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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 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Microscopic understanding of the effects of impurities in low RRR SRF cavities

The SRF community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurities of niobium coupons with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low RRR cavities so that the mechanism of impurity-based improvements can be better understood and improved upon. The combination of RF testing, temperature mapping, frequency vs temperature analysis, and materials studies reveals a microscopic picture of why low RRR cavities experience low BCS resistance behavior more prominently than their high RRR counterparts. We evaluate how differences in the mean free path, grain structure, and impurity profile affect RF performance. The results of this study have the potential to unlock a new understanding on SRF materials and enable the next generation of high Q/high gradient surface treatments.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Understanding the Inner-Workings of Language Models Through Representation Dissimilarity

We use model stitching to understand the internal representations of language models. Similar to vision models, we find that "more is better," and representations learned with more data and larger width can improve the performance of weaker models via stitching. We likewise find that certain architecture choices, using GeLU vs SoLU activation functions, influence the quality of learned representations. Finally, model stitching (as opposed to other model diagnostic methods, like mode connectivity) can localize the different generalization strategies of text classifiers under domain shift to certain hidden layers.

Brown, Davis R.↗
DOE OSTI2026

Understanding the Costs and Barriers of Residential Electrical Panel and Service Upgrades

Upgrading electrical panels and services in U.S. homes represents a significant barrier to building modernization, imposing considerable costs, delays, and procedural uncertainties on homeowners, contractors, utilities, and building departments. Although cost databases document individual infrastructure activities, they rarely capture the integrated, whole-project perspective required to understand how electrical upgrades are planned, executed, and regulated. Existing research is often geographically constrained, narrowly scoped, or derived from limited samples, leaving significant knowledge gaps unaddressed. This study examines the timelines and costs associated with residential electrical panel and service upgrades using data from a national cross- sectional survey conducted in summer 2025. The survey captured responses from 140 stakeholders across 34 states, including building industry professionals, utility staff, and building department staff. Findings indicate that project duration and cost increase substantially with building size though patterns vary by infrastructure type. Most single-family and small multifamily projects were completed within 30 days, whereas medium and large multifamily buildings show longer and less predictable timelines. Service rating increases modestly extend project duration, but building type and size were the primary determinants of delays. Cost patterns were similar: customer-side equipment and panel replacements scale predictably with building size, while utility-side costs are highly variable, often triggered by threshold-driven infrastructure upgrades such as transformer replacements. Permit fees vary considerably between jurisdictions but generally represent a minor proportion of total project costs. These findings identify electrical upgrades as a significant barrier to residential building costs and highlight the need for improved stakeholder coordination, streamlined permitting, and strategies that reduce upgrade requirements while maintaining safety and code compliance.

Casquero-Modrego, Nuria↗
DOE OSTI2023

The Next-Generation Ecosystem Experiment Arctic Rainfall Simulator: a tool to understand the effects of changing rainfall patterns in the Arctic

Rainfall frequency and intensity are expected to increase in the Arctic, with potential detrimental impacts on permafrost, leading to enhanced thawing and carbon release to the atmosphere. However, there have been very few studies on the effect of discrete rain events on permafrost in the Arctic and sub-Arctic. Conducting controlled rainfall experiments within permafrost landscapes can provide an improved understanding of the effect of changing intensity, duration, and timing of rain events on permafrost tundra ecosystems. Here, we describe the design and implementation of the Next-Generation Ecosystem Experiment Arctic Rainfall Simulator (NARS), a variable intensity (4–82 mm/h) rainfall simulator that can be used to study the effects of rainfall on permafrost stability. The NARS design includes a 3D-printed 4 cm H-flume and uses an eTape resistivity sensor that was calibrated (R 2 = 0.9–0.96) to measure discharge from the system. NARS is designed to be lightweight, simple to construct, and can be easily deployed in remote locations. As a field validation of updated rainfall simulator design and modernized controls, NARS was tested on the Seward Peninsula, AK. Because of its portability, versatility in deployment, dimensions, and rainfall intensity, NARS represents a methodological innovation for researching the impacts of rainfall on permafrost environments.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Dogs That Haven't Barked: Towards an Understanding of the Absence of Expected Technological Threats Workshop Bibliography

Lawrence Livermore National Laboratory’s Center for Global Security Research hosted a workshop to investigate why some consistently predicted threats from science and technology (S&T) have not manifested with the impacts to international security as forecasted. During the workshop, “Dogs That Haven’t Barked: Towards an Understanding of the Absence of Expected Technological Threats,” participants used two specific cases to focus the discussion: biotechnology and man-portable air defense systems (MANPADS).

