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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 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Characterization of deliberately nickel-doped silicon wafers and solar cells

Microstructural and electrical evaluation tests were performed on nickel-doped p-type silicon wafers before and after solar cell fabrication. The concentration levels of nickel in silicon were 5 x 10 to the 14th power, 4 x 10 to the 15th power, and 8 x 10 to the 15th power atoms/cu cm. It was found that nickel precipitated out during the growth process in all three ingots. Clumps of precipitates, some of which exhibited star shape, were present at different depths. If the clumps are distributed at depths approximately 20 micron apart and if they are larger than 10 micron in diameter, degradation occurs in solar cell electrical properties and cell conversion efficiency. The larger the size of the precipitate clump, the greater the degradation in solar cell efficiency. A large grain boundary around the cell effective area acted as a gettering center for the precipitates and impurities and caused improvement in solar cell efficiency. Details of the evaluation test results are given.

Salama, A. M.↗
NASA NTRS1996

Characterization of individual polynucleotide molecules using a membrane channel

We show that an electric field can drive single-stranded RNA and DNA molecules through a 2.6-nm diameter ion channel in a lipid bilayer membrane. Because the channel diameter can accommodate only a single strand of RNA or DNA, each polymer traverses the membrane as an extended chain that partially blocks the channel. The passage of each molecule is detected as a transient decrease of ionic current whose duration is proportional to polymer length. Channel blockades can therefore be used to measure polynucleotide length. With further improvements, the method could in principle provide direct, high-speed detection of the sequence of bases in single molecules of DNA or RNA.

NASA Discipline Exobiology↗
DOE OSTI2023

Theory of electric, magnetic, and toroidal polarizations in crystalline solids with applications to hexagonal lonsdaleite and cubic diamond

Multipolar order in bulk crystalline solids is characterized by multipole densities-denoted as polarizations in this work-that cannot be cleanly defined using the concepts of classical electromagnetism. Here we use group theory to overcome this difficulty and present a systematic study of electric, magnetic, and toroidal multipolar order in crystalline solids. Based on our symmetry analysis, we identify five categories of polarized matter, each of which is characterized by distinct features in the electronic band structure. For example, Rashba spin splitting in electropolar bulk materials like wurtzite represents the electric dipolarization in these materials. We also develop a general formalism of indicators for individual multipole densities that provide a physical interpretation and quantification of multipolar order. Our work clarifies the relation between patterns of localized multipoles and macroscopic multipole densities they give rise to. To illustrate the general theory, we discuss its application to polarized variants of hexagonal lonsdaleite and cubic diamond structures. In conclusion, our work provides a general framework for classifying and expanding current understanding of multipolar order in complex materials.

36 MATERIALS SCIENCE↗
NASA NTRS1997

Preparation, Fabrication, and Evaluation of Advanced Polymeric and Composite Materials

The thesis titles are given below: physical and mechanical behavior of amorphous poly(arylene ether-co-imidasole)s and poly(arylene ether-co-imidasole) modification epoxies; the requirements of patentability as applied to the chemical arts; fabrication of thermoplastic polymer composite ribbon; blend of reactive diluents with phenylethynyl-terminated arylene ether oligomers; the synthesis, characterization, and application of ether-containing polyimides; the synthesis of reflective and electrically conductive polyimide films via an in-situ self-metalization procedure using silver (I) complexes; the thermal cure of phenylethynyl terminated polyimides and selected model compounds; and the synthesis, characterization, and molecular modeling of cyclic arylene ether oligomers.

Orwoll, Robert A.↗
NASA NTRSDate not supplied

Simulated Ball Lightning on A Submarine

Silberg (1962) discusses the observation of a ball-shaped glowing plasma (labeled a “plasmoid”) that occurred aboard a diesel-electric submarine when the switchgear opened a circuit carrying a current of 156,000 amps. In 1968 joint NASA/Navy experiments were conducted for an analogous situation aboard a similar submarine to characterize the plasmoids and to determine if they were reproducible with more modest electrical currents. Movies and spectra were obtained for approximately 40 arc events. Several events showed the presence of clouds of glowing gas as well as small plasmoids. The plasmoids had diameters of several mm that lasted approximately 0.2 seconds. Spectra of the initiating arcs showed the presence of emission lines from atomic copper and silver from the electrodes as well as those from singly excited oxygen and nitrogen atoms. Peak currents of several kiloamps were measured. Graphs of the time-histories of plasmoid motion, size, relative color ratios, and relative optical flux will be shown for two plasmoids.

