Science.gov

Sample records for 3m empore carbon

  1. 3M Empore(R)-Membrane Filter Technology: Cesium Removal from Fuel Storage Water Basin

    SciTech Connect

    Oji, L.N.

    2003-07-15

    This paper describes results from a seven-day demonstration of the use of 3M Empore(R) membrane filter loaded with ion exchange material (potassium cobalt hexacynoferrate) for cesium uptake from the R-Disassembly Basin at the Savannah River Site. The goal of the demonstration was to evaluate the ability of the Process Absorber Development unit, a water pre-filtration /CoHex configuration on a skid, to remove cesium from R-Disassembly Basin at a linear processing flow rate of 22.9 liters per minute (1,204 liters/minute/m2). Over 210,000 liters of R-Disassembly Basin water was processed through the PADU without a cesium breakthrough, that is, the effluent after treatment with CoHex, contained less than detectable amounts of radioactive cesium. Some of the observed advantages of the Empore(R) membrane filter technology over conventional packed column ion exchange systems include rapid flow rates without channeling effects, low volume secondary waste and fast extraction or rapid kinetics per unit of flow.

  2. Experimental investigation of the phase equilibria in the carbon dioxide-propane-3 M MDEA system

    SciTech Connect

    Jou, F.Y.; Mather, A.E.; Otto, F.D.; Carroll, J.J.

    1995-07-01

    The treating of liquefied petroleum gas (LPG) to remove carbon dioxide and hydrogen sulfide using aqueous alkanolamine solutions is an important aspect of gas processing. One of the amines used in the natural gas industry is methyldiethanolamine (MDEA). Measurements of the phase equilibria in the carbon dioxide-propane-3 M MDEA system have been made at 25 and 40 C at pressures up to 15.5 MPa. Vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria were determined. The vapor-liquid equilibrium data were compared with the model of Deshmukh and Mather.

  3. Event monitoring of herbicides with naked and membrane-covered Empore disk integrative passive sampling devices.

    PubMed

    Stephens, B Scott; Kapernick, Anita P; Eaglesham, Geoff; Mueller, Jochen F

    2009-08-01

    Subsequent to an initial wet season flood event in the Brisbane River, Australia, both fast (naked disk) and slow (membrane-covered) variants of SDB-RPS Empore disk passive sampling devices were deployed with an automated grab sampling program. A trend increase in the aquatic dissolved concentrations of diuron and simazine was observed over a 10-day period. Kinetic and equilibrium parameters for each sampler were calculated based on the dynamic concentration. Absolute percent difference for duplicate passive samples was <10% in the fast and <25% in the slow samplers. For kinetic sampling, significantly shortened integrative periods are available with the fast compared with the slow variant, with higher sampling rates offering improved detection limits. The study demonstrates a method for determining kinetic parameters of passive samplers in a variable concentration field deployment, and illustrates the differences in quality between active and passive data, in terms of capturing changes in concentration associated with rainfall events. PMID:19520390

  4. Application of Empore C-8 extraction disks for screening urine in systematic toxicological analysis.

    PubMed

    Ensing, K; Franke, J P; Temmink, A; Chen, X H; de Zeeuw, R A

    1992-03-01

    Solid-phase extraction (SPE) by means of disposable columns has become a widely accepted technique for sample pretreatment in toxicology, both for directed analyses and for screening analyses. However, the sample capacity in SPE is usually limited to a few millilitres. Therefore, we have investigated to what extent these problems can be overcome by using Empore extraction disks, consisting of chemically modified C-8 reversed-phase silica, embedded in an inert polytetrafluoroethylene (PTFE) matrix. Human urine was selected as the matrix and dexetimide and mepyramine were initially used as test drugs because these drugs were available in tritiated form. Additional drugs investigated included codeine, hexobarbital, imipramine, methamphetamine, and nitrazepam. In these investigations, the sample capacity for untreated urine was at least 25 mL, and analyte quantities up to 250 micrograms could be retained by these filters. Washing with water/methanol mixtures was successful in removing substantial amounts of endogenous interferences, and methanol proved to be an acceptable eluent. Thus, these disks seem to have interesting potential for toxicological analysis in that sample concentration and cleanup can be achieved at the same time. PMID:1354247

  5. Rapid sampling using 3M membrane technology. Innovative Technology Summary Report

    SciTech Connect

    2000-01-01

    The 3M-Empore (TM) High Performance Extraction Disks have become the solid-phase extraction industry standard for meeting U.S. EPA requirements for water analysis of various analytes, including Cs, Sr, Ra, Tc, and U as well as several non-radionuclides including Pb, Hg, Sb, and As. These disks utilize adsorbing particles embedded in a membrane, greatly simplifying radiometric sampling and analysis. After liquid samples are passed through the disks, the disks are placed onto planchets or into liquid-scintillation vials for radiometric counting. For field use they are available in Rapid Liquid Sampler (RLS) form; this is a rugged, color-coded, disposable plastic holder (2-1/8' diameter), which readily adapts Rad Disks to commercial devices such as the Isco field sampler and 3M attended field sampler.

  6. The use of 3M porous polymer extraction discs in assessing protective clothing chemical permeation.

    PubMed

    Vo, E; Berardinelli, S P; Boeniger, M

    2001-07-01

    The aim of the study was to assess the use of 3M porous polymer extraction discs (3M Empore sorbent filters) for detection of chemical permeation of protective clothing. Analysis of some commonly used solvents on 3M Empore sorbent filters was performed for methanol, acetone, trichloroethylene (TriCE), and toluene by solvent desorption and gas chromatography. All solvents exhibited >98 percent adsorption on the filters at a spiking level of 1.8 microL for each solvent. Solvent recovery for the system was calculated for each solvent, ranging from 72-94 percent (RSD < or = 4.0%) for all solvents over the spiking range 0.2-1.8 microL. The modified ASTM F739 method was used to determine breakthrough times for five protective glove materials (polyvinyl chloride, natural rubber, polymerized alkene, nitrile, and nitrile butyl rubber) using the model solvents as test chemicals. Breakthrough times for each type of protective glove were determined, and found to range from 36 s to 9 min for acetone, from 142 s to 52 min for methanol, from 18 s to 12 min for TriCE, and from 32 s to 28 min for toluene. The quantitative mass of the solvents on the filters at the time of breakthrough detection ranged from 150-159, 157-166, 570-581, and 371-382 microg/cm2 for acetone, methanol, TriCE, and toluene, respectively. The sorbent filter should find utility in collecting chemical permeation samples through protective gloves in both laboratory and field studies for quantitative analysis. PMID:11458919

  7. σ-Aromatic cyclic M3(+) (M = Cu, Ag, Au) clusters and their complexation with dimethyl imidazol-2-ylidene, pyridine, isoxazole, furan, noble gases and carbon monoxide.

    PubMed

    Pan, Sudip; Saha, Ranajit; Mandal, Subhajit; Chattaraj, Pratim K

    2016-04-28

    The σ-aromaticity of M3(+) (M = Cu, Ag, Au) is analyzed and compared with that of Li3(+) and a prototype σ-aromatic system, H3(+). Ligands (L) like dimethyl imidazol-2-ylidene, pyridine, isoxazole and furan are employed to stabilize these monocationic M3(+) clusters. They all bind M3(+) with favorable interaction energy. Dimethyl imidazol-2-ylidene forms the strongest bond with M3(+) followed by pyridine, isoxazole and furan. Electrostatic contribution is considerably more than that of orbital contribution in these M-L bonds. The orbital interaction arises from both L → M σ donation and L ← M back donation. M3(+) clusters also bind noble gas atoms and carbon monoxide effectively. In general, among the studied systems Au3(+) binds a given L most strongly followed by Cu3(+) and Ag3(+). Computation of the nucleus-independent chemical shift (NICS) and its different extensions like the NICS-rate and NICS in-plane component vs. NICS out-of-plane component shows that the σ-aromaticity in L bound M3(+) increases compared to that of bare clusters. The aromaticity in pyridine, isoxazole and furan bound Au3(+) complexes is quite comparable with that in the recently synthesized Zn3(C5(CH3)5)3(+). The energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital also increases upon binding with L. The blue-shift and red-shift in the C-O stretching frequency of M3(CO)3(+) and M3(OC)3(+), respectively, are analyzed through reverse polarization of the σ- and π-orbitals of CO as well as the relative amount of OC → M σ donation and M → CO π back donation. The electron density analysis is also performed to gain further insight into the nature of interaction. PMID:26624276

  8. Application of the Empore solid-phase extraction membrane to the isolation of drugs from blood. I. Amiodarone and desethylamiodarone.

    PubMed

    Lensmeyer, G L; Wiebe, D A; Doran, T

    1991-05-01

    We describe the use of a new form of solid-phase material, the Empore solid-phase extraction membrane (SPEM), for therapeutic drug monitoring. We evaluated the new extraction procedure with the companion high-performance liquid chromatographic (HPLC) method for the antiarrhythmic drug amiodarone and its metabolite, desethylamiodarone, in patients' serum. Acidified serum (250 microliters) was passed through an octyl (C8) SPEM secured in an MF-1 microfilter unit. Serum proteins and potential interferences were removed with an acetonitrile:water wash, and the retained drugs eluted with HPLC mobile phase. This eluate was injected directly onto the analytical column. Both drugs averaged 85% recovery with a linear response from a lower limit of detection at 0.05 mg/L up to 6 mg/L, and between-run precision coefficients of variation ranging from 3.1 to 6.4% over the concentration range of 0.5-3.0 mg/L. We observed significant advantages of the novel SPEM over conventional liquid-liquid or large-particle size solid-phase sorbents packed in cartridges. Minimal amounts of solvents were required, elution volume was smaller, time-consuming evaporating/concentrating steps that can influence drug stability were avoided, and little throw-away material was generated. Only the small membrane was discarded. PMID:1926279

  9. Spin Hamiltonian parameters and local structures for Co 2+ ions in calcite-type trigonal carbonates MCO 3 (M=Co, Cd and Ca)

    NASA Astrophysics Data System (ADS)

    Wen-Chen, Zheng; Shao-Yi, Wu; Hui-Ning, Dong; Sheng, Tang

    2004-01-01

    From the perturbation formulas based on the cluster approach for 3d 7 ion in trigonal octahedral sites of crystals, the spin Hamiltonian parameters ( g factors g , g⊥ and hyperfine structure constants A , A⊥) for Co 2+ in calcite-type MCO 3 (M=Co, Cd, Ca) crystals are calculated. In the calculations, for CoCO 3 crystal, the structural data of pure crystal are used, whereas for the Co 2+-doped CdCO 3 and CaCO 3 crystals, the local structural data caused by the impurity-induced local lattice relaxation are considered. The calculated results show good agreement with the observed values obtained from electron paramagnetic and antiferromagnetic resonance experiments. The difficulty shown in the previous paper related to the g⊥ value of CoCO 3 obtained from the change of the g factor as a function of the crystallographic data (i.e., the unit cell parameters) a0 and α0 of pure MCO 3 crystals is removed.

  10. Short communication: a new dataset for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region

    NASA Astrophysics Data System (ADS)

    Hugelius, G.; Tarnocai, C.; Bockheim, J. G.; Camill, P.; Elberling, B.; Grosse, G.; Harden, J. W.; Johnson, K.; Jorgenson, T.; Koven, C. D.; Kuhry, P.; Michaelson, G.; Mishra, U.; Palmtag, J.; Ping, C.-L.; O'Donnell, J.; Schirrmeister, L.; Schuur, E. A. G.; Sheng, Y.; Smith, L. C.; Strauss, J.; Yu, Z.

    2013-04-01

    High latitude terrestrial ecosystems are key components in the global carbon (C) cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (18.7 × 106 km2). The NCSCD is a digital Geographical Information systems (GIS) database compiled from harmonized regional soil classification maps, in which data on soil coverage has been linked to pedon data from the northern permafrost regions. Previously, the NCSCD has been used to calculate SOC content (SOCC) and mass (SOCM) to the reference depths 0-30 cm and 0-100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100-300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon dataset for SOCC in deep soils of the northern circumpolar permafrost regions, with separate datasets for the 100-200 cm (524 pedons) and 200-300 cm (356 pedons) depth ranges. These pedons have been grouped into the American and Eurasian sectors and the mean SOCC for different soil taxa (subdivided into Histels, Turbels, Orthels, Histosols, and permafrost-free mineral soil taxa) has been added to the updated NCSCDv2. The updated version of the database is freely available online in several different file formats and spatial resolutions that enable spatially explicit usage in e.g. GIS and/or terrestrial ecosystem models. The potential applications and limitations of the NCSCDv2 in spatial analyses are briefly discussed. An open access data-portal for all the described GIS-datasets is available online at: http://dev1.geo.su.se/bbcc/dev/v3/ncscd/download.php. The NCSCDv2

  11. A new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region

    NASA Astrophysics Data System (ADS)

    Hugelius, G.; Bockheim, J. G.; Camill, P.; Elberling, B.; Grosse, G.; Harden, J. W.; Johnson, K.; Jorgenson, T.; Koven, C. D.; Kuhry, P.; Michaelson, G.; Mishra, U.; Palmtag, J.; Ping, C.-L.; O'Donnell, J.; Schirrmeister, L.; Schuur, E. A. G.; Sheng, Y.; Smith, L. C.; Strauss, J.; Yu, Z.

    2013-12-01

    High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0-30 cm and 0-100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100-300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m-2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100-200 cm (524 pedons) and 200-300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100-300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin

  12. A new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region

    USGS Publications Warehouse

    Hugelius, G.; Bockheim, J.G.; Camill, P.; Elberling, B.; Grosse, G.; Harden, J.W.; Johnson, K.; Jorgenson, T.; Koven, C.D.; Kuhry, P.; Michaelson, G.; Mishra, U.; Palmtag, J.; Ping, C.-L.; O'Donnell, J.; Schirrmeister, L.; Schuur, E.A.G.; Sheng, Y.; Smith, L.C.; Strauss, J.; Yu, Z.

    2013-01-01

    High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m-2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas

  13. Creating breakthroughs at 3M.

    PubMed

    von Hippel, E; Thomke, S; Sonnack, M

    1999-01-01

    Most senior managers want their product development teams to create break-throughs--new products that will allow their companies to grow rapidly and maintain high margins. But more often they get incremental improvements to existing products. That's partly because companies must compete in the short term. Searching for breakthroughs is expensive and time consuming; line extensions can help the bottom line immediately. In addition, developers simply don't know how to achieve breakthroughs, and there is usually no system in place to guide them. By the mid-1990s, the lack of such a system was a problem even for an innovative company like 3M. Then a project team in 3M's Medical-Surgical Markets Division became acquainted with a method for developing breakthrough products: the lead user process. The process is based on the fact that many commercially important products are initially thought of and even prototyped by "lead users"--companies, organizations, or individuals that are well ahead of market trends. Their needs are so far beyond those of the average user that lead users create innovations on their own that may later contribute to commercially attractive breakthroughs. The lead user process transforms the job of inventing breakthroughs into a systematic task of identifying lead users and learning from them. The authors explain the process and how the 3M project team successfully navigated through it. In the end, the team proposed three major new product lines and a change in the division's strategy that has led to the development of breakthrough products. And now several more divisions are using the process to break away from incrementalism. PMID:10621267

  14. Genetics Home Reference: 3-M syndrome

    MedlinePlus

    ... Understand Genetics Home Health Conditions 3-M syndrome 3-M syndrome Enable Javascript to view the expand/ ... boxes. Download PDF Open All Close All Description 3-M syndrome is a disorder that causes short ...

  15. SAGE III/Meteor - 3M

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Full view of the SAGE III Bench Checkout Unit, Collimated Source Bench (CSB), Portable Image Generator (PIG) on tripod, and Stratospheric Aerosol Gastropheric Experiment (SAGE)/Meteor - 3M flight instrument. Photographed in building 1250, 40 foot clean room.

  16. SAGE III/Meteor - 3M

    NASA Technical Reports Server (NTRS)

    1999-01-01

    From left to right: Richard Rawls, Chip Holloway, and Art Hayhurst standing next to the Stratospheric Aerosol Gastropheric Experiment (SAGE)/Meteor - 3M flight instrument. Photographed in building 1250, 40 foot clean room.

  17. SAGE III/Meteor - 3M

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Back view of the SAGE III Bench Checkout Unit, Portable Image Generator (PIG) on tripod, and the Stratospheric Aerosol Gastropheric Experiment (SAGE)/Meteor - 3M flight instrument. Photographed in building 1250, 40 foot clean room.

  18. The Block-P 3M algorithm

    NASA Astrophysics Data System (ADS)

    Eastwood, J. W.

    2008-07-01

    The Block-P 3M algorithm is a new development of the P 3M (particle-particle/particle-mesh) method [J. Eastwood, Optimal P 3M algorithms for molecular dynamics simulations, in: M. Hooper (Ed.), Computational Methods in Classical and Quantum Physics, Advance Publications Ltd, 1976, pp. 206-228; R. Hockney, J. Eastwood, Computer Simulation using Particles, McGraw-Hill, 1981 (Student Ed., Adam-Hilger, 1988)] for boundary integral and N-body calculations. It gives O(NlogN) complexity and O(N) storage of action-at-a-distance convolution sums for non-uniform distributions of sources and for any displacement invariant Green's function. It gives optimal accuracy and, unlike the Fast Multipole Method, it does not suffer from low frequency breakdown problems.

  19. "Scrubbing" Data for D3M

    ERIC Educational Resources Information Center

    Mercurius, Neil

    2005-01-01

    Data-driven decision-making (D3M) appears to be the new buzz phrase for this century, the information age. On the education front, teachers and administrators are engaging in data-centered dialog in grade-level meetings, lounges, hallways, and classrooms as they brainstorm toward closing the gap in student achievement. Clearly, such discussion…

  20. In situ formation of oxygen vacancy in perovskite Sr0.95Ti0.8Nb0.1M0.1O3 (M = Mn, Cr) toward efficient carbon dioxide electrolysis

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Xie, Kui; Wei, Haoshan; Qin, Qingqing; Qi, Wentao; Yang, Liming; Ruan, Cong; Wu, Yucheng

    2014-11-01

    In this work, redox-active Mn or Cr is introduced to the B site of redox stable perovskite Sr0.95Ti0.9Nb0.1O3.00 to create oxygen vacancies in situ after reduction for high-temperature CO2 electrolysis. Combined analysis using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis confirms the change of the chemical formula from oxidized Sr0.95Ti0.9Nb0.1O3.00 to reduced Sr0.95Ti0.9Nb0.1O2.90 for the bare sample. By contrast, a significant concentration of oxygen vacancy is additionally formed in situ for Mn- or Cr-doped samples by reducing the oxidized Sr0.95Ti0.8Nb0.1M0.1O3.00 (M = Mn, Cr) to Sr0.95Ti0.8Nb0.1M0.1O2.85. The ionic conductivities of the Mn- and Cr-doped titanate improve by approximately 2 times higher than bare titanate in an oxidizing atmosphere and 3-6 times higher in a reducing atmosphere at intermediate temperatures. A remarkable chemical accommodation of CO2 molecules is achieved on the surface of the reduced and doped titanate, and the chemical desorption temperature reaches a common carbonate decomposition temperature. The electrical properties of the cathode materials are investigated and correlated with the electrochemical performance of the composite electrodes. Direct CO2 electrolysis at composite cathodes is investigated in solid-oxide electrolyzers. The electrode polarizations and current efficiencies are observed to be significantly improved with the Mn- or Cr-doped titanate cathodes.

  1. In situ formation of oxygen vacancy in perovskite Sr(0.95)Ti(0.8)Nb(0.1)M(0.1)O3 (M = Mn, Cr) toward efficient carbon dioxide electrolysis.

