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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Preliminary Study of Information Extraction of LANDSAT TM Data for a Suburban/regional Test Site

A substantial amount of spectral information is available from TM (as compared to MSS) data for a 14.25 square km area between Beltsville and Laurel, Maryland. Large buildings and street patterns were resolved in the TM imagery. While there was added information content in TM data for discriminating surburban/regional land cover, characteristics of MSS can improve land cover discrimination over TM when conventional classification procedures are used on digital data. The improved qualitization of TM is likely valuable in situations where there are spectral similarities between classes. The spatial resolution in TM decreased land cover discrimination as a result of increased within class variability. For many general digital evaluations, inclusion of four bands representing the four spectral regions can provide much useful land cover discrimination. Inclusion of TM 6 indicates an improvement in spectral class discrimination. Of primary spectral importance is the discrimination between water, vegetative surfaces, and impervious surfaces due to differences in thermal properties. Results from the principle component transformed data clearly indicates additional information content in TM over MSS.

Toll, D. L.↗
NASA NTRS1991

Comparison of spectroscopic properties of Tm and Ho in YAG and YLF crystals

The paper compares the cross-relaxation, energy transfer and loss processes in Tm- and Ho-doped YAG and YLF as a function of temperature, Tm concentration, and excitation power. Significant differences in the behavior of Tm and Tm,Ho in YAG and YLF crystals were found. The cross-relaxation rates of Tm(6 pct) are faster in YLF (about 5 microsec) than YAG (about 10 microsec). The energy transfer rates between Tm and Ho are faster in YLF than YAG. The time it takes for the maximum intensity of 1.7-micron emission to drop 10 percent is 25 microsec for YLF:Tm(6 pct),Ho(0.6 pct) and 65 microsec YAG:Tm(6 pct),Ho(0.5 pct). The losses occurring with increasing pump power for 2.1-micron emission of the above samples are 30 percent less in YLF than YAG. These qualitative differences point to YLF as a valuable 2-micron laser host material.

Armagan, G.↗
DOE OSTI2020

Metal Bioavailability and Ecotoxicity of Bioremediated Oils and Tailings by BioTiger{sup TM}, a Microbial Consortium

Oil Sands and Mature Fine Tailings: Oil sand reserves are a major source of oil for the United States. Oil sands are a mixture of sand, clay, water, and bitumen. The refining process requires large volumes of water and generates hazardous Mature Fine Tailings (MFTs) that are stored in engineered settling ponds. They are of major environmental concern due to their persistence and difficulty to naturally biodegrade. MFT Contaminants of Concern: Naphthenic Acids (NAs), Polycyclic Aromatic Hydrocarbons (PAHs), Benzene, Toluene, Ethylbenzene and Xylene (BTEX), Metals, Residual Bitumen. BioTiger{sup TM} (BT{sup TM}), the SRNL patented 12 component microbial consortia was found to cometabolically degrade some NAs and PAHs. Previous studies performing short term exposure (48 hours and 7 days) to BT{sup TM} have resulted in increased toxicity due to the partial degradation of PAHs forming toxic intermediates. Objective: Evaluate the ecotoxicity of BT{sup TM} remediated MFTs exposed to a 2 week period w/ yeast (Y) extract. This work will determine BT{sup TM}'s remediation of MFTs from Fort McMurray, Alberta. Acute toxicity tests will be performed under section 9 of EPA's Method for Measuring Acute Toxicity using the freshwater organism, Ceriodaphnia dubia. Monitor BT{sup TM} growth through Most Probable Number (MPN) counts, pH, and metal bioavailability will also be evaluated. Preparing tailing solutions for biodegradation: BT{sup TM} components were grown in R2A media and combined. Mother BT{sup TM} was centrifuged at 7000 rpm for 20 minutes and resuspended in Bushnell Haus. 33 g of tailings were added to 1100 mL Bushnell Haus along with yeast extract (11 g) to create a 3% tailing solution. Treatments were performed in triplicate. Preparing solutions for toxicity tests using C. dubia: Supernatant was collected immediately after centrifuging at 7000 rpm for 20 min. Supernatant was filtered via a 0.22 μm sterile system. All treatments except MFT, Y peaked at T=4. This decrease in microbial growth could be associated with toxicity from intermediate byproducts. Treatments containing only MFTs decreased in the initial 11 days before growing significantly. Final solution for MFT, Y treatment had the highest pH. This could potentially be due to increased microbial activity linked with yeast consumption. All treatments except MFT, Y peaked at T=4. This decrease in microbial growth could be associated with toxicity from intermediate byproducts. Treatments containing only MFTs decreased in the initial 11 days before growing significantly. Future Direction: Await results from Acute Toxicity Tests and Metal Bioavailability Quantification of biosurfactant production. Evaluate hydrocarbon degradation byproducts using an analytical chemistry approach. More toxicity experiments with variations in time and conditions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on Tm(SiNi5)2 by Materials Project