plasma↗
DOE OSTI2021

Environmental Influence on Fracture and Delamination of Electrically Conductive Adhesives

This paper presents our continued work on developing a degradation model for electrically conductive adhesive (ECA) interconnects in photovoltaic modules. Here, we characterize the fracture mechanics properties of an epoxy based ECA, for both critical and subcritical loading conditions. Emphasis is put on the influence of different environmental conditions such as temperature and humidity. We found that high levels of humidity not only weaken the adhesive joint but also promote subcritical debonding at significantly lower driving forces than in dry environments.

41 EE - Solar Energy Technologies Office (EE-4S)↗
NASA NTRSDate not supplied

Design and Development of an Aircraft Electric Powertrain Test Stand

Recent advancements in battery technology and power electronics are enabling novel approaches to powered flight that rely on fully electric or hybrid-electric powertrain systems. To mitigate the risk surrounding such unproven systems, it is necessary to characterize their performance on a component-wide and system-wide basis. In this paper, we discuss the design and development of an electric powertrain test stand that can collect high-fidelity data of motor, controller, and battery performance, thereby allowing us to determine system performance, efficiencies, and thermal characteristics.

test stand↗
NASA NTRS1990

Ongoing nickel-hydrogen energy storage device testing at George C. Marshall Space Flight Center

The primary objective of the testing is to characterize Ni-H2 cells for successful integration into the electrical power system (EPS) of the Hubble Space Telescope (HST). A broad spectrum of Ni-H2 design technology is encompassed by the testing configurations; tests include cells with dates of manufacture as early as 1976. The database includes cells of varied storage times, capacity, plate design, stack design, terminal configuration, pressure vessel thickness, separator material, potassium hydroxide (KOH) concentration, and thermal control. Currently, 196 Ni-H2 cells are being tested, grouped as follows: 12 RNH-35-3, 14 RNH-30-1, 22 HST cells (1 battery, flight spare lot), 132 HST cells (6 batteries, test modules 1 and 2, called TM1 and TM2), 12 HST cells (3 four-cell packs, TM1, TM2, flight spare module FSM), and 4 HST cells (engineering lot). In addition to the characterization and life testing, an extensive thermal vacuum and purge test was conducted in November 1989 and February 1990 using the HST FSM (3 batteries composed of 69 HST cells from the flight spare lot) to help verify thermal design. A report is presented of the progress, significant findings, and future objectives of the testing.

Lowery, John E.↗
DOE OSTI2020

Sequential Doping of Ladder-Type Conjugated Polymers for Thermally Stable n-Type Organic Conductors

Doping of organic semiconductors is a powerful tool to optimize the performance of various organic (opto)electronic and bioelectronic devices. Despite recent advances, the low thermal stability of the electronic properties of doped polymers still represents a significant obstacle to implementing these materials into practical applications. Hence, the development of conducting doped polymers with excellent long-term stability at elevated temperatures is highly desirable. Here, we report on the sequential doping of the ladder-type polymer poly(benzimidazobenzophenanthroline) (BBL) with a benzimidazole-based dopant (i.e., N-DMBI). By combining electrical, UV–vis/infrared, X-ray diffraction, and electron paramagnetic resonance measurements, we quantitatively characterized the conductivity, Seebeck coefficient, spin density, and microstructure of the sequentially doped polymer films as a function of the thermal annealing temperature. Importantly, we observed that the electrical conductivity of N-DMBI-doped BBL remains unchanged even after 20 h of heating at 190 °C. This finding is remarkable and of particular interest for organic thermoelectrics.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Advancing Transportation Efficiency and Electric Vehicles in Tonga: A Review of Relevant Trends, Best Practices, and Future Work

Tonga is facing a transportation sector characterized by private passenger vehicles, poorly maintained roads and walkways, and an inadequate public transit system. By understanding detailed global and regional trends for transport energy efficiency and electric vehicles (EVs) within this context, the Government of Tonga can proactively plan its future transportation systems. In addition to global and regional trends, this presentation also briefly examines Tonga's own transportation policies and actions. Jurisdictions leading in EV adoption have implemented policies such as reducing taxes on EVs compared to internal combustion engine (ICE) vehicles, providing subsidies and rebates for EV charger installation, instituting an age limit on imported ICE vehicles, and developing EV maintenance courses to expand the skill set of current automotive technicians. This presentation was developed for the Pacific Islands Workshop on Electric Mobility, held from November 28th to November 30th 2022 in Fiji. NREL presented virtually and the conference was sponsored by the Pacific Centre for Renewable Energy and Energy Efficiency (PCREEE).