    PubMed

    Zhang, Jun; Xie, Kui; Wei, Haoshan; Qin, Qingqing; Qi, Wentao; Yang, Liming; Ruan, Cong; Wu, Yucheng

    2014-01-01

    In this work, redox-active Mn or Cr is introduced to the B site of redox stable perovskite Sr(0.95)Ti(0.9)Nb(0.1)O3.00 to create oxygen vacancies in situ after reduction for high-temperature CO2 electrolysis. Combined analysis using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis confirms the change of the chemical formula from oxidized Sr(0.95)Ti(0.9)Nb(0.1)O3.00 to reduced Sr(0.95)Ti(0.9)Nb(0.1)O2.90 for the bare sample. By contrast, a significant concentration of oxygen vacancy is additionally formed in situ for Mn- or Cr-doped samples by reducing the oxidized Sr(0.95)Ti(0.8)Nb(0.1)M(0.1)O3.00 (M = Mn, Cr) to Sr(0.95)Ti(0.8)Nb(0.1)M0.1O2.85. The ionic conductivities of the Mn- and Cr-doped titanate improve by approximately 2 times higher than bare titanate in an oxidizing atmosphere and 3-6 times higher in a reducing atmosphere at intermediate temperatures. A remarkable chemical accommodation of CO2 molecules is achieved on the surface of the reduced and doped titanate, and the chemical desorption temperature reaches a common carbonate decomposition temperature. The electrical properties of the cathode materials are investigated and correlated with the electrochemical performance of the composite electrodes. Direct CO2 electrolysis at composite cathodes is investigated in solid-oxide electrolyzers. The electrode polarizations and current efficiencies are observed to be significantly improved with the Mn- or Cr-doped titanate cathodes. PMID:25403738

  2. Fabrication and metrology study for M3M of TMT

    NASA Astrophysics Data System (ADS)

    Luo, Xiao

    2014-09-01

    The M3M (Mirror 3 Mirror) of TMT (Thirty Meter Telescope) project is a3.5m×2.5m solid flat elliptical mirror. CIOMP is responsible for the fabrication of the M3M. A primary study on the fabrication and metrology is done in the past 2 years, and this paper introduces our work on the project. The fabrication strategy is based on large orbital tools and a plan combining with multiple measure methods is developed based on the requirement of M3M. A concept of dualsupporting system is also studied in the program to reduce the effect of gravity deformation.

  3. Strategic stories: how 3M is rewriting business planning.

    PubMed

    Shaw, G; Brown, R; Bromiley, P

    1998-01-01

    Virtually all business plans are written as a list of bullet points. Despite the skill or knowledge of their authors, these plans usually aren't anything more than lists of "good things to do." For example: Increase sales by 10%. Reduce distribution costs by 5%. Develop a synergistic vision for traditional products. Rarely do these lists reflect deep thought or inspire commitment. Worse, they don't specify critical relationships between the points, and they can't demonstrate how the goals will be achieved. 3M executive Gordon Shaw began looking for a more coherent and compelling way to present business plans. He found it in the form of strategic stories. Telling stories was already a habit of mind at 3M. Stories about the advent of Post-it Notes and the invention of masking tape help define 3M's identity. They're part of the way people at 3M explain themselves to their customers and to one another. Shaw and his coauthors examine how business plans can be transformed into strategic narratives. By painting a picture of the market, the competition, and the strategy needed to beat the competition, these narratives can fill in the spaces around the bullet points for those who will approve and those who will implement the strategy. When people can locate themselves in the story, their sense of commitment and involvement is enhanced. By conveying a powerful impression of the process of winning, narrative plans can mobilize an entire organization. PMID:10179653

  4. The Role of Training at 3M Company

    ERIC Educational Resources Information Center

    Training and Development Journal, 1976

    1976-01-01

    The interview with L. W. Lehr, President of the U.S. Operation of the 3M Company, presents a management view of the company's training and development activities. The activities are based on behavior modification programs and organizational development approaches. (EC)

  5. Deployment of a Pair of 3 M telescopes in Utah

    SciTech Connect

    Finnegan, G.; Adams, B.; Butler, K.; Cardoza, J.; Colin, P.; Hui, C. M.; Kieda, D.; Kirkwood, D.; Kress, D.; Kress, M.; LeBohec, S.; McGuire, C.; Newbold, M.; Nunez, P.; Pham, K.

    2008-12-24

    Two 3 m telescopes are being installed in Grantsville Utah. They are intended for the testing of various approaches to the implementation of intensity interferometry using Cherenkov Telescopes in large arrays as receivers as well as for the testing of novel technology cameras and electronics for ground based gamma-ray astronomy.

  6. Stephen Hawking bags big new 3m physics prize

    NASA Astrophysics Data System (ADS)

    Johnston, Hamish

    2013-01-01

    A massive 3m in prize money has gone to the British cosmologist Stephen Hawking for his work on black holes, quantum gravity and the early universe. The award is one of two "special fundamental physics prizes" from the Fundamental Physics Prize Foundation, which was set up earlier this year by the Russian physicist-turned-entrepreneur Yuri Milner.

  7. Concerning neutral flux shielding in the U-3M torsatron

    SciTech Connect

    Dreval, N. B.

    2015-03-15

    The volume of the torsatron U-3M vacuum chamber is about 70 m{sup 3}, whereas the plasma volume is about 0.3 m{sup 3}. The large buffer volume of the chamber serves as a source of a substantial neutral flux into the U-3M plasma. A fraction of this flux falls onto the torsatron helical coils located in front of the plasma, due to which the dynamics of neutral influx into the plasma modifies. The shielding of the molecular flux from the buffer volume into the plasma is estimated using numerical calculations. Only about 10% of the incident flux reaches the plasma volume. Estimates show that about 20% of atoms escape beyond the helical coils without colliding with them. Under these conditions, the helical coils substantially affect the neutral flux. A discharge regime with a hot low-density plasma produced by a frame antenna is considered. The spatial distribution of the molecular density produced in this regime by the molecular flux from the chamber buffer volume after it has passed between the helical coils is calculated. The contributions of the fluxes emerging from the side and inner surfaces of the helical coils are considered. The calculations show that the shape of the spatial distribution of the molecular density differs substantially from the shape of the magnetic surfaces.

  8. Testing of the 3M Company Composite Conductor

    SciTech Connect

    Stovall, John P; Rizy, D Tom; Kisner, Roger A

    2010-10-01

    The 3M Company has developed a high-temperature low-sag conductor referred to as Aluminum-Conductor Composite-Reinforced or ACCR. The conductor uses an aluminum metal matrix material to replace the steel in conventional conductors. The objective of this work is to accelerate the commercial acceptance by electric utilities of this new conductor design by testing four representative conductor classes in controlled conditions. A unique facility called the Powerline Conductor Accelerated Testing (PCAT) Facility was built at ORNL for testing overhead conductors. The PCAT has been uniquely designed for testing overhead bare transmission line conductors at high currents and temperatures after they have been installed and tensioned to the manufacturer's specifications. The ability to operate a transmission line conductor in this manner does not exist elsewhere in the United States. Four classes of ACCR cable designed by the 3M Company have been successfully test at ORNL small, medium, large and small/compact. Based on these and other manufacturer tests, the 3M Company has successfully introduced the ACCR into the commercial market and has completed over twenty installations for utility companies.

  9. Concerning neutral flux shielding in the U-3M torsatron

    NASA Astrophysics Data System (ADS)

    Dreval, N. B.

    2015-03-01

    The volume of the torsatron U-3M vacuum chamber is about 70 m3, whereas the plasma volume is about 0.3 m3. The large buffer volume of the chamber serves as a source of a substantial neutral flux into the U-3M plasma. A fraction of this flux falls onto the torsatron helical coils located in front of the plasma, due to which the dynamics of neutral influx into the plasma modifies. The shielding of the molecular flux from the buffer volume into the plasma is estimated using numerical calculations. Only about 10% of the incident flux reaches the plasma volume. Estimates show that about 20% of atoms escape beyond the helical coils without colliding with them. Under these conditions, the helical coils substantially affect the neutral flux. A discharge regime with a hot low-density plasma produced by a frame antenna is considered. The spatial distribution of the molecular density produced in this regime by the molecular flux from the chamber buffer volume after it has passed between the helical coils is calculated. The contributions of the fluxes emerging from the side and inner surfaces of the helical coils are considered. The calculations show that the shape of the spatial distribution of the molecular density differs substantially from the shape of the magnetic surfaces.

  10. GAM observation in the TUMAN-3M tokamak

    NASA Astrophysics Data System (ADS)

    Bulanin, V. V.; Askinazi, L. G.; Belokurov, A. A.; Kornev, V. A.; Lebedev, V.; Petrov, A. V.; Tukachinsky, A. S.; Vildjunas, M. I.; Wagner, F.; Yashin, A. Yu

    2016-04-01

    Results of an experimental study of geodesic acoustic modes (GAM) in the TUMAN-3M tokamak are reported. With Doppler backscattering (DBS) the basic properties of the GAM such as frequency, conditions for the GAM existence and the GAM radial location have been identified. The two-frequency Doppler reflectometer system was employed to reveal an interplay between low frequency sheared poloidal rotation, ambient turbulence level and the GAM intensity. Bicoherence analysis of the DBS data evidences the presence of a nonlinear interaction between the GAM and plasma turbulence.

  11. 3M corporate incinerator environmental monitoring study and risk analysis

    SciTech Connect

    Stevens, J.B.; Elnabarawy, M.T.; Pilney, J.

    1998-12-31

    A one-year multi-media environmental monitoring study was performed around the 3M Cottage Grove Facility. Particulate metals from the 3M Corporate hazardous waste incinerator were the focus of the study. Two environmental media were of primary interest: area soil sampling was conducted to investigate the impact of past incinerator emissions on the environment, and ambient air monitoring was conducted to address current impacts. Over 180 soil samples were taken from both agricultural and forested land in the vicinity of the Facility. More than 25 chemical parameters were then quantified in the samples. The potential impacts of past emissions from the incinerator were assessed by comparing chemical concentrations from locations where incinerator impacts were expected to be greatest (based on air dispersion modeling) to chemical concentrations in matched samples from sites expected to be least impacted. The ambient air monitoring network consisted of six stations. Source-receptor modeling was used to determine the most likely contribution of the incinerator and six additional major area sources for the air monitoring (i.e. filter) data at each station. The model provided a best-fit analysis regarding the likely contributions of each source to the sample results. The results of these evaluations lead to the conclusion that the current emissions from this Facility do not present an unacceptable risk to human health.

  12. Hamline/3M Project: Liaison for Curricular Change

    NASA Astrophysics Data System (ADS)

    Rundquist, Andy

    2002-03-01

    This project was designed to catalyze curricular changes to better prepare students for the workplace. Industrial managers provided a list of 16 characteristics valued in the workplace: most were NOT related to science course content. The project formed 5 teams each including 3M professionals and students. Each team developed curricular changes in one of the 16 areas. Team goals were to improve skills in communication, data analysis, business/economics, team problem solving, and culture competency. Curricular changes realized include communication skill activities embodied in science courses and faculty communication teaching skill seminars, self learning tools in data analysis, statistics and model building, a new course developed with assistance from 3M personnel focussing on topics directly related to technological industries, high performance team problem solving training/coaching for faculty and workshops for students and faculty relative to importance of cultural competencies in the workplace, and a new course focusing on culture, team problem solving and conflict resolution in the technical workplace. Process for developing and content of curricular changes will be reported.

  13. Hamline/3M Corp. Project: Liason for Curricular Change*

    NASA Astrophysics Data System (ADS)

    Artz, Jerry L.

    2002-04-01

    This project was designed to catalyze curricular changes to better prepare students for the workplace. Industrial managers provided a list of 16 characteristics valued in the workplace; most were NOT related to science course content. The project formed 5 teams each including 3M professionals and students. Each team developed curricular changes in one of the 16 areas. Team goals were to improve skills in communication, data analysis, business/economics, team problem solving, and cultural competency. Curricular changes realized include communication skill activities embodied in science courses and faculty communication teaching skill seminars; self learning tools in data analysis, statistics and model building; a new course developed with assistance from 3M personnel focusing on topics directly related to technological industries; high performance team problem solving training/coaching for faculty; workshops for students and faculty relative to importance of cultural competencies in the workplace; and a new course focusing on culture, team problem solving and conflict resolution in the technical workplace. Process for developing and content of curricular changes will be reported. *Thanks to: NSF GOALI CHE-99010782

  14. Dinosaur extinction: closing the ‘3 m gap’

    PubMed Central

    Lyson, Tyler R.; Bercovici, Antoine; Chester, Stephen G. B.; Sargis, Eric J.; Pearson, Dean; Joyce, Walter G.

    2011-01-01

    Modern debate regarding the extinction of non-avian dinosaurs was ignited by the publication of the Cretaceous–Tertiary (K–T) asteroid impact theory and has seen 30 years of dispute over the position of the stratigraphically youngest in situ dinosaur. A zone devoid of dinosaur fossils reported from the last 3 m of the Upper Cretaceous, coined the ‘3 m gap’, has helped drive controversy. Here, we report the discovery of the stratigraphically youngest in situ dinosaur specimen: a ceratopsian brow horn found in a poorly rooted, silty, mudstone floodplain deposit located no more than 13 cm below the palynologically defined boundary. The K–T boundary is identified using three criteria: (i) decrease in Cretaceous palynomorphs without subsequent recovery, (ii) the existence of a ‘fern spike’, and (iii) correlation to a nearby stratigraphic section where primary extraterrestrial impact markers are present (e.g. iridium anomaly, spherules, shocked quartz). The in situ specimen demonstrates that a gap devoid of non-avian dinosaur fossils does not exist and is inconsistent with the hypothesis that non-avian dinosaurs were extinct prior to the K–T boundary impact event. PMID:21752814

  15. Testing of the 3M Company ACCR Conductor

    SciTech Connect

    Stovall, J.P.; RIzy, D.T.; Kisner, R.A.; Deve, H.E.

    2010-09-15

    The 3M Company has developed a high-temperature low-sag conductor referred to as Aluminum- Conductor Composite-Reinforced or ACCR. The conductor uses an aluminum metal matrix material to replace the steel in conventional conductors so the core has a lower density and higher conductivity. The objective of this work is to accelerate the commercial acceptance by electric utilities of these new conductor designs by testing four representative conductor classes in controlled conditions. Overhead transmission lines use bare aluminum conductor strands wrapped around a steel core strands to transmit electricity. The typical cable is referred to as aluminum-conductor steel-reinforced (ACSR). The outer strands are aluminum, chosen for its conductivity, low weight, and low cost. The center strand is of steel for the strength required to support the weight without stretching the aluminum due to its ductility. The power density of a transmission corridor has been directly increased by increasing the voltage level. Transmission voltages have increased from 115-kV to 765- kV over the past 80 years. In the United States, further increasing the voltage level is not feasible at this point in time, so in order to further increase the power density of a transmission corridor, conductor designs that increase the current carrying capability have been examined. One of the key limiting factors in the design of a transmission line is the conductor sag which determines the clearance of the conductor above ground or underlying structures needed for electrical safety. Increasing the current carrying capability of a conductor increases the joule heating in the conductor which increases the conductor sag. A conductor designed for high-temperature and lowsag operation requires an engineered modification of the conductor materials. To make an advanced cable, the 3M Company solution has been the development of a composite conductor consisting of Nextel ceramic fibers to replace the steel core and

  16. In vivo conductivity imaging of human knee using 3 mA injection current in MREIT

    NASA Astrophysics Data System (ADS)

    Jeong, W. C.; Kim, Y. T.; Minhas, A. S.; Lee, T. H.; Kim, H. J.; Nam, H. S.; Kwon, O.; Woo, E. J.

    2010-04-01

    Recent in vivo human leg MREIT experiments showed successful conductivity image reconstructions using carbon-hydrogel electrodes and optimized RF coils. However, it is still difficult to perform in vivo human and disease model animal experiments primarily due to a long scan time and high injection current of about 9 mA. Compared to previous MREIT pulse sequences, a newly developed multi-echo pulse sequence provides a higher SNR of MR magnitude image and better quality of magnetic flux density data. Unlike the human calf, the knee has sensitive nerve bundles and mainly consists of the bone. In this study, we tried to obtain high-resolution conductivity images of in vivo human knees using the multi-echo pulse sequence. We injected as much as 3 mA current in the form of an 81 ms pulse into the knee without producing a painful sensation and motion artifacts. Reconstructed conductivity images well distinguish different parts of the subcutaneous adipose tissue, muscle, synovial capsule, cartilage and bone inside the knee. Considering clinical applications, future work should be focused on in vivo human and disease model animal experiments.

  17. 3M's Model Rewards and Recognition Program Engages Employees and Drives Energy Savings Efforts

    SciTech Connect

    2010-06-11

    3M has implemented more than 1,900 employee-inspired projects that have realized a 22% improvement in energy efficiency and yielded $100 million in energy savings. This case study provides information about 3M's approach to energy efficiency.

  18. Qualification Of Kapton Pretreatment Process Using 3M Scotch Weld 2216 For Solar Panel Application

    NASA Astrophysics Data System (ADS)

    Swamy, B. R.; Krishna, Priya G.; Venkatesh, K.; Nagendra, H. R.; Nanjundaswamy, T. S.

    2011-10-01

    Substrates for solar arrays intended to be used on satellite systems are generally made of aluminum honeycomb structure sandwiched with Carbon Fiber Reinforced Plastic (CFRP) face skin. Two mil thick KaptonTM sheets are co cured on one side of the aluminum /CFRP composite structure while realizing the substrate panels. This Kapton sheet would serve as an insulator over which solar cell blankets are bonded with suitable adhesive for the satellite solar panels. The satellite solar panels demands highest degree of quality and reliability and one of the prime factors in this regards is the bond strength of adhesive which is used to bond the solar cell blankets. Various methods of pretreatments of Kapton surface are in use for increasing the surface energy, which in turn results in improved bond strengths. These methods generally provide roughened surface of the Kapton which is achieved either by abrasive means like scrubbing the surface using fine silica chip, or plasma etching or alternatively by an additive process wherein suitable polyester, phenolic or other resins are coated on to the Kapton surface to achieve the desired results. For spacecraft solar panel applications at ISRO, polyester resin coating on to the Kapton surface was used as pretreatment prior to adhesive application. This process had provided adequate bond strengths between the solar cells and Kapton. Due to issues related to the supply of the polyester resin material from the vendor alternative methods of pretreatments were explored. In this paper, a novel process developed for Kapton pretreatment is described along with results of relevant qualifications for the satellite solar panel application. This newly developed pretreatment process for Kapton successfully adopts an epoxy based material 3M Scotch weld 2216 which is widely used in spacecraft electronic hardware.

  19. Pre- and post-natal growth in two sisters with 3-M syndrome.

    PubMed

    Lugli, Licia; Bertucci, Emma; Mazza, Vincenzo; Elmakky, Amira; Ferrari, Fabrizio; Neuhaus, Christine; Percesepe, Antonio

    2016-04-01

    3-M syndrome (OMIM #273750) is a rare autosomal recessive growth disorder characterized by severe pre- and post-natal growth restriction, associated with minor skeletal abnormalities and dysmorphisms. Although the 3-M syndrome is well known as a primordial dwarfism, descriptions of the prenatal growth are missing. We report a family with variable phenotypic features of 3-M syndrome and we describe the prenatal and postnatal growth pattern of two affected sisters with a novel homozygous CUL7 mutation (c.3173-1G>C), showing a pre- and post-natal growth deficiency and a normal cranial circumference. PMID:26850509

  20. Magnetic and dielectric properties of metal organic frameworks [C(NH2)3]M(HCOO)3 (M = Mn, Co, Ni, Cu)

    NASA Astrophysics Data System (ADS)

    Ramdin, Daram; Yan, Liqin; Wu, Weida

    Multiferroic materials has been the subject of intense research activity in recent years due to its fundamental scientific interests as well as potential to applications. A few of the recently discovered multiferroics with metal-organic-frameworks (MOFs) show a coexistence of magnetism and ferroelectricity, such as ABX3-type [NH2(CH3)2]M(HCOO)3 (M = Mn, Fe). Compared to inorganic compounds, the high tunability of organic materials in building blocks and molecular functionalities may open up new routes to lead-free compounds exhibiting strong polarization. In this work, we investigate the multiferrocity and magnetoelectric coupling of a class of perovskite MOFs [C(NH2)3]M(HCOO)3 (M = Mn, Co, Ni, Cu). The [C(NH2)3]Cu(HCOO)3 compound was predicted and experimentally shown to be a hybrid improper ferroelectric because of Jahn-Teller distortions and tilting of the organic cation. Yet it is not clear whether other compounds are also multiferroics. We synthesize single crystals of these compounds. Preliminary results of magnetic and dielectric characterization will be presented. This work is supported by DOE BES under Award # DE-SC0008147.

  1. 115. JOB NO. 1347K, SHEET 3M, 1929/1930, FORD MOTOR COMPANY; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    115. JOB NO. 1347-K, SHEET 3M, 1929/1930, FORD MOTOR COMPANY; BOILER HOUSE ASSEMBLY PLANT; BOILER SETTING - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  2. 101. JOB NO. 1347F, SHEET 3M, 1927, ASSEMBLY BUILDING; FORD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    101. JOB NO. 1347-F, SHEET 3M, 1927, ASSEMBLY BUILDING; FORD MOTOR COMPANY; ONE-EIGHTH SCALE OF OFFICES - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  3. SAGE III Meteor-3M L2 Solar Event Species Profiles (Native) V003

    Atmospheric Science Data Center

    2016-06-14

    SAGE III Meteor-3M L2 Solar Event Species Profiles (Native) V003 Project Title:  SAGE III ... Data Pool V3 Parameters:  Aerosol Extinction Ozone Atmospheric Pressure Water Vapor Nitrogen Dioxide ...

