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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 1,567 records · Page 87
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Measurements of associated production of vector bosons and heavy flavours with the CMS detector

Thanks to its excellent lepton reconstruction and secondary vertex identification, the CMS detector gives a unique possibility to study processes involving the production of a vector boson in association with heavy quarks. These kind of final states are background to many channels of new physics, as well as Standard Model Higgs searches. Moreover, theoretical predictions about these processes have different approaches and large uncertainties making a test of these predictions even more important. Here different measurements related to this topic are presented, based on the data collected in 2010 and 2011 runs by the CMS detector, namely the inclusive production of Z+b(b) jets and the agular correlation of B-hadron pairs.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Seeing the cis -Dihydroxylating Intermediate: A Mononuclear Nonheme Iron-Peroxo Complex in cis -Dihydroxylation Reactions Modeling Rieske Dioxygenases

The nature of reactive intermediates and the mechanism of the cis-dihydroxylation of arenes and olefins by Rieske dioxygenases and synthetic nonheme iron catalysts have been the topic of intense research over the past several decades. In this study, we report that a spectroscopically well characterized mononuclear nonheme iron(III)-peroxo complex reacts with olefins and naphthalene derivatives, yielding iron(III) cycloadducts that are isolated and characterized structurally and spectroscopically. Further, kinetics and product analysis reveal that the nonheme iron(III)-peroxo complex is a nucleophile that reacts with olefins and naphthalenes to yield cis-diol products. The present study reports the first example of the cis-dihydroxylation of substrates by a nonheme iron(III)-peroxo complex that yields cis-diol products.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

A two-fluid model for relativistic heat conduction

Three years ago it was presented in these proceedings the relativistic dynamics of a multi-fluid system together with various applications to a set of topical problems [1]. In this talk, I will start from such dynamics and present a covariant formulation of relativistic thermodynamics which provides us with a causal constitutive equation for the propagation of heat in a relativistic setting.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2026

A New Chapter in Solar: Bifacial PV from Emerging Topic to Core Curriculum

Associated with the new edition of the bifacial PV book, this talk reviews the transition of bifacial PV from niche innovation to standard practice, including progress in modeling and performance evaluation, and ongoing challenges in reliability, new applications, and fleet repowering.

14 SOLAR ENERGY↗
DOE OSTI2022

Modeling the partitioning of amphiphilic molecules and co-solvents in biomembranes

We report amphiphilic co-solvents can have a significant impact on the structure, organization and physical properties of lipid bilayers. Describing the mutual impact of partitioning and induced structure changes is therefore a crucial consideration for a range of topics such as anesthesia and other pharmacokinetic effects, as well as microbial solvent tolerance in the production of biofuels and other fermentation products, where molecules such as ethanol, butanol or acetic acid might be generated. Small-angle neutron scattering (SANS) is a key method for studying lipid and polymer bilayer structures, with many models for extracting bilayer structure (thickness, area per lipid etc.) from scattering data in use today. However, the molecular details of co-solvent partitioning are conflated with induced changes to bilayer structure, making interpretation and modeling of the scattering curves a challenge with the existing set of models. To address this, a model of a bilayer structure is presented which invokes a two-term partition constant accounting for the localization of the co-solvent within the bilayer. This model was validated using a series of SANS measurements of lipid vesicles in the presence of the co-solvent tetrahydrofuran (THF), showing several strategies of how to deploy the two-parameter partition constant model to describe scattering data and extract both structure and partitioning information from the data. Molecular dynamics simulations are then used to evaluate assumptions of the model, provide additional molecular scale details and illustrate its complementary nature to the data fitting procedure. This approach results in estimates of the partition coefficient for THF in 1,2-dimyristoyl-sn-glycero-3-phosphocholine at 35°C, along with an estimate of the fraction of THF residing in the hydrophobic core of the membrane. The authors envision that this model will be applicable to a wide range of other bilayer/amphiphile interactions and provide the associated code needed to implement this model as a fitting algorithm for scattering data in the SasView suite.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2020

