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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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Atmospheric carbon monoxide in the upper troposphere and lower stratosphere for the period March 1977 through October 1978 was analyzed. The CO data are summarized and the distribution and variations in space and time of this gas are presented. The data show that the CO mixing ratios are higher in the troposphere than those in the stratosphere. In the Northern Hemisphere the highest value of CO mixing ratio occurs in spring, although more data are needed to verify these findings. Correlation coefficients among CO, O3, air temperature (T) and winds were calculated for different regions under different seasons. It was found that the CO correlates negatively with O3 above 20 degrees latitude and positively below that latitude. Case studies using the data of CO, O3, and T measured simultaneously were performed. Discussions and suggestions are made. Ozone data on seasonal basis is also summarized.
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This paper reports on the successful application of variable-angle spectroscopic ellipsometry to quantitative thin-film hermeticity evaluation. It is shown that, under a variety of film preparations and moisture introduction conditions, water penetrates only a very thin diamondlike carbon (DLC) top surface-roughness region. Thus, DLC is an excellent candidate for use as protective coatings in adverse chemical and aqueous environments.
Automatic equipment for sampling and preparing gases by dual column gas chromatography for subsequent mass spectral analysis of carbon isotopes during methane metabolism
The demand for carbon fibers and carbon fiber-reinforced polymers (CFRPs) is rapidly growing due to their outstanding mechanical properties and potential to enhance sustainability, particularly for lightweighting applications. However, carbon fibers are typically produced from fossil-based feedstocks, involve energy-intensive processes, and have limited options for sustainable end-of-life management or circularity. Despite these challenges, the energy demand and lifecycle environmental implications of their production remain poorly understood. Here, we conduct a critical literature review and meta-analysis of carbon fiber manufacturing, revealing significant variations in reported energy demand, carbon footprint, and lifecycle inventory data. Our analysis makes two novel contributions. First, we identify key underlying factors driving these variations. Second, we highlight that carbon fiber, far from being a homogeneous product, has grades varying substantially in mechanical properties, end-use markets, energy intensity of manufacturing processes, and therefore environmental impacts—an aspect often underrepresented in life cycle assessments. We assert that current data are insufficient for reliably evaluating environmental impacts, posing a risk of misleading decision-making. Addressing this gap requires new lifecycle inventory datasets clearly incorporating carbon fiber heterogeneity and key influencing factors identified in this study. Additionally, we propose actionable recommendations, including a checklist, to advance sustainability in the carbon fiber sector.
Description of one approach to the analysis for carbon compounds in lunar materials from the Apollo 11 mission. The sequential scheme followed generally accepted organic geochemical practices, but was unusual in its application to a single sample. The procedures of the scheme were designed to minimize handling of the solids and extracts or hydrolysates. The solid lunar sample was retained in all steps of the sequential analysis in the vessel in which it was originally placed. Centrifugation was used to separate solid and liquid phases after extraction or refluxing. Liquids were recovered from solids by decantation.
The talk will describe modeling and analysis of cryogenic systems for carbon capture from industrial point sources, thermodynamic and process simulation requirements to predict capture from typical flue gases, quantification of temperature and flow profiles for a range of gas feed compositions and capture levels, and impacts of process conditions and heat transfer on energy requirements for heat integration.
Presentation given at the 2023 Carbon Management Research Project Review Meeting on August 28, 2023 in Pittsburgh, PA. Gives an overview of LCA research and support at NETL for the Carbon Conversion program.
The first detailed atmospheric analysis of the DQ white dwarf G35 - 26 is presented. The analysis is based on published spectra and on helium-rich, homogeneous, blanketed LTE models containing carbon, hydrogen, and small amounts of N, O, and Ca, and on the assumption that G35 - 26 is a single star. The observed spectra are fitted against the model spectra, and T(eff), log(g), and abundances of H, He, C are determined along with upper limits on N, O, and Ca. The mass and zero temperature Hamada-Salpeter (ZTHS) radius, distance, parallax, and tangential velocity are derived. The mass, 1.2-1.33 solar, is the highest yet observed for a single white dwarf if the star is on the ZTHS relation. O + Ne + Mg white dwarf in this mass range are predicted by theory and G35 - 26 may be the first such object discovered. Given an ZTHS radius, the distance is between 33 and 69 pc.
Analysis of the field measurements of carbon dioxide and water vapor fluxes is discussed. These data were examined in conjunction with reflectance obtained from helicopter mounted Modular Multiband Radiometer. These measurements are representative of the canopy scale (10 to 100 m)(exp 2) and provide a good basis for investigating the hypotheses/relationship potentially useful in remote sensing applications. All the micrometeorological data collected during FIFE-89 were processed and fluxes of CO2, water vapor, and sensible heat were calculated. Soil CO2 fluxes were also estimated. Employing these soil CO2 flux values, in conjunction with micrometeorological measurements, canopy photosynthesis is being estimated. A biochemical model of leaf photosynthesis was adapted to the prairie vegetation. The modeled leaf photosynthesis rates were scaled up to the canopy level. This model and a multiplicative stomatal conductance model are also used to calculate canopy conductance.
Poster for presentation at the American Geophysical Union Fall Meeting 2023 detailing work conducted for the Carbon Storage Data Field Work Proposal. This poster presents an inventory and meta-analysis conducted for Carbon Storage Data Task 4, which includes a review of offshore geologic carbon storage projects worldwide including site characterization, resource estimates, and transport information.
This paper presents the development of a stability analysis for the nose cap of the NASA Space Shuttle Orbiter. Stability is evaluated by the differential stiffness analysis of the NASTRAN finite-element computer code, addressing those nonstandard characteristics in the nose cap such as nonuniform curvature, asymmetrical and nonuniform loads, support fixity, and various combinations of membrane and bending stresses. A full-sized nose cap, thinner than production, was statically tested and stability analyzed. The failing load level correlated to within 30%. The region and mode of buckling that occurred during test was accurately predicted by analysis. The criterion for predicting instability is based on the behavior of the nonlinear deflections. The deflections are nonlinear elastic in that the stresses are well within the elastic range of the material, but the geometry-load relationship produces nonlinear deflections. The load-deflection relationship is well defined by differential stiffness analysis up to the zero-slope portion of the curve, the point of neutral stability or where the shell 'snaps through' just prior to general instability.
Conductivity method of quantitative analysis for carbon traces in tungsten
A presentation providing an overview of the work the NETL life cycle analysis (LCA) team performs to support the U.S. DOE Carbon Conversion program, including the NETL CO2U LCA Guidance Toolkit and other LCA-related tasks. Presented at the 2022 Carbon Management Project Review Meeting in Pittsburgh, PA on August 15, 2022.
An improved protocol for thermogravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material. In most cases, TGA of carbon nanotube materials is performed in gas mixtures that contain oxygen at various concentrations. The improved protocol is summarized.
Presentation given to the CCU TEA and LCA Guidance – A Harmonized Approach Workshop on May 18, 2023. Describes carbon conversion-related life cycle analysis efforts at NETL.