  4. The LIULIN-3M Radiometer for Measuring Particle Doses in Space and on Aircraft

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Stauffer, C. A.; Dachev, T. P.; Brucker, G. J.; Tomov, B. T.; Dimitrov, P. G.

    1999-01-01

    This paper reports on the development of a compact radiation monitor/dosimeter, the LIULIN-3M, and on extended measurements conducted on the ground and on commercial aircraft on domestic and international flights.

  5. Measurements of Radiation Exposure on Commercial Aircraft with the LIULIN-3M Instrument

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Stauffer, C. A.; Dachev, T. P.; Brucker, G. J.; Tomov, B. T.; Dimitrov, P. G.

    1998-01-01

    This paper reports on the development of a compact radiation monitor/dosimeter, the LIULIN-3M, and on extended measurements conducted on the ground and on commercial aircraft on domestic and international flights.

  6. The LIULIN-3M Radiometer for Measuring Particle Doses in Space and on Aircraft

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Stauffer, C. A.; Dachev, T. P.; Tomov, B. T.; Dimitrov, P. G.; Brucker, G. J.; Obenschain, Art (Technical Monitor)

    2002-01-01

    This paper reports on the development of a compact radiation monitor/dosimeter, the LIULIN-3M, and on extended measurements conducted on the ground and on commercial aircraft on domestic and international flights.

  7. 3-M syndrome: a growth disorder associated with IGF2 silencing.

    PubMed

    Murray, P G; Hanson, D; Coulson, T; Stevens, A; Whatmore, A; Poole, R L; Mackay, D J; Black, G C M; Clayton, P E

    2013-01-01

    3-M syndrome is an autosomal recessive disorder characterised by pre- and post-natal growth restriction, facial dysmorphism, normal intelligence and radiological features (slender long bones and tall vertebral bodies). It is known to be caused by mutations in the genes encoding cullin 7, obscurin-like 1 and coiled-coil domain containing 8. The mechanisms through which mutations in these genes impair growth are unclear. The aim of this study was to identify novel pathways involved in the growth impairment in 3-M syndrome. RNA was extracted from fibroblast cell lines derived from four 3-M syndrome patients and three control subjects, hybridised to Affymetrix HU 133 plus 2.0 arrays with quantitative real-time PCR used to confirm changes found on microarray. IGF-II protein levels in conditioned cell culture media were measured by ELISA. Of the top 10 downregulated probesets, three represented IGF2 while H19 was identified as the 23rd most upregulated probeset. QRT-PCR confirmed upregulation of H19 (P<0.001) and downregulation of IGF2 (P<0.001). Levels of IGF-II secreted into conditioned cell culture medium were higher for control fibroblasts than those for 3-M fibroblasts (10.2±2.9 vs 0.6±0.9 ng/ml, P<0.01). 3-M syndrome is associated with a gene expression profile of reduced IGF2 expression and increased H19 expression similar to that found in Silver-Russell syndrome. Loss of autocrine IGF-II in the growth plate may be associated with the short stature seen in children with 3-M syndrome. PMID:24148222

  8. 3M Optical Videodisc Project: Part Two--Preparing the Premaster Tape.

    ERIC Educational Resources Information Center

    Troeltzsch, Lloyd

    1984-01-01

    This second article in a three-part series on 3M's Optical Videodisc Project deals with technical considerations involved in preparing premaster videotapes for laser videodisc mastering and replication. Premastering requirements at four levels of interactivity and considerations when transferring source materials from videotape and film are…

  9. CDKN3 mRNA as a Biomarker for Survival and Therapeutic Target in Cervical Cancer

    PubMed Central

    Barrón, Eira Valeria; Roman-Bassaure, Edgar; Sánchez-Sandoval, Ana Laura; Espinosa, Ana María; Guardado-Estrada, Mariano; Medina, Ingrid; Juárez, Eligia; Alfaro, Ana; Bermúdez, Miriam; Zamora, Rubén; García-Ruiz, Carlos; Gomora, Juan Carlos; Kofman, Susana; Pérez-Armendariz, E. Martha; Berumen, Jaime

    2015-01-01

    The cyclin-dependent kinase inhibitor 3 (CDKN3) gene, involved in mitosis, is upregulated in cervical cancer (CC). We investigated CDKN3 mRNA as a survival biomarker and potential therapeutic target for CC. CDKN3 mRNA was measured in 134 CC and 25 controls by quantitative PCR. A 5-year survival study was conducted in 121 of these CC patients. Furthermore, CDKN3-specific siRNAs were used to investigate whether CDKN3 is involved in proliferation, migration, and invasion in CC-derived cell lines (SiHa, CaSki, HeLa). CDKN3 mRNA was on average 6.4-fold higher in tumors than in controls (p = 8 x 10−6, Mann-Whitney). A total of 68.2% of CC patients over expressing CDKN3 gene (fold change ≥ 17) died within two years of diagnosis, independent of the clinical stage and HPV type (Hazard Ratio = 5.0, 95% CI: 2.5–10, p = 3.3 x 10−6, Cox proportional-hazards regression). In contrast, only 19.2% of the patients with lower CDKN3 expression died in the same period. In vitro inactivation of CDKN3 decreased cell proliferation on average 67%, although it had no effect on cell migration and invasion. CDKN3 mRNA may be a good survival biomarker and potential therapeutic target in CC. PMID:26372210

  10. A DS106 Thing Happened on the Way to the 3M Tech Forum

    ERIC Educational Resources Information Center

    Lockridge, Rochelle; Levine, Alan; Funes, Mariana

    2014-01-01

    This case study illustrates how DS106, a computer science course in Digital Storytelling from the University of Mary Washington (UMW) and accessible as an open course on the web, is being explored in a corporate environment at 3M, an American multinational corporation based in St. Paul, Minnesota, to build community, collaboration, and more…

  11. A Study of the Rating Structure Requirements for the Aviation 3M Data Analyst.

    ERIC Educational Resources Information Center

    Heinzel, Joseph R.; May, R. V., Jr.

    The purpose of this research was to determine the optimum means of identifying personnel qualified to perform Aviation 3M Data Analysis. Resolution of this objective involved the identification of numerous problem areas contributing to the instability of the Data Analysis work force and the scarcity of personnel in that work force. The approach…

  12. miR-155 targets Caspase-3 mRNA in activated macrophages.

    PubMed

    De Santis, Rebecca; Liepelt, Anke; Mossanen, Jana C; Dueck, Anne; Simons, Nadine; Mohs, Antje; Trautwein, Christian; Meister, Gunter; Marx, Gernot; Ostareck-Lederer, Antje; Ostareck, Dirk H

    2016-01-01

    To secure the functionality of activated macrophages in the innate immune response, efficient life span control is required. Recognition of bacterial lipopolysaccharides (LPS) by toll-like receptor 4 (TLR4) induces downstream signaling pathways, which merge to induce the expression of cytokine genes and anti-apoptotic genes. MicroRNAs (miRNAs) have emerged as important inflammatory response modulators, but information about their functional impact on apoptosis is scarce. To identify miRNAs differentially expressed in response to LPS, cDNA libraries from untreated and LPS-activated murine macrophages were analyzed by deep sequencing and regulated miRNA expression was verified by Northern blotting and qPCR. Employing TargetScan(TM) we identified CASPASE-3 (CASP-3) mRNA that encodes a key player in apoptosis as potential target of LPS-induced miR-155. LPS-dependent primary macrophage activation revealed TLR4-mediated enhancement of miR-155 expression and CASP-3 mRNA reduction. Endogenous CASP-3 and cleaved CASP-3 protein declined in LPS-activated macrophages. Accumulation of miR-155 and CASP-3 mRNA in miRNA-induced silencing complexes (miRISC) was demonstrated by ARGONAUTE 2 (AGO2) immunoprecipitation. Importantly, specific antagomir transfection effectively reduced mature miR-155 and resulted in significantly elevated CASP-3 mRNA levels in activated macrophages. In vitro translation assays demonstrated that the target site in the CASP-3 mRNA 3'UTR mediates miR-155-dependent Luciferase reporter mRNA destabilization. Strikingly, Annexin V staining of macrophages transfected with antagomir-155 and stimulated with LPS prior to staurosporine (SSP) treatment implied that LPS-induced miR-155 prevents apoptosis through CASP-3 mRNA down-regulation. In conclusion, we report that miR-155-mediated CASP-3 mRNA destabilization in LPS-activated RAW 264.7 macrophages suppresses apoptosis, as a prerequisite to maintain their crucial function in inflammation. PMID:26574931

  13. Assessment of zenith tropospheric delay derived from UNB3m model over Asia area

    NASA Astrophysics Data System (ADS)

    Huang, Liangke; Xie, Shaofeng; Liu, Lilong; Feng, Haiyang; Jiang, Maofang

    2015-12-01

    The tropospheric delay is one of the main errors for earth observation and a variety of radio navigation technologies, and the UNB3m model can be used to calculate the zenith tropospheric delay (ZTD) without any real measured meteorological data, which taking the major changes in water vapor profiles with latitude into account, and it widely applied in Wide Area Augmentation System in America. However, there are few researches carried out on the assessment of ZTD from UNB3m model over Asia area. In this study, three years of the ZTD data observed from 56 IGS (International GNSS service) sites distributed in Asia area is used to assess the effectiveness and accuracy of ZTD calculated from UNB3m model. The results are: (1) relative to IGS observed ZTD, the bias and root mean square (RMS) for ZTD calculated from UNB3m model are -0.1 cm and 6.0 cm, respectively. Besides, the bias shows significant periodic characteristics in Asia area. (2) The bias and RMS present seasonal variations, which generally show larger values in summer months. (3) The precision of ZTD calculated from UNB3m model increases with increasing altitude or latitude, and also the bias and RMS show inconsistently in different Asia areas. At last, the best results can be achieved in inland area where presents the mean yearly RMS of 2.4 cm. These results provide a reference for the study of the tropospheric delay correction model and the applications of real-time GNSS navigation and positioning.

  14. Exploring the spectrum of 3-M syndrome, a primordial short stature disorder of disrupted ubiquitination.

    PubMed

    Clayton, Peter E; Hanson, Dan; Magee, Lucia; Murray, Philip G; Saunders, Emma; Abu-Amero, Sayeda N; Moore, Gudrun E; Black, Graeme C M

    2012-09-01

    3-M syndrome is an autosomal recessive primordial growth disorder characterized by small birth size and post-natal growth restriction associated with a spectrum of minor anomalies (including a triangular-shaped face, flat cheeks, full lips, short chest and prominent fleshy heels). Unlike many other primordial short stature syndromes, intelligence is normal and there is no other major system involvement, indicating that 3-M is predominantly a growth-related condition. From an endocrine perspective, serum GH levels are usually normal and IGF-I normal or low, while growth response to rhGH therapy is variable but typically poor. All these features suggest a degree of resistance in the GH-IGF axis. To date, mutations in three genes CUL7, OBSL1 and CCDC8 have been shown to cause 3-M. CUL7 acts an ubiquitin ligase and is known to interact with p53, cyclin D-1 and the growth factor signalling molecule IRS-1, the link with the latter may contribute to the GH-IGF resistance. OBSL1 is a putative cytoskeletal adaptor that interacts with and stabilizes CUL7. CCDC8 is the newest member of the pathway and interacts with OBSL1 and, like CUL7, associates with p53, acting as a co-factor in p53-medicated apoptosis. 3-M patients without a mutation have also been identified, indicating the involvement of additional genes in the pathway. Potentially damaging sequence variants in CUL7 and OBSL1 have been identified in idiopathic short stature (ISS), including those born small with failure of catch-up growth, signifying that the 3-M pathway could play a wider role in disordered growth. PMID:22624670

  15. Relevance of the ligand exchange rate and mechanism of fac-[(CO)3M(H2O)3]+ (M = Mn, Tc, Re) complexes for new radiopharmaceuticals.

    PubMed

    Grundler, Pascal V; Helm, Lothar; Alberto, Roger; Merbach, André E

    2006-12-11

    The water exchange process on fac-[(CO)3Mn(H2O)3]+ and fac-[(CO)3Tc(H2O)3]+ was kinetically investigated by 17O NMR as a function of the acidity, temperature, and pressure. Up to pH 6.3 and 4.4, respectively, the exchange rate is not affected by the acidity, thus demonstrating that the contribution of the monohydroxo species fac-[(CO)3M(OH)(H2O)2] is not significant, which correlates well with a higher pKa for these complexes compared to the homologue fac-[(CO)3Re(H2O)3]+ complex. The water exchange rate K298ex/s(-1) (DeltaHex double dagger/kJ mol(-1); DeltaSex double dagger/J mol(-1) K(-1); DeltaV double dagger/cm3 mol-1) decreases down group 7 from Mn to Tc and Re: 23 (72.5; +24.4; +7.1) > 0.49 (78.3; +11.7; +3.8) > 5.4 x 10(-3) (90.3; +14.5; -). For the Mn complex only, an O exchange on the carbonyl ligand could be measured (K338co = 4.3 x 10(-6) s(-1)), which is several orders of magnitude slower than the water exchange. In the case of the Tc complex, the coupling between 17O (I = 5/2) and 99Tc (I = 9/2) nuclear spins has been observed (1J99Tc,17O = 80 +/- 5 Hz). The substitution of water in fac-[(CO)3M(H2O)3]+ by dimethyl sulfide (DMS) is slightly faster than that by CH3CN: 3 times faster for Mn, 1.5 times faster for Tc, and 1.2 times faster for Re. The pressure dependence behavior is different for Mn and Re. For Mn, the change in volume to reach the transition state is always clearly positive (water exchange, CH3CN, DMS), indicating an Id mechanism. In the case of Re, an Id/Ia changeover is assigned on the basis of reaction profiles with a strong volume maximum for pyrazine and a minimum for DMS as the entering ligand. PMID:17140248

  16. BaCO3: High-Temperature crystal Structures and the Pmcn → R3m Phase Transition at 811 Celius

    SciTech Connect

    Antao,S.; Hassan, I.

    2007-01-01

    The temperature (T) evolution of the barium carbonate (BaCO3) structure was studied using Rietveld structure refinements based on synchrotron X-ray diffraction and a powdered synthetic sample. BaCO3 transforms from an orthorhombic, Pmcn, a phase to a trigonal, R3m, {beta} phase at 811 C. The orthorhombic BaCO3 structure is isotypic with aragonite, CaCO3. In trigonal R3m BaCO3, the CO3 group occupies one orientation and shows no rotational disorder. The average distances increase while the distances decrease linearly with T in the orthorhombic phase. After the 811 C phase transition, the distances increase while C-O distances decrease. There is also a significant volume change of 2.8% at the phase transition.

  17. Stimulation of high-frequency breakdown of gas in Uragan-3M torsatron by runaway electrons

    NASA Astrophysics Data System (ADS)

    Tarasov, I. K.; Tarasov, M. I.; Sitnikov, D. A.; Pashnev, V. K.; Lytova, M. A.

    2016-01-01

    In experiments on confinement and heating of plasma in the Uragan-3M torsatron, the method of high-frequency breakdown of the working gas is used. In these experiments, in conditions of a relatively stable magnetic field, the rf power supplied to the setup chamber has a frequency close to the ion-cyclotron frequency. Such a method of gas breakdown is not always sufficiently reliable. In our experiments, preliminary ionization of the working gas by the run-away electron beam is used for stabilizing the breakdown. This work contains the results of experiments on enhancement of the runaway electron beam and on the interaction of the runaway electron beam in the Uragan-3M torsatron with the HF electromagnetic pump field. This enables us to formulate a number of recommendations for using spontaneously formed beams of accelerated particles for stimulating the rf breakdown. Our results confirm the possibility of gas breakdown by runaway electrons.

  18. Ultra Barrier Topsheet Film for Flexible Photovoltaics with 3M Company

    SciTech Connect

    Funkenbusch, Arnie; Ruth, Charles

    2014-12-30

    In this DOE sponsored program, 3M achieved the critical UBT features to enable durable flexible high efficiency modules to be produced by a range of customers who have now certified the 3M UBT and are actively developing said flexible modules. The specific objectives and accomplishments of the work under this program were; Scale-up the current Generation-1 UBT from 12” width, as made on 3M’s pilot line, to 1+meter width full-scale manufacturing, while maintaining baseline performance metrics (see table below); This objective was fully met; Validate service life of Generation-1 UBT for the 25+ year lifetime demanded by the photovoltaic market; Aggressive testing revealed potential failure modes in the Gen 1 UBT. Deficiencies were identified and corrective action taken in the Gen 2 UBT; Develop a Generation-2 UBT on the pilot line, targeting improved performance relative to baseline, including higher %T (percent transmission), lower water vapor transmission rate (WVTR) with targets based on what the technology needs for 25 year lifetime, proven lifetime of 25 years in solar module construction in the field, and lower cost; Testing of UBT Gen 2 under a wide range of conditions presented in this report failed to reveal any failure mode. Therefore UBT Gen 2 is known to be highly durable. 3M will continue to test towards statistically validating a 25 year lifetime under 3M funding; Transfer Generation-2 UBT from the pilot line to the full-scale manufacturing line within three years; and This objective was fully met.

  19. A 3 m. y. record of Pliocene-Pleistocene loess in interior Alaska

    SciTech Connect

    Westgate, J.A.; Stemper, B.A. ); Pewe, T.L. )

    1990-09-01

    Many distal tephra beds exist in the thick, fossiliferous loess deposits near Fairbanks interior Alaska. Isothermal plateau fission-track ages, determined on glass shards from tephra beds, in conjunction with tephrostratigraphic and magnetostratigraphic techniques, indicate that loess deposition began in the late Pliocene-an antiquity previously unsuspected. Hence, there is the opportunity now to reconstruct a detailed, well-dated record of environmental changes in interior Alaska during the past 3 m.y.

  20. Analysis of the Cyclotron Facility Calibration and Aircraft Results Obtained by LIULIN-3M Instrument

    NASA Technical Reports Server (NTRS)

    Dachev, T. P.; Stassinopoulos, E. G.; Tomov, B. T.; Dimitrov, P. G.; Matviichuk, Y. N.; Shurshakov, V. A.; Petrov, V. M.

    1998-01-01

    The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, which has been used on the NffR space station in the 1988-1994 time period, The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and 1 cm(exp 2) area is used in the instrument. Pulse high analysis technique is used for measurement of the energy losses in the detector. The final data sets from the instrument are the flux and the dose rate for the exposition time and 256 channels of LET spectra if a non-nal coincidence of the particles to the detector is considered. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and was used for space radiation measurements during commercial aircraft flights. Obtained calibration and flight results are analyzed in the paper.

  1. Neurotrophin-3 mRNA a putative target of miR21 following status epilepticus

    PubMed Central

    Risbud, Rashmi M.; Lee, Carolyn; Porter, Brenda E.

    2014-01-01

    Status epilepticus induces a cascade of protein expression changes contributing to the subsequent development of epilepsy. By identifying the cascade of molecular changes that contribute to the development of epilepsy we hope to be able to design therapeutics for preventing epilepsy. MicroRNAs influence gene expression by altering mRNA stability and/or translation and have been implicated in the pathology of multiple diseases. MiR21 and its co-transcript miR21*, microRNAs produced from either the 5″ or 3′ ends of the same precursor RNA strand, are increased in the hippocampus following status epilepticus. We have identified a miR21 binding site, in the 3′ UTR of neurotrophin-3 that inhibits translation. Neurotrophin-3 mRNA levels decrease in the hippocampus following SE concurrent with the increase in miR21. MiR21 levels in cultured hippocampal neurons inversely correlate with neurotrophin-3 mRNA levels. Treatment of hippocampal neuronal cultures with excess K+Cl−, a depolarizing agent mimicking the episode of status epilepticus, also results in an increase in miR21 and a decrease in neurotrophin-3 mRNA. MiR21 is a candidate for regulating neurotrophin-3 signaling in the hippocampus following status epilepticus. PMID:22019057

  2. Accuracy Assessment Study of UNB3m Neutral Atmosphere Model for Global Tropospheric Delay Mitigation

    NASA Astrophysics Data System (ADS)

    Farah, Ashraf

    2015-12-01

    Tropospheric delay is the second major source of error after the ionospheric delay for satellite navigation systems. The transmitted signal could face a delay caused by the troposphere of over 2m at zenith and 20m at lower satellite elevation angles of 10 degrees and below. Positioning errors of 10m or greater can result from the inaccurate mitigation of the tropospheric delay. Many techniques are available for tropospheric delay mitigation consisting of surface meteorological models and global empirical models. Surface meteorological models need surface meteorological data to give high accuracy mitigation while the global empirical models need not. Several hybrid neutral atmosphere delay models have been developed by (University of New Brunswick, Canada) UNB researchers over the past decade or so. The most widely applicable current version is UNB3m, which uses the Saastamoinen zenith delays, Niell mapping functions, and a look-up table with annual mean and amplitude for temperature, pressure, and water vapour pressure varying with respect to latitude and height. This paper presents an assessment study of the behaviour of the UNB3m model compared with highly accurate IGS-tropospheric estimation for three different (latitude/height) IGS stations. The study was performed over four nonconsecutive weeks on different seasons over one year (October 2014 to July 2015). It can be concluded that using UNB3m model gives tropospheric delay correction accuracy of 0.050m in average for low latitude regions in all seasons. The model's accuracy is about 0.075m for medium latitude regions, while its highest accuracy is about 0.014m for high latitude regions.