NASA Global Satellite and Model Data Products and Services for Tropical Meteorology and Climatology

Satellite remote sensing and model data play an important role in research and applications of tropical meteorology and climatology over vast, data sparse oceans and remote continents. Since the first weather satellite was launched by NASA in 1960, a large collection of NASA's Earth science data is freely available to the research and application communities around the world, significantly improving our overall understanding of the Earth system and environment. Established in the mid-80s, the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), located in Maryland, USA, is a data archive center for multidisciplinary, satellite and model assimilation data products. As one of the 12 NASA data centers in Earth Sciences, GES DISC hosts several important NASA satellite missions for tropical meteorology and climatology such as the Tropical Rainfall Measuring Mission (TRMM), the Global Precipitation Measurement (GPM) mission and the Modern-Era Retrospective analysis for Research and Applications (MERRA). Over the years, GES DISC has developed data services to facilitate data discovery, access, distribution, analysis and visualization, including Giovanni, an online analysis and visualization tool without the need to download data and software. Despite many efforts for improving data access, still quite a number of challenges remain, such as finding datasets and services for a specific research topic or project, especially for inexperienced users or users outside the remote sensing community. In this article, we list and describe major NASA satellite remote sensing and model datasets and services for tropical meteorology and climatology along with examples of using the data and services, in hope that may help users better utilize the information in their research and applications.

tropical meteorology and climatology, data, servic↗
DOE OSTI2016

Modeling used fuel response to normal conditions of transportation package drops to access geometric sensitivities

The US Department of Energy Used Fuel Disposition program is performing research to determine the loading conditions that used nuclear fuel (UNF) experiences during normal conditions of transportation (NCT). This loading environment includes mechanical shock and vibration as the UNF is transported by rail or truck, and it also includes potential package free drop conditions, which are the topic of this study. NCT drop test requirements for UNF package designs are defined in 10 CFR 71.71. The free drop test height is 30 cm for the UNF packages considered in this study. Explicit dynamic finite element models of generic rail and truck UNF packages containing a highly resolved 17x17 PWR fuel assembly are used to estimate the potential range of loading experienced by UNF during NCT horizontal package drops onto an unyielding surface. There are many variables and uncertainties that can affect the loading of UNF during this type of free drop scenario. This study focuses on geometric variables, such as gap conditions and small adjustments to the angle of impact, in a number of analysis cases. The LS-DYNA finite element analyses calculate detailed results for all the components of the fuel assembly. The results show that the peak localized axial strain in the fuel cladding is estimated to be 0.006421 (nominal) with an upper bound of 0.014511, based on the peak instantaneous bending moment of 63.65 N-m and other uncertainty factors. For the assumed low burnup condition of the UNF, the cladding yield strain is 0.011027 and the failure strain is 0.015574, which means that the calculated upper bound strain approaches the cladding failure limit without exceeding it. The peak shear force on the cladding was calculated to be 7879 N. This could be significant to cladding integrity if applied to the UNF in a situation where the fuel pellets do not support the shear transfer. Further evaluation is needed to determine if this is a credible threat to cladding integrity for these 30 cm free drop scenarios.

42 ENGINEERING↗
DOE OSTI2024

The Naturally Unnatural Standard Model: Symmetry Remnants at the Weak Scale

The project had significant impact on the success of the Snowmass 2021 Community study undertaken from 2020-2, focused on planning the future of High Energy Physics in the US for the period 2025-35. The PI served as a topical convener for the Energy Frontier, and the work undertaken resulted in the topical group report as well as the final Energy Frontier report. The PI further undertook significant work on electroweak baryogenesis and the possibility of CP violation in the Higgs sector, exploring the matter-antimatter asymmetry of the Universe. Further work was also accomplished in investigating possible new explanations for the anomalous magnetic moment of the muon, measured at Fermilab, showing deviations from the Standard Model expectations.