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2017

Final Report: Improving the understanding of the coupled thermal-mechanical-hydrologic behavior of consolidating granular salt

The goal of this project is to improve the understanding of key aspects of the coupled thermal-mechanical-hydrologic response of granular (or crushed) salt used as a seal material for shafts, drifts, and boreholes in mined repositories in salt. The project is organized into three tasks to accomplish this goal: laboratory measurements of granular salt consolidation (Task 1), microstructural observations on consolidated samples (Task 2), and constitutive model development and evaluation (Task 3). Task 1 involves laboratory measurements of salt consolidation along with thermal properties and permeability measurements conducted under a range of temperatures and stresses expected for potential mined repositories in salt. Testing focused on the role of moisture, temperature and stress state on the hydrologic (permeability) and thermal properties of consolidating granular salt at high fractional densities. Task 2 consists of microstructural observations made on samples after they have been consolidated to interpret deformation mechanisms and evaluate the ability of the constitutive model to predict operative mechanisms under different conditions. Task 3 concerns the development of the coupled thermal-mechanical-hydrologic constitutive model for granular salt consolidation. The measurements and observations in Tasks 1 and 2 were used to develop a thermal-mechanical constitutive model. Accomplishments and status from each of these efforts is reported in subsequent sections of this report

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

A high-fidelity model for coupling flow and mechanical deformation of the porous paper web - a key to improved understanding of dewatering and rewet at the press section in paper making

The U.S. pulp and paper industry is the third-largest manufacturing user of energy, with an energy demand of 2,540 trillion Btu in 2010. Within the papermaking process, drying consumes over 400 trillion Btu annually which makes it one of the largest energy saving opportunities. In the 2014 Forest Products Industry Technology Roadmap, it is concluded that increasing the paper web solid content entering the dryer section from the current 45- 55 percent to approaching 65 percent, which would save 1.0 MMBtu per ton or 20 percent of the energy used in drying, is one of the most needed technology breakthroughs to achieve a more sustainable approach for manufacturing pulp and paper products. Achieving such significant energy savings highly depends on understanding the fundamental dynamics of the wet press process and then developing optimized solutions for design of more energy-efficient press processes and equipment. The objective of this project is to develop reliable computational capabilities to accurately simulate the flow of water from/to the porous pulp medium (dewatering/rewetting) during the pressing process in paper making.

42 ENGINEERING↗
DOE OSTI2017

Energy Upgrades at City-Owned Facilities: Understanding Accounting for Energy Efficiency Financing Options. City of Dubuque Case Study

The city of Dubuque, Iowa, aimed for a twofer — lower energy costs for public facilities and reduced air emissions. To achieve that goal, the city partnered with the Iowa Economic Development Authority to establish a revolving loan fund to finance energy efficiency and other energy projects at city facilities. But the city needed to understand approaches for financing energy projects to achieve both of their goals in a manner that would not be considered debt — in this case, obligations booked as a liability on the city’s balance sheet. With funding from the U.S. Department of Energy’s Climate Action Champions Initiative, Lawrence Berkeley National Laboratory (Berkeley Lab) provided technical assistance to the city to identify strategies to achieve these goals. Revolving loans use a source of money to fund initial cost-saving projects, such as energy efficiency investments, then use the repayments and interest from these loans to support subsequent projects. Berkeley Lab and the city examined two approaches to explore whether revolving loans could potentially be treated as non-debt: 1) financing arrangements containing a non-appropriation clause and 2) shared savings agreements. This fact sheet discusses both, including considerations that may factor into their treatment as debt from an accounting perspective.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Understanding Photon / Free Carrier Interaction in LVP Signals on Ultra-Thin Silicon ICs.