  3. The holistic 3M modality of drug delivery nanosystems for cancer therapy

    NASA Astrophysics Data System (ADS)

    Sun, Jin; Luo, Cong; Wang, Yongjun; He, Zhonggui

    2013-01-01

    Cancer has become the leading cause of human death worldwide. There are many challenges in the treatment of cancer and the rapidly developing area of nanotechnology has shown great potential to open a new era in cancer therapy. This article, rather than being exhaustive, focuses on the striking progress in the drug delivery nanosystems (DDNS) for cancer therapy and selects typical examples to point out the emerging mode of action of DDNS from our perspective. Among the outstanding advances in DDNS for cancer therapy is the development of ``multicomponent delivery systems'', ``multifunctional nanocarriers'' and ``multistage delivery systems''. However, these represent only one aspect of DDNS research. In addition, nature is the best teacher and natural evolution pressure has meant that virions conform to the ``multitarget, multistage and multicomponent'' (3M) mode of action. Amazingly, traditional Chinese medicine (TCM), used for over 4000 years in China, also displays the same mode of action. Integrating the previous notable progress in nanoparticle technology, learned from the building mode of natural virions and the action concept of TCM, we propose an integrity-based 3M mode DDNS for cancer therapy: multitarget, multistage and multicomponent, which are not fragmented parts but an interconnected integrity. Based on the physiological multitarget and the pharmacokinetic multistage, multicomponent DDNS are rationally designed, where different components with individual specific functions act in a synergistic manner against each target at each disposition stage to maximize the targeted delivery effectiveness. In this article, we introduce each component of 3M DDNS in detail and describe some typical cases to realize the tumor-homing purposes.

  4. A new parallel P3M code for very large-scale cosmological simulations

    NASA Astrophysics Data System (ADS)

    MacFarland, Tom; Couchman, H. M. P.; Pearce, F. R.; Pichlmeier, Jakob

    1998-12-01

    We have developed a parallel Particle-Particle, Particle-Mesh (P3M) simulation code for the Cray T3E parallel supercomputer that is well suited to studying the time evolution of systems of particles interacting via gravity and gas forces in cosmological contexts. The parallel code is based upon the public-domain serial Adaptive P3M-SPH (http://coho.astro.uwo.ca/pub/hydra/hydra.html) code of Couchman et al. (1995)[ApJ, 452, 797]. The algorithm resolves gravitational forces into a long-range component computed by discretizing the mass distribution and solving Poisson's equation on a grid using an FFT convolution method, and a short-range component computed by direct force summation for sufficiently close particle pairs. The code consists primarily of a particle-particle computation parallelized by domain decomposition over blocks of neighbour-cells, a more regular mesh calculation distributed in planes along one dimension, and several transformations between the two distributions. The load balancing of the P3M code is static, since this greatly aids the ongoing implementation of parallel adaptive refinements of the particle and mesh systems. Great care was taken throughout to make optimal use of the available memory, so that a version of the current implementation has been used to simulate systems of up to 109 particles with a 10243 mesh for the long-range force computation. These are the largest Cosmological N-body simulations of which we are aware. We discuss these memory optimizations as well as those motivated by computational performance. Performance results are very encouraging, and, even without refinements, the code has been used effectively for simulations in which the particle distribution becomes highly clustered as well as for other non-uniform systems of astrophysical interest.

  5. USAF Bioenvironmental Noise Data Handbook. Volume 167: MA-3M air conditioner

    NASA Astrophysics Data System (ADS)

    Rau, T. H.

    1982-06-01

    The MA-3M is an electric motor-driven air conditioner designed to cool electronic equipment on aircraft during ground maintenance. This report provides measured and extrapolated data defining the bioacoustic environments produced by this unit operating at a normal rated condition. Near-field data are reported for 37 locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference levels, perceived noise levels, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors.

  6. Theoretical study of 'Mixed' ligands superhalogens: Cl-M-NO3 (M = Li, Na, K)

    NASA Astrophysics Data System (ADS)

    Zhao, Xinghua; Liu, Weihui; Wang, Jiesheng; Li, Chun; Yuan, Guang

    2016-08-01

    MCl2-, M(NO3)2-, and (Cl-M-NO3)- (M = Li, Na, K) species are systematically investigated using the density functional theory. In all the cases studied, the vertical detachment energies (VDEs) exceed the electron affinity of chlorine atom, leading to the conclusion that MCl2-, M(NO3)2- and (Cl-M-NO3)- are superhalogens. The VDEs of (Cl-M-NO3)- are between that of MCl2- and M(NO3)2-, showing that replacing one ligand with a larger electronegative ligand leads to the higher VDE. Superhalogens with suitable VDEs can be built by using different ligands.

  7. 29 CFR 516.27 - “Board, lodging, or other facilities” under section 3(m) of the Act.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false âBoard, lodging, or other facilitiesâ under section 3(m) of...” under section 3(m) of the Act. (a) In addition to keeping other records required by this part, an... these terms are used in sec. 3(m) of the Act) furnished to them by the employer or by an...

  8. 29 CFR 516.27 - “Board, lodging, or other facilities” under section 3(m) of the Act.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âBoard, lodging, or other facilitiesâ under section 3(m) of...” under section 3(m) of the Act. (a) In addition to keeping other records required by this part, an... these terms are used in sec. 3(m) of the Act) furnished to them by the employer or by an...

  9. Unique Roll-Off Roof for Housing 1.3 m Telescope at Devasthal, Nainital

    NASA Astrophysics Data System (ADS)

    Bangia, Tarun

    2016-05-01

    Aryabhatta Research Institute of Observational Sciences (ARIES) had set up a 1.3 m telescope at Devasthal, Nainital, India in the year 2010. Country's largest roll-off roof was indigenously designed, fabricated and installed on top of a building (17 × 8 m) for housing 1.3 m telescope. Telescope was supplied by M/s DFM Engineering Inc., USA to ARIES and was installed in the building with unique roll-off roof to protect it from external environment. Roll-off roof was designed and fabricated considering various parameters and available manpower and resources at ARIES. This paper presents mechanical development work, simple but distinct design approach and innovative selection of materials to economically manufacture roll-off roof of large size (8 × 8 × 4 m) at hilly remote site of Devasthal situated in Central Himalayan region. All operations in the roof viz. opening of shutters and rolling of roof were motorized to facilitate observers during night observations.

  10. Development of 3M`s oxide/oxide candle filter

    SciTech Connect

    Visser, L.; Smith, R.G.

    1996-12-31

    3M has had a silicon carbide, SiC, matrix/oxide fiber, ceramic composite, candle filter in test and on the market for several years. Because of the effects of some corrosive environments, 3M is developing an oxide matrix/oxide fiber hot gas candle filter which will be better suited for some of the environments which can degrade SiC. This paper will discuss the progress of the development of the oxide/oxide candle filter. Composite panels using three different Nextel{trademark} fibers but the same matrix material have been exposed to different simulated environmental conditions in the laboratory. Data will be presented on the effects of these environments on the composite panels. Also prototype candles have been made from the oxide/oxide system and data will be presented on the filtration characteristics, construction, and laboratory environmental exposures of these filters. Finally, if available, data will be presented on 12-in candle filters which have been exposed in an industrial test facility.

  11. Test of P3M-1 nacelle in Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Test of P3M-1 nacelle in Full-Scale Tunnel (FST). The NACA conducted drag tests on P3M-1 nacelle in 1931 which were presented in a special report to the Navy. Smith DeFrance described this work in the report's introduction: 'Tests were conducted in the full-scale wind tunnel on a five to four geared Pratt and Whitney Wasp engine mounted in a P3M-1 nacelle. In order to simulate the flight conditions the nacelle was assembled on a 15-foot span of wing from the same airplane. The purpose of the tests was to improve the cooling of the engine and to reduce the drag of the nacelle combination. Thermocouples were installed at various points on the cylinders and temperature readings were obtained from these by the power plants division. These results will be reported in a memorandum by that division. The drag results, which are covered by this memorandum, were obtained with the original nacelle condition as received from the Navy with the tail of the nacelle modified, with the nose section of the nacelle modified, with a Curtiss anti-drag ring attached to the engine, with a Type G ring developed by the N.A.C.A., and with a Type D cowling which was also developed by the N.A.C.A.' (p. 1) This picture shows the engine with a Curtiss anti-drag ring attached. The NACA tested several different modifications and cowlings as noted above. The Navy did not want to make any major structural alterations to the original wing and nacelle installation. Thus, the NACA did not conduct a full investigation of the aerodynamics of this particular configuration. DeFrance concludes his report with this note: 'in view of the limitations of the test, the drag data for the combinations tested may be summarized, and considering the necessity of temperature control and accessibility to the engine it is apparent that the best combination tested was with the large nose piece, the Curtiss anti-drag ring, and the modified tail section.'

  12. Pressure- and Temperature-Sensitive Paint at 0.3-m Transonic Cryogenic Tunnel

    NASA Technical Reports Server (NTRS)

    Watkins, A. Neal; Leighty, Bradley D.; Lipford, William E.; Goodman, Kyle Z.

    2015-01-01

    Recently both Pressure- and Temperature-Sensitive Paint experiments were conducted at cryogenic conditions in the 0.3-m Transonic Cryogenic Tunnel at NASA Langley Research Center. This represented a re-introduction of the techniques to the facility after more than a decade, and provided a means to upgrade the measurements using newer technology as well as demonstrate that the techniques were still viable in the facility. Temperature-Sensitive Paint was employed on a laminar airfoil for transition detection and Pressure-Sensitive Paint was employed on a supercritical airfoil. This report will detail the techniques and their unique challenges that need to be overcome in cryogenic environments. In addition, several optimization strategies will also be discussed.

  13. Automated 1.3-m near-infrared telescope system triggered by gamma-ray burst

    NASA Astrophysics Data System (ADS)

    Murakami, Toshio; Yonetoku, Daisuke; Kinoshita, Shin; Masui, Hiroki; Okuno, Shinya; Yoshinari, Satoru; Kidamura, Takashi; Tanabe, Sachiko; Yokota, Satoshi; Kobayashi, Yukiyasu; Nakagawa, Takao; Nakamura, Takashi

    2006-06-01

    The design for robotic telescopes to observe Gamma-Ray Burst (GRB) afterglows and the results of observations are presented. Quickly fading bright GRB flashes and afterglows provide a good tool to study an extremely early universe. However, most large ground-based telescopes cannot afford to follow-up the afterglows and flashes quickly within a few hours since a GRB explosion. We re-modeled the existing middle-class 1.3 m ø telescope of the near infrared band at ISAS in Japan to match for the above requirement. We also set a small telescope of 30 cm diameter with a conventional CCD. These telescopes can monitor afterglows quickly within a few minutes in J, H, Ks and R band with a grism spectrometer.

  14. How gold nanoparticles have stayed in the light: the 3M's principle.

    PubMed

    Odom, Teri W; Nehl, Colleen L

    2008-04-01

    Simultaneous advances in making, measuring, and modeling noble metal (plasmonic) particles--designated as the 3M's principle--have led to a perfect storm in discoveries and applications of gold nanoparticles. Three articles in this issue of ACS Nano illustrate this concept. First, exquisite control over gold nanorod length and diameter and testing of fundamental ideas are presented. Second, gold nanorods as localized surface plasmon resonance sensors to monitor the kinetics of antibody-antigen binding are reported. Third, strategies to prepare gold nanoshell substrates to enhance Raman scattering and infrared absorption are proposed. In this Perspective, we discuss how these reports fit into current challenges in plasmonics and how the prospects of localized surface plasmons will continue to shine when the right applications are revealed. PMID:19206589

  15. Experience and Challenges in Implementing Stratospheric Aerosol Gas Experiment on Meteor-3M Platform

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Newsom, Jerry; Rawls, Richard

    2001-01-01

    Implementation of Stratospheric Aerosol Gas Experiment (SAGE) is a joint science mission between the Rosavioskosmos, also called Russian Aviation and Space Agency (RASA) and the National Aeronautics and Space Administration (NASA). Under the global collaboration agreement established by President Clinton and Yeltsin in 1995 between the United States and Russia, space was one of the major areas identified for joint scientific collaboration. There were several collaborative projects identified under space, earth, human exploration of space and aeronautics. SAGE was one of the key Earth Science instruments selected common to both countries' interests in ozone research. SAGE has a long space heritage, and four earlier versions of this instrument have flown in space for the last 15-year period. It has provided a vital ozone and aerosol data in the mid latitudes and has contributed in the overall ozone depletion research. SAGE II, the fourth instrument has been flying in space on NASA's Earth Radiation Budget Satellite (ERBS) for the last 14 years. Ball Aerospace built the instrument under Langley Research Center's (LaRC) management. SAGE III for Russian Meteor-3M mission is a third generation design with more spectral bands, elaborate data gathering and storage and intelligent terrestrial software. The Russian collaboration required a complete integration of SAGE III on the Russian Meteor-3M satellite and a launch on a Zenit-2 launch vehicle manufactured in Ukraine. The whole complex is scheduled to be launched from Baikonur cosmodrome in early 2001. This cooperative mission has presented a number of management, technical and logistical challenges on both sides. This paper makes an attempt to review and document such experiences.

  16. Modeling the hydrothermal circulation and the hydrogen production at the Rainbow site with Cast3M

    NASA Astrophysics Data System (ADS)

    Perez, F.; Mügler, C.; Charlou, J.; Jean-baptiste, P.

    2012-12-01

    On the Mid-Atlantic Ridge, the Rainbow venting site is described as an ultramafic-hosted active hydrothermal site and releases high fluxes of methane and hydrogen [1, 2]. This behavior has first been interpreted as the result of serpentinization processes. But geochemical reactions involving olivine and plagioclase assemblages, and leading to chlorite, tremolite, talc and magnetite assemblages, could contribute to the observed characteristics of the exiting fluid [2]. The predominance of one of these geochemical reactions or their coexistence strongly depend on the hydrothermal fluid circulation. We developed and validated a 2D/3D numerical model using a Finite Volume method to simulate heat driven fluid flows in the framework of the Cast3M code [3, 4]. We also developed a numerical model for hydrogen production and transport that is based on experimental studies of the serpentinization processes [5-6]. This geochemical model takes into account the exothermic and water-consuming behavior of the serpentinization reaction and it can be coupled to our thermo-hydrogeological model. Our simulations provide temperatures, mass fluxes and venting surface areas very close to those estimated in-situ [7]. We showed that a single-path model [8] was necessary to simulate high values such as the in-situ measured temperatures and estimated water mass fluxes of the Rainbow site [7]. This single-path model will be used to model the production and transport of hydrogen at the Rainbow hydrothermal site. References [1]Charlou et al. (2010) AGU Monograph series. [2]Seyfried et al. (2011) Geochim. Cosmochim. Acta 75, 1574-1593. [3]http://www-cast3m.cea.fr. [4]Martin & Fyfe (1970) Chem. Geol. 6, 185-202. [5] Marcaillou et al. (2011) Earth and Planet. Sci. Lett. 303, 281-290. [6]Malvoisin et al. (2012) JGR, 117, B01104. [7]Perez et al. (2012) submited to Computational Geosciences. [8]Lowell & Germanovich (2004) AGU, Washington DC, USA.

  17. The refurbished 1.3-m Robotically Controlled Telescope at Kitt Peak

    NASA Astrophysics Data System (ADS)

    Gelderman, R.; Guinan, E.; Howell, S.; Mattox, J. R.; McGruder, C. H.; Walter, D. K.; Davis, D. R.; Everett, M.

    2003-05-01

    In 1999, the National Optical Astronomy Observatories (NOAO) announced the opportunity to "assume responsibility for operation of the Kitt Peak 1.3-m telescope." A group of astronomers/educators from institutions across the USA successfully proposed to refurbish and automate the observatory and operate it as the Robotically Controlled Telescope (RCT). The RCT Consortium has been established between Francis Marion University, the Planetary Science Institute, South Carolina State University, Villanova University, and Western Kentucky University to oversee the refurbishment and automation, and operate the telescope to successfully achieve its research and education goals. The RCT was commissioned in 1964 as the Remotely Controlled Telescope and utilized that epoch's computing and communication technology to provide unattended operation from NOAO headquarters in Tucson, about 90 km distant. The original incarnation of the RCT allowed astronomers to gain experience in the remote operation of observatories in order to both develop techniques for operating space-based telescopes and to increase the productivity of ground-based telescopes (Maran 1967 Science 158, 867). While these tests worked as well as could be expected given the technology of the time, the telescope and observatory were refitted in 1969 for classical, attended operations. The second life of the 1.3-m was as a heavily subscribed KPNO visitor facility, first with photoelectric photometers and later as an important testbed for the newest infrared instrumentation. In 1996 the telescope was removed from the list of available KPNO facilities and stood idle until the RCT Consortium hired EOS Technologies, Inc. to refurbish and automate the observatory. In winter 2003 most of the observatory systems have been refurbished and the commissioning has begun. Refurbishment of the RCT has been made possible by NASA grant NAG58762.

  18. Astrometric and Photometric Accuracy of the 1.3 m Robotically Controlled Telescope on Kitt Peak

    NASA Astrophysics Data System (ADS)

    McGruder, Charles H.; Carini, M. T.; Engle, S. G.; Gelderman, R.; Guinan, E. F.; Laney, D.; Strolger, L.; Treffers, R. R.; Walter, D. K.

    2014-01-01

    The 1.3 m (50 inch) telescope on Kitt Peak has been refurbished and provided with an autonomous scheduler. It is operated by The Robotically Controlled Telescope (RCT) consortium whose members are: South Carolina State, Villanova and Western Kentucky Universities. The facility possesses 5 board (UBVRI) and 11 narrow-band filters. Attached to the RCT camera is a 2048 x 2048 SITe SI-424A back-illuminated CCD with 24 micrometer pixels. We used over 7,000 star measurements from 37, 198s R-images to compute the astrometric and photometric accuracy. The difference of the J2000 coordinates computed from the RCT images and the J2000 Nomad catalog coordinate values in right ascension peaks at 0.058”, while the declination peaks at -0.125”. We obtained these astrometric results using the simplest assumptions: linear relationship between standard coordinates and measured coordinates, no color or magnitude dependency and no differential refraction (all images taken in the zenith). We express the photometric accuracy in the following manner: The Signal-to-Noise-Ratio as a function of apparent magnitude shows that the RCT is not noise dominated at m < 20 magnitude.

  19. 3D hexagonal (R-3m) mesostructured nanocrystalline titania thin films : synthesis and characterization.

    SciTech Connect

    Choi, S. Y.; Lee, B.; Carew, D. B.; Mamak, M; Peiris, F. C.; Speakman, S.; Chopra, N.; Ozin, G. A.; X-Ray Science Division; Univ. of Toronto; ORNL; Xerox Research Centre of Canada

    2006-01-01

    A straightforward and reproducible synthesis of crack-free large-area thin films of 3D hexagonal (R-3m) mesostructured nanocrystalline titania (meso-nc-TiO{sub 2}) using a Pluronic triblock copolymer (P123)/1-butanol templating system is described. The characterization of the films is achieved using a combination of electron microscopy (high-resolution scanning electron microscopy and scanning transmission electron microscopy), grazing-incidence small-angle X-ray scattering, in situ high-temperature X-ray diffraction, and variable-angle spectroscopic ellipsometry. The mesostructure of the obtained films is found to be based upon a 3D periodic array of large elliptically shaped cages with diameters around 20 nm interconnected by windows of about 5 nm in size. The mesopores of the film calcined at 300 C are very highly ordered, and the titania framework of the film has a crystallinity of 40 % being composed of 5.8 nm sized anatase crystallites. The film displays high thermal stability in that the collapse of the pore architecture is incomplete even at 600 C. The accessible surface area of 3D hexagonal meso-nc-TiO{sub 2} estimated by the absorption of methylene blue is nearly twice as large as that of 2D hexagonal meso-nc-TiO{sub 2} at the same annealing temperature.