ADVANCED PROPULSION SYSTEMS,POWER TRANSMISSION AND↗
NASA NTRS2014

Dependence of Lunar Surface Charging on Solar Wind Plasma Conditions and Solar Irradiation

The surface of the Moon is electrically charged by exposure to solar radiation on its dayside, as well as by the continuous flux of charged particles from the various plasma environments that surround it. An electric potential develops between the lunar surface and ambient plasma, which manifests itself in a near-surface plasma sheath with a scale height of order the Debye length. This study investigates surface charging on the lunar dayside and near-terminator regions in the solar wind, for which the dominant current sources are usually from the pohotoemission of electrons, J(sub p), and the collection of plasma electrons J(sub e) and ions J(sub i). These currents are dependent on the following six parameters: plasma concentration n(sub 0), electron temperature T(sub e), ion temperature T(sub i), bulk flow velocity V, photoemission current at normal incidence J(sub P0), and photo electron temperature T(sub p). Using a numerical model, derived from a set of eleven basic assumptions, the influence of these six parameters on surface charging - characterized by the equilibrium surface potential, Debye length, and surface electric field - is investigated as a function of solar zenith angle. Overall, T(sub e) is the most important parameter, especially near the terminator, while J(sub P0) and T(sub p) dominate over most of the dayside.

Photoemission↗
NASA NTRS1982

Spatially Characterizing Effective Timber Supply

The structure of a computer-oriented cartographic model for assessing roundwood supply for generation of base load electricity is discussed. The model provides an analytical procedure for coupling spatial information of harvesting economics and owner willingness to sell stumpages. Supply is characterized in terms of standing timber; of accessibility considering various harvesting and hauling factors; and of availability as affected by ownership and residential patterns. Factors governing accessibility to timber include effective harvesting distance to haulic roads as modified by barriers and slopes. Haul distance is expressed in units that take into account the relative ease of travel along various road types to a central processing facility. Areas of accessible timber are grouped into spatial units, termed 'timbersheds', of common access to particular haul road segments that belong to unique 'transport zones'. Timber availability considerations include size of ownership parcels, housing density and excluded areas. The analysis techniques are demonstrated for a cartographic data base in western Massachusetts.

Berry, J. K.↗
NASA NTRS1990

A review of nuclear electric propulsion spacecraft system concepts

The last 25-30 years of system concepts and design philosophies for spacecraft employing nuclear-electric propulsion (NEP) are reviewed. NEP spacecraft-system design constraints and criteria are identified, including radiation exposure of humans and electronics, thermal control requirements, effluent contamination of spacecraft surfaces, surface erosion, launch-vehicle integration, operations and safety requirements, attitude control, EM interference, and power control and distribution. The impact on spacecraft design philosophy of these constraints and criteria is explored. Several NEP spacecraft are characterized and discussed with respect to the propulsion system used. The electric propulsion system catagories are electrothermal (arcjet), EM (magnetoplasmadynamic and pulsed-inductive thruster) and electrostatic (ion engine). A brief summary of the mission, nuclear power source, electric propulsion system, and spacecraft configuration are provided for each NEP spacecraft concept.

Deininger, W. D.↗
DOE OSTI2024

High-angular-momentum Rydberg states in a room-temperature vapor cell for dc electric-field sensing