This project investigated a recently patented Sandia technology known as visible light Laser Voltage Probing (LVP). In this effort we carefully prepared well understood and characterized samples for testing. These samples were then operated across a range of configurations to minimize the possibility of superposition of multiple photon carrier interactions as data was taken with conventional and visible light LVP systems. Data consisted of LVP waveforms and Laser Voltage Images (LVI). Visible light (633 nm) LVP data was compared against 1319 nm and 1064 nm conventional LVP data to better understand the similarities and differences in mechanisms for all wavelengths of light investigated. The full text can be obtained by reaching the project manager, Ed Cole or the Cyber IA lead, Justin Ford.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Next Generation Anodes for Lithium Ion Batteries: Thermodynamic Understanding and Abuse Performance.

The objectives of this project are to elucidate degradation mechanisms, decomposition products, and abuse response for next generation silicon based anodes; and understand the contribution of various materials properties and cell build parameters towards thermal runaway enthalpies. Quantify the contributions from various cell parameters such as particle size, composition, state of charge (SOC), electrolyte to active materials ratio, etc.

25 ENERGY STORAGE↗
DOE OSTI2017

Using Modeling and Simulation to Complement Testing for Increased Understanding of Weapon Subassembly Response.

As part of Sandia’s nuclear deterrence mission, the B61-12 Life Extension Program (LEP) aims to modernize the aging weapon system. Modernization requires requalification and Sandia is using high performance computing to perform advanced computational simulations to better understand, evaluate, and verify weapon system performance in conjunction with limited physical testing. The Nose Bomb Subassembly (NBSA) of the B61-12 is responsible for producing a fuzing signal upon ground impact. The fuzing signal is dependent upon electromechanical impact sensors producing valid electrical fuzing signals at impact. Computer generated models were used to assess the timing between the impact sensor’s response to the deceleration of impact and damage to major components and system subassemblies. The modeling and simulation team worked alongside the physical test team to design a large-scale reverse ballistic test to not only assess system performance, but to also validate their computational models. The reverse ballistic test conducted at Sandia’s sled test facility sent a rocket sled with a representative target into a stationary B61-12 (NBSA) to characterize the nose crush and functional response of NBSA components. Data obtained from data recorders and high-speed photometrics were integrated with previously generated computer models in order to refine and validate the model’s ability to reliably simulate real-world effects. Large-scale tests are impractical to conduct for every single impact scenario. By creating reliable computer models, we can perform simulations that identify trends and produce estimates of outcomes over the entire range of required impact conditions. Sandia’s HPCs enable geometric resolution that was unachievable before, allowing for more fidelity and detail, and creating simulations that can provide insight to support evaluation of requirements and performance margins. As computing resources continue to improve, researchers at Sandia are hoping to improve these simulations so they provide increasingly credible analysis of the system response and performance over the full range of conditions.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2017

Understanding and Predicting Effect of Sodium Exposure on Microstructure of Grade 91 Steel

This report provides an update on the understanding of the effect of sodium exposures on microstructure and tensile properties of Grade 91 (G91) steel in support of the design and operation of G91 components in sodium-cooled fast reactors (SFRs). The report is a Level 3 deliverable in FY17 (M3AT-17AN1602018), under the Work Package AT-17AN160201, “SFR Materials Testing” performed by the Argonne National Laboratory (ANL), as part of the Advanced Reactor Technologies Program.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Report on Understanding and Predicting Effects of Thermal Aging on Microstructure and Tensile Properties of Grade 91 Steel for Structural Components

This report provides an update on understanding and predicting the effects of long-term thermal aging on microstructure and tensile properties of G91 to corroborate the ASME Code rules in strength reduction due to elevated temperature service. The research is to support the design and long-term operation of G91 structural components in sodium-cooled fast reactors (SFRs). The report is a Level 2 deliverable in FY17 (M2AT-17AN1602017), under the Work Package AT-17AN160201, “SFR Materials Testing” performed by the Argonne National Laboratory (ANL), as part of the Advanced Reactor Technologies Program.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions: Quarterly Report.

Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO 2 and H 2 O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH 4 ) during hydrofracturing and gas extraction. Note that liquid or supercritical CO 2 has been suggested as an alternative fluid for subsurface fracturing such that CO 2 enhanced gas recovery can also serve as a CO 2 sequestration process. Limited data indicate that CO 2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH 4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH 4 in shale matrix. Therefore, fundamental understanding of CH 4 -CO 2 -H 2 O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO 2 sequestration. This project focuses on the systematic study of CH 4 -CO 2 -H 2 O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Characterizing and Understanding Aerosol Optical Properties: CARES - Final Report

The scientific focus of this study was to use ambient measurements to develop new insights into the understanding of the direct radiative forcing by atmospheric aerosol particles. The study used data collected by the PI’s and others as part of both the 2010 U.S. Department of Energy (DOE) sponsored Carbonaceous Aerosols and Radiative Effects Study (CARES), which took place in and around Sacramento, CA, and the 2012 Clean Air for London (ClearfLo) study. We focus on measurements that were made of aerosol particle optical properties, namely the wavelength-dependent light absorption, scattering and extinction. Interpretation of these optical property measurements is facilitated through consideration of complementary measurements of the aerosol particle chemical composition and size distributions. With these measurements, we addressed the following general scientific questions: 1. How does light scattering and extinction by atmospheric aerosol particles depend on particle composition, water uptake, and size? 2. To what extent is light absorption by aerosol particles enhanced through the mixing of black carbon with other particulate components? 3. What relationships exist between intensive aerosol particle optical properties, and how do these depend on particle source and photochemical aging? 4. How well do spectral deconvolution methods, which are commonly used in remote sensing, retrieve information about particle size distributions?

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Computed Tomography Scanning to Understand Micro-to-Macro Controls on Multiphase Flow during Geologic Carbon Storage; NETL-TRS-3-2017; NETL Technical Report Series; U.S. Department of Energy, National Energy Technology Laboratory: Morgantown, WV, 2017; p 24.

Evaluation of the fate and transport of carbon dioxide (CO 2 ) in deep reservoirs is crucial to the development of long-term geologic carbon sequestration (GCS) technologies. In this report, various studies using computed tomography (CT) scanning are utilized in conjunction with traditional flow tests to observe the multi-scale phenomena associated with CO 2 injection in geologic media. Pore scale analyses were performed to determine the infiltration characteristics of CO 2 into a brine saturated reservoir rock. Multiphase floods were performed to evaluate the saturation of CO 2 into a brine-saturated reservoir rock and determine how structural changes within the lithology affect such interactions. Additionally, CO 2 induced swelling of unconventional reservoir rock was evaluated with respect to reductions in fracture transmissivity due to matrix swelling. These studies are just a few examples of the benefits of multi-scale CT imaging in conjunction with traditional laboratory methodology to gain a better understanding of the interactions between CO 2 and the lithologies it interacts with during GCS.

58 GEOSCIENCES↗
DOE OSTI2018

DOE Final Report: A Unified Understanding of Residual Stress in Thin Films: Kinetic Models, Experiments and Simulations

Thin films are critical for a wide range of advanced technologies. However, the deposited films often have high levels of residual stress that can limit their performance or lead to failure. The stress is known to depend on many variables, including the processing conditions, type of material, deposition technique and the film’s microstructure. The goal of this DOE program was to develop a fundamental understanding of how the different processes that control thin film growth under different conditions can be related to the development of stress. In the program, systematic experiments were performed or analyzed that related the stress to the processing conditions that were used. Measurements of stress were obtained for films that were grown at different rates, different solutions (for electrodeposition), different particle energies (for sputter deposition) and different microstructures. Based on this data, models were developed to explain the observed dependence on the different parameters. The models were based on considering the balance among different stress-inducing mechanism occurring as the film grows (for both non-energetic and energetic deposition). Comparison of the model predictions with the experiments enabled the kinetic parameters to be determined for different materials. The resulting model equations provide a comprehensive picture of how stress changes with the processing conditions that can be used to optimize the growth of thin films.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions.

Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO 2 and H 2 O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH 4 ) during hydrofracturing and gas extraction. Note that liquid or supercritical CO 2 has been suggested as an alternative fluid for subsurface fracturing such that CO 2 enhanced gas recovery can also serve as a CO 2 sequestration process. Limited data indicate that CO 2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH 4 in shale matrix. Therefore, fundamental understanding of CH 4 -CO 2 -H 2 O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO 2 sequestration. This project focuses on the systematic study of CH 4 -CO 2 -H 2 O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