2HDM↗
DOE OSTI2025

Chapter 4 - Recent Advances in Identification of Differential Equations from Noisy Data: IDENT Review

Differential equations and numerical methods are extensively used to model various real-world phenomena in science and engineering. With modern developments, we aim to find the underlying differential equation from a single observation of time-dependent data. If we assume that the differential equation is a linear combination of various linear and nonlinear differential terms, then the identification problem can be formulated as solving a linear system. The goal then reduces to finding the optimal coefficient vector that best represents the time derivative of the given data. We review some recent works on the identification of differential equations. We find some common themes for the improved accuracy: (i) The formulation of linear system with proper denoising is important, (ii) how to utilize sparsity and model selection to find the correct coefficient support needs careful attention, and (iii) there are ways to improve the coefficient recovery. We present an overview and analysis of recent developments on the topic.

97 MATHEMATICS AND COMPUTING↗
NASA NTRS2006

HFGMC Enhancement of MAC/GMC

Additional information about a mathematical model denoted the high-fidelity generalized method of cells (HFGMC) and implementation of the HFGMC within version 4.0 of the MAC/GMC software has become available. MAC/GMC (Micromechanics Analysis Code With Generalized Method of Cells) was a topic of several prior NASA Tech Briefs articles, version 4.0 having been described in "Comprehensive Micromechanics-Analysis Code - Version 4.0" (LEW-17495-1), NASA Tech Briefs, Vol. 29, No. 9 (September 2005), page 54. MAC/GMC predicts elastic and inelastic thermomechanical responses of composite materials. MAC/GMC utilizes the generalized method of cells (GMC) - a model of micromechanics that predicts macroscopic responses of a composite material as functions of the properties, sizes, shapes, and responses of its constituents (e.g., matrix and fibers). The accuracy of the GMC is limited by neglect of coupling between normal and shear stresses. The HFGMC was developed by combining elements of the GMC and a related model, denoted the higher-order theory for functionally graded materials (HOTFGM), that can account for this coupling. Hence, the HFGMC enables simulation of stress and strain with greater accuracy. Some alterations of the MAC/GMC data structure were necessitated by the greater computational complexity of the HFGMC.

Arnold, Steven M.↗
NASA NTRS1991

Modeling the pilot in visually controlled flight

The simplest model for a human operator is a gain with a time delay. However, there have been no comprehensive studies evaluating human control strategies in visually controlled flight. The results of preliminary studies on this topic are described. Human visually guided flight control is important both in low level flight, where it predominates, and in higher altitude flights, where instrument failure is always a potential danger. Two general approaches to this problem, one founded on high order perceptual psychophysics and the other on control systems engineering, are described. Initial results show that the use of control engineering modeling techniques, together with a psychophysical analysis of information in the perspective scene, holds promise for capturing the manual control strategies used during visual flight.

Johnson, Walter W.↗
DOE OSTI2019

Status Update on IAEA MODARIA II Working Group 1 (Assessment and Decision Making) - 19391

