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NASA NTRS2019

Satellite-Detected Ocean Ecosystem Response to Volcanic Eruption in the Subarctic Northeast Pacific Ocean

Volcanic eruptions in the Aleutian archipelago during the summer of 2008 deposited large quantities of iron-laden ash to the Subarctic North Pacific Ocean. The surface ocean ecosystem response has been previously characterized using limited in situ and autonomous field measurements and numerical modeling, but basin-scale satellite remote sensing has been limited to a simple description of chlorophyll variability. Here, we show that the ecosystem response is a complex combination of phytoplankton biomass and physiology that can be described with satellite ocean color diagnostics such as the chlorophyll to carbon biomass ratio (Chl:Cphyto) and chlorophyll fluorescence yield. Together, these quantities outline a more complete picture of ecological response spanning unique signals of iron stress (and relief from), photo acclimation, changes in phytoplankton growth rate, increases in biomass, and timescales of decay for these processes.

Ocean Ecosystem↗

DOE OSTI2024

Rare earth element enrichment in coal and coal-adjacent strata of the Uinta Region, Utah and Colorado

This study aims to quantify rare earth element enrichment within coal and coal-adjacent strata in the Uinta Region of central Utah and western Colorado. Rare earth elements are a subset of critical minerals as defined by the U.S. Geological Survey. These elements are used for a wide variety of applications, including renewable energy technology in the transition toward carbon-neutral energy. While rare earth element enrichment has been associated with Appalachian coals, there has been a more limited evaluation of western U.S. coals. Here, samples from six active mines, four idle/historical mines, four mine waste piles, and seven stratigraphically complete cores within the Uinta Region were geochemically evaluated using portable X-ray fluorescence ( n = 3,113) and inductively coupled plasma-mass spectrometry ( n = 145) elemental analytical methods. Results suggest that 24%–45% of stratigraphically coal-adjacent carbonaceous shale and siltstone units show rare earth element enrichment (>200 ppm), as do 100% of sampled igneous material. A small subset (5%–8%) of coal samples display rare earth element enrichment, specifically in cases containing volcanic ash. This study proposes two multi-step depositional and diagenetic models to explain the enrichment process, requiring the emplacement and mobilization of rare earth element source material due to hydrothermal and other external influences. Historical geochemical evaluations of Uinta Region coal and coal-adjacent data are sparse, emphasizing the statistical significance of this research. These results support the utilization of active mines and coal processing waste piles for the future of domestic rare earth element extraction, offering economic and environmental solutions to pressing global demands.

Coe, Haley H.↗

NASA NTRS1986

Rhyolitic components of the Michipicoten greenstone belt, Ontario: Evidence for late Archaen intracontinental rifts or convergent plate margins in the Canadian Shield?

Rhyolitic rocks often are the dominant felsic end member of the biomodal volcanic suites that characterize many late Archean greenstone belts of the Canadian Shield. The rhyolites primarily are pyroclastic flows (ash flow tuffs) emplaced following plinian eruptions, although deposits formed by laval flows and phreatomagmatic eruptions also are presented. Based both on measured tectono-stratigraphic sections and provenance studies of greenstone belt sedimentary sequences, the rhyolites are believed to have been equal in abundance to associated basaltic rocks. In many recent discussions of the tectonic setting of late Archean Canadian greenstone belts, rhyolites have been interpreted as products of intracontinental rifting . A study of the tectono-stratigraphic relationships, rock associations and chemical characteristics of the particularly ell-exposed late Archean rhyolites of the Michipicoten greenstone belt, suggests that convergent plate margin models are more appropriate.

Sylvester, P. J.↗

NASA NTRS1992

Preliminary analysis of thermal-infrared multispectral scanner data of the Iron Hill, Colorado carbonatite-alkalic rock complex

The Iron Hill carbonatite-alkalic igneous rock complex is in the Powderhorn mining district, approximately 40 km south-southwest of Gunnison, Colorado. The complex, which occupies about 30 sq km, was emplaced in metasedimentay and metavolcanic rocks during the later Precambrian or early Cambrian. The main rock types in the complex, from oldest to youngest, are fenite, pyroxenite, uncompahgrite, ijolite, nepheline syenite, and dolomitic carbonatite. The carbonatite is limonitic and forms an elliptially shaped 4 sq km stock. Calcitic and dolomitic carbonatite dikes are also numerous throughout the complex and in the pre-existing rocks. Pyroxenite is the most widespread rock type within the complex, but pyroxene is extensively altered to biotite, phlogopite, and vermiculite. Fenite, which formed through Na, K-metasomatism of the country rocks, typically contains more feldspar and less quartz than the equivalent unaltered country rocks. The other alkalic rock types are less widespread and less well exposed. Parts of the complex are covered by Oligocene ash-flow tuff and alluvial, colluvial, and glacial deposits. Sagebrush and grass cover is moderately dense to very dense at low to intermediate elevations; coniferous tree cover is dense at high elevations and on some north-facing slopes at lower elevations. A new algorithm was used to compute spectral emissivity ratios, independent of any emissivity assumptions. This algorithm has the advantage that any of the possible emissivity ratios can be computed and, thus, a large variety of composite ratio images can be constructed, which permits examination of various geologic hypotheses based on the spectral properties of the surface materials.