  20. 3D HEXAGONAL (R-3M) MESOSTRUCTURED NANOCRYSTALLINE TITANIA THIN FILMS: SYNTHESIS AND CHARACTERIZATION

    SciTech Connect

    Choi, S Y; Lee, B; Carew, D B; Peiris, F C; Mamak, M; Speakman, Scott A; Chopra, N; Ozin, G A

    2006-01-01

    A straightforward and reproducible synthesis of crack-free large-area thin films of 3D hexagonal (R-3m) mesostructured nanocrystalline titania (meso-nc-TiO{sub 2}) using a Pluronic triblock copolymer (P123)/1-butanol templating system is described. The characterization of the films is achieved using a combination of electron microscopy (high-resolution scanning electron microscopy and scanning transmission electron microscopy), grazing-incidence small-angle X-ray scattering, in situ high-temperature X-ray diffraction, and variable-angle spectroscopic ellipsometry. The mesostructure of the obtained films is found to be based upon a 3D periodic array of large elliptically shaped cages with diameters around 20 nm interconnected by windows of about 5 nm in size. The mesopores of the film calcined at 300 C are very highly ordered, and the titania framework of the film has a crystallinity of 40 % being composed of 5.8 nm sized anatase crystallites. The film displays high thermal stability in that the collapse of the pore architecture is incomplete even at 600 C. The accessible surface area of 3D hexagonal meso-nc-TiO{sub 2} estimated by the absorption of methylene blue is nearly twice as large as that of 2D hexagonal meso-nc-TiO{sub 2} at the same annealing temperature.

  1. 3M Petrifilm enterobacteriaceae count plate method for enumeration of enterobacteriaceae in selected foods: collaborative study.

    PubMed

    Silbernagel, Karen M; Lindberg, Kathryn G

    2003-01-01

    The practice of detecting and enumerating all oxidase-negative, glucose-fermenting-Gram-negative rods (i.e., the family Enterobacteriaceae) is used to indicate unsanitary or inadequate food processing conditions. The objective of this interlaboratory collaborative study was to evaluate and compare the methods described in Standard Methods for the Examination of Dairy Products (SMEDP) and the Compendium of Methods for the Microbiological Examination of Foods (Compendium) with a commercial product, the 3M Petrifilm Enterobacteriaceae Count Plate, for the recovery of Enterobacteriaceae in foods. Six foods--cheddar cheese, milk, flour, frozen prepared meals, frozen broccoli, and nut pieces--were analyzed for Enterobacteriaceae by 12 collaborating laboratories. For each food tested, the collaborators received 8 blind test portions consisting of a control test portion and 3 levels of inoculated test portion, each in duplicate. Each test portion was tested by the Petrifilm Enterobacteriaceae Count Plate method as well as the SMEDP or Compendium methods. The precision estimates (repeatability or within-laboratory variation, and reproducibility or between-laboratory variation) were calculated with standard statistical techniques. PMID:14509441

  2. High-pressure phase transition of MH3 (M: Er, Ho)

    NASA Astrophysics Data System (ADS)

    Hou, Pugeng; Tian, Fubo; Li, Da; Chu, Binhua; Zhao, Zhonglong; Liu, Bingbing; Cui, Tian

    2014-08-01

    Motivated by the potential high temperature superconductivity in hydrogen-rich materials, high-pressure structures of ErH3 and HoH3 were studied by using genetic algorithm method. Our calculations indicate that both ErH3 and HoH3 transform from P-3c1 structure to a monoclinic C2/m structure at about 15 GPa, and then transforms into a cubic Fm-3m structure at about 40 GPa. ErH3 and HoH3 adopt the same P63/mmc structure with space group P63/mmc at above about 220 and 196 GPa, respectively. For ErH3, the P63/mmc phase is stable up to at least 300 GPa, while for HoH3, a phase transformation P63/mmc → Cmcm occurs at about 216 GPa, and the Cmcm phase is stable up to at least 300 GPa. The P-3c1 ErH3 and HoH3 are calculated to demonstrate non-metallic character, and the other phases are all metallic phases.

  3. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    SciTech Connect

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a β hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an α hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  4. The RCT 1.3 m robotic telescope: broadband color transformation and extinction calibration

    SciTech Connect

    Strolger, L.-G.; Gott, A. M.; Carini, M.; Gelderman, R.; Laney, C. D.; McGruder, C.; Engle, S.; Guinan, E.; Treffers, R. R.; Walter, D. K.

    2014-03-01

    The Robotically Controlled Telescope (RCT) 1.3 m telescope, formerly known as the Kitt Peak National Observatory (KPNO) 50 inch telescope, has been refurbished as a fully robotic telescope, with an autonomous scheduler to take full advantage of the observing site without the requirement of a human presence. Here we detail the current configuration of the RCT and present, as a demonstration of its high-priority science goals, the broadband UBVRI photometric calibration of the optical facility. In summary, we find the linear color transformation and extinction corrections to be consistent with similar optical KPNO facilities, to within a photometric precision of 10% (at 1σ). While there were identified instrumental errors that likely added to the overall uncertainty, associated with since-resolved issues in engineering and maintenance of the robotic facility, a preliminary verification of this calibration gave a good indication that the solution is robust, perhaps to a higher precision than this initial calibration implies. The RCT has been executing regular science operations since 2009 and is largely meeting the science requirements set during its acquisition and redesign.

  5. High Resolution P3M-GRAPE-SPH Simulations of PopIII Star Formation

    NASA Astrophysics Data System (ADS)

    Suwa, Tamon; Umemura, Masayuki; Sato, Daisuke; Susa, Hajime

    2008-03-01

    In order to investigate the mass distribution of Population III stars, we have developed high-resolution cosmological hydrodynamic simulations in a standard ΛCDM universe. We use a Particle-Particle-Particle-Mesh (P3M) scheme for gravity force calculations, where the PP part is calculated by GRAPE (special purpose board for gravity calculation). The baryon component is treated by Smoothed Particle Hydrodynamics (SPH) method. The simulations are performed on a newly developed dedicated PC-cluster system named FIRST simulator with the peak speed of 36 T flops at the University of Tsukuba. Using this simulator, we perform high-resolution simulations with 2×107 of dark matter and SPH particles, respectively. With this large number of particles, sub-solar mass resolution for baryon particles can be achieved all over the simulation box. Therefore, we can resolve small scale density fluctuations, which may play an important role in the formation of intermediate-mass Pop III stars formation.

  6. Characteristics of ICR-produced peripheral plasma in the Uragan-3M torsatron

    NASA Astrophysics Data System (ADS)

    Besedin, N. T.; Chechkin, V. V.; Fomin, I. P.

    Some plasma parameters outside the confinement volume near the last closed magnetic surface (LCMS) and in the divertor fluxes were studied by probe and microwave techniques during ICR production and heating of the plasma in the Uragan-3M torsatron. When moving around the LCMS, the steepness of the radial density, electron temperature, and potential profiles increase with distance away from the 'rib' of the LCMS. The quasi-steady radial electric field E(sub r) near the LCMS exceeds 100 V/cm and is directed outwards, opposite to the calculated ambipolar electric field inside the confinement volume. It is shown that the total flow of the diverted plasma in the spacing between two helical windings consists of a weakly mobile non-resonant component which is presumably formed at the periphery due to ionization, and a component whose value and poloidal location are sensitive to resonance conditions for RF power absorption, this flow being apparently formed by a plasma diffusing through the LCMS and/or generated near the LCMS, where the filed E(sub r) is localized. Based on plasma parameters measurements after the RF pulse is switched off, a qualitative model of peripheral plasma dynamics after the end of the RF heating is constructed.

  7. Understanding the spin-driven polarizations in Bi MO3 (M = 3 d transition metals) multiferroics

    NASA Astrophysics Data System (ADS)

    Kc, Santosh; Lee, Jun Hee; Cooper, Valentino R.

    Bismuth ferrite (BiFeO3) , a promising multiferroic, stabilizes in a perovskite type rhombohedral crystal structure (space group R3c) at room temperature. Recently, it has been reported that in its ground state it possess a huge spin-driven polarization. To probe the underlying mechanism of this large spin-phonon response, we examine these couplings within other Bi based 3 d transition metal oxides Bi MO3 (M = Ti, V, Cr, Mn, Fe, Co, Ni) using density functional theory. Our results demonstrate that this large spin-driven polarization is a consequence of symmetry breaking due to competition between ferroelectric distortions and anti-ferrodistortive octahedral rotations. Furthermore, we find a strong dependence of these enhanced spin-driven polarizations on the crystal structure; with the rhombohedral phase having the largest spin-induced atomic distortions along [111]. These results give us significant insights into the magneto-electric coupling in these materials which is essential to the magnetic and electric field control of electric polarization and magnetization in multiferroic based devices. Research is supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division and the Office of Science Early Career Research Program (V.R.C) and used computational resources at NERSC.

  8. Observation of 20-400 kHz fluctuations in the U-3M torsatron

    NASA Astrophysics Data System (ADS)

    Dreval, M. B.; Yakovenko, Yu. V.; Sorokovoy, E. L.; Slavnyj, A. S.; Pavlichenko, R. O.; Kulaga, A. E.; Zamanov, N. V.; Hirose, A.

    2016-02-01

    First observations of quasi-coherent fluctuations in the frequency range of 20-400 kHz in Alfvén-wave-heated plasmas of the U-3M torsatron are presented. The excitation conditions of these modes depend on the radio frequency antenna type and the plasma density, the appearance of the modes correlating with the presence of both suprathermal electrons and high-energy ions in the plasma, which supports our opinion that the modes are excited by energetic particles. Complicated evolution of the mode frequencies with abrupt changes at the instants of plasma confinement transitions is observed at the initial stage of each discharge. The frequencies become stable at the stage of the plasma current flattop. Raw estimates show that toroidicity-induced Alfvén eigenmodes could be responsible for the 150-400 kHz fluctuations. Low-frequency 20-70 kHz bursts are observed during plasma confinement transitions. The poloidal mode number of one of these bursts with the frequency of 20 kHz burst was determined to be m = 2. This mode rotated in the electron diamagnetic rotation direction with a frequency lower than the geodesic acoustic mode frequency and can be identified as a drift-sound-type mode.

  9. The first-principle studies of the crystal phase transitions: Fd3m-MgAl 2O 4→F4-3m-MgAl 2O 4

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Ji, Guang-Fu; Zhao, Feng; Meng, Chuan-Min; Wei, Dong-Qing

    2011-02-01

    Magnesium aluminum spinel (MgAl 2O 4) is a major constituent of the shallow upper mantle. It is of great geophysical importance to explore its physical properties under high pressure and temperature. The first-principle density functional theory (DFT) with the plane wave along with pseudopotential was employed to obtain the total energy for both Fd3m-MgAl 2O 4 and F4-3m-MgAl 2O 4, which was used to generate the Gibbs free energy as a function of temperature and pressure with the quasi-harmonic Debye model. It is found that the phase transition temperature from Fd3m-MgAl 2O 4 to F4-3m-MgAl 2O 4 is beyond 452.6 K in the pressure regime studied, which is consistent with the experiment. The phase transition temperature is related to pressure by a linear function, i.e. T=8.05 P+452.6, which is the first equation of this kind to describe the phase transition Fd3m→F4-3m. The elastic constants, equation of states and thermodynamic properties of Fd3m-MgAl 2O 4 are also reported in this paper to make a complete study.

  10. Modifications to Langley 0.3-m TCT adaptive wall software for heavy gas test medium, phase 1 studies

    NASA Technical Reports Server (NTRS)

    Murthy, A. V.

    1992-01-01

    The scheme for two-dimensional wall adaptation with sulfur hexafluoride (SF6) as test gas in the NASA Langley Research Center 0.3-m Transonic Cryogenic Tunnel (0.3-m TCT) is presented. A unified version of the wall adaptation software has been developed to function in a dual gas operation mode (nitrogen or SF6). The feature of ideal gas calculations for nitrogen operation is retained. For SF6 operation, real gas properties have been computed using the departure function technique. Installation of the software on the 0.3-m TCT ModComp-A computer and preliminary validation with nitrogen operation were found to be satisfactory. Further validation and improvements to the software will be undertaken when the 0.3-m TCT is ready for operation with SF6 gas.

  11. Initial operation and checkout of stratospheric aerosol gas experiment and Meteor-3M satellite

    NASA Astrophysics Data System (ADS)

    Habib, Shahid; Makridenko, Leonid; Chu, William P.; Salikhov, Rashid; Moore, Alvah S., Jr.; Trepte, Charles R.; Cisewski, Michael S.

    2003-04-01

    Under a joint agreement between the National Aeronautics and Space Agency (NASA) and the Russian Aviation and Space Agency (RASA), the Stratospheric Aerosol Gas Experiment III (SAGE III) instrument was launched in low earth orbit on December 10, 2001 aboard the Russian Meteor-3M(1) satellite from the Baikonur Cosmodrome. SAGE III is a spectrometer that measures attenuated radiation in the 282 nm to 1550 nm wavelength range to obtain the vertical profiles of ozone, aerosols, and other chemical species that are critical in studying the trends for the global climate change phenomena. This instrument version is more advanced than any of the previous versions and has more spectral bands, elaborate data gathering and storage, and intelligent terrestrial software. There are a number of Russian scientific instruments aboard the Meteor satellite in addition to the SAGE III instrument. These instruments deal with land imaging and biomass changes, hydro-meteorological monitoring, and helio-geophysical research. This mission was under development for over a period of six years and offered a number of unique technical and program management challenges for both Agencies. SAGE III has a long space heritage, and four earlier versions of this instrument have flown in space for nearly two decades now. In fact, SAGE II, the fourth instrument, is still flying in space on NASA's Earth Radiation Budget Satellite (ERBS), and has been providing important atmospheric data over the last 18 years. It has provided vital ozone and aerosol data in the mid latitudes and has contributed vastly in ozone depletion research. Ball Aerospace built the instrument under Langley Research Center's (LaRC) management. This paper presents the process and approach deployed by the SAGE III and the Meteor teams in performing the initial on-orbit checkout. It further documents a number of early science results obtained by deploying low risk, carefully coordinated procedures in resolving the serious operational

  12. Initial Operation and Checkout of Stratospheric Aerosol Gas Experiment and Meteor-3M Satellite

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Makridenko, L.; Chu, W.; Salikhov, R.; Moore, A.; Trepte, C.; Cisewski, M.

    2002-01-01

    Under a joint agreement between the National Aeronautics and Space Agency (NASA) and the Russian Aviation and Space Agency (RASA), the Stratospheric Aerosol Gas Experiment III (SAGE III) instrument was launched in low earth orbit on December 10,2001 aboard the Russian Meteor-3M satellite from the Baikonur Cosmodrome. SAGE III is a spectrometer that measures attenuated radiation in the 282 nm to 1550 nm wavelength range to obtain the vertical profiles of ozone, aerosols, and other chemical species that are critical in studying the trends for the global climate change phenomena. This instrument version is more advanced than any of the previous versions and has more spectral bands, elaborate data gathering and storage, and intelligent terrestrial software. There are a number of Russian scientific instruments aboard the Meteor satellite in addition to the SAGE III instrument. These instruments deal with land imaging and biomass changes, hydro-meteorological monitoring, and helio-geophysical research. This mission was under development for over a period of six years and offered a number of unique technical and program management challenges for both Agencies. SAGE III has a long space heritage, and four earlier versions of this instrument have flown in space for nearly two decades now. In fact, SAGE II, the fourth instrument, is still flying in space on NASA s Earth Radiation Budget Satellite (ERBS), and has been providing important atmospheric data over the last 18 years. It has provided vital ozone and aerosol data in the mid latitudes and has contributed vastly in ozone depletion research. Ball Aerospace built the instrument under Langley Research Center s (LaRC) management. This paper presents innovative approaches deployed by the SAGE III and the Meteor teams in performing the initial on-orbit checkout. It further documents a number of early science results obtained by deploying low risk, carefully coordinated procedures in resolving the serious operational issues

  13. PLANET ENGULFMENT BY {approx}1.5-3 M{sub sun} RED GIANTS

    SciTech Connect

    Kunitomo, M.; Ikoma, M.; Sato, B.; Ida, S.; Katsuta, Y.

    2011-08-20

    Recent radial-velocity surveys for GK clump giants have revealed that planets also exist around {approx}1.5-3 M{sub sun} stars. However, no planets have been found inside 0.6 AU around clump giants, in contrast to solar-type main-sequence stars, many of which harbor short-period planets such as hot Jupiters. In this study, we examine the possibility that planets were engulfed by host stars evolving on the red-giant branch (RGB). We integrate the orbital evolution of planets in the RGB and helium-burning phases of host stars, including the effects of stellar tide and stellar mass loss. Then we derive the critical semimajor axis (or the survival limit) inside which planets are eventually engulfed by their host stars after tidal decay of their orbits. Specifically, we investigate the impact of stellar mass and other stellar parameters on the survival limit in more detail than previous studies. In addition, we make detailed comparisons with measured semimajor axes of planets detected so far, which no previous study has done. We find that the critical semimajor axis is quite sensitive to stellar mass in the range between 1.7 and 2.1 M{sub sun}, which suggests a need for careful comparison between theoretical and observational limits of the existence of planets. Our comparison demonstrates that all planets orbiting GK clump giants that have been detected are beyond the survival limit, which is consistent with the planet-engulfment hypothesis. However, on the high-mass side (>2.1M{sub sun}), the detected planets are orbiting significantly far from the survival limit, which suggests that engulfment by host stars may not be the main reason for the observed lack of short-period giant planets. To confirm our conclusion, the detection of more planets around clump giants, especially with masses {approx}> 2.5M{sub sun}, is required.

  14. Clinical evaluation of the 3M Littmann Electronic Stethoscope Model 3200 in 150 cats.

    PubMed

    Blass, Keith A; Schober, Karsten E; Bonagura, John D; Scansen, Brian A; Visser, Lance C; Lu, Jennifer; Smith, Danielle N; Ward, Jessica L

    2013-10-01

    Detection of murmurs and gallops may help to identify cats with heart disease. However, auscultatory findings may be subject to clinically relevant observer variation. The objective of this study was to evaluate an electronic stethoscope (ES) in cats. We hypothesized that the ES would perform at least as well as a conventional stethoscope (CS) in the detection of abnormal heart sounds. One hundred and fifty consecutive cats undergoing echocardiography were enrolled prospectively. Cats were ausculted with a CS (WA Tycos Harvey Elite) by two observers, and heart sounds were recorded digitally using an ES (3M Littmann Stethoscope Model 3200) for off-line analysis. Echocardiography was used as the clinical standard method for validation of auscultatory findings. Additionally, digital recordings (DRs) were assessed by eight independent observers with various levels of expertise, and compared using interclass correlation and Cohen's weighted kappa analyses. Using the CS, a heart murmur (n = 88 cats) or gallop sound (n = 17) was identified in 105 cats, whereas 45 cats lacked abnormal heart sounds. There was good total agreement (83-90%) between the two observers using the CS. In contrast, there was only moderate agreement (P <0.001) between results from the CS and the DRs for murmurs, and poor agreement for gallops. The CS was more sensitive compared with the DRs with regard to murmurs and gallops. Agreement among the eight observers was good-to-excellent for murmur detection (81%). In conclusion, DRs made with the ES are less sensitive but comparably specific to a CS at detecting abnormal heart sounds in cats. PMID:23599254

  15. T-carbon: a novel carbon allotrope.

    PubMed

    Sheng, Xian-Lei; Yan, Qing-Bo; Ye, Fei; Zheng, Qing-Rong; Su, Gang

    2011-04-15

    A structurally stable crystalline carbon allotrope is predicted by means of the first-principles calculations. This allotrope can be derived by substituting each atom in diamond with a carbon tetrahedron, and possesses the same space group Fd3m as diamond, which is thus coined as T-carbon. The calculations on geometrical, vibrational, and electronic properties reveal that T-carbon, with a considerable structural stability and a much lower density 1.50  g/cm3, is a semiconductor with a direct band gap about 3.0 eV, and has a Vickers hardness 61.1 GPa lower than diamond but comparable with cubic boron nitride. Such a form of carbon, once obtained, would have wide applications in photocatalysis, adsorption, hydrogen storage, and aerospace materials. PMID:21568576

  16. Coordinated observations of F region 3 m field-aligned plasma irregularities associated with medium-scale traveling ionospheric disturbances

    NASA Astrophysics Data System (ADS)

    Lin, F. F.; Wang, C. Y.; Su, C. L.; Shiokawa, K.; Saito, S.; Chu, Y. H.