During WM2018, the work being done under the International Atomic Energy Agency (IAEA)'s Modelling and Data for Radiological Impact Assessments (MODARIA) II Programme (https://wwwns.iaea.org/projects/modaria/modaria2.asp?s=8 and l=129) was introduced. The Programme comprises seven working groups covering a wide range of topics. Amongst them, Working Group 1 (WG1) is focused on dose assessment and decision aiding tools to address existing exposure situations due to past practices involving naturally occurring radioactive material (NORM) and nuclear legacy sites. Specifically, this covers the development of methods and toolsets for risk-informed decision-making for such complex sites, and includes practical demonstration of decision-making processes and tools through case studies. During 2018 WG1 participants met twice to discuss the status and plans of work being conducted by the WG. The group held its Second Interim Meeting from 7 to 11 May 2018 at the Jozef Stefan Institute (JSI) in Ljubljana, Slovenia. The objectives of the meeting were to: (1) Discuss the status of WG1 work; (2) Start preparation of the interim draft version of the MODARIA II WG1 Report (herein referred to as the 'Interim Report'); (3) Review the progress of planned data analyses, model-model comparisons, and model-data comparisons being conducted through case studies for the Tessenderlo Chemie Site in Belgium, the Zapadnoe Uranium Mill Tailings Site in Ukraine, and a Former Tin Processing Facility Site in Brazil; (4) Discuss calculations conducted for a NORM Site in China for potential addition to the WG1 case studies; (5) Report on progress on topical studies and other assignments performed to support the preparation of several sections of the Interim Report; and (6) Discuss plans for incorporating some preliminary case studies considered by MODARIA I WG1 and MODARIA I WG3. During the meeting in Slovenia, WG1 participants also visited the Zirovski vrh (RZV) Uranium Mine and Mill Tailings Site near Ljubljana. From 22 to 25 October 2018, WG1 members also participated in the MODARIA II Third Technical Meeting in Vienna, Austria. The meeting facilitated analysis of the progress made so far by the seven working groups, as well as exploration of the dissemination of the results of the MODARIA II Programme through publication in scientific journals dealing with the various subject areas covered by the Programme. WG1 participants focused on the preparation of its Interim Report, and engaged in technical exchanges with the IAEA Le Trench Project on characterization, assessment, remediation and management of buried waste at legacy trench sites, as well as the To Enhance uncertainties Reduction and stakeholders Involvement Towards integrated and graded Risk management of humans and wildlife In long-lasting radiological Exposure Situations (TERRITORIES) project (https://territories.eu/). Currently, WG1 is in the process of preparing a draft report to document the results of its various case studies and special topics, and is preparing for the final Interim Meeting in May 2019 and the final Technical Meeting in October 2019, before the conclusion of the MODARIA II Program at the end of 2019. This paper will provide a status update of these activities, along with preliminary information on the WG1 report, including potential recommendations for future activities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Circular Economy Contributions to Decarbonizing the US Steel Sector

The potential benefits of the circular economy (CE) for decarbonization have recently attracted much attention in the academic and grey literature. The department of energy (DOE) industrial decarbonization roadmap highlight that in addition to the four pillars (energy efficiency, electrification, low-carbon fuels, feedstocks, and energy sources, and carbon capture, utilization, and storage (CCUS)) identified in the roadmap, "scenarios [...] will need to be developed that incorporate materials efficiency and circular economy strategies". Moreover, the roadmap identifies hard-to-abate CO2 emissions across the five industrial subsectors included in the analysis (iron & steel, chemical, food & beverage, refining, and cement manufacturing). Thus, additional options to decarbonize the industrial sector, like the CE, could prove beneficial to address those hard-to-abate emissions. Moreover, they may be less costly, require less R&D or incentives, and be more readily adopted than other strategies such as energy efficiency and CCUS. While the Industrial Decarbonization Roadmap includes some CE strategies (e.g., the increasing market share of steel from electric arc furnaces - which incorporate steel scrap), a deeper dive into what role the CE could play in the United States (US) industrial decarbonization is needed. In this work, we present several industrial decarbonization scenarios that incorporate materials efficiency and circular economy strategies for the iron & steel subsector. The scenarios identify barriers (including technical limits and constraints), opportunities, and R&D needs.Moreover, we estimate the contribution of those scenarios to reducing the industrial sector's CO2 emissions and their potential synergies with the Industrial Decarbonization Roadmap's four pillars. Iron & steel manufacturing was responsible for 90 million tons of industrial CO2 emissions in 2020 - 7% of the industrial sector's total process- related emissions. Besides recycling - which presents technical limitations due to trace contaminants - CE strategies on the demand side could lower iron & steel manufacturing emissions (e.g., the development of lighter products or business models that encourage a more intensive use). This study reviews barriers, opportunities, and trade-offs for 5 material efficiency strategies. Many topics explored in the review call for further research.