TmNi10Si2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Tm is bonded in a 12-coordinate geometry to sixteen Ni and four equivalent Si atoms. There are a spread of Tm–Ni bond distances ranging from 2.87–3.06 Å. All Tm–Si bond lengths are 3.15 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Tm, eight Ni, and two equivalent Si atoms to form NiTm2Si2Ni8 cuboctahedra that share corners with six equivalent SiTm2Ni10 cuboctahedra, corners with twelve NiTm2Si2Ni8 cuboctahedra, edges with four equivalent NiTm2Si2Ni8 cuboctahedra, edges with four equivalent SiTm2Ni10 cuboctahedra, faces with two equivalent SiTm2Ni10 cuboctahedra, and faces with twelve NiTm2Si2Ni8 cuboctahedra. There are four shorter (2.40 Å) and four longer (2.46 Å) Ni–Ni bond lengths. Both Ni–Si bond lengths are 2.33 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to one Tm, eleven Ni, and two equivalent Si atoms. There are a spread of Ni–Ni bond distances ranging from 2.40–2.96 Å. Both Ni–Si bond lengths are 2.51 Å. In the third Ni site, Ni is bonded to two equivalent Tm, eight Ni, and two equivalent Si atoms to form distorted NiTm2Si2Ni8 cuboctahedra that share corners with four equivalent SiTm2Ni10 cuboctahedra, corners with fourteen NiTm2Si2Ni8 cuboctahedra, edges with two equivalent SiTm2Ni10 cuboctahedra, edges with five NiTm2Si2Ni8 cuboctahedra, faces with four equivalent SiTm2Ni10 cuboctahedra, and faces with eleven NiTm2Si2Ni8 cuboctahedra. Both Ni–Ni bond lengths are 2.55 Å. Both Ni–Si bond lengths are 2.31 Å. Si is bonded to two equivalent Tm and ten Ni atoms to form distorted SiTm2Ni10 cuboctahedra that share corners with four equivalent SiTm2Ni10 cuboctahedra, corners with fourteen NiTm2Si2Ni8 cuboctahedra, edges with eight NiTm2Si2Ni8 cuboctahedra, faces with four equivalent SiTm2Ni10 cuboctahedra, and faces with ten NiTm2Si2Ni8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(Al2Cu)4 by Materials Project

Tm(CuAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 12-coordinate geometry to eight equivalent Cu and twelve Al atoms. All Tm–Cu bond lengths are 3.36 Å. There are four shorter (3.05 Å) and eight longer (3.20 Å) Tm–Al bond lengths. Cu is bonded in a 12-coordinate geometry to two equivalent Tm, two equivalent Cu, and eight Al atoms. Both Cu–Cu bond lengths are 2.56 Å. There are four shorter (2.56 Å) and four longer (2.68 Å) Cu–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to two equivalent Tm, four equivalent Cu, and four equivalent Al atoms. There are two shorter (2.80 Å) and two longer (2.82 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 10-coordinate geometry to one Tm, four equivalent Cu, and five Al atoms. The Al–Al bond length is 2.68 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(Al2Cr)4 by Materials Project

Tm(CrAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 12-coordinate geometry to eight equivalent Cr and twelve Al atoms. All Tm–Cr bond lengths are 3.39 Å. There are four shorter (2.98 Å) and eight longer (3.20 Å) Tm–Al bond lengths. Cr is bonded to two equivalent Tm, two equivalent Cr, and eight Al atoms to form distorted CrTm2Al8Cr2 cuboctahedra that share corners with eight equivalent AlTm2Al6Cr4 cuboctahedra, corners with ten equivalent CrTm2Al8Cr2 cuboctahedra, edges with four equivalent CrTm2Al8Cr2 cuboctahedra, edges with four equivalent AlTm2Al6Cr4 cuboctahedra, faces with six equivalent CrTm2Al8Cr2 cuboctahedra, and faces with eight equivalent AlTm2Al6Cr4 cuboctahedra. Both Cr–Cr bond lengths are 2.53 Å. There are four shorter (2.57 Å) and four longer (2.67 Å) Cr–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to two equivalent Tm, four equivalent Cr, and six Al atoms to form distorted AlTm2Al6Cr4 cuboctahedra that share corners with eight equivalent CrTm2Al8Cr2 cuboctahedra, corners with ten equivalent AlTm2Al6Cr4 cuboctahedra, edges with three equivalent AlTm2Al6Cr4 cuboctahedra, edges with four equivalent CrTm2Al8Cr2 cuboctahedra, faces with seven equivalent AlTm2Al6Cr4 cuboctahedra, and faces with eight equivalent CrTm2Al8Cr2 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.72–2.88 Å. In the second Al site, Al is bonded in a 10-coordinate geometry to one Tm, four equivalent Cr, and five Al atoms. The Al–Al bond length is 2.92 Å.