    2016-04-01

    Three meter field-aligned irregularities (3 m FAIs) associated with medium-scale traveling ionospheric disturbances (MSTIDs) that occurred on 5 February 2008 were observed by using the Chung-Li 52 MHz coherent scatter radar. Interferometry measurements show that the plasma structures responsible for the 3 m FAI echoes are in a clumpy shape with a horizontal dimension of about 10-78 km in a height range of 220-300 km. In order to investigate the dynamic behaviors of the plasma irregularities at different scales in the bottomside of F region, the VHF radar echo structures from the 3 m FAIs combined with the 630 nm airglow images provided by the Yonaguni all-sky imager are compared and analyzed. The results show that the radar echoes were located at the west edge of the depletion zones of the 630 nm airglow image of the MSTIDs. The bulk echo structures of the 3 m FAIs drifted eastward at a mean trace velocity of about 30 m/s that is in general agreement with the zonal trace velocity of the MSTIDs shown in the 630 nm airglow images. These results suggest that the observed F region 3 m FAIs for the present case can be regarded as the targets that are frozen in the local region of the MSTIDs. In addition, the radar-observed 3 m FAI echo intensity and spectral width bear high correlations to the percentage variations of the 630 nm emission intensity. These results seem to suggest that through the nonlinear turbulence cascade process, the MSTID-associated 3 m FAIs are very likely generated from the kilometer-scale plasma irregularities with large amplitude excited by the gradient drift instability.

  17. 2D and 3D Ultrasonographic Evaluation of Fetal Midface Hypoplasia in Two Cases with 3-M Syndrome

    PubMed Central

    Vimercati, A.; Chincoli, A.; de Gennaro, A. C.; DʼAddario, V.; Cicinelli, E.

    2016-01-01

    This paper highlights the utility of 2D and 3D ultrasonography in the prenatal diagnosis of facial dysmorphisms suggestive of very rare syndromes such as 3-M syndrome. Two pregnant women at risk for fetal skeletal dysplasias were referred to our clinic for 2D/3D ultrasound scan in the second trimester of pregnancy. Only one of the patients had a familial history of 3-M syndrome. Karyotyping and genetic testing of abortion material were performed in both cases. 2D ultrasonography revealed growth retardation of the long bones in both cases. In the case without a familial history of the syndrome, 2D and 3D ultrasonography showed an absence of nasal bones and a flat malar region suggestive of 3-M syndrome, although the difficult differential diagnosis included other dysmorphic growth disorders with prenatal onset. The karyotype was normal but the pregnancy was terminated in both cases. Postmortem examination confirmed 3-M syndrome as indicated by prenatal findings. In high-risk cases with a familial history of 3-M syndrome, prenatal diagnosis of 3-M syndrome is possible by analyzing fetal DNA. In the absence of risk, a definitive prenatal diagnosis is often not possible but may be suspected in the presence of shortened long bones, normal head size and typical flattened malar region (midface hypoplasia) shown on complementary 2D and 3D sonograms. 2D and 3D ultrasonography has been shown to offer reliable information for the prenatal study of skeletal and facial anomalies and can be useful if there is a suspicion of 3-M syndrome in a pregnancy not known to be at risk. PMID:27453585

  18. Maternal uniparental isodisomy and heterodisomy on chromosome 6 encompassing a CUL7 gene mutation causing 3M syndrome.

    PubMed

    Sasaki, K; Okamoto, N; Kosaki, K; Yorifuji, T; Shimokawa, O; Mishima, H; Yoshiura, K-i; Harada, N

    2011-11-01

    We report a case of segmental uniparental maternal hetero- and isodisomy involving the whole of chromosome 6 (mat-hUPD6 and mat-iUPD6) and a cullin 7 (CUL7) gene mutation in a Japanese patient with 3M syndrome. 3M syndrome is a rare autosomal recessive disorder characterized by severe pre- and postnatal growth retardation that was recently reported to involve mutations in the CUL7 or obscurin-like 1 (OBSL1) genes. We encountered a patient with severe growth retardation, an inverted triangular gloomy face, an inverted triangle-shaped head, slender long bones, inguinal hernia, hydrocele testis, mild ventricular enlargement, and mild mental retardation. Sequence analysis of the CUL7 gene of the patient revealed a homozygous missense mutation, c.2975G>C. Genotype analysis using a single nucleotide polymorphism array revealed two mat-hUPD and two mat-iUPD regions involving the whole of chromosome 6 and encompassing CUL7. 3M syndrome caused by complete paternal iUPD of chromosome 6 involving a CUL7 mutation has been reported, but there have been no reports describing 3M syndrome with maternal UPD of chromosome 6. Our results represent a combination of iUPDs and hUPDs from maternal chromosome 6 involving a CUL7 mutation causing 3M syndrome. PMID:21166787

  19. Synthesis of Li 2MO 3 ( M = Ti or Zr) by the combustion method

    NASA Astrophysics Data System (ADS)

    Cruz, Daniel; Pfeiffer, Heriberto; Bulbulian, Silvia

    2006-05-01

    The advantages and disadvantages of the combustion method to prepare Li 2TiO 3 and Li 2ZrO 3 ceramics were studied. Firstly, the ceramic powders were prepared by the combustion process using LiOH, MO 2 (where M = Ti or Zr) and urea in different molar ratios (from 2:1:3 to 3:1:3) at different temperatures for 5 minutes. Li 2TiO 3 and Li 2ZrO 3 were also obtained by the solid-state method, and the results were compared with those obtained by the combustion process. The powders were characterized by X-ray diffraction and scanning electron microscopy. It was found that the combustion process reduces the synthesis time of Li 2TiO 3 (1 minute at 750 °C), but it does not have any advantage on producing Li 2ZrO 3, due to thermodynamic factors. On the other hand, the combustion process produces carbon contaminants in the solids. It was necessary to add excess of lithium hydroxide, in order to compensate the quantity of Li sublimated during the production of the ceramics. Finally, it seems that both reactions follow the same mechanism, which is determined by the lithium diffusion into the metal oxides.

  20. Properties near magnetic instability of heavy-electron compounds Ce3M4Sn13 and La3M4Sn13, with M=Co, Rh and Ru

    NASA Astrophysics Data System (ADS)

    Ślebarski, Andrzej

    2015-02-01

    In this review, we report the thermodynamic, magnetic and electronic transport properties of the skutterudite-related Ce3M4Sn13 and La3M4Sn13 intermetallic compounds with M = Co, Rh and Ru, which display a variety of behaviours. Ce3M4Sn13 exhibit a large increase in C/T with a maximum value of about 4 JK-2mol-1Ce due to strong electron and short-range magnetic correlations. These compounds show a crossover from a magnetically correlated heavy-fermion state to a single impurity state in applied magnetic fields. In order to study the proximity of Ce3Co4Sn13 to the possible magnetic quantum critical point (QCP), we investigated the system of Ce3-xLaxCo4Sn13 alloys. We found the critical concentration ?, which separates the magnetically correlated state (?) from a single impurity state (?), however the low-T C(T)/T and the magnetic susceptibility behaviours are not characteristic of the QCP. With increasing of the magnetic field, resistivity follows power law behaviour for the samples ?, with n strongly field dependent. The ?-anomaly is discussed on the base of spin-fluctuation theory of Moriya and Takimoto. Specific heat data show that La3M4Sn13 are typical BCS superconductors, however, La3Rh4Sn13 and La3Ru4Sn13 exhibit a second superconducting phase, characteristic of inhomogeneous superconductors.

  1. Draft Genome Sequence of Ornatilinea apprima P3M-1, an Anaerobic Member of the Chloroflexi Class Anaerolineae.

    PubMed

    Hemp, James; Ward, Lewis M; Pace, Laura A; Fischer, Woodward W

    2015-01-01

    We report the draft genome sequence of Ornatilinea apprima P3M-1, a strictly anaerobic member of the Chloroflexi class Anaerolineae. This genome provides insight into the diversity of metabolism within the Anaerolineae, and the evolution of respiration within the Chloroflexi. PMID:26586890

  2. Rhythmic control of mRNA stability modulates circadian amplitude of mouse Period3 mRNA.

    PubMed

    Kim, Sung-Hoon; Lee, Kyung-Ha; Kim, Do-Yeon; Kwak, Eunyee; Kim, Seunghwan; Kim, Kyong-Tai

    2015-03-01

    The daily oscillations observed in most living organisms are endogenously generated with a period of 24 h, and the underlying structure of periodic oscillation is an autoregulatory transcription-translation feedback loop. The mechanisms of untranslated region (UTR)-mediated post-transcriptional regulation (e.g., mRNA degradation and internal ribosomal entry site (IRES)-mediated translation) have been suggested to fine-tune the expression of clock genes. Mouse Period3 (mPer3) is one of the paralogs of Period gene and its function is important in peripheral clocks and sleep physiology. mPer3 mRNA displays a circadian oscillation as well as a circadian phase-dependent stability, while the stability regulators still remain unknown. In this study, we identify three proteins - heterogeneous nuclear ribonucleoprotein (hnRNP) K, polypyrimidine tract-binding protein (PTB), and hnRNP D - that bind to mPer3 mRNA 3'-UTR. We show that hnRNP K is a stabilizer that increases the amplitude of circadian mPer3 mRNA oscillation and hnRNP D is a destabilizer that decreases it, while PTB exhibits no effect on mPer3 mRNA expression. Our experiments describe their cytoplasmic roles for the mRNA stability regulation and the circadian amplitude formation. Moreover, our mathematical model suggests a mechanism through which post-transcriptional mRNA stability modulation provides not only the flexibility of oscillation amplitude, but also the robustness of the period and the phase for circadian mPer3 expression. Mouse Period3 (mPer3) is one of well-known clock genes. We identified three 3'-UTR-binding proteins that modulate the mRNA stability, and they influenced to the amplitude of circadian mPer3 mRNA oscillation. Our mathematical model not only showed the relationship between mRNA stability and its oscillation profile but provided the molecular mechanism for the robustness of the period and the phase in circadian oscillation. hnK, heterogeneous nuclear ribonucleoprotein (hnRNP) K; hnD, hn

  3. Density functional theory studies on theelectronic, structural, phonon dynamicaland thermo-stability properties of bicarbonates MHCO3, M D Li, Na, K

    SciTech Connect

    Duan, Yuhua; Zhang, Bo; Sorescu, Dan C.; Johnson, Karl; Majzoub, Eric H; Luebke, David R.

    2012-07-01

    The structural, electronic, phonon dispersion and thermodynamic properties of MHCO3 (M D Li, Na, K) solids were investigated using density functional theory. The calculated bulk properties for both their ambient and the high-pressure phases are in good agreement with available experimental measurements. Solid phase LiHCO3 has not yet been observed experimentally. We have predicted several possible crystal structures for LiHCO3 using crystallographic database searching and prototype electrostatic ground state modeling. Our total energy and phonon free energy .FPH/ calculations predict that LiHCO3 will be stable under suitable conditions of temperature and partial pressures of CO2 and H2O. Our calculations indicate that the HCO􀀀 3 groups in LiHCO3 and NaHCO3 form an infinite chain structure through O#1; #1; #1;H#1; #1; #1;O hydrogen bonds. In contrast, the HCO􀀀 3 anions form dimers, .HCO􀀀 3 /2, connected through double hydrogen bonds in all phases of KHCO3. Based on density functional perturbation theory, the Born effective charge tensor of each atom type was obtained for all phases of the bicarbonates. Their phonon dispersions with the longitudinal optical–transverse optical splitting were also investigated. Based on lattice phonon dynamics study, the infrared spectra and the thermodynamic properties of these bicarbonates were obtained. Over the temperature range 0–900 K, the FPH and the entropies (S) of MHCO3 (M D Li, Na, K) systems vary as FPH.LiHCO3/ > FPH.NaHCO3/ > FPH.KHCO3/ and S.KHCO3/ > S.NaHCO3/ > S.LiHCO3/, respectively, in agreement with the available experimental data. Analysis of the predicted thermodynamics of the CO2 capture reactions indicates that the carbonate/bicarbonate transition reactions for Na and K could be used for CO2 capture technology, in agreement with experiments.

  4. Density functional theory studies on the electronic, structural, phonon dynamical and thermo-stability properties of bicarbonates MHCO3, M = Li, Na, K

    NASA Astrophysics Data System (ADS)

    Duan, Yuhua; Zhang, Bo; Sorescu, Dan C.; Johnson, J. Karl; Majzoub, Eric H.; Luebke, David R.

    2012-08-01

    The structural, electronic, phonon dispersion and thermodynamic properties of MHCO3 (M = Li, Na, K) solids were investigated using density functional theory. The calculated bulk properties for both their ambient and the high-pressure phases are in good agreement with available experimental measurements. Solid phase LiHCO3 has not yet been observed experimentally. We have predicted several possible crystal structures for LiHCO3 using crystallographic database searching and prototype electrostatic ground state modeling. Our total energy and phonon free energy (FPH) calculations predict that LiHCO3 will be stable under suitable conditions of temperature and partial pressures of CO2 and H2O. Our calculations indicate that the {{HCO}}_{3}^{-} groups in LiHCO3 and NaHCO3 form an infinite chain structure through O⋯H⋯O hydrogen bonds. In contrast, the {{HCO}}_{3}^{-} anions form dimers, ({{HCO}}_{3}^{-})_{2}, connected through double hydrogen bonds in all phases of KHCO3. Based on density functional perturbation theory, the Born effective charge tensor of each atom type was obtained for all phases of the bicarbonates. Their phonon dispersions with the longitudinal optical-transverse optical splitting were also investigated. Based on lattice phonon dynamics study, the infrared spectra and the thermodynamic properties of these bicarbonates were obtained. Over the temperature range 0-900 K, the FPH and the entropies (S) of MHCO3 (M =Li, Na, K) systems vary as FPH(LiHCO3) > FPH(NaHCO3) > FPH(KHCO3) and S(KHCO3) > S(NaHCO3) > S(LiHCO3), respectively, in agreement with the available experimental data. Analysis of the predicted thermodynamics of the CO2 capture reactions indicates that the carbonate/bicarbonate transition reactions for Na and K could be used for CO2 capture technology, in agreement with experiments.

  5. Na2TeS3, Na2TeSe3-mP24, and Na2TeSe3-mC48: Crystal Structures and Optical and Electrical Properties of Sodium Chalcogenidotellurates(IV).

    PubMed

    Pompe, Constantin; Preitschaft, Christian; Weihrich, Richard; Pfitzner, Arno

    2015-12-01

    Pure samples of Na2TeS3 and Na2TeSe3 were synthesized by the reactions of stoichiometric amounts of the elements Na, Te, and Q (Q = S, Se) in the ratio 2:1:3. Both compounds are highly air- and moisture-sensitive. The crystal structures were determined by single-crystal X-ray diffraction. Yellow Na2TeS3 crystallizes in the space group P21/c. Na2TeSe3 exists in a low-temperature modification (Na2TeSe3-mP24, space group P21/c) and a high-temperature modification (Na2TeSe3-mC48, space group C2/c); both modifications are red. Density functional theory calculations confirmed the coexistence of both modifications of Na2TeSe3 because they are very close in energy (ΔE = 0.18 kJ mol(-1)). To the contrary, hypothetic Na2TeS3-mC48 is significantly less favored (ΔE = 1.8 kJ mol(-1)) than the primitive modification. Na2TeS3 and Na2TeSe3-mP24 are isotypic to Li2TeS3, whereas Na2TeSe3-mC48 crystallizes in its own structure type, which was first described by Eisenmann and Zagler. The title compounds have two common structure motifs. Trigonal TeQ3 pyramids form layers, and the Na atoms are surrounded by a distorted octahedral environment of chalcogen atoms. Raman spectra are dominated by the vibration modes of the TeQ3 units. The activation energies of the total conductivity of the title compounds range between 0.68 eV (Na2TeS3) and 1.1 eV (Na2TeSe3). Direct principal band gaps of 1.20 and 1.72 eV were calculated for Na2TeSe3 and Na2TeS3, respectively. The optical band gaps are in the range from 1.38 eV for Li2TeSe3 to 2.35 eV for Na2TeS3. PMID:26600068

  6. Third molar maturity index (I3M) for assessing age of majority in a black African population in Botswana.

    PubMed

    Cavrić, Jelena; Galić, Ivan; Vodanović, Marin; Brkić, Hrvoje; Gregov, Jelena; Viva, Serena; Rey, Laura; Cameriere, Roberto

    2016-07-01

    Assessment of legal age, also known as age of majority, is a controversial issue as there are few body biomarkers or evidence during late adolescence differentiating a subject from being a minor or adult. The third molar was recognized as a suitable site for age examination in late adolescence. We analyzed the development of the left mandibular third molar by the third molar maturity index (I3M) and a specific cut-off value of I3M = 0.08, established by Cameriere et al. in 2008 and used it for discriminating between minors and adult black Africans from Gaborone, Botswana. A final sample of panoramic radiographs (OPTs) of 1294 people (582 males and 712 females) aged between 13 and 23 years was evaluated. The real age decreased as I3M gradually increased. There was no statistically significant difference in the third molar development evaluated using I3M between males and females (p > 0.05) across different I3M classes. Results of 2 × 2 contingency tables for different cut-off values indicated that I3M = 0.08 was useful in discriminating between adults and minors. Precisely, for I3M = 0.08, the values of accuracy or overall fraction of correctly classified were 0.91 in males with a 95 % confidence interval (95 % CI) of 0.88 to 0.93 and 0.92 (95 % CI, 0.90 to 0.93) in females. Values of sensitivity of the test or the proportion of participants being 18 years and older were 0.88 (95 % CI, 0.87 to 0.90) in males and 0.88 (95 % CI, 0.90 to 0.93) in females, while values of specificity or proportion of individuals younger than 18 who have I3M <0.08 were 0.94 (95 % CI, 0.91 to 0.96) in males and 0.96 (95 % CI, 0.94 to 0.98) in females. Positive predictive values of the test, where the participants whose I3M <0.08 were adults, were 0.94 (95 % CI 0.91 to 0.96) in males and 0.97 (95 % CI, 0.94 to 0.98) in females, while negative predictive values of the test, where the participants whose I3M was ≥0.08 were minors, were 0.88 (95 % CI 0.85 to

  7. On the multi-index (3m-parametric) Mittag-Leffler functions, fractional calculus relations and series convergence

    NASA Astrophysics Data System (ADS)

    Paneva-Konovska, Jordanka

    2013-10-01

    In this paper we consider a family of 3m-indices generalizations of the classical Mittag-Leffler function, called multi-index (3m-parametric) Mittag-Leffler functions. We survey the basic properties of these entire functions, find their order and type, and new representations by means of Mellin-Barnes type contour integrals, Wright pΨq-functions and Fox H-functions, asymptotic estimates. Formulas for integer and fractional order integration and differentiations are found, and these are extended also for the operators of the generalized fractional calculus (multiple Erdélyi-Kober operators). Some interesting particular cases of the multi-index Mittag-Leffler functions are discussed. The convergence of series of such type functions in the complex plane is considered, and analogues of the Cauchy-Hadamard, Abel, Tauber and Littlewood theorems are provided.

  8. On the multi-index (3 m-parametric) Mittag-Leffler functions, fractional calculus relations and series convergence

    NASA Astrophysics Data System (ADS)

    Paneva-Konovska, Jordanka

    2013-10-01

    In this paper we consider a family of 3 m-indices generalizations of the classical Mittag-Leffler function, called multi-index (3 m-parametric) Mittag-Leffler functions. We survey the basic properties of these entire functions, find their order and type, and new representations by means of Mellin-Barnes type contour integrals, Wright p Ψ q -functions and Fox H-functions, asymptotic estimates. Formulas for integer and fractional order integration and differentiations are found, and these are extended also for the operators of the generalized fractional calculus (multiple Erdélyi-Kober operators). Some interesting particular cases of the multi-index Mittag-Leffler functions are discussed. The convergence of series of such type functions in the complex plane is considered, and analogues of the Cauchy-Hadamard, Abel, Tauber and Littlewood theorems are provided.

