human model library. Results: Mean contour conversion period was found to be 580 (N=2) and 394.5 (N=8) seconds for 50 organs in the adult and pediatric models respectively. A good agreement for large organs (NRMSD <1.0%) and small organs (NRMSD <7.7%) was also observed between the original volumes and corresponding DICOM-RT structure volumes of the organs. Conclusion: The ICRP reference human models were converted into DICOM-RT format to support the epidemiological study using a large cohort of conventional radiotherapy patients. Due to its DICOM-compatibility, the library may be implemented to many other different applications. We also expect to develop the library by including additional models in future.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

The new silver borate Ag{sub 3}B{sub 5}O{sub 9}

Single crystals of Ag{sub 3}B{sub 5}O{sub 9} were obtained via high-pressure synthesis at 3 GPa and 600 °C, using a Walker-type multianvil high-pressure device. Ag{sub 3}B{sub 5}O{sub 9} crystalizes with a=674.7(2), b=943.5(2), c=1103.5(2) pm, V=0.7025(2) nm{sup 3}, and Z=4 in the noncentrosymmetric space group P2{sub 1}2{sub 1}2{sub 1} (no. 19). The orthorhombic structure was refined from 3740 independent reflections with R1=0.0496 and wR2=0.587 (all data). It is built up from infinite corner-sharing chains of BO{sub 4} tetrahedra along the a axis, which are interconnected by BO{sub 3} groups to form a network. In the structure, three crystallographically independent sites are occupied with Ag{sup +} cations exhibiting argentophillic interactions. The synthetic conditions as well as the results of the single crystal structure analysis are presented. - Graphical abstract: Noncentrosymmetric silver borate: During investigations in the system Ag–B–O, a new noncentrosymmetric silver borate Ag{sub 3}B{sub 5}O{sub 9} was discovered. The new structure type is built up from corner-sharing BO{sub 3} and BO{sub 4} groups, forming a network. Argentophillic interactions are clearly indicated by the Ag{sup +}⋯Ag{sup +} distances present in the structure. - Highlights: • A noncentrosymmetric borate Ag{sub 3}B{sub 5}O{sub 9} is accessible via high-pressure synthesis. • Ag{sub 3}B{sub 5}O{sub 9} is the second high-pressure silver borate. • Ag{sup +}⋯Ag{sup +} distances in Ag3B5O9 clearly indicate the presence of argentophillic interactions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2026

NOCI-F Electronic Couplings in Assemblies of Indolonaphthyridine Molecules: From Dimers to the Full Stack

Key electronic processes related to molecular excitonic states of finite stacks of indolonaphthyridine molecules are analyzed via the non-orthogonal configuration interaction with fragments (NOCI-F) method. Indolonaphthyridine is an organic chromophore that can undergo several electronic photoexcitation-related intermolecular processes, such as exciton and electron transfer. The structures studied here are noncrystalline arrangements built as either ordered stacks of indolonaphthyridine or stacks extracted from molecular dynamics simulations including thermal disorder. Taking dimers or trimers from either model, we performed CASSCF and NOCI-F calculations to quantify the intermolecular electronic couplings governing singlet fission, excited singlet and triplet diffusion, and hole and electron diffusion processes. Also, comparing the results for the different models, we studied the effect of structural disorder and distortion on these couplings. Finally, we present a newly developed, advanced postanalysis tool. It takes the NOCI-F data as input to carry out a multifragment full Hamiltonian procedure that involves the complete stack, providing physical information not available from the dimer/trimer models, hence giving access to additional insight into the material’s properties.

coupling reactions↗
DOE OSTI2014

Nexus EnergyHomes, Frederick, Maryland (Fact Sheet)

