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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

SU-F-I-57: Evaluate and Optimize PET Acquisition Overlap in 18F-FDG Oncology Wholebody PET/CT: Can We Scan PET Faster?

Purpose: The longer patient has to remain on the table during PET imaging, the higher the likelihood of motion artifacts due to patient discomfort. This study was to investigate and optimize PET acquisition overlap in 18F-FDG oncology wholebody PET/CT to speed up PET acquisition and improve patient comfort. Methods: Wholebody 18F-FDG PET/CT of phantoms, 8 pre-clinical patients (beagles) and 5 clinical oncology patients were performed in 90s/bed on a time-of-flight Gemini TF 64 system. Imaging of phantoms and beagles was acquired with reduced PET overlaps (40%, 33%, 27%, 20%, 13% and no overlap) in addition to the system default (53%). In human studies, 1 or 2 reduced overlaps from the listed options were used to acquire PET/CT sweeps right after the default standard of care imaging. Image quality was blindly reviewed using visual scoring criteria and quantitative SUV assessment. NEMA PET sensitivity was performed under different overlaps. Results: All PET exams demonstrated no significant impact on the visual grades for overlaps >20%. Blinded reviews assigned the best visual scores to PET using overlaps 53%–27%. Reducing overlap to 27% for oncology patients (12-bed) saved an average of ∼40% acquisition time (11min) compared to using the default overlap (18min). No significant SUV variances were found when reducing overlap to half of default for cerebellum, lung, heart, aorta, liver, fat, muscle, bone marrow, thighs and target lesions (p>0.05), except expected variability in urinary system. Conclusion: This study demonstrated by combined phantom, pre-clinical and clinical PET/CT scans that PET acquisition overlap in axial of today’s systems can be reduced and optimized. It showed that a reduction of PET acquisition overlap to 27% (half of system default) can be implemented to reduce table time by ∼40% to improve patient comfort and minimize potential motion artifacts, without prominently degrading image quality or compromising PET quantification.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Faster spectral density calculation using energy moments

Abstract Accurate predictions of inclusive scattering cross sections in the linear response regime require efficient and controllable methods to calculate the spectral density in a strongly-correlated many-body system. In this work we reformulate the recently proposed Gaussian Integral Transform technique in terms of Fourier moments of the system Hamiltonian which can be computed efficiently on a quantum computer. One of the main advantages of this framework is that it allows for an important reduction of the computational cost by exploiting previous knowledge about the energy moments of the spectral density. For a simple model of medium mass nucleus like $$^{40}$$ 40 Ca and target energy resolution of 1 MeV we find an expected speed-up of $$\approx 125$$ ≈ 125 times for the calculation of the giant dipole response and of $$\approx 50$$ ≈ 50 times for the simulation of quasi-elastic electron scattering at typical momentum transfers.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Faster Than You Think: Renewable Energy and Developing Countries

Since 2007, large and unexpected declines in generation costs for renewable energy systems, particularly solar but also wind, combined with policy measures designed to limit greenhouse gas emissions, have created a paradigm shift in energy systems. Variable renewable energy now dominates total investment in electricity power generation systems. This dominance of variable renewable energy in investment has thrust the systems integration task of matching electricity supply with demand to center stage, presenting new challenges for energy policy and planning as well as for the institutional organization of power systems. Despite these challenges, there is ample reason to believe that variable renewables will attain very high levels of penetration into energy systems, particularly in regions well endowed with solar and wind potential. Similar to their success with mobile phone telephony, many developing countries have a significant opportunity to leapfrog directly to more advanced energy technologies that are low cost, reliable, environmentally more benign, and well suited to serving dispersed rural populations.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2014

Messages Do Diffuse Faster than Messengers: Reconciling Disparate Estimates of the Morphogen Bicoid Diffusion Coefficient

The gradient of Bicoid (Bcd) is key for the establishment of the anterior-posterior axis in Drosophila embryos. The gradient properties are compatible with the SDD model in which Bcd is synthesized at the anterior pole and then diffuses into the embryo and is degraded with a characteristic time. Within this model, the Bcd diffusion coefficient is critical to set the timescale of gradient formation. This coefficient has been measured using two optical techniques, Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Correlation Spectroscopy (FCS), obtaining estimates in which the FCS value is an order of magnitude larger than the FRAP one. This discrepancy raises the following questions: which estimate is "correct’’; what is the reason for the disparity; and can the SDD model explain Bcd gradient formation within the experimentally observed times? In this paper, we use a simple biophysical model in which Bcd diffuses and interacts with binding sites to show that both the FRAP and the FCS estimates may be correct and compatible with the observed timescale of gradient formation. The discrepancy arises from the fact that FCS and FRAP report on different effective (concentration dependent) diffusion coefficients, one of which describes the spreading rate of the individual Bcd molecules (the messengers) and the other one that of their concentration (the message). The latter is the one that is more relevant for the gradient establishment and is compatible with its formation within the experimentally observed times.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