36 MATERIALS SCIENCE↗
NASA NTRS1983

Performance evaluation and geologic utility of LANDSAT 4 TM and MSS scanners

Experiments using artificial targets (polyethylene sheets) to help calibrate and evaluate atmospheric effects as well as the radiometric precision and spatial characteristics of the NS-001 and TM sensor systems were attempted and show the technical feasibility of using plastic targets for such studies, although weather precluded successful TM data acquisition. Tapes for six LANDSAT 4 TM scenes were acquired and data processing began. Computer enhanced TM simulator and LANDSAT 4 TM data were compared for a porphyry copper deposit in Southern Arizona. Preliminary analyses performed on two TM scenes acquired in the CCT-PT format, show the TM data appear to contain a marked increase in geologically useful information; however, a number of instrumental processing artifacts may well limit the ability of the geologist to fully extract this information.

Paley, H. N.↗
NASA NTRS1984

Preliminary Comparisons of the Information Content and Utility of TM Versus MSS Data

Comparisons were made between subscenes from the first TM scene acquired of the Washington, D.C. area and a MSS scene acquired approximately one year earlier. Three types of analyses were conducted to compare TM and MSS data: a water body analysis, a principal components analysis and a spectral clustering analysis. The water body analysis compared the capability of the TM to the MSS for detecting small uniform targets. Of the 59 ponds located on aerial photographs 34 (58%) were detected by the TM with six commission errors (15%) and 13 (22%) were detected by the MSS with three commission errors (19%). The smallest water body detected by the TM was 16 meters; the smallest detected by the MSS was 40 meters. For the principal components analysis, means and covariance matrices were calculated for each subscene, and principal components images generated and characterized. In the spectral clustering comparison each scene was independently clustered and the clusters were assigned to informational classes. The preliminary comparison indicated that TM data provides enhancements over MSS in terms of (1) small target detection and (2) data dimensionality (even with 4-band data). The extra dimension, partially resultant from TM band 1, appears useful for built-up/non-built-up area separation.

Markham, B. L.↗
NASA NTRS1985

Characterization of LANDSAT-4 TM and MSS Image Quality for the Interpretation of California's Agricultural Resources

The quality of LANDSAT-4 MSS and TM data was determined by analyzing TM spectral and spatial performance in terms of spectral variability of natural targets and the TM-ground instantaneous field-of-view (IFOV) variability in level and mountainous terrain; and by assessing the suitability of TM and MSS image products for characterizing renewable resourse features. The TM data should be extremelly valuable for crop type and area proportion estimation; undating agricultural land use survey maps at 1:24,000 scale and smaller, field boundary definition; and determining the size and location of individual farmsteads. Ongoing research activities are focused on making spectral and spatial analyses of both MSS and TM analytical film products. The improved spectral, spatial, and radiometric quality of the TM data, should promote a renewed emphasis and interest in direct visual interpretation of these image products, both for updating and improving land stratification in support of resource inventory and for enhancing the image analyst's contribution to computer-assisted analysis procedures.

Degloria, S. D.↗
NASA NTRS1985

Preliminary Evaluation of TM for Soils Information

The capability of the LANDSAT TM for providing information for soil association maps and for detecting soil properties (variability within vegetated fields) was assessed using TM imagery of fields in Mississippi County, Arkansas that were planted with rice, cotton, and soybeans. Results indicate that the TM bands are providing information that is related to the soil properties within the field. Over large areas, these bands also appear to provide information that is related to the soil properties that are important to plant condition. While these results are only an indication of the information that TM can provide, they do indicate the TM data--especially, the mid-TR and thermal bands--show the capability for separating vegetated soil landscapes on a broad basis. The analysis at the field level with a growing crop also indicates that TM, with its additional and narrower bands and improved spatial and radiometric resolution is influenced by within field variability due to soils that has to be accounted for in the analysis of TM data.

