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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
NASA NTRS1992

Coronal energy distribution and X-ray activity in the small scale magnetic field of the quiet sun

The energy distribution in the small-scale magnetic field that pervades the solar surface, and its relationship to X-ray/coronal activity are discussed. The observed emission from the small scale structures, at temperatures characteristic of the chromosphere, transition region and corona, emanates from the boundaries of supergranular cells, within coronal bright points. This emission is characterized by a strong temporal and spatial variability with no definite pattern. The analysis of simultaneous, multiwavelength EUV observations shows that the spatial density of the enhanced as well as variable emission from the small scale structures exhibits a pronounced temperature dependence with significant maxima at 100,000 and 1,000,000 K. Within the limits of the spatial (1-5 arcsec) and temporal (1-5 min) resolution of data available at present, the observed variability in the small scale structure cannot account for the coroal heating of the quiet sun. The characteristics of their emission are more likely to be an indicator of the coronal heating mechanisms.

Habbal, S. R.↗
NASA NTRS1987

Quasar energy distributions. I - Soft X-ray spectra of quasars

As the initial stage of a study of quasar energy distributions (QEDs), Einstein IPC spectra of 24 quasars are presented. These are combined with previously reported IPC spectra to form a sample of 33 quasars with well-determined soft X-ray slopes. A correlation analysis shows that radio loudness, rather than redshift or luminosity, is fundamentally related to the X-ray slope. This correlation is not followed by higher energy spectra of active galaxies. Two components are required to explain both sets of results. The best-fit column densities are systematically smaller than the Galactic values. The same effect is not present in a sample of BL Lac objects, implying that the effect is intrinsic to the quasars and is caused by a low-energy turnup in the quasar spectra.

Wilkes, Belinda J.↗
NASA NTRS1982

Electron energy distribution produced by beam-plasma discharge

In an investigation of a beam-plasma discharge (BPD), the electron energy distribution of an electron beam moving through a partially ionized gas is analyzed. Among other results, it is found that the occurrence of BPD heats the initially cold electron beam from the accelerator. The directional intensity of electrons measured outside the beam core indicates that most particles suffer a single scattering in energy and pitch angle. At low currents this result is expected as beam particles collide with the neutral atmosphere, while in BPD the majority of particles is determined to still undergo a single scattering near the original beam core. The extended energy spectra at various beam currents show two rather distinct plasma populations, one centered at the initial beam energy (approximately 1500 eV) and the other at approximately 150 eV.

Anderson, H. R.↗
NASA NTRS1974

Electron energy distribution in a helium plasma created by nuclear radiations

An integral balance technique for calculation of the electron energy distribution in a radiation-induced plasma is described. Results predict W-values reasonably well and compare favorably with more complicated Monte-Carlo calculations. The distribution found differs from that in a normal electrical discharge and is of interest in radiation-pumped laser research.

Lo, R. H.↗
NASA NTRS1986

Spectral energy distributions of active galactic nuclei between 0.1 and 100 microns

The 0.1-100-micron line-free spectral energy distributions of 29 AGN are characterized by fitting simple models to data from IRAS and IUE observations and ground-based NIR and optical spectrophotometry. The data are presented in tables and graphs and discussed in detail. It is found that nuclear dust does not play a major role in most of the Seyfert 1 galaxies and QSOs, which can be described by a model with four spectral components.

Edelson, R. A.↗
NASA NTRS1997

Collisionless Plasma Modeling in an Arbitrary Potential Energy Distribution

A new technique for calculating a collisionless plasma along a field line is presented. The primary feature of the new model is that it can handle an arbitrary (including nonmonotonic) potential energy distribution. This was one of the limiting constraints on the existing models in this class, and these constraints are generalized for an arbitrary potential energy composition. The formulation for relating current density to the field-aligned potential as well as formulas for density, temperature and energy flux calculations are presented for several distribution functions, ranging from a bi-Lorentzian with a loss cone to an isotropic Maxwellian. A comparison of these results with previous models shows that the formulation reduces.to the earlier models under similar assumptions.

Liemohn, M. W.↗
DOE OSTI2025

Development of an Interactive Valuation Model for Distributed Energy Resource Value: Cooperative Research and Development (Final Report)

The Oklahoma Office of the Secretary of Energy and Environment (OSEE) seeks to address perceived challenges and barriers to the deployment of distributed energy generation resources (DERs), including solar and other technologies, in the state of Oklahoma. The Scope of Work (SOW) associated with CRD-18-762 covers two tasks: (1) Interactive Valuation Model Requirements Document and (2) Consumer Protection Assessment. Follow-on work was completed under a separate CRADA (CRD-19-00788).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

Cybersecurity Certification Requirements for Distributed Energy Resources: A Survey of SunSpec Alliance Standards

