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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Model evaluation of the radiative and temperature effects of the ozone content changes in the global atmosphere of 1980's

Radiative and temperature effects of the observed ozone and greenhouse gas atmospheric content changes in 1980 - 1990 are evaluated using the two-dimensional energy balance radiative-convective model of the zonally and annually averaged troposphere and stratosphere. Calculated radiative flux changes for standard conditions quantitatively agree with their estimates in WMO/UNEP 1991 review. Model estimates indicate rather small influence of ozone depletion in the lower stratosphere on the greenhouse tropospheric warming rate, being more significant in the non-tropical Southern Hemisphere. The calculated cooling of the lower stratosphere is close to the observed temperature trends there in the last decade.

Karol, Igor L.↗
DOE OSTI2025

Doppler Broadening and Other Temperature Effects

In this paper I attempt to document what I have learned and still remember about temperature effects, particularly Doppler broadening, on nuclear data, as it applies to ENDF formatted data. My focus is on the SIGMA1 method of Doppler broadening that I developed over 50 years ago. However, I do realize that there are currently many different methods used in computer codes, and I have tried to keep my discussion general as it applies to ALL of these methods. In particular, ALL of the MYTHS I describe below apply to all Doppler broadening methods: they all solve the parabolic diffusion equation in spherical geometry in (speed, reaction rate) versus temperature. These methods differ only in how the cross section is represented. So, at 85 years old here is what I still remember.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Elevated Temperature Effects on Protein Turnover Dynamics in Arabidopsis thaliana Seedlings Revealed by 15 N-Stable Isotope Labeling and ProteinTurnover Algorithm

Global warming poses a threat to plant survival, impacting growth and agricultural yield. Protein turnover, a critical regulatory mechanism balancing protein synthesis and degradation, is crucial for the cellular response to environmental changes. We investigated the effects of elevated temperature on proteome dynamics in Arabidopsis thaliana seedlings using 15 N-stable isotope labeling and ultra-performance liquid chromatography-high resolution mass spectrometry, coupled with the ProteinTurnover algorithm. Analyzing different cellular fractions from plants grown under 22 °C and 30 °C growth conditions, we found significant changes in the turnover rates of 571 proteins, with a median 1.4-fold increase, indicating accelerated protein dynamics under thermal stress. Notably, soluble root fraction proteins exhibited smaller turnover changes, suggesting tissue-specific adaptations. Significant turnover alterations occurred with redox signaling, stress response, protein folding, secondary metabolism, and photorespiration, indicating complex responses enhancing plant thermal resilience. Conversely, proteins involved in carbohydrate metabolism and mitochondrial ATP synthesis showed minimal changes, highlighting their stability. This analysis highlights the intricate balance between proteome stability and adaptability, advancing our understanding of plant responses to heat stress and supporting the development of improved thermotolerant crops.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1988

Vacuum weathering of sulfur - Temperature effects and applications to Io

The effect of surface temperature on the initial transient and subsequent steady-state behavior of the vacuum-sublimation rate and the UV/visible spectral reflectance of frozen sulfur has been investigated. Surface temperature is found to be the dominant parameter controlling the rate of vacuum weathering of sulfur. The present results suggest that any freshly-frozen sulfur deposits on Io at typical Io hotspot temperatures should display major transient changes in color in a matter of hours to days. It is noted that these rapid changes in spectral reflectivity should be readily detectable by future high-resolution synotopic observations of Io spectrum in the UV/visible.

Nash, Douglas B.↗
NASA NTRS1994

Ambient temperature effects on broadband UV-B measurements using fluorescent phosphor (MgWO4)-based detectors

Results of field tests on a group of broadband UV-B pyranometers are presented. A brief description of the instrument is given. The effects of ambient temperature on thermally unregulated fluorescent phosphor (Robertson type) meters are presented and compared with the performance of thermally stabilized instruments. Means for correcting data from thermally unregulated instruments, where the prevailing ambient temperatures are known, are outlined.

Dichter, Bronislaw K.↗
NASA NTRS1994

Isolating Gas Sensor From Pressure And Temperature Effects

Two-stage flow system enables oxygen sensor in system to measure oxygen content of low-pressure, possibly-high-temperature atmosphere in test environment while protecting sensor against possibly high temperature and fluctuations in pressure of atmosphere. Sensor for which flow system designed is zirconium oxide oxygen sensor sampling atmospheres in high-temperature wind tunnels. Also adapted to other gas-analysis instruments that must be isolated from pressure and temperature effects of test environments.

Sprinkle, Danny R.↗
NASA NTRS1975

On the effective temperature of alpha Herculis A

Measurements of alpha Her A with the amplitude interferometer yield a uniform disk angular diameter of about 0.058 sec. The fundamental effective temperature, 2450 K, obtained from this measurement is in good accord with those of luminous stars of neighboring spectral types, and differs markedly from previous determinations.

Knapp, S. L.↗
NASA NTRS1982

UV fluxes and effective temperatures of extreme helium stars

Low resolution IUE spectra of a complete ensemble of extreme helium stars are presented and their appearance in comparison with normal stars is discussed. Effective temperatures from these observations by means of line blanketed model atmospheres are determined. It is found that the temperatures are in accordance with earlier results from ground based observations.

Schoenberner, D.↗
DOE OSTI2025

Analysis of temperature effects on self-powered neutron detectors in a gamma field

Self-powered neutron detectors (SPND) are small, robust, in-core radiation sensors that have the potential to operate in high temperature environments (above 600°C). However, previous experiments indicated temperature related effects in the form of displacement currents. Given the recent irradiation at The Ohio State University Research Reactor using a delayed-response rhodium-based SPND alongside a prompt-response tantalum-based SPND, it was concluded that only low-energy electrons from gamma interactions were the cause of these temperature effects. A series of heated gamma irradiations with temperatures up to 750°C of SPNDs were performed at the Advanced Test Reactor Gamma Facility in order to better characterize these displacement currents. The results from the experiments demonstrated a strong relation between the displacement currents that occurred during temperature ramps to thermoluminescence (TL) glow peaks—the SPND with Al2O3 insulation has one glow peak within 750°C and the SPND with MgO has three. A demonstration was performed to calculate the trap energy levels of the displacement currents through TL glow peak analysis. Unfortunately, the methods employed provided inconsistent results, requiring an updated model based on ongoing irradiation instead of post-irradiation measurements.

46 - INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AN↗
NASA NTRS1976

The effective temperature of Uranus

Uranus was observed in the spectral region from 40 to 250 microns with a 102-cm balloon-borne telescope, and the results were interpreted in terms of model atmosphere calculations to yield an effective temperature of 58 plus or minus 3 K; this sets an upper limit of about 28 per cent on the relative contribution of an internal heat source to the total thermal radiation. On the same flight, the brightness temperatures of Venus (215 plus or minus 13 K) and Jupiter (135 plus or minus 6 K) were also measured, thus reconfirming the existence of an internal heat source for Jupiter.

Fazio, G. G.↗
NASA NTRS1977

The effective temperature of Neptune

The brightness temperature of Neptune has been measured in two broad passbands with flux-weighted mean wavelengths of 45 and 93 microns, permitting a direct determination of its effective temperature. The derived value of 55.5 plus or minus 2.3 K implies that Neptune radiates twice as much power as it receives from the sun.

Loewenstein, R. F.↗