Rowan, Lawrence C.↗

NASA NTRS1985

Mass transfer across combustion gas thermal boundary layers - Power production and materials processing implications

The effects of Soret diffusion (for vapors) and thermophoresis (for particles) are illustrated using recent optical experiments and boundary layer computations. Mass transfer rate augmentations of up to a factor of 1000 were observed and predicted for submicron-particle capture by cooled solid surfaces, while mass transfer suppressions of more than 10 to the -10th-fold were predicted for 'overheated' surfaces. It is noted that the results obtained are of interest in connection with such technological applications as fly-ash capture in power generation equipment and glass droplet deposition in optical-waveguide manufacture.

Rosner, D. E.↗

DOE OSTI2020

Pilot Plant Reliability Metrics for Grinding and Fast Pyrolysis of Woody Residues

The reliability of biomass size reduction, feeding, and conversion processes remains a critical technical hurdle and important cost driver for biomass conversion systems. While Biorefinery projects have typically focused on scaling up conversion technologies that maximize yield of desired products, e.g. fuels and chemicals, solids handling and reactor feeding systems are often considered secondarily. These are frequently scaled down or adapted from other industries, without a full appreciation of how biomass heterogeneity and variability impact process reliability. Here we present the effects of feedstock variability on relative throughput, mass loss, plant uptime, operator intervention, product yield, and product quality for grinding and fast pyrolysis operations at the pilot scale. Loblolly pine residues were sourced and collected using commercial harvesting techniques. Grinding and pyrolysis experiments were performed at INL's Biomass Feedstock National User Facility and NREL's Thermal and Catalytic Process Development Unit, respectively. Preprocessing throughput using a hammer mill varied between 31-48% of nameplate capacity (5 tons/hr), and fast pyrolysis throughput varied between 57-72% of nameplate capacity (20 kg/hr) for an overall system throughput of 18-35% of nameplate capacity across biomass preprocessing and conversion to pyrolysis oil. Pyrolysis oil yields varied between 46-53% (feedstock carbon to oil, dry basis). Grinder overloads in the size reduction step were more prevalent for lower ash and higher moisture materials. During fast pyrolysis operations, downtime was caused by bridging in the feed and char removal systems and plugging in the condensation system, and significant variation in the type and frequency of operator intervention was observed between feedstocks. Cohesion of solids (feedstock and char) leading to system plugging appeared less problematic for higher ash feedstocks, and differences in condenser plugging behavior between high and low ash feedstocks indicates the composition and physical nature of the deposited material is important for process reliability and is feedstock dependent.

09 BIOMASS FUELS↗

DOE OSTI2020

Novel Membrane and Electrodeposition-Based Separation and Recovery of Rare Earth Elements from Coal Combustion Residues (Final Report)

This project developed a hydrometallurgical-based technology to extract and concentrate rare earth elements (REEs) from a representative group of coal combustion residuals (CCRs) from major coal sources in the United States. The approach for REE recovery comprises two general components: (1) Leaching of REEs from CCRs and (2) Separation of REEs from other major ions in the CCR leachate. The leaching step entails acid leaching with nitric or hydrochloric acid, and in some cases, pretreatment of CCRs with alkaline roasting prior to acid leaching. The follow-up REE recovery steps involve a series of membrane-based methods to separate and concentrate rare earth ions from other major ions in acid leachates of CCRs. These methods include liquid emulsion membranes, supported liquid membranes and electrodeposition with carbon nanotube electrochemical filters. The advantage of these separation approaches (relative to conventional approaches such as solvent extraction) is a reduction in the usage of solvents and other costly chemicals and a reduction of hazardous waste products that are challenges in conventional REE separation methods. In the testing of our process, we selected a representative set of CCR samples from our collection and performed a suite of characterization measurements (total REE content and major mineralogy). The major results of this work demonstrated that heated acid leaching could efficiently extract REEs from PRB-based coal fly ashes while the Appalachian and Illinois Basin CCRs required alkaline roasting with NaOH prior to acid leaching at room temperature. The supported liquid membrane (SLM) configuration and electrochemical deposition (ED) system yielded the most promising methods of REE recovery from the acid leachates of fly ash. Our most concentrated product to date comprised 1 wt.% (dry basis) REEs produced from an Appalachian-based fly ash leached and purified by SLM. The SLM separation process was more selective for heavy REEs over the light REEs. When SLM was combined with ED, preliminary results demonstrated that a final product of >2 wt.% REEs was possible.