ISO 50001 and SEP Faster and Cheaper - Exploring the Enterprise-Wide Approach

ISO 50001 and other management systems (e.g., ISO 9001 and ISO 14001) allow for implementation and certification at the enterprise level. The "Central Office" concept, which allows a small group of employees to manage and facilitate the organization’s energy management system (EnMS) at the enterprise level, was introduced within the ISO 50003 standard to provide guidance to ISO 50001 certification bodies. Four industrial companies have partnered with the United States Department of Energy to pilot the enterprise-wide ISO 50001/SEP concept under the Better Buildings Superior Energy Performance (SEP) Enterprise-wide Accelerator. Each organization developed a Central Office to host their EnMS while implementing ISO 50001/SEP at multiple physically separated sites. The four corporate partners tailored their Central Office implementation model to meet their own specific circumstances and needs. This paper reviews the commonalities, differences, and benefits of each of these enterprise-wide implementation models, including organizational structures, Central Office staff responsibilities, and key strategies. The cost savings and benefits of using the enterprise-wide approach were assessed, including the cost per site compared with that of a conventional, single-site ISO 50001/SEP implementation approach. This paper also discusses the drivers for the cost reductions realized through these enterprise-wide approaches. The four partner companies worked with 30 total sites. On average, these 30 sites improved energy performance by 5% annually over their SEP achievement periods, saved more than $600,000 annually in energy costs and reduced implementation cost for ISO 50001 and SEP by $19,000 and 0.8 Full Time Equivalent × years (FTE-yr) of staff time per site. The results can inform other organizations seeking to implement enterprise-wide ISO 50001/SEP, as well as energy efficiency organizations seeking to promote wider adoption of ISO 50001 implementation.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Cell-free Systems for Faster, Economical Bioprocessing

The goal of this CRADA was to advance the technology for converting renewable biomass to higher-order chemicals. Our ability to engineer microbes to produce biofuels and chemicals is critical to securing our Nation’s energy security and to utilizing renewable biomass feedstocks. To realize this goal, CRADA efforts were focused on advancing Tierra Biosciences’ (previously Synvitrobio) cell free metabolic engineering technology by leveraging Oak Ridge National Laboratory’s (ORNL) expertise and instrumentation related to cell free protein synthesis, proteomics, and metabolomics. Mass spectrometry based proteomics were developed and utilized to understand the protein synthesis capabilities of Tierra Biosciences’ cell free expression systems and for understanding and advancing the ability of these expression systems for preparing post translationally modified proteins.

09 BIOMASS FUELS↗
DOE OSTI2019

Nek5000 Enhancements for Faster Running Analysis

The goal of this milestone is to enhance the performance of Nek5000 for thermal-hydraulics analysis. In this milestone, the focus is to accelerate the time-to-solution for coupled calculations of turbulent flows and thermal variations having different time scales that which require resolution of fine-scale structures. The main artifacts delivered include the following: Steady state solvers for rod bundles and pebble beds; Enhancing RANS solvers with improved stability and performance. This document covers work primarily funded under the NEAMS program. We note that the achievements listed here would have been impossible without a strong collaboration between the NEAMS team and ECPCEED team.This synergy was enabled by algorithmic developments funded by DOE ECP Co-Design CEED and DOE ASCR Applied Math program. In this document we are reporting some details on the algorithmic strategies and their results.

47 OTHER INSTRUMENTATION↗
DOE OSTI2016

Progress Report 2016: Moving Our Nation Forward, Faster

This annual report from the Better Buildings Initiative contains information about partner projects, energy and cost savings, and new program initiatives. The 2016 Progress Report also recognizes the latest group of Better Buildings Goal Achievers - organizations who have met their energy, water, and/or financing commitments under the Better Buildings or Better Plants Challenge.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Data Mining for Faster, Interpretable Solutions to Inverse Problems:A Case Study Using Additive Manufacturing

Solving inverse problems, where we nd the input values that result in desired values of outputs, can be challenging. The solution process is often computationally expensive and it can be di cult to interpret the solution in high-dimensional input spaces. In this paper, we use a problem from additive manufacturing to address these two issues with the intent of making it easier to solve inverse problems and exploit their results. First, focusing on Gaussian process surrogates that are used to solve inverse problems, we describe how a simple modi cation to the idea of tapering can substantially speed up the surrogate without losing accuracy in prediction. Second, we demonstrate that Kohonen self-organizing maps can be used to visualize and interpret the solution to the inverse problem in the high-dimensional input space. For our data set, as not all input dimensions are equally important, we show that using weighted distances results in a better organized map that makes the relationships among the inputs obvious

