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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

The Relationships Between Insoluble Precipitation Residues, Clouds, and Precipitation Over California's Southern Sierra Nevada During Winter Storms

Ice formation in orographic mixed-phase clouds can enhance precipitation and depends on the type of aerosols that serve as ice nucleating particles (INP). The resulting precipitation from these clouds is a viable source of water, especially for regions such as the California Sierra Nevada. Thus, a better understanding of the sources of INP that impact orographic clouds is important for assessing water availability in California. This study presents a multi-site, multi-year analysis of single particle insoluble residues in precipitation samples that likely influenced cloud ice and precipitation formation above Yosemite National Park. Dust and biological particles represented the dominant fraction of the residues (64% on average). Cloud glaciation, determined using GOES satellite observations, not only depended on high cloud tops (greater than 6.2 km) and low temperatures (less than -26 C), but also on the composition of the dust and biological residues. The greatest prevalence of ice-phase clouds occurred in conjunction with biologically-rich residues and mineral dust rich in calcium, followed by iron and aluminosilicates. Dust and biological particles are known to be efficient INP, thus these residues are what likely influenced ice formation in clouds above the sites and subsequent precipitation quantities reaching the surface during events with similar meteorology. The goal of this study is to use precipitation chemistry information to gain a better understanding of the potential sources of INP in the south-central Sierra Nevada, where cloud-aerosol-precipitation interactions are under-studied and where mixed-phase orographic clouds represent a key element in the generation of precipitation and thus the water supply in California.

Creamean, Jessie M.↗
NASA NTRS2019

Mid-Course Correction Contingency Analysis for the James Webb Space Telescope

This investigation details two analyses performed as part of an early orbit contingency operations study related to the James Webb Space Telescope’s limited ability to maneuver in a sunward direction. First, contingency planning developed by the Flight Dynamics Team and shared with the Science and Operations Center to quickly assess the available timeline in the event of a delayed mid-course correction maneuver is presented. Second, the methods for recovering from a maneuver over-burn using observatory geometry to exploit the solar radiation pressure perturbation contributions from the large sunshield as well as adjusting the maneuver campaign to recover the observatory are examined.

JWST↗
NASA NTRS2020

Chapter 15: Propulsion System

During mission design, many trades are made that have varying levels of impact on the spacecraft. The types of subsystems that are selected affect the spacecraft mass,volume, power, and cost. Choosing the right propulsion system for a CubeSat mission is key to that mission’s success. There are many CubeSat propulsion systems on the market today. The CubeSat community desires to understand how to assess the available propulsion systems and how to apply them to their mission designs. The purpose of this chapter is to inform the reader of the key factors that must be considered when evaluating and applying these systems for various missions.

CubeSat↗
NASA NTRSDate not supplied

Moog SureFly® Hover Test Update

An update on the Moog SureFly vehicle acoustic hover test is presented. The intent of the effort was to acquire data that will be used to identify the acoustic far-field for the vehicle and the importance of electric motor noise relative to other sound sources for hover. The data will also be available to assess sound levels for future vertiports. The flights were completed in June 2022 at the Cincinnati Municipal Airport – Lunken Field.

jet noise↗
DOE OSTI2015

EARLY-STAGE DESIGN AND EVALUATION FOR NUCLEAR POWER PLANT CONTROL ROOM UPGRADES

As control rooms are modernized with new digital systems at nuclear power plants, it is necessary to evaluate operator performance with these systems as part of a verification and validation process. While there is regulatory and industry guidance for some modernization activities, there are no well defined standard processes or predefined metrics available for assessing what is satisfactory operator interaction with new systems, especially during the early design stages. This paper proposes a framework defining the design process and metrics for evaluating human system interfaces as part of control room modernization. The process and metrics are generalizable to other applications and serve as a guiding template for utilities undertaking their own control room modernization activities.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2018

Defect Length and Profile Influence on Frequency Domain Reflectometry

Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. Although system tests verify cable function under normal loads, demonstration of some cable’s ability to perform under exceptional loads associated with design-basis events is essential to assuring plant integrity. The cable’s ability to perform safely over the initial 40 year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found in an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program that includes condition monitoring to justify cable performance under normal operation as well as accident conditions. A variety of tests are available to assess various aspects of electrical and mechanical cable performance, but none are suitable for all cable configurations nor does any single test confirm all features of interest. One particularly promising test that is beginning to be used more and more by utilities is frequency domain reflectometry (FDR). FDR is a nondestructive electrical inspection technique used to detect and localize faults in power and communication system conductors along the length of a cable from a single connection point. FDR detects discontinuities in the electrical impedance that arise due to cable splices or similar changes along the path of the conductor pair. In addition, FDR has the potential to provide sensitivity to insulation degradation by detecting small changes in impedance between the cable conductors being examined. The technique is also sensitive to cable bends, the particular lay of the cable in tray, proximity to other cable, and other factors that bear consideration when interpreting the test results. This paper examines various influences on the FDR approach particularly using FEM modeling methods and focusing on defect length and defect profile.