  9. N- and O-linked glycosylation site profiling of the human basic salivary proline-rich protein 3M.

    PubMed

    Manconi, Barbara; Cabras, Tiziana; Sanna, Monica; Piras, Valentina; Liori, Barbara; Pisano, Elisabetta; Iavarone, Federica; Vincenzoni, Federica; Cordaro, Massimo; Faa, Gavino; Castagnola, Massimo; Messana, Irene

    2016-05-01

    In the present study, we show that the heterogeneous mixture of glycoforms of the basic salivary proline-rich protein 3M, encoded by PRB3-M locus, is a major component of the acidic soluble fraction of human whole saliva in the first years of life. Reversed-phase high-performance liquid chromatography with high-resolution electrospray ionization mass spectrometry analysis of the intact proteoforms before and after N-deglycosylation with Peptide-N-Glycosidase F and tandem mass spectrometry sequencing of peptides obtained after Endoproteinase GluC digestion allowed the structural characterization of the peptide backbone and identification of N- and O-glycosylation sites. The heterogeneous mixture of the proteoforms derives from the combination of 8 different neutral and sialylated glycans O-linked to Threonine 50, and 33 different glycans N-linked to Asparagine residues at positions 66, 87, 108, 129, 150, 171, 192, and 213. PMID:26991339

  10. Design of multichord Hα detector arrays for the U-3M torsatron and identification of rotating plasma perturbations

    NASA Astrophysics Data System (ADS)

    Dreval, M. B.; Shapoval, A. M.; Ozherelyev, F. I.; Makhov, M. M.

    2016-07-01

    An Hα camera has been designed and installed in the U-3M torsatron for spatially and temporally resolved measurements. This device provides fast measurements of the emission brightness profile in the noisy environment of the radio frequency (RF) heated plasma. Unusual topology of diagnostics and the data acquisition system are applied. All the system components, including digitizers, are assembled in a single unit. It allows the suppression of a low-frequency electromagnetic interference by eliminating the ground loops. And the suppression of RF noises is achieved by eliminating the signal interface cables and digital interface cables in the design. The Wi-Fi interface is used to prevent a ground loop in the data transfer stage. The achieved sensitivity of our diagnostics is high enough for measuring the Hα emission from the low-density (ne ≈ (1-2)ṡ1010 cm-3) plasma with a temporal resolution of about 20 μs in the noisy environment. Different types of Hα emission fluctuations within the frequency range of 1-5 kHz and poloidal mode numbers m = 0 and m = 5 have been observed in U-3M. A simple technique of the line-of-sight data analysis, based on the U-3M magnetic surface asymmetry, is proposed and used for the spatial localization of the rotating mode and for the determination of mode numbers and its poloidal rotation direction using a single Hα array.

  11. Design of multichord Hα detector arrays for the U-3M torsatron and identification of rotating plasma perturbations.

    PubMed

    Dreval, M B; Shapoval, A M; Ozherelyev, F I; Makhov, M M

    2016-07-01

    An Hα camera has been designed and installed in the U-3M torsatron for spatially and temporally resolved measurements. This device provides fast measurements of the emission brightness profile in the noisy environment of the radio frequency (RF) heated plasma. Unusual topology of diagnostics and the data acquisition system are applied. All the system components, including digitizers, are assembled in a single unit. It allows the suppression of a low-frequency electromagnetic interference by eliminating the ground loops. And the suppression of RF noises is achieved by eliminating the signal interface cables and digital interface cables in the design. The Wi-Fi interface is used to prevent a ground loop in the data transfer stage. The achieved sensitivity of our diagnostics is high enough for measuring the Hα emission from the low-density (ne ≈ (1-2)⋅10(10) cm(-3)) plasma with a temporal resolution of about 20 μs in the noisy environment. Different types of Hα emission fluctuations within the frequency range of 1-5 kHz and poloidal mode numbers m = 0 and m = 5 have been observed in U-3M. A simple technique of the line-of-sight data analysis, based on the U-3M magnetic surface asymmetry, is proposed and used for the spatial localization of the rotating mode and for the determination of mode numbers and its poloidal rotation direction using a single Hα array. PMID:27475555

  12. SF3M 2.0: improvement of 3D photo-reconstruction interface based on freely available software

    NASA Astrophysics Data System (ADS)

    Castillo, Carlos; James, Michael R.; Pérez, Rafael; Gómez, Jose A.

    2016-04-01

    During recent years, a number of tools based on Structure-from-Motion algorithms have been released for full image-based 3D reconstruction either freely (e.g. Bundler, PMVS2, VisualSFM, MicMac) or commercially (e.g. Agisoft PhotoScan). The SF3M interface was developed in Matlab® to use link software developments (VisualSFM, CloudCompare) and new applications to create a semi-automated workflow including reconstruction, georeferencing and point-cloud filtering, and has been tested for gully erosion assessment with terrestrial images (Castillo et al., 2015). The main aim of this work to provide an improved freely-available and easy-to-use alternative for 3D reconstruction intended for public agencies, non-profit organisations, researchers and other stakeholders interested in 3D modelling. In this communication we present SF3M 2.0, a new version of the graphical user interface. In this case, the SfM module is based on MicMac, an open-software tool (Pierrot-Deseilligny and Cléry, 2011) which provides advanced features such as camera calibration and constrained bundle adjustment using ground control points. SF3M 2.0 will be tested in two scenarios: a) using the same ground-based image set tested in Castillo et al. (2015) to compare the performance of both versions and b) using aerial images taken from a helium balloon to assess a gully network in a 40-hectares catchment. In this study we explore the advantages of SF3M 2.0, explain its operation and evaluate its accuracy and performance. This tool will be also available for free download. References Castillo, C., James, M.R., Redel-Macías, M. D., Pérez, R., and Gómez, J.A.: SF3M software: 3-D photo-reconstruction for non-expert users and its application to a gully network, SOIL, 1, 583-594. Pierrot-Deseilligny, M and Cléry, I. APERO, an Open Source Bundle Adjusment Software for Automatic Calibration and Orientation of a Set of Images. Proceedings of the ISPRS Commission V Symposium, Image Engineering and Vision

  13. The impact of Ghana’s R3M programme on the provision of safe abortions and postabortion care

    PubMed Central

    Sundaram, Aparna; Juarez, Fatima; Ahiadeke, Clement; Bankole, Akinrinola; Blades, Nakeisha

    2015-01-01

    In 2006, in response to the high maternal mortality, driven largely by unsafe abortions, the government of Ghana, in partnership with other organizations, launched the reducing maternal mortality and morbidity (R3M) programme in seven districts in Greater Accra, Ashanti and Eastern, to improve comprehensive abortion care services. This article examines whether this intervention made a difference to the provision of safe abortion services and postabortion care (PAC). We also examine the role played by provider attitudes and knowledge of the abortion law, on providers with clinical training in service provision. Primary data on health care providers in Ghana, collected using a quasi-experimental design, were analysed using propensity score weighting. Apart from the treatment group, the sample included two controls: (1) Districts in Accra, Ashanti and Eastern, not exposed to the treatment; and (2) Districts from distant Brong Ahafo, also not exposed to the treatment. The findings show that providers in the treatment group are nearly 16 times as likely to provide safe abortions compared with their peers in Brong Ahafo, and ∼2.5 times as likely compared with providers in the other control group. R3M providers were also different from their peers in providing PAC. Associations between provider attitudes and knowledge of the law on both outcomes were either non-significant or inconsistent including for providers with clinical knowledge of abortion provision. Provider confidence however is strongly associated with service provision. We conclude that the R3M programme is helping safe abortion provision, with the differences being greater with control groups that are geographically distant, perhaps owing to lower contamination from movement of providers between facilities. Increasing provider confidence is key to improving both safe abortion provision and PAC. PMID:25261230

  14. Genetic structure of the Caribbean giant barrel sponge Xestospongia muta using the I3-M11 partition of COI

    NASA Astrophysics Data System (ADS)

    López-Legentil, S.; Pawlik, J. R.

    2009-03-01

    In recent years, reports of sponge bleaching, disease, and subsequent mortality have increased alarmingly. Population recovery may depend strongly on colonization capabilities of the affected species. The giant barrel sponge Xestospongia muta is a dominant reef constituent in the Caribbean. However, little is known about its population structure and gene flow. The 5'-end fragment of the mitochondrial gene cytochrome oxidase subunit I is often used to address these kinds of questions, but it presents very low intraspecific nucleotide variability in sponges. In this study, the usefulness of the I3-M11 partition of COI to determine the genetic structure of X. muta was tested for seven populations from Florida, the Bahamas and Belize. A total of 116 sequences of 544 bp were obtained for the I3-M11 partition corresponding to four haplotypes. In order to make a comparison with the 5'-end partition, 10 sequences per haplotype were analyzed for this fragment. The 40 resulting sequences were of 569 bp and corresponded to two haplotypes. The nucleotide diversity of the I3-M11 partition (π = 0.00386) was higher than that of the 5'-end partition (π = 0.00058), indicating better resolution at the intraspecific level. Sponges with the most divergent external morphologies (smooth vs. digitate surface) had different haplotypes, while those with the most common external morphology (rough surface) presented a mixture of haplotypes. Pairwise tests for genetic differentiation among geographic locations based on F ST values showed significant genetic divergence between most populations, but this genetic differentiation was not due to isolation by distance. While limited larval dispersal may have led to differentiation among some of the populations, the patterns of genetic structure appear to be most strongly related to patterns of ocean currents. Therefore, hydrological features may play a major role in sponge colonization and need to be considered in future plans for management and

  15. IF-combined smRNA FISH reveals interaction of MCPIP1 protein with IER3 mRNA

    PubMed Central

    Kochan, Jakub; Wawro, Mateusz

    2016-01-01

    ABSTRACT MCPIP1 and IER3 are recently described proteins essential for maintenance of immune homeostasis. IER3 is involved in the regulation of apoptosis and differentiation and has been shown lately to protect activated T cells and macrophages from apoptosis. MCPIP1 is an RNase critical for controlling inflammation-related mRNAs. MCPIP1 interacts with and degrades a set of stem-loop-containing mRNAs (including IL-6). Our results demonstrate the involvement of MCPIP1 in the regulation of IER3 mRNA levels. A dual luciferase assay revealed that over-expression of MCPIP1 resulted in a decrease of luciferase activity in the samples co-transfected with constructs containing luciferase CDS attached to IER3 3′UTR. We identified a stem-loop structure similar to that described to be important for destabilization of the IL-6 mRNA by MCPIP1. Examination of IER3 3′UTR sequence, structure and evolutionary conservation revealed that the identified stem-loop is buried within a bigger element. Deletion of this fragment abolished the regulation of IER3 3′UTR-containing transcript by MCPIP1. Finally, using immunofluorescence-combined single-molecule RNA FISH we have shown that the MCPIP1 protein co-localizes with IER3 mRNA. By this method we also proved that the presence of the wild-type NYN/PIN-like domain of MCPIP1 correlated with the decreased level of IER3 mRNA. RNA immunoprecipitation further confirmed the interaction of MCPIP1 with IER3 transcripts in vivo. PMID:27256408

  16. 3M: Hutchinson Plant Focuses on Heat Recovery and Cogeneration during Plan-Wide Energy-Efficiency Assessment

    SciTech Connect

    2003-06-01

    3M performed a plant-wide energy efficiency assessment at its Hutchinson, Minnesota, plant to identify energy- and cost-saving opportunities. Assessment staff developed four separate implementation packages that represented various combinations of energy-efficiency projects involving chiller consolidation, air compressor cooling improvements, a steam turbine used for cogeneration, and a heat recovery boiler for two of the plant's thermal oxidizers. Staff estimated that the plant could save 6 million kWh/yr in electricity and more than 200,000 MMBtu/yr in natural gas and fuel oil, and avoid energy costs of more than $1 million during the first year.

  17. Design and performance estimate of a focal reducer for the 2.3 m Thai National Telescope.

    PubMed

    Buisset, Christophe; Deboos, Alexis; Lépine, Thierry; Poshyachinda, Saran; Soonthornthum, Boonrucksar

    2016-01-25

    We have designed a new kind of focal reducer for the 2.3 m Thai National Telescope (TNT) to image the TNT specified FOV Δθ = 14.6' with an angular resolution α ≈1.2 arcsec. This, at a minimum cost by using common glasses, spherical surfaces and by requiring comfortable mechanical tolerance. This focal reducer comprises 1 lens placed at the level of the fork entrance and 1 lens placed in front of the detector. In this paper, we present the focal reducer paraxial model, we describe the optical design and we present the performance. PMID:26832523

  18. Mutual transformation of light waves by reflection holograms in photorefractive crystals of the 4-bar 3m symmetry

    SciTech Connect

    Naunyka, V. N.; Shepelevich, V. V.

    2011-05-15

    The mutual transformation of light waves in the case of their simultaneous diffraction from a bulk reflection phase hologram, which was formed in a cubic photorefractive crystal of the 4-bar 3m symmetry class, has been studied. The indicator surfaces of the polarization-optimized values of the relative intensity of the object wave, which make it possible to determine the amplification of this wave for any crystal cut, are constructed. The linear polarization azimuths at which the energy exchange between the light waves reaches a maximum are found numerically for crystals of different cuts.

  19. Structural, electronic and optical properties of Li intercalated on MO3 (M: Mo, W): A first principle investigation

    NASA Astrophysics Data System (ADS)

    Mahmoudi, A.; Faraoun, H. I.; Benabadji, M. K.; Abdellaoui, I.; Dergal, M.

    2016-03-01

    The correlations between electronic and optical properties of pure MO3 (M=Mo, W) and the effect of Li intercalated in the matrix are investigated within density functional theory using both the revised gradient-corrected Perdew-Burke-Ernzerhof (GGA-PBE), GGA+U and HSE06 functional frameworks along with ab initio pseudopotentials method. Calculation performed with HSE06 functional proves that all these compounds are wide band gap semiconductors. The energy gap value is found to decrease with lithium incorporation, affecting the visible absorption coefficients.

  20. Protrusion-localized STAT3 mRNA promotes metastasis of highly metastatic hepatocellular carcinoma cells in vitro

    PubMed Central

    Liu, Yan-hong; Jin, Jia-lu; Wang, Yu-zhe; Tan, Ying; Zhou, Ying-ying; Peng, Ting; Li, Feng; Liang, Wan-dong; Chartrand, Pascal; Jiang, Yu-yang; Shen, Zhi-fa

    2016-01-01

    Aim: Recent evidence shows that localization of mRNAs and their protein products at cellular protrusions plays a decisive function in the metastasis of cancer cells. The aim of this study was to identify the variety of proteins encoded by protrusion-localized mRNAs and their roles in the metastasis and invasion of liver cancer cells. Methods: Highly metastatic hepatocellular carcinoma cell line HCCLM3 and non-metastatic hepatocellular carcinoma cell line SMMC-7721 were examined. Cell protrusions (Ps) were separated from cell bodies (CB) using a Boyden chamber assay; total mRNA population in CB and Ps fractions was analyzed using high-throughput direct RNA sequencing. The localization of STAT3 mRNA and protein at Ps was confirmed using RT-qPCR, RNA FISH, and immunofluorescence assays. Cell migration capacity and invasiveness of HCCLM3 cells were evaluated using MTT, wound healing migration and in vitro invasion assays. The interaction between Stat3 and growth factor receptors was explored with co-immunoprecipitation assays. Results: In HCCLM3 cells, 793 mRNAs were identified as being localized in the Ps fraction according to a cut-off value (Ps/CB ratio) >1.6. The Ps-localized mRNAs could be divided into 4 functional groups, and were all closely related to the invasive and metastatic properties. STAT3 mRNA accumulated in the Ps of HCCLM3 cells compared with non-metastatic SMMC-7721 cells. Treatment of HCCLM3 cells with siRNAs against STAT3 mRNA drastically decreased the cell migration and invasion. Moreover, Ps-localized Stat3 was found to interact with pseudopod-enriched platelet-derived growth factor receptor tyrosine kinase (PDGFRTK) in a growth factor-dependent manner. Conclusion: This study reveals STAT3 mRNA localization at the Ps of metastatic hepatocellular carcinoma HCCLM3 cells by combining application of genome-wide and gene specific description and functional analysis. PMID:27133294

  1. Design and construction of 2 transonic airfoil models for tests in the NASA Langley C.3-M TCT

    NASA Technical Reports Server (NTRS)

    Schaechterle, G.; Ludewig, K. H.; Stanewsky, E.; Ray, E. J.

    1982-01-01

    As part of a NASA/DFVLR cooperation program two transonic airfoils were tested in the NASA Langley 0.3-m TCT. Model design and construction was carried out by DFVLR. The models designed and constructed performed extremely well under cryogenic conditions. Essentially no permanent changes in surface quality and geometric dimensions occurred during the tests. The aerodynamic results from the TCT tests which demonstrate the large sensitivity of the airfoil CAST 10-Z/DOAZ to Reynolds number changes compared well with results from other facilities at ambient temperatures.

  2. In situ study of the R{bar 3}c-R{bar 3}m orientational disorder in calcite.

    SciTech Connect

    Antao, S. M.; Hassan, I.; Mulder, W. H.; Lee, P. L.; Toby, B. H.; X-Ray Science Division; Univ. of West Indies

    2009-01-01

    The temperature dependences of the crystal structure and intensities of the (113) and (211) reflections in calcite, CaCO{sub 3}, were studied using Rietveld structure refinements based on synchrotron powder X-ray diffraction data. Calcite transforms from R{bar 3}c to R{bar 3}m at about T{sub c} = 1240 K. A CO{sub 3} group occupies, statistically, two positions with equal frequency in the disordered R{bar 3}m phase, but with unequal frequency in the partially ordered R{bar 3}c phase. One position for the CO{sub 3} group is rotated by 180{sup o} with respect to the other. The unequal occupancy of the two orientations in the partially ordered R{bar 3}c phase is obtained directly from the occupancy factor, x, for the O1 site and gives rise to the order parameter, S = 2x - 1. The a cell parameter shows a negative thermal expansion at low T, followed by a plateau region at higher T, then a steeper contraction towards T{sub c}, where the CO{sub 3} groups disorder in a rapid process. Using a modified Bragg-Williams model, fits were obtained for the order parameter S, and for the intensities of the (113) and (211) reflections.

  3. Anatomical characterization of bombesin receptor subtype-3 mRNA expression in the rodent central nervous system.

    PubMed

    Zhang, Li; Parks, Gregory S; Wang, Zhiwei; Wang, Lien; Lew, Michelle; Civelli, Olivier

    2013-04-01

    Bombesin receptor subtype-3 (BRS-3) is an orphan G-protein-coupled receptor (GPCR) involved in the regulation of energy homeostasis. Mice deficient in BRS-3 develop late-onset mild obesity with metabolic defects, while synthetic agonists activating BRS-3 show antiobesity profiles by inhibiting food intake and increasing metabolic rate in rodent models. The molecular mechanisms and the neural circuits responsible for these effects, however, remain elusive and demand better characterization. We report here a comprehensive mapping of BRS-3 mRNA in the rat and mouse brain through in situ hybridization. Furthermore, to investigate the neurochemical characteristics of the BRS-3-expressing neurons, double in situ hybridization was performed to determine whether BRS-3 colocalizes with other neurotransmitters or neuropeptides. Many, but not all, of the BRS-3-expressing neurons were found to be glutamatergic, while few were found to be cholinergic or GABAergic. BRS-3-containing neurons do not express some of the well-characterized neuropeptides, such as neuropeptide Y (NPY), proopiomelanocortin (POMC), orexin/hypocretin, melanin-concentrating hormone (MCH), thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH), and kisspeptin. Interestingly, BRS-3 mRNA was found to partially colocalize with corticotropin-releasing factor (CRF) and growth hormone-releasing hormone (GHRH), suggesting novel interactions of BRS-3 with stress- and growth-related endocrine systems. Our study provides important information for evaluating BRS-3 as a potential therapeutic target for the treatment of obesity. PMID:22911445

  4. Photoelectron velocity-map imaging and theoretical studies of heteronuclear metal carbonyls MNi(CO)3 (-) (M = Mg, Ca, Al).