barriers↗
DOE OSTI2023

Natural transformation as a tool in Acinetobacter baylyi : Streamlined engineering and mutational analysis

Natural transformation and homologous recombination in a soil bacterium, Acinetobacter baylyi ADP1, occur with exceptionally high efficiency. These genetic features can be harnessed to address a wide variety of fundamental and applied scientific topics. Recent advances in synthetic biology and laboratory evolution have led to renewed appreciation for the use of A. baylyi as a model organism. To complement several review articles that highlight new tool sets, this chapter focuses on simple protocols and examples of transformation assays that facilitate genetic analysis and engineering. Whole genome sequencing often reveals extensive genetic variation among closely related isolates that can confound the association of genotypic and phenotypic changes. In A. baylyi, such associations can be deciphered in unique ways by directly transforming cells with linear DNA fragments. The resulting allelic replacement, which occurs at high frequency, rapidly generates desired mutants via targeted chromosomal editing. Diverse screening and selection methods can be used to test hypotheses and streamline experimental strategies to reveal the significance of specific DNA sequences. Moreover, large procedural variations are well tolerated, and techniques can be readily adapted for new purposes. Furthermore, one goal of highlighting natural transformation methodology in A. baylyi is to expand the community of researchers using this versatile bacterial host.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Fundamental Neutron Physics: Theory and Analysis

The research topic of the project focus on the theoretical study of the possibility to search for manifestations of new physics beyond the Standard model in fundamental neutron physics, with emphasis on fundamental symmetries and "exotic'' interactions. The mail goals concentrate on the search for Time Reversal Invariance Violation (TRIV) in neutron nuclei scattering, and on possible manifestations of new physics in neutron-antineutron oscillations and their interactions with nuclei. Theoretical methods for analysis and interpretations of TRIV parameters in neutron scattering with the possible background interactions, and for unambiguous separation of the effects related to manifestations of new physics have been developed. The obtained results will be applied for the development of experimental programs in fundamental neutron physics at the Spallation Neutron Sources (SNS) in USA, Japan, and Europe.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

Design Principles of Microbial Communities: From Understanding to Engineering

The goal of this thematic issue is to provide an overview of advances in fundamental and applied research on microbial communities - advances that promote our understanding of the design principles of microbial interactions. The three papers in this issue address this goal by providing focused reviews on the following key science topics: 1) the resistome, which is the collection of all genes and their precursors involved in antibiotic resistance; 2) community metabolic network modeling; and 3) synthesis of model consortia

Song, Hyun-Seob↗
NASA NTRS1979

Overview - Electric fields

The electric fields session is designed to review progress in observation, theory, and modeling of magnetospheric electric fields, and to expose important new results. The present report comments on the state and prospects of electric field research, with particular emphasis on relevance to quantitative modeling of the magnetospheric processes. Attention is given to underlying theories and models. Modeling philosophy is discussed relative to explanatory models and representative models. Modeling of magnetospheric electric fields, while in its infancy, is developing rapidly on many fronts employing a variety of approaches. The general topic of magnetospheric electric fields is becoming of prime importance in understanding space plasmas.

Cauffman, D. P.↗
NASA NTRS1983

Thermal design and analysis in the Orbiter bay

Thermal design and integration of payloads located in the Orbiter bay are addressed. Methods used to satisfy equipment thermal requirements are discussed with particular emphasis on passive thermal control. Both fixed and tiltable payload configurations are covered. Design methodology, integration techniques, constraints and mission peculiar requirements are presented. Past and future Spacelab missions, including those utilizing the instrument pointing system are of special interest. The OSS-1 payload flown on STS-3 is presented in some detail. Design concepts for the 'all-up' thermal modeling techniques for this payload are discussed. A brief summary of orbital results for OSS-1 are given. Finally, as a special topic, a low power independent pumping system is described in some depth.

Humphries, W. R.↗