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2021

Automation is all you need: Faster Earth system models with AI/ML

Focal Area: Data acquisition and assimilation enabled by machine learning (ML), artificial intelligence (AI) and advanced methods. Science Challenge: Tropical cyclones can in- duce extreme water cycle events through dramatic precipitation and storm surge. More reliable models of intensity will translate into better prediction of the impact of extreme events in large scale Earth systems simulations. We demonstrate and describe AI/ML methodologies for rapid assimilation of new, in situ data products.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Facilitating better and faster simulations of aerosol-cloud interactions in Earth system models

Focal Area(s): 1. Predictive modeling through the use of AI techniques and AI-derived model components; the use of AI and other tools to design a prediction system comprising a hierarchy of models. 2. Insight gleaned from complex data (both observed and simulated) using AI, big data analytics, and other advanced methods, including explainable AI and physics- or knowledge-guided AI. Science Challenge: One major challenge that Earth system models (ESMs) face in providing credible prediction of the Earth system and its water cycle characteristics (e.g., mean state, variability, and extreme events) is to accurately simulate aerosol-cloud interactions (ACI). The physical, chemical, and dynamical processes affecting ACI are extremely complex and they range from nanoscale to planetary scale. In each model development cycle, scientists spend significant efforts investigating model deficiencies and uncertainties associated with aerosols (e.g., emissions, chemical processes, aerosol microphysics, and transport) and clouds (e.g., macrophysics, microphysics, turbulence, and large-scale circulation) in order to develop improved treatments. However, despite decades of active research, ACI is still a major source of uncertainty in climate projections, even though great progress has been made. Specific scientific challenges include: (i) Parameterizations are developed based on limited data; (ii) The complexity of a parameterization required for accurate predictions is not understood; (iii) Incomplete and unknown physics leads to errors in the fully coupled Earth system; and (iv) Complex physics is computationally too expensive to employ in ESMs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

A Mountaintop View Requires Minimal Sorting: A Faster Contour Tree Algorithm

Consider a scalar field f : M → R, where M is a triangulated simplicial mesh in R d . A level set, or contour, at value v is a connected component of f –1 (v). As v is changed, these contours change topology, merge into each other, or split. Contour trees are concise representations of f that track this contour behavior. The vertices of these trees are the critical points of f, where the gradient is zero. The edges represent changes in the topology of contours. It is a fundamental data structure in data analysis and visualization, and there is significant previous work (both theoretical and practical) on algorithms for constructing contour trees. Suppose M has n vertices, N facets, and t critical points. A classic result of Carr, Snoeyink, and Axen (2000) gives an algorithm that takes O(n log n+Nα(N)) time (where α(·) is the inverse Ackermann function). A further improvement to O(t log t + N) time was given by Chiang et al. All these algorithms involve a global sort of the critical points, a significant computational bottleneck. Unfortunately, lower bounds of Ω(t log t) also exist. We present the first algorithm that can avoid the global sort and has a refined time complexity that depends on the contour tree structure. Intuitively, if the tree is short and fat, we get significant improvements in running time. For a partition of the contour tree into a set of descending paths, P, our algorithm runs in O($\Sigma$ pϵP |p| log |p| + tα(t) + N). This is at most O(t log D + N), where D is the diameter of the contour tree. Moreover, it is O(tα(t) + N) for balanced trees, a significant improvement over the previous complexity. Our algorithm requires numerous ideas: partitioning the contour tree into join and split trees, a local growing procedure to iteratively build contour trees, and the use of heavy path decompositions for the time complexity analysis. There is a crucial use of a family of binomial heaps to maintain priorities, ensuring that any comparison made is between comparable nodes of the contour tree. We also prove lower bounds showing that the $\Sigma$ pϵP |p| log |p| complexity is inherent to computing contour trees.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

DevOps and Data: Faster-Time-to-Knowledge through SageOps, MLOps, and DataOps

This report describes the approach, investigation, and prototyping efforts to develop an efficient, reusable methodology and reference framework for applying DevOps to disparate data for data science and data analytics at scale, based on focused application of this methodology and reusable reference framework within Sandia National Laboratories’ Pulsed Power community. Additionally, this report reviews: engineered instantiation of the reference framework used for development and production solutions, our experiences and results in using the reference framework, and future plans regarding research and development.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

An Application of Faster R-CNNs in Object Detection Efforts Applied to the Critical Infrastructure Domain

Object detection and segmentation approaches have been successfully applied to multiple interdisciplinary domains ranging from medical imaging to autonomous vehicles. The following study details efforts to apply segmentation methods to the critical infrastructure domain. Specifically, the identification of critical sub-components of four facilities: airports, hospitals, hydroelectric dams, and water treatment plants. Data for this study was extracted from the U.S. Department of Agriculture’s National Agriculture Imagery Program data set. Each facility class was considered independently of the other facilities, producing four different segmentation models during the testing and training process. Ultimately, the study team concluded there are significant challenges associated with object detection modeling when applied to facility analysis within the critical infrastructure domain. The study team was able to identify possible sources of these challenges that could be potentially addressed in future work.

97 MATHEMATICS AND COMPUTING↗