    PubMed

    Xie, Hua; Zou, Jinghan; Yuan, Qinqin; Fan, Hongjun; Tang, Zichao; Jiang, Ling

    2016-03-28

    The heteronuclear metal carbonyl anions MNi(CO)3 (-) (M = Mg, Ca, Al) have been investigated using photoelectron velocity-map imaging spectroscopy. Electron affinities of neutral MNi(CO)3 (M = Mg, Ca, Al) are measured from the photoelectron spectra to be 1.064 ± 0.063, 1.050 ± 0.064, and 1.541 ± 0.040 eV, respectively. The C-O stretching mode in these three clusters is observed and the vibrational frequency is determined to be 2049, 2000, and 2041 cm(-1) for MgNi(CO)3, CaNi(CO)3, and AlNi(CO)3, respectively. Density functional theory calculations are carried out to elucidate the geometric and electronic structures and to aid the experimental assignments. It has been found that three terminal carbonyls are preferentially bonded to the nickel atom in these heterobinuclear nickel carbonyls MNi(CO)3 (-1/0), resulting in the formation of the Ni(CO)3 motif. Ni remains the 18-electron configuration for MgNi(CO)3 and CaNi(CO)3 neutrals, but not for AlNi(CO)3. This is different from the homobinuclear nickel carbonyl Ni-Ni(CO)3 with the involvement of three bridging ligands. Present findings would be helpful for understanding CO adsorption on alloy surfaces. PMID:27036444

  5. Photoelectron velocity-map imaging and theoretical studies of heteronuclear metal carbonyls MNi(CO)3- (M = Mg, Ca, Al)

    NASA Astrophysics Data System (ADS)

    Xie, Hua; Zou, Jinghan; Yuan, Qinqin; Fan, Hongjun; Tang, Zichao; Jiang, Ling

    2016-03-01

    The heteronuclear metal carbonyl anions MNi(CO)3- (M = Mg, Ca, Al) have been investigated using photoelectron velocity-map imaging spectroscopy. Electron affinities of neutral MNi(CO)3 (M = Mg, Ca, Al) are measured from the photoelectron spectra to be 1.064 ± 0.063, 1.050 ± 0.064, and 1.541 ± 0.040 eV, respectively. The C-O stretching mode in these three clusters is observed and the vibrational frequency is determined to be 2049, 2000, and 2041 cm-1 for MgNi(CO)3, CaNi(CO)3, and AlNi(CO)3, respectively. Density functional theory calculations are carried out to elucidate the geometric and electronic structures and to aid the experimental assignments. It has been found that three terminal carbonyls are preferentially bonded to the nickel atom in these heterobinuclear nickel carbonyls MNi(CO)3-1/0, resulting in the formation of the Ni(CO)3 motif. Ni remains the 18-electron configuration for MgNi(CO)3 and CaNi(CO)3 neutrals, but not for AlNi(CO)3. This is different from the homobinuclear nickel carbonyl Ni-Ni(CO)3 with the involvement of three bridging ligands. Present findings would be helpful for understanding CO adsorption on alloy surfaces.

  6. Evaluation of the 3M Petrifilm Enterobacteriaceae Count plate method for the enumeration of Enterobacteriaceae in foods.

    PubMed

    Silbernagel, Karen M; Lindberg, Kathryn G

    2002-09-01

    Results of the 3M Petrifilm Enterobacteriaceae Count (EB) plate method were compared with those of the standard violet red bile glucose agar (VRBG) method for the detection and enumeration of Enterobacteriaceae. Studies involving 107 bacterial strains demonstrated that the Petrifilm EB plate method is as sensitive as and more selective than the VRBG method. Sixty of the 62 pure Enterobacteriaceae cultures were recovered by both methods. In addition, 38 of the 45 non-Enterobacteriaceae organisms did not grow on the Petrifilm EB plate, while 28 of the 45 non-Enterobacteriaceae organisms did not grow on the VRBG plate. Colony counts from 174 naturally contaminated and 120 artificially inoculated dairy and nondairy food samples showed that the Petrifilm EB plate method performed as well as or better than the standard VRBG method for the enumeration of Enterobacteriaceae. PMID:12233857

  7. Measurement of recovery temperature on an airfoil in the Langley 0.3-m transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Adcock, J. B.

    1981-01-01

    Experimental measurements of recovery temperature were made on an airfoil in the Langley 0.3-m Transonic Cryogenic Tunnel at Mach numbers of 0.60 and 0.84 over a Reynolds number per meter range from about 15,000,000 to about 335,000,000. The measured recovery temperatures were considerably below those associated with ideal-gas ambient temperature wind tunnels. This difference was accentuated as the stagnation pressure increased and the total temperature decreased. A boundary-layer code modified for use with cryogenic nitrogen adequately predicted the measured adiabatic wall temperature at all conditions. A quantitative, on-line assessment of the nonadiabatic condition of a model can be made during the operation of a cryogenic wind tunnel by using a correlation for the adiabatic wall temperature which is only a function of total temperature, total pressure, and local Mach number on the model.

  8. CUL9 mediates the functions of the 3M complex and ubiquitylates survivin to maintain genome integrity

    PubMed Central

    Li, Zhijun; Pei, Xin-Hai; Yan, Jun; Yan, Feng; Cappell, Kathryn M.; Whitehurst, Angelique W.; Xiong, Yue

    2014-01-01

    SUMMARY The Cullin 9 (CUL9) gene encodes a putative E3 ligase that localizes in the cytoplasm. Cul9 null mice develop spontaneous tumors in multiple organs, however either the cellular or molecular mechanisms of CUL9 in tumor suppression are currently not known. We show here that deletion of Cul9 leads to abnormal nuclear morphology, increased DNA damage and aneuploidy. CUL9 knockdown rescues the microtubule and mitosis defects in cells depleted for CUL7 or OBSL1, two genes that are mutated in a mutually exclusive manner in 3M growth retardation syndrome and function in microtubule dynamics. CUL9 promotes the ubiquitylation and degradation of survivin and is inhibited by CUL7. Depletion of CUL7 decreases survivin level and overexpression of survivin rescues the defects caused by CUL7 depletion. We propose a 3M–CUL9-survivin pathway in maintaining microtubule and genome integrity, normal development and tumor suppression. PMID:24793696

  9. Magnetic properties of Co 1- xM xPt 3 (M  Mn, Fe) compounds with competing interactions

    NASA Astrophysics Data System (ADS)

    Kim, T. H.; Dinia, A.; Cadeville, M. C.

    1995-02-01

    Magnetic properties of the pseudo-binary Co 1- xM xPt 3 (M  Mn, Fe) compounds have been investigated. Under adequate preparation conditions, these compounds display the L1 2 structure. For M  Mn the magnetic phase diagram presents a continuous ferromagnetic region from CoPt 3 to MnPt 3 with a re-entrant spin glass (RSG) phase emerging at low T and H between x = 0.2 and 0.6. For M  Fe, a spin glass (SG) phase separates the ferromagnetic region on the Co-rich side, from the antiferromagnetic region on the Fe-rich side. The results are qualitatively discussed in terms of the three dominant competing magnetic interactions JCoCo, JCoM, JMM.

  10. Piezoelectric Enhancement of (PbTiO3)m/(BaTiO3)n Ferroelectric Superlattices through Domain Engineering

    SciTech Connect

    Hong, Liang; Wu, Pingping; Li, Yulan; Gopalan, Venkatraman; Eom, C.B.; Schlom, Darrell G.; Chen, Long-Qing

    2014-11-20

    The phase diagram of (PbTiO3)m/(BaTiO3)n ferroelectric superlattices was computed using the phase-field approach as a function of layer volume fraction and biaxial strain to tune ferroelectric properties through domain engineering. Two interesting domain structures are found: one with mixed Bloch-Néel-Ising domain wall structures and the other with stabilized monoclinic phases. The polarization of the monoclinic phase is able to rotate from out-of-plane to in-plane or vice versa under an electric field, and thus facilitates the domain reversal of rhombohedral domains. This contributes significantly to both reduced coercive fields and enhanced piezoelectric responses.

  11. Trends in (LaMnO3)n/(SrTiO3)m superlattices with varying layer thicknesses

    PubMed Central

    Jilili, J.; Cossu, F.; Schwingenschlögl, U.

    2015-01-01

    We investigate the thickness dependence of the structural, electronic, and magnetic properties of (LaMnO3)n/(SrTiO3)m (n, m = 2, 4, 6, 8) superlattices using density functional theory. The electronic structure turns out to be highly sensitive to the onsite Coulomb interaction. In contrast to bulk SrTiO3, strongly distorted O octahedra are observed in the SrTiO3 layers with a systematic off centering of the Ti atoms. The systems favour ferromagnetic spin ordering rather than the antiferromagnetic spin ordering of bulk LaMnO3 and all show half-metallicity, while a systematic reduction of the minority spin band gaps as a function of the LaMnO3 and SrTiO3 layer thicknesses originates from modifications of the Ti dxy states. PMID:26323361

  12. Competition between splicing and polyadenylation reactions determines which adenovirus region E3 mRNAs are synthesized

    SciTech Connect

    Brady, H.A.; Wold, W.S.M.

    1988-08-01

    Complex transcription units encode multiple mRNAs which arise by alternative processing of a common pre-mRNA precursor. It is not known how the pre-mRNA processing pathways are determined or controlled. The authors are investigating this problem by using the E3 complex transcription unit of adenovirus as a model. Their approach is to construct virus mutants with lesions in E3 and then determine how the mutation affects the accumulation of E3 mRNAs in vivo. They report results which indicate that competition between splicing reactions and polyadenylation reactions occurs in vivo and that this plays an important role in alternative pre-mRNA processing.

  13. Characteristics of the three-half-turn-antenna-driven RF discharge in the Uragan-3M torsatron

    SciTech Connect

    Grigor’eva, L. I.; Chechkin, V. V. Moiseenko, V. E.; Grekov, D. L.; Pavlichenko, R. O.; Lozin, A. V.; Tarasov, I. K.; Kulaga, A. Ye.; Zamanov, N. V.; Tretiak, K. K.; Kozulya, M. M.; Beletskii, A. A.; Kasilov, A. A.; Mironov, Yu. K.; Romanov, V. S.; Voitsenya, V. S.

    2015-12-15

    In the ℓ = 3 Uragan-3M torsatron hydrogen plasma is produced by RF fields in the Alfvén range of frequencies (ω ≤ ω{sub ci}). The initial (target) plasma with the line-averaged density of units 10{sup 12} cm{sup −3} is produced by a frame antenna with a broad spectrum of generated parallel wavenumbers. After this, to heat the plasma and bring its density to ∼10{sup 13} cm{sup –3}, another, shorter wavelength three-half-turn antenna with large transverse currents is used. The behavior of the density, electron temperature, and loss of the plasma supported by the three-half-turn antenna is studied depending on the RF power fed to the antenna and initial values of the density and electron temperature supplied by the frame antenna.

  14. Theoretical electronic structures and relative stabilities of the spinel oxynitrides M3NO3 (M=B,Al,Ga,In)

    NASA Astrophysics Data System (ADS)

    Okeke, Onyekwelu U.; Lowther, J. E.

    2008-03-01

    A spinel structure of an oxynitride material in the form M3NO3 ( M=B , Al, Ga, or In) is considered to be derived from a reaction of the form MN+M2O3→M3NO3 . Various possible phases of MN and M2O3 , which could lead to the M3NO3 spinel material, are considered. The spinels containing B and Al exhibit higher resistance to compression and shear than those containing Ga and In, and these are suggested to be potentially important hard materials possibly formed under extreme conditions. Calculated energetics of the proposed reaction favor the formation of spinels containing Ga and In with such materials having potentially significant optoelectronic applications.

  15. The structural and electronic properties of cubic AgMO3 (M=Nb, Ta) by first principles calculations

    NASA Astrophysics Data System (ADS)

    Prasad, K. Ganga; Niranjan, Manish K.; Asthana, Saket

    2016-05-01

    We report the electronic structure of the AgMO3(M=Nb, Ta) within the frame work of density functional theory and calculations are performed within the generalized gradient approximation (GGA) by using ultrasoft pseudopotentials. The calculated equilibrium lattice parameters and volumes are extracted from fitting of Birch third order equation of state and which are reasonable agreement with the available experimental results. The density of states,band structure of Ag(Nb,Ta)O3 reveals that the valance bands mostly occupied with O-2p and O-2s states and whereas conduction band occupied with Nb (Ta) 4d(5d) states including less contribution from Ag 5s states.

  16. Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

    NASA Astrophysics Data System (ADS)

    Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lerot, C.; Loyola, D.; Määttä, A.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

    2015-07-01

    The three GOME-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 products are important e.g. for air quality studies, climate modeling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as trace gas columns (NO2, BrO, H2CO, H2O, SO2), tropospheric columns of NO2, total ozone columns and vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices from the main science channels as well as from the polarization channels (AAI, AAI-PMD), Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Ozone Monitoring and Atmospheric Composition Satellite Application Facility (O3M SAF) processing and data dissemination is operational and running 24/7. Data quality is quarantined by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This is an overview paper providing the O3M SAF project background, current status and future plans to utilization of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with the product sample images. Furthermore, this paper collects the references to the detailed product algorithm and validation papers.

  17. Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

    NASA Astrophysics Data System (ADS)

    Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kauppi, A.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lang, R.; Lerot, C.; Loyola, D.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

    2016-02-01

    The three Global Ozone Monitoring Experiment-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 (Global Ozone Monitoring Experiment-2) products are important e.g. for air quality studies, climate modelling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as ozone and minor trace gas columns (NO2, BrO, HCHO, H2O, SO2), vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices, surface Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) processes and disseminates data 24/7. Data quality is guaranteed by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This paper provides an overview of the O3M SAF project background, current status and future plans for the utilisation of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with sample images. Furthermore, this paper collects references to the detailed product algorithm and validation papers.

  18. KIF14 and E2F3 mRNA expression in human retinoblastoma and its phenotype association

    PubMed Central

    Mitra, Moutushy; Mallikarjuna, Kandalam; Pranav, Oberoi; Srinivasan, Ramalingam; Nagpal, Amit; Venkatesan, Perumal; Kumaramanickavel, Govindasamy

    2009-01-01

    Purpose We quantified mRNA expression of candidate genes for proliferation (KIF14 and E2F3) in a large retinoblastoma tumor cohort and associated with disease phenotype. Methods KIF14 and E2F3 mRNA expression was quantified by real time PCR in 57 retinoblastoma (RB) tumors, 3 RB cell lines, and control samples that included 4 each fetal, age-matched, adult retinas. Immunohistochemistry was done to confirm KIF14 and E2F3 protein expression in tumor cells. The mRNA expression levels were correlated with disease phenotypes including the significance of chemotherapy on tumors. Results There was statistically significant overexpression of KIF14 and E2F3 mRNA in tumors compared with control retinas (p<0.0001). Further, E2F3 also showed a significant overexpression compared to RB cell lines (p=0.01). Immunohistochemistry confirmed KIF14 and E2F3 protein overexpression in tumor cells. KIF14 had significant mRNA overexpression with older age (p=0.01) in presenting patients and in unilateral RB patients (p=0.04). Chemotherapy-treated tumors showed a significant decrease in KIF14 and E2F3 expression compared to untreated tumors (p<0.01 and 0.001, respectively). Conclusions This report confirms significant mRNA overexpression of KIF14 and E2F3 together in a large cohort of RB tumors. The decreased expression in chemotherapy treated cases needs further validation in a large chemotherapy-treated cohort. PMID:19190782

  19. Structural, magnetic and electrical properties of the hexagonal ferrites MFeO{sub 3} (M=Y, Yb, In)

    SciTech Connect

    Downie, Lewis J.; Goff, Richard J.; Kockelmann, Winfried; Forder, Sue D.; Parker, Julia E.; Morrison, Finlay D.; Lightfoot, Philip

    2012-06-15

    The hexagonal ferrites MFeO{sub 3} (M=Y, Yb, In) have been studied using a combination of neutron and X-ray powder diffraction, magnetic susceptibility, dielectric measurements and {sup 57}Fe Moessbauer spectroscopy. This study confirms the previously reported crystal structure of InFeO{sub 3} (YAlO{sub 3} structure type, space group P6{sub 3}/mmc), but YFeO{sub 3} and YbFeO{sub 3} both show a lowering of symmetry to at most P6{sub 3}cm (ferrielectric YMnO{sub 3} structure type). However, Moessbauer spectroscopy shows at least two distinct Fe sites for both YFeO{sub 3} and YbFeO{sub 3} and we suggest that the best model to rationalise this involves phase separation into more than one similar hexagonal YMnO{sub 3}-like phase. Rietveld analysis of the neutron diffraction data was carried out using two hexagonal phases as a simplest case scenario. In both YFeO{sub 3} and YbFeO{sub 3}, distinct dielectric anomalies are observed near 130 K and 150 K, respectively. These are tentatively correlated with weak anomalies in magnetic susceptibility and lattice parameters, for YFeO{sub 3} and YbFeO{sub 3}, respectively, which may suggest a weak magnetoelectric effect. Comparison of neutron and X-ray powder diffraction shows evidence of long-range magnetic order in both YFeO{sub 3} and YbFeO{sub 3} at low temperatures. Due to poor sample crystallinity, the compositional and structural effects underlying the phase separation and possible magnetoelectric phenomena cannot be ascertained. - Graphical abstract: Hexagonal MFeO{sub 3} (M=Y, Yb) exhibit phase separation into two YMnO{sub 3}-like phases. Variable temperature crystallographic, electrical and magnetic studies suggest weak correlations between electrical and magnetic responses and long-range magnetic order at low temperature. Highlights: Black-Right-Pointing-Pointer Multi-technique study of multiferroic hexagonal MFeO{sub 3}. Black-Right-Pointing-Pointer Phase separation into two similar hexagonal phases. Black

  20. Study of d -electron correlations in skutterudite-related Ce3M4 Sn13 (M =Co , Ru, and Rh)

    NASA Astrophysics Data System (ADS)

    Ślebarski, A.; Goraus, J.; Witas, P.; Kalinowski, L.; Fijałkowski, M.

    2015-01-01

    We investigate the electronic structure of the skutterudite-related Ce3M4Sn13 compounds, where metal M is Co, Ru, or Rh, using x-ray photoemission spectroscopy (XPS) and band structure calculations, both within local density approximation scheme and within scheme including additional Coulomb correlations (LDA+U ). The d -electron states located near the Fermi level slightly change the intensity with applying the correlation energy U . We note the large impact of d -electron correlation, which is clearly observed in the change of Ce 5 p states located about 18 eV in the valence band. Namely, for Ce3Rh4Sn13 and Ce3Ru4Sn13 the d -electron correlations significantly shift the 5 p states towards higher binding energies, while for Ce3Co4Sn13 the energy of the Ce 5 p states almost does not depend on U . The influence of the d -electron correlations is also manifested by the positive magnetoresistivity (MR) of Ce3Rh4Sn13 and the Ce3 -xLaxRh4Sn13 alloys that reaches 40% at the highest magnetic field (B =9 T) for the sample x =0.6 , whereas only a small positive MR˜0.5 % is observed in Ce3Ru4Sn13 . The magnetoresistivity of Ce3Co4Sn13 exhibits quite different behavior and is negative.

  1. Fluoride-bridged {Gd(III)3M(III)2} (M = Cr, Fe, Ga) molecular magnetic refrigerants.

    PubMed

    Pedersen, Kasper S; Lorusso, Giulia; Morales, Juan José; Weyhermüller, Thomas; Piligkos, Stergios; Singh, Saurabh Kumar; Larsen, Dennis; Schau-Magnussen, Magnus; Rajaraman, Gopalan; Evangelisti, Marco; Bendix, Jesper

    2014-02-24

    The reaction of fac-[M(III)F3(Me3tacn)]⋅x H2O with Gd(NO3)3⋅5H2O affords a series of fluoride-bridged, trigonal bipyramidal {Gd(III)3M(III)2} (M = Cr (1), Fe (2), Ga (3)) complexes without signs of concomitant GdF3 formation, thereby demonstrating the applicability even of labile fluoride-complexes as precursors for 3d-4f systems. Molecular geometry enforces weak exchange interactions, which is rationalized computationally. This, in conjunction with a lightweight ligand sphere, gives rise to large magnetic entropy changes of 38.3 J kg(-1)  K(-1) (1) and 33.1 J kg(-1)  K(-1) (2) for the field change 7 T→0 T. Interestingly, the entropy change, and the magnetocaloric effect, are smaller in 2 than in 1 despite the larger spin ground state of the former secured by intramolecular Fe-Gd ferromagnetic interactions. This observation underlines the necessity of controlling not only the ground state but also close-lying excited states for successful design of molecular refrigerants. PMID:24574031

  2. Encapsulating MAl 2O 4:Eu 2+, Dy 3+ (M = Sr, Ca, Ba) phosphors with triethanolamine to enhance water resistance

    NASA Astrophysics Data System (ADS)

    Ji, Ping Ting; Chen, Xiang Ying; Wu, Ye Qin

    2011-12-01

    Traditional aluminates phosphors with persistent luminescence are chemically unstable to water or moisture. Thus, how to improve the water-resistance of these phosphors is becoming a key issue in their practical applications. In this work, a series of alkaline earth aluminate phosphors including MAl 2O 4:Eu 2+, Dy 3+ (M = Sr, Ca, Ba) have been prepared by a co-precipitation synthesis and postannealing approach