01 COAL, LIGNITE, AND PEAT↗

NASA NTRS1990

Volcanic geology of Tyrrhena Patera, Mars

Consideration is given to the geology of Tyrrhena Patera, a large low-relief volcano in the southern cratered highlands of Mars. The general geology of Tyrrhena Patera is outlined and models for the formation of the volcano are described. Models derived from studies of terrestrial pyroclastic flows are applied to deposits at Tyrrhena Patera, showing that the characteristics of the deposits are consistent with an origin by the emplacement of gravity-driven ash flows generated by hydromagmatic or magmatic explosive eruptions.

Greeley, Ronald↗

NASA NTRSDate not supplied

Investigating Pyroclastic Volcanism in the Taurus-Littrow Valley (TLV) Using the Station 3 Double Drive Tube 73001-73002

Well over 100 pyroclastic deposits have been identified on the Moon. Eruptive processes such as represented by these deposits transported endogenous volatiles from the Moon’s mantle to its surface. Debris from pyroclastic deposits has been identified in all Apollo and Luna samples. The high-Ti pyroclastic de- posit sampled at Shorty Crater by the Station 4 double drive tube (74001-74002) is our best sampling of these types of deposits. Samples 78500 and 78526, NAC images of fissures in the Sculptured Hills, ash identified in 70001-7, and other green volcanic glass indicate that very low-Ti basalt (VLT) erup- tions also occurred in TLV. The double drive tube core being investigated by the ANGSA initiative provides an- other view of TLV pyroclastic eruptions. The regolith in 73001-73002 and the regolith breccias therein have nu- merous pyroclastic beads. Some individual regolith brec- cia fragments have abundant pyroclastic beads (>50 in a polished surface). In this work, we address the following questions. Do these glass beads overlap in composition with those sampled elsewhere in the TLV or do they rec- ord another episode of pyroclastic eruption? Are the magmas associated with pyroclastic eruptions petroge- netically related to the crystalline mare basalts in the TLV? Finally, is the volatile record of the pyroclastic eruptions better preserved in the newly opened and spe- cially contained Station 3 double drive tube core?

C.K. Shearer↗

NASA NTRS1982

Correlation and prediction of thermophoretic and inertial effects on particle deposition from non-isothermal turbulent boundary layers

The problem of small particle deposition which can cause hot stage corrosion and/or fouling in combustion turbines operating on fuels containing ash or inorganic salts is investigated. Two boundary layer transport phenomena are shown to assume importance in these cases: particle thermophoresis (migration down a temperature gradient) and particle inertia. Thermophoretic and eddy transport across turbulent boundary layers without and with particle inertia effects are quantitatively analyzed. The effects of streamwise blade curvature on particle transport across turbulent boundary layers are determined. It is shown that these phenomena destroy the analogy between mass and heat transfer or mass and momentum transfer. Also studied are the effects on particle deposition of distributed or localized wall blowing, surface roughness, and mainstream turbulence.

Rosner, D. E.↗

NASA NTRS1991

Ashfall dispersal for the 16 September 1986, eruption of Lascar, Chile, calculated by a turbulent diffusion model

A two dimensional model for the dispersal of volcanic ash, modified from that of Suzuki (1983), is applied to the September 16, 1986 eruption of Lascar, in northern Chile. The result is an isopach map predicting ground concentrations of ash. The map shows two local maxima along distinct dispersal axes and predicts that the deposit was detached from the source. Predicted concentrations are in agreement with a single reported thickness measurement.

Glaze, Lori S.↗

NASA NTRS1973

Emplacement of the Cayley formation

Analysis of the effects of ejection of materials from large lunar craters, photogeologic evidence, remote measurements of surface chemistry and petrology of lunar samples are synthesized. Previous theories for emplacement of the Cayley are volcanic ash emplacement and emplacement as ejecta from multiringed basins. Calculations show that materials ejected beyond the continuous deposits of large lunar craters produce secondary impact craters that excavate and deposit masses of local material equal to multiples of the crater ejecta deposited at the same place. It is shown that the main influence of a large cratering event on terrain at distances greater than 50 km from large lunar craters is one of cratering and deposition of local material by secondary craters rather than deposition of ejecta from the large crater.