Thompson, D. R.↗
NASA NTRS1997

Use of the Aromascan(TM) Instrument for Nonsubjective Evaluation of Rodent Spaceflight Hardware

This report describes the verification and utilization of the AromaScan(TM) (Hollis, NH) instrument for the ground-based evaluation of odor containment by various spaceflight habitats developed at NASA's Ames Research Center (ARC). The AromaScan(TM) instrument is an electronic odor detection system consisting of 32 polymer sensors that respond differentially to 10 different chemical groups present in an air sample. The AromaScan(TM) system also includes neural network software for constructing a database of known odors, against which an unknown odor can be compared. At present, the standard method for characterizing rodent odor containment during the development and testing of spaceflight hardware is the use of a human odor assessment panel. However, this can be a very time consuming and costly process, and the results are inherently subjective. The AromaScan(TM) system should produce more consistent and objective results, as well as a cost savings in the long term. To test and verify the AromaScan(TM) instrument, daily air samples will be collected from the exhaust port of rodent habitats, during experiment development tests, then injected into the instrument and used to create a database of recognizable odors. Human sniff tests will be performed in conjunction with the AromaScan(TM) analysis, and the results will be correlated. We will then teach the neural network to differentiate between an acceptable and an unacceptable odor profile, as defined by the human sniff test, and to be able to accurately identify an odor that would not pass a sniff panel. The results of our efforts will be to verify that the AromaScan(TM) system is a valuable alternative to human sniff panel assessments for the early iterative process of designing and testing rodent waste filters for spaceflight. Acceptance by a human panel will remain one of the final criteria for successful rodent habitat development.

Scribner, K. A.↗
DOE OSTI2020

Materials Data on Tm(BC)2 by Materials Project

Tm(BC)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Tm–B bond lengths are 2.71 Å. All Tm–C bond lengths are 2.65 Å. B is bonded in a distorted trigonal planar geometry to four equivalent Tm and three equivalent C atoms. There is one shorter (1.52 Å) and two longer (1.60 Å) B–C bond length. C is bonded in a 3-coordinate geometry to four equivalent Tm and three equivalent B atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(FeB)2 by Materials Project

Tm(FeB)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent B atoms. All Tm–Fe bond lengths are 2.92 Å. All Tm–B bond lengths are 2.72 Å. Fe is bonded to four equivalent Tm and four equivalent B atoms to form a mixture of edge, face, and corner-sharing FeTm4B4 tetrahedra. All Fe–B bond lengths are 2.11 Å. B is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Fe, and one B atom. The B–B bond length is 2.33 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(FeGe)2 by Materials Project

Tm(FeGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent Ge atoms. All Tm–Fe bond lengths are 3.22 Å. All Tm–Ge bond lengths are 3.07 Å. Fe is bonded to four equivalent Tm and four equivalent Ge atoms to form a mixture of distorted face, edge, and corner-sharing FeTm4Ge4 tetrahedra. All Fe–Ge bond lengths are 2.35 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Fe, and one Ge atom. The Ge–Ge bond length is 2.56 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(GeRh)2 by Materials Project

Tm(RhGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Ge atoms. All Tm–Rh bond lengths are 3.30 Å. All Tm–Ge bond lengths are 3.17 Å. Rh is bonded to four equivalent Tm and four equivalent Ge atoms to form a mixture of distorted edge, face, and corner-sharing RhTm4Ge4 tetrahedra. All Rh–Ge bond lengths are 2.46 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Rh, and one Ge atom. The Ge–Ge bond length is 2.48 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(GeRu)2 by Materials Project

Tm(RuGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Ru and eight equivalent Ge atoms. All Tm–Ru bond lengths are 3.25 Å. All Tm–Ge bond lengths are 3.27 Å. Ru is bonded in a 4-coordinate geometry to four equivalent Tm and four equivalent Ge atoms. All Ru–Ge bond lengths are 2.44 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Ru, and one Ge atom. The Ge–Ge bond length is 2.54 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(SiPd)2 by Materials Project

Tm(PdSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent Si atoms. All Tm–Pd bond lengths are 3.24 Å. All Tm–Si bond lengths are 3.14 Å. Pd is bonded to four equivalent Tm and four equivalent Si atoms to form a mixture of distorted corner, edge, and face-sharing PdTm4Si4 tetrahedra. All Pd–Si bond lengths are 2.46 Å. Si is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Pd, and one Si atom. The Si–Si bond length is 2.30 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(SiRh)2 by Materials Project

Tm(RhSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Si atoms. All Tm–Rh bond lengths are 3.20 Å. All Tm–Si bond lengths are 3.11 Å. Rh is bonded to four equivalent Tm and four equivalent Si atoms to form a mixture of distorted corner, edge, and face-sharing RhTm4Si4 tetrahedra. All Rh–Si bond lengths are 2.40 Å. Si is bonded in a 9-coordinate geometry to four equivalent Tm, four equivalent Rh, and one Si atom. The Si–Si bond length is 2.40 Å.

36 MATERIALS SCIENCE↗