With this new home - which achieved the highest rating possible under the National Green Building Standard - Nexus EnergyHomes demonstrated that green and affordable can go hand in hand. The mixed-humid climate builder, along with the U.S. Department of Energy Building America team Partnership for Home Innovation, embraced the challenge to create a new duplex home in downtown Frederick, Maryland, that successfully combines affordability with state-of-the-art efficiency and indoor environmental quality. To limit costs, the builder designed a simple rectangular shape and kept interesting architectural features such as porches outside the building's structure. This strategy avoided the common pitfall of creating potential air leakage where architectural features are connected to the structure before the building is sealed against air infiltration. To speed construction and limit costs, the company chose factory-assembled components such as structural insulated panel walls and floor and roof trusses. Factory-built elements were key in achieving continuous insulation around the entire structure. Open-cell spray foam at the rim joist and attic roofline completed the insulation package, and kept the heating, ventilating, and air-conditioning system in conditioned space.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

New Whole-House Solutions Case Study: Nexus EnergyHomes, Frederick, Maryland

With this new home—which achieved the highest rating possible under the National Green Building Standard—Nexus EnergyHomes demonstrated that green and affordable can go hand in hand. The mixed-humid climate builder, along with the U.S. Department of Energy Building America team Partnership for Home Innovation, embraced the challenge to create a new duplex home in downtown Frederick, Maryland, that successfully combines affordability with state-of-the-art efficiency and indoor environmental quality. To limit costs, the builder designed a simple rectangular shape and kept interesting architectural features such as porches outside the building’s structure. This strategy avoided the common pitfall of creating potential air leakage where architectural features are connected to the structure before the building is sealed against air infiltration. To speed construction and limit costs, the company chose factory-assembled components such as structural insulated panel walls and floor and roof trusses. Factory-built elements were key in achieving continuous insulation around the entire structure. Open-cell spray foam at the rim joist and attic roofline completed the insulation package, and kept the heating, ventilating, and air-conditioning system in conditioned space.

affordable↗
DOE OSTI2019

Big Data Framework with Machine Learning for D and D Applications - 19108

The nuclear industry is experiencing a steady increase in maintenance costs even though plants are maintained under high levels of safety, capability and reliability. Nuclear power plants are expected to run every unit at maximum capacity at all times, efficiently utilizing assets with minimal downtime. Surveillance and maintenance of nuclear decommissioning infrastructure provides lot challenges with respect to maintenance or decommissioning of the buildings. There is a need for a framework to analyze the huge amount of data generated by the sensors on the nuclear reactor components as well as structures, to monitor the conditions of these building over a period of time. Emerging technologies such as big data analytics have become a requirement in the nuclear industry to improve structural health monitoring and diagnostics. FIU will make use of existing mature technologies in the areas of imaging, robotics, big data, and machine learning/deep learning to assess the structural integrity of aging facilities at DOE sites. As these facilities await decommissioning, there is a need to understand the structural health of these structures. Many of these facilities were built over 50 years ago and in some cases these facilities have gone beyond the operational life expectancy. In other cases, the facilities have been placed in a state of 'cold and dark' and they are sitting unused, awaiting decommissioning. Finally, some older facilities are one-of-a-kind operational/production facilities supporting critical DOE missions and cannot be shut down. In any of these scenarios, the structural integrity of these facilities may be compromised, so it is imperative that adequate inspections and data collection/analysis be performed on a continuous and ongoing basis. The primary goals of the research include collecting various formats of data such as structured, unstructured and streaming data from the various sensors deployed in buildings, collect videos/pictures from various imaging sources, ingest them using a Hadoop distributed file system and process the data using Spark to perform batch processing and real time analytics. Research and development on various machine learning/deep learning algorithms will also be performed to analyze the heterogeneous data collected from nuclear decommission infrastructure. FIU will design the big data framework to ingest, store and process huge amounts of heterogeneous data collected from many sources and optimize the algorithms to provide insights into the data and predict anomalies observed when compared against baseline conditions. Various modules of this framework will include heterogeneous data sources, message broker, Hadoop distributed file system, Spark for stream and batch processing, machine learning/ deep learning, Cassandra - persistent data store and visualization. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