Cable Inspection, Frequency Domain Reflectometry, ↗
DOE OSTI2020

Testing of Crystalline Silicotitanate to Support Tank-Side Cesium Removal System Operations - 20458

The direct feed of waste from the Hanford tank farms to the Low-Activity Waste Facility at the Hanford Waste Treatment and Immobilization Plant requires an intermediate treatment step that prepares the waste for vitrification. Washington River Protection Solutions (WRPS) selected a near-tank treatment system known as the Tank-Side Cesium Removal (TSCR) system to perform the required intermediate treatment functions. The approach in the TSCR system is to filter waste supernatant with a sintered metal dead-end filter and then use a series of ion exchange columns to remove cesium; this system has several similarities to the Tank Closure Cesium Removal system that has been deployed on the Savannah River Site. The ion exchange media proposed for use is crystalline silicotitanate (CST), which is a non-elutable media with a high affinity for cesium. Because the media is non-elutable, loaded columns will be blown down with compressed air, moved into interim storage, and replaced with new columns when cesium capacity is reached. The assumed extent and rate of drying that could be achieved in the TSCR column geometry lacked confirmation by experimental data. In addition, once the columns are loaded with cesium, they generate flammable gases (primarily hydrogen) via radiolysis acting on any resident liquids, i.e., moisture, remaining in the media bed. An assessment of available information on CST concluded that gas generation data that bounds expected operational conditions were needed to support the TSCR system safety basis and planned operations. Working with WRPS, Pacific Northwest National Laboratory (PNNL) designed and conducted testing with CST media to address the need for (a) representative in-column drying data, and (b) bounding flammable gas generation data. Drying testing was performed using a full-height column with a diameter of approximately 2 inches with injected air at temperatures of 18 deg. C and 30 deg. C. Gas generation testing was conducted in an engineered bunker that allowed simultaneous irradiation of up to eight samples at a time. These two experimental approaches used at PNNL for the CST testing are summarized and the major outcomes are presented. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Plan for Post-Irradiation Examination of Zion Reactor Pressure Vessel Beltline Materials

The reactor pressure vessel (RPV) is a potentially life-limiting component in light-water reactors (LWR) because replacement of the RPV is not considered a viable option. Researchers studying the effects of radiation on RPV materials have long been interested in evaluating service-irradiated materials to assess currently available models for predicting radiation embrittlement of RPV steels. The decommissioning of the Zion Unit 1 NPP in Zion, Illinois presents a unique opportunity for characterization of an actual reactor pressure vessel (RPV) material after inservice degradation. The main interests in this case are the belt-line weld and base metals. Through-RPV wall thickness attenuation and chemical composition distributions are the obvious objectives of this characterization program. However, it also provides an opportunity to examine the inservice degradation and its comparison with currently available models for prediction of radiation embrittlement of RPV steels. All of these efforts will provide a better understanding of materials degradation and other issues associated with extending the lifetime of existing NPPs beyond 60 years of service. The primary foci are the Linde 80 flux, wire heat 72105 (WF-70) circumferential belt-line weld and the A533B-1 base metal from the intermediate shell harvested from a region of peak fluence (0.7 x 10{sup 19} n/cm{sup 2}, E > 1.0 MeV) on the internal surface of the Zion Unit 1 vessel. Following determination of the through-thickness chemical composition, Charpy impact, fracture toughness, tensile, and hardness testing will be being performed to characterize the through-thickness mechanical properties of the base metal and belt-line-weld materials. In addition to mechanical properties, microstructural characterizations will be performed using various techniques, including Atom Probe Tomography, Small Angle Neutron Scattering, and Positron Annihilation Spectroscopy.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2020

High Penetration Power Electronics Grid: Modeling and Simulation Gap Analysis

Increased penetration of power electronics in the grid is happening through development of high-power drives (like in Type 3 or 4 wind turbines, industrial drives, etc.), high-voltage direct current (HVdc) systems, flexible alternating current transmission systems (FACTS), energy storage systems (ESSs), inverter-based renewables like solar and wind, electric vehicle chargers, and other technologies. Ongoing research and development in new power electronic technologies including, but not limited to, solid-state power substations (SSPS), extreme fast charging (XFC), solid-state transformers, and multi-port power electronics that integrate multiple sources/loads will further increase penetration levels. To ensure stakeholders can integrate high penetration of power electronic technologies safely and reliably requires tools and methods to assess and evaluate their impact on the grid. Objectives: This report surveys, assesses, and analyzes commercially available and open-source tools that can support the assessment and evaluation of power electronics in future grids with high penetration levels. The study includes aspects that range from power flow analysis to dynamics evaluation (including hardware-in-the-loop – HIL testing) for such systems. The challenges and gaps associated with the current generation of toolsets available to assess the technical impact of introducing high penetration of power electronics are reported. The method is summarized in Figure ES-1.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2015

Purification and characterization of lipopolysaccharides from six strains of non-O157 Shiga toxin-producing Escherichia coli

Certain Shiga toxin-producing Escherichia coli (STEC) are virulent human pathogens that are most often acquired through contaminated food. The United States Department of Agriculture, Food Safety and Inspection Service has declared several serogroups of STEC as adulterants in non-intact raw beef products. Hence, sensitive and specific tests for the detection of these STEC are a necessity for implementation in food safety programs. E. coli serogroups are identified by their respective O-antigen moiety on the lipopolysaccharide (LPS) macromolecule. We propose that the development of O-antigen-specific immunological assays can facilitate simple and rapid discriminatory detection of STEC in beef. However, the resources (antigens and antibodies) required for such development are not readily available. To overcome this, we extracted and characterized LPS and O-antigen from six STEC strains. Using hot phenol extraction, we isolated the LPS component from each strain and purified it using a series of steps to eliminate proteins, nucleic acids, and lipid A antigens. Antigens and crude LPS extracts were characterized using gel electrophoresis, immunoblotting, and modified Western blotting with commercially available antibodies, thus assessing the serogroup specificity and sensitivity of available ligands as well. The results indicate that, while many commercially available antibodies bind LPS, their activities and specificities are highly variable, and often not as specific as those required for serogroup discrimination. This variability could be minimized by the production of antibodies specific for the O-antigen. Additionally, the antigens generated from this study provide a source of characterized LPS and O-antigen standards for six serogroups of STEC.

59 BASIC BIOLOGICAL SCIENCES↗