Oberbeck, V. R.↗

NASA NTRS1984

Chronology, morphology and stratigraphy of pumiceous pyroclastic-flow (ignimbrite) deposits from the eruption of Mount St. Helens on 18 May 1983

Between 1217 and 1620 hours (PDT), on May 18, 1980, the magmatic eruption column of Mount St. Helens formed an ash fountain and pyroclastic flows dominated the eruption process over tephra ejection. Eurption-rate pulsations generally increased to a maximum at 1600 to 1700 hrs. After 1620 hrs, the eruption assumed an open-vent discharge with strong, vertical ejection of tephra. Relative eruption rates (relative mass flux rates) of the pyroclastic flows were determined by correlating sequential photographs and SLAR images, obtained during the eruption, with stratigraphy and surface morphology of the deposits.

Criswell, C. W.↗

DOE OSTI2025

Halide Vapor Phase Epitaxy of Ge from an Elemental Source

Halide vapor phase epitaxy shows promise for low-cost photovoltaic device manufacturing because of its high growth rates and lower cost elemental precursors but previously has not been used to deposit epitaxial Ge. Here, we demonstrate Ge deposition by generating GeCl 2 in situ from solid Ge and HCl in a N 2 ambient. To achieve Ge growth, we inject AsH 3 and PH 3 as sources of active hydrogen to the growth surface to create a driving force for growth. We do not observe Ge growth unless a supply of hydrogen is added, consistent with thermodynamic calculations. Furthermore, we show the hydrogen source must crack readily on the substrate surface to enable growth; relatively stable sources such as H 2 do not cause growth. Unintentional group V doping is one drawback of using AsH 3 and PH 3 to drive the Ge reaction. We observed As or P concentrations in the Ge films ranging from 4 x 10 17 to 1 x 10 18 atoms/cm 3 , concentrations that can drastically influence device characteristics. However, we note there are numerous other "helper molecule" options that can provide active hydrogen without doping or etching the material. This work provides a path forward for Ge deposition for optoelectronic devices from an elemental source.

14 SOLAR ENERGY↗

NASA NTRS2006

Covering a Crucible with Metal Containing Channels

In a procedure that partly resembles the lost-wax casting process, a crucible made of a brittle material (ceramic, quartz, or glass) is covered with a layer of metal containing channels. The metal cover and the channels can serve any or all of several purposes, depending upon the application: Typically, the metal would serve at least partly to reinforce the crucible. The channels could be used as passages for narrow objects that could include thermocouples and heat-transfer strips. Alternatively or in addition, channels could be used as flow paths for liquid or gaseous coolants and could be positioned and oriented for position- or direction-selective cooling. In some cases, the channels could be filled with known gases and sealed so that failure of the crucibles could be indicated by instruments that detect the gases. The process consists of three main steps. In the first step, a pattern defining the channels is formed by wrapping or depositing a material in the desired channel pattern on the outer surface of the crucible. The pattern material can be a plastic, wax, low-ash fibrous material, a soluble material, or other suitable material that can subsequently be removed easily. In a proof-of-concept demonstration (see figure), the crucible was an alumina cylinder and the mold material was plastic tie-down tape. In the second step, the patterned crucible is coated with metal. In one variation of the second step, a very thin layer containing or consisting of an electrically conductive material (e.g., gold, silver, or carbon) is painted or otherwise deposited on the mold-covered crucible, then the covering metal required for the specific application is electrodeposited on the very thin conducting layer. In another variation of the second step, the metal coat is formed by chemical vapor deposition. In the proof-of-concept demonstration, a layer of nickel 0.003 in. ( 0.08 mm) thick was electrodeposited. In the third step, the patterned material is removed. This is generally done by heating the crucible assembly until the patterned material melts and runs out, vaporizes, and/or decomposes to an ash, leaving the channels. Alternatively, if the patterned material is soluble, it can be removed by use of a suitable solvent. In the proof-of-concept demonstration, the tape was burned away by heating the assembly to a temperature of 600 C.