This survey paper explores the cybersecurity certification requirements defined by the SunSpec Alliance for Distributed Energy Resource (DER) devices, focusing on aspects such as software updates, device communications, authentication mechanisms, device security, logging, and test procedures. The SunSpec cybersecurity standards mandate support for remote and automated software updates, secure communication protocols, stringent authentication practices, and robust logging mechanisms to ensure operational integrity. Furthermore, the paper discusses the implementation of the SAE J3072 standard using the IEEE 2030.5 protocol, emphasizing the secure interactions between electric vehicle supply equipment (EVSE) and plug-in electric vehicles (PEVs) for functionalities like vehicle-to-grid (V2G) capabilities. This research also examines the SunSpec Modbus standard, which enhances the interoperability among DER system components, facilitating compliance with grid interconnection standards. This paper also analyzes the existing SunSpec Device Information Models, which standardize data exchange formats for DER systems across communication interfaces. Finally, this paper concludes with a detailed discussion of the energy storage cybersecurity specification and the blockchain cybersecurity requirements as proposed by SunSpec Alliance.

Tsikteris, Sean (ORCID:0009000524202250)↗
NASA NTRS1994

EUV energy distributions of accretion disks in active galactic nuclei

We have calculated UV/EUV (300 A less than or = lambda less than or = 1500 A) continuous energy distributions of accretion disks in the centers of active galactic nuclei (AGNs) for disk luminosities in the range 0.1 L(sub Edd) and central masses ranging from 10(exp 8) solar mass to 10(exp 10) solar mass. The vertical gas pressure structure of the disk is obtained analytically, the temperature stratification and the resulting continuum radiation fields are calculated numerically. We show that weak Lyman edges are an intrinsic feature of such disks. The strength of the H I Lyman edge decreases for increasing accretion rate and fixed mass of the central black hole. It increases for increasing central mass and fixed luminosity in terms of the Eddington luminosity.

Storzer, H.↗
NASA NTRS1972

Liquid rocket performance computer model with distributed energy release

Development of a computer program for analyzing the effects of bipropellant spray combustion processes on liquid rocket performance is described and discussed. The distributed energy release (DER) computer program was designed to become part of the JANNAF liquid rocket performance evaluation methodology and to account for performance losses associated with the propellant combustion processes, e.g., incomplete spray gasification, imperfect mixing between sprays and their reacting vapors, residual mixture ratio striations in the flow, and two-phase flow effects. The DER computer program begins by initializing the combustion field at the injection end of a conventional liquid rocket engine, based on injector and chamber design detail, and on propellant and combustion gas properties. It analyzes bipropellant combustion, proceeding stepwise down the chamber from those initial conditions through the nozzle throat.

Combs, L. P.↗
NASA NTRS1971

Energy Distribution among Reaction Products. III: The Method of Measured Relaxation Applied to H + Cl2

The method of measured relaxation is described for the determination of initial vibrational energy distribution in the products of exothermic reaction. Hydrogen atoms coming from an orifice were diffused into flowing chlorine gas. Measurements were made of the resultant ir chemiluminescence at successive points along the line of flow. The concurrent processes of reaction, diffusion, flow, radiation, and deactivation were analyzed in some detail on a computer. A variety of relaxation models were used in an attempt to place limits on k(nu prime), the rate constant for reaction to form HCl in specified vibrational energy levels: H+Cl2 yields (sup K(nu prime) HCl(sub nu prime) + Cl. The set of k(?) obtained from this work is in satisfactory agreement with those obtained by another experimental method (the method of arrested relaxation described in Parts IV and V of the present series.

Pacey, P. D.↗
DOE OSTI2025

Evaluating Air-Source Heat Pumps with Distributed Energy Resources in REopt

This training introduces attendees to NREL's REopt(R) web tool and its capabilities in evaluating air-source heat pumps (ASHP) alongside distributed energy resources (DERs). Designed for energy managers, facility operators, and sustainability managers, this session will explore how REopt provides techno-economic analysis to assess the financial viability of ASHP while identifying synergies with solar PV and battery storage. Participants will gain practical insights into using REopt to optimize energy strategies, reduce costs, and improve site resilience.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1979

On the energy distribution in Sirius B

A spectrum of Sirius B in the wavelength region 1100-1900 A taken with the IUE satellite shows an absolute flux and spectral energy distribution in the continuum in agreement with theoretical white-dwarf models with T(eff) of 26,000 K plus or minus 1000 K for log g equals 8.65 and R equals 5.08 x 10 to the 8th cm. The Lyman-alpha profile is also in agreement with these parameters. No obvious emission lines in the spectrum of Sirius B or A which could indicate the presence of a chromosphere or corona in either of the stars are observed.

Boehm-Vitense, E.↗