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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 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Pre- and post-coppice production and biomass chemistry of eastern cottonwood and hybrid poplars in the southeastern US

Sustainably grown feedstocks for bioenergy and bioproducts are important tools to fight climate change, provide ecosystem services, and sequester carbon. Populus species including hybrid poplars have been utilized around the world, and in the southeastern US native eastern cottonwood (P. deltoides) is often favored due to its resistance to stem cankers. However, P. deltoides has historically been grown in single stem production and its relative performance in short rotation coppice production, prevalent in Europe, is not well documented. Therefore, this study's goals were to evaluate eastern cottonwood (D × D) and hybrid poplar (P. deltoides × P. maximowiczii (D × M) and P. deltoides × P. trichocarpa (D × T) taxa) productivity under a two-year establishment and two-year coppice cycle, analyze biomass chemistry properties, identify drivers of productivity, and select clones suited for marginal vs. optimal sites. We found that D × M and D × D grew best in both establishment and coppice rotation with production increasing after coppice. Taxa and clones exhibited few differences in select biomass chemistry properties despite differences in growth rate and stem size. Across years and sites, production was correlated with the soil's carbon to nitrogen ratio, percentage of sand, and shrink-swell potential of the soil. A D × M clone ‘9709’ tended to perform better than other tested clones on marginal sites and had the highest survival rate after four years. Overall, this research suggests that Populus species can be grown in coppice rotation in the southeastern US with the potential for hybrid poplars to be successful on certain sites in the region although longer term studies are necessary to confirm these results.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Controls on rare earth element distributions in ancient organic-rich sedimentary sequences: Role of post-depositional diagenesis of phosphorus phases

Here, the processes that dictate the formation and preservation of rare earth element (REE) signatures in ancient marine black shales are incompletely understood, thus potentially limiting the utility of the REEs as geochemical tracers. Here, we report on whole-rock REE analyses of six black shale formations from different ages and depositional settings, which fall within three general groupings: Group 1 is characterized by low whole-rock REE content (ΣREE) (< 250 μg/g) and middle- and heavy-REE-enriched patterns (Gd N /La N < 2, Yb N /La N < 2.5); Group 2 is characterized by low ΣREE (< 250 μg/g) but greater middle-REE-enriched patterns (Gd N /La N > 2, Yb N /La N < 3); and Group 3 is characterized by high ΣREE (> 250 μg/g) and moderately middle-REE-enriched patterns (Gd N /La N ~ 1.5–2.5, Yb N /La N ~ 1). Representative samples from these groups were selected from the Marcellus and Hushpuckney shales and subjected to a multi-step leaching procedure, to isolate four extractable P-phases (reducible, authigenic carbonate-associated, detrital apatite, organic). In Group 1 samples with low carbonate content (< 4% CaCO 3 ), REEs were hosted mainly in the organic (50% of ΣREE) and siliciclastic fractions (37%); whereas in samples with greater carbonate content (> 25% CaCO 3 ), REEs were hosted mainly in carbonate-associated phases (53%). In Group 2, REEs were hosted mainly in the carbonate-associated (64%) and organic fractions (30%), and in Group 3, REEs were hosted mainly in the carbonate-associated (60%), detrital apatite (23%), and siliciclastic fractions (16%). Authigenic phases include minerals such as carbonate fluorapatite and authigenic calcite that, if present, tend to dominate the whole-rock REE inventory. In the absence of carbonate, whole-rock REE content depends on the relative REE contributions of the organic and siliciclastic fractions.

58 GEOSCIENCES↗
DOE OSTI2017

Are Water-lean Solvent Systems Viable for Post-Combustion CO 2 Capture?

Here, we present here an overview of water-lean solvents that compares their projected costs and performance to aqueous amine systems, emphasizing critical areas of study needed to evaluate their performance against their water-based brethren. The work presented her focuses on bridging these knowledge gaps. Because the majority of water-lean solvents are still at the lab scale, substantial studies are still needed to model their performance at scale. This presents a significant challenge as eachformulation has different physical and thermodynamic properties and behavior, and quantifying how these different properties manifest themselves in conventional absorber-stripper configurations, or identifying new configurations that are specific for a solvent’s signature behavior. We identify critical areas of study that are needed, and our efforts (e.g. custom infrastructure, molecular models) to predict, measure, and model these behaviors. Such findings are critical for determining the rheology required for heat exchanger design; absorber designs and packing to accommodate solvents with gradient changes (e.g. viscosity, contact angle, surface tension), and stripper configurations without direct steam utilization or water reflux. Another critical area of research need is to understand the molecular structure of the liquid interface and bulk as a function of CO 2 loading, and to assess whether conventional film theories accurately quantify solvent behavior, or if thermodynamic models adequately quantify activity coefficients of ions in solution. We conclude with an assessment of our efforts to aid in bridging the knowledge gaps in understanding water-lean solvents, and suggestions of what is needed to enable large-scale demonstrations to meet the United States Department of Energy’s year 2030 goal.

15 GEOTHERMAL ENERGY↗
DOE OSTI2017

EIAMUO methodology for environmental assessment of the post-war housing estates renovation: Practical application in Seville (Spain)

This paper reports on the environmental impact assessment of a specific urban fabric: the housing estate. This urban-growth typology arose in the second half of the twentieth century to supply the existing needs of the time. It involved short-term processes, reduced costs, and lower comfort standards, which are far from present European guidelines. Currently, they represent situations of unsustainability in cities worldwide that are undergoing improvement. Here, the environmental impact assessment and minimization for urban organisms (EIAMUO) methodology is presented. This consists of a system of eco-indicators created specifically for estimating the impacts associated with these fabrics. Through its practical application, a snapshot of the current situation is achieved and the targets designed to minimize the environmental impact are proposed. - Highlights: • An environmental-impact minimization methodology for housing estates is proposed. • The paper presents a new definition for city analysis: urban organism. • The areas for the assessment are energy, water, materials and waste and atmosphere. • Energy and water areas determine most of the housing estate environmental behavior. • The building character prevails in the urban organism's environmental assessment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Lifetime-ever pneumonia among pre-school children across China – Associations with pre-natal and post-natal early life environmental factors

Highlights: • Childhood pneumonia can be influenced by prenatal and perinatal indoor exposure. • Mould and window condensation at birth is a risk factor for childhood pneumonia. • Prenatal exposure to redecoration and new furniture can increase the risk. • Cockroaches, mosquitos and flies are other risk factors in the home environment. • Farm exposure, breastfeeding and suburban or rural environment can be protective. Biomass burning is associated with childhood pneumonia but few studies exist on other indoor factors.

54 ENVIRONMENTAL SCIENCES↗