Grugel, Richard N.↗

NASA NTRS2017

Thermochemistry of Calcium-Magnesium-Aluminum-Silicate (CMAS) and Components of Advanced Thermal and Environmental Barrier Coating Systems

There is increasing interest in the degradation mechanism studies of thermal and environmental barrier coatings (TEBCs) of gas turbines by molten CaO-MgO-Al(exp. 2)O(exp. 3)-SiO(exp. 2) CMAS). CMAS minerals are usually referred as silicon-containing sand dust and volcano ash materials that are carried by the intake air into gas turbines, e.g. in aircraft engines, and their deposits often react at high temperatures (greater than 1200 degrees C) with the engine turbine coating systems and components. The high temperature reactions causes degradation and accelerated failure of the static and rotating components of the turbine engines. We discuss some results of the reactions between the CMAS and Rare-Earth (RE = Y, Yb, Dy, Gd, Nd and Sm) - oxide stabilized ZrO(exp. 2) or HfO(exp. 2) systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples (outside diameter = 4.7 mm, wall thickness = 0.76 mm and = 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat treated at 1310 degrees C for 5h. Samples were characterized by differential scanning calorimetry (DSC), X-ray diffraction, and cross-section electron microscopy analysis and energy dispersive X-ray spectroscopy. It was found that CMAS penetrated the samples at the grain boundaries and dissolved the TEBC materials to form silicate phases containing the rare-earth elements. Furthermore, it was found that apatite crystalline phases were formed in the samples with total rare-earth content higher than 12 mol% in the reaction zone for the ZrO(exp. 2) system. In general, samples with the nominal compositions (30YSZ), HfO(exp. 2)-7Dy(exp. 2)O(exp. 2) and ZrO(exp. 2)-9.5Y(exp. 2)O(exp. 3)-2.25Gd(exp. 2)O(exp. 3)-2.25Yb(exp. 2)O(exp. 3) exhibited lower reactivity or more resistance to CMAS than the other coating compositions of this work.

degradation↗

DOE OSTI2022

Occurrences of REE and CM in volcanic ash beds associated with coals in SW Wyoming & NW Colorado

Rare earth elements (REEs) and critical minerals (CMs) are vital components in the nation’s economy, national security, and the further strengthening of our renewable energy capabilities and infrastructure. Recent work has revealed more insight into previously unknown modes of occurrence for REEs, particularly in coal seams and adjacent noncoal sediments, but many data gaps persist. Temporal relationships between coal beds and adjacent tonstiens, ash beds, or other partings are widely recognized but not fully understood. Variations in REE concentration and their direct or indirect association with coal beds are not predictable. This study presents findings from examining lateral and potentially stratigraphic variation of REE and CM occurrences in coals of late Cretaceous and Paleocene age. In this study we collected and examined samples of differing ages both core and coal mine exposures for qualitative x-ray fluorescence (XRF), and multi-element geochemistry. Preliminary XRF data indicates variable levels of light REEs in a core from the Yampa coalfield of Moffat County in northwest Colorado. An absence of similar enrichments in slightly older coals in the Adaville Formation of the Fold and Thrust belt in southwest Wyoming is described from XRF and ICP-MS evaluation. Previous work has shown an association with the Yampa Bed and REE enrichment in coals of the Upper Cretaceous Williams Fork Formation. While not common and widespread, this association suggests that leaching or reworking of the ash bed could lead to elevated REEs in the adjacent coal. We investigate differences between the two data occurringas geologic compositions and post-depositional histories. In-depth petrography and precise geochemistry should reveal data that at the very least will help improve some aspects of the geologic models of coal basins and the effect of an influx of non-coal sediments.

REE, CM, ash, volcanic ash, coal↗

NASA NTRS2017

High Temperature Degradation of Advanced Thermal and Environmental Barrier Coatings (TEBCs) by CaO-MgO-Al2O3-SiO2 (CMAS)

There is increasing interest in the degradation studies of thermal and environmental barrier coatings (TEBCs) of gas turbines by molten CaO-MgO-Al2O3-SiO2 (CMAS). CMAS minerals are usually referred as silica-containing sand dust and volcano ash materials that are carried by the intake air into gas turbines, e.g. aircraft engines. The low-melting deposits react at high temperatures (1000C) with the coating materials. This causes degradation and accelerated coating failure of the static and rotating components of the turbine engines. We discuss some preliminary results of the reactions between CMAS and Rare-Earth (RE Y, Yb, Dy, Gd, Nd and Sm) oxide stabilized ZrO2 or HfO2 systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples (outer diameter 4.7 mm, wall thickness 0.76 mm and 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat- treated at 1310 C for 5h. Samples were characterized by differential scanning calorimetry, X-ray diffraction and cross section electron microscopy analysis.

Thermal and environmental barrier coatings↗