We prepare and analyze Rydberg states with orbital quantum numbers ℓ ≤ 6 using three-optical-photon electromagnetically induced transparency (EIT) and radio frequency (rf) dressing, and employ the high- ℓ states in electric-field sensing. Rubidium-85 atoms in a room-temperature vapor cell are first promoted into the 25 F 5 / 2 state via Rydberg-EIT with three infrared laser beams. Two rf dressing fields then (near-)resonantly couple the 25 F , 25 H ( ℓ = 5 ) , and 25 I ( ℓ = 6 ) Rydberg states. The dependence of the rf-dressed Rydberg-state level structure on rf powers, rf and laser frequencies is characterized using EIT. Furthermore, we discuss the principles of dc-electric-field sensing using high- ℓ Rydberg states and experimentally demonstrate the method using test electric fields of ≲ 50 V/m induced via photo-illumination of the vapor-cell wall. We measure the highly nonlinear dependence of the dc-electric-field strength on the power of the photo-illumination laser. Numerical calculations, which reproduce our experimental observations well, elucidate the underlying physics. Our paper is relevant to high-precision spectroscopy of high- ℓ Rydberg states, Rydberg-atom-based electric-field sensing, and plasma electric-field diagnostics. Published by the American Physical Society 2024

Duspayev, Alisher (ORCID:0000000153225762)↗
DOE OSTI2024

HERO WEC V1 Upgrade - 2023 Laboratory Testing (processed data)

The following submission includes processed laboratory data from NREL's Hydraulic and Electric Reverse Osmosis Wave Energy Converter (HERO WEC), in the form of MATLAB workspaces. This dataset was created using NREL's Large Amplitude Motion Platform (LAMP) and collected between August and September 2023. Included with this submission is a test log of all the processed data "HERO WEC LAMP test run log.xlsx" so that the user can easily find the data of interest. Additionally, more detailed descriptions of the type of data and how it was processed, or calculated, can be found in the document titled "Lamp Data Description.docx". The MATLAB workspaces can be visualized using the file "LAMP_Data_Viewer_Ver2.m/mlx". The user simply needs to upload the workspace of interest and run the file "LAMP_Data_Viewer_Ver2.m/mlx". Both the .m and .mlx file format has been provided depending on the user's preference. The MATLAB workspaces have been separated into zip files corresponding to either Drivetrain, Hydraulic, or Electric configuration runs representing the respective test cases that were run. The drivetrain runs were used to characterize the drivetrain only (no pump or generator). The Hydraulic runs represent the configuration when the seawater pump is installed, and the Electric runs represents the configuration when the generator is installed. The following sub-categories of data are included for each type: - DW - Deep water sine wave profile (not run in drivetrain configuration) - Heave - Heave only sine wave profile - Heave_NoRO (hydraulic configuration only) - Heave_ACC (hydraulic configuration only) - IR - Surge and heave irregular wave profile (not run in drivetrain configuration) - RW - Heave only profile created from real world encoder data (not run in drivetrain configuration) For those interested in the raw, unprocessed, data the authors have created a separate submission, linked below. This submission includes the raw TDMS files and associated files necessary to translate the data into either python or MATLAB formats. This data set has been developed by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Water Power Technologies Office.

16 TIDAL AND WAVE POWER↗
DOE OSTI2024

HERO WEC V1 Upgrade - 2023 Laboratory Testing (Raw Data)

This submission contains the original, unprocessed data from the 2023 Large Amplitude Motion Platform (LAMP) testing of NREL's Hydraulic and Electric Reverse Osmosis Wave Energy Converter (HERO WEC). This data serves as a companion to MHKDR #520. Data was collected using NREL's Modular Ocean Data AcQuisition (MODAQ) system in TDMS format. Specifications of TDMS files can be found on the NI website. The TDMS files have been separated into zip files corresponding to either Drivetrain, Hydraulic, or Electric configuration runs representing the respective test cases that were run. The drivetrain runs were used to characterize the drivetrain only (no pump or generator). The Hydraulic runs represent the configuration when the seawater pump is installed, and the Electric runs represents the configuration when the generator is installed. The following sub-categories of data are included for each type: - DW - Deep water (monochromatic sine wave) profile (not run in drivetrain configuration) - Heave - Heave only (monochromatic sine wave) profile - Heave_NoRO (hydraulic configuration only) - Heave_ACC (hydraulic configuration only) - IR - Surge and heave irregular wave profile (not run in drivetrain configuration) - RW - Heave only profile created from real world encoder data (not run in drivetrain configuration) Reference documents: - "HERO WEC Lamp Test Run Log.xlsx": contains specifications for each test run - "Lamp Data Description.docx": provides detailed information about data types and processing methods For those interested in the processed data the authors have created a separate submission, MHKDR #520, linked below. This data set has been developed by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Water Power Technologies Office.

16 TIDAL AND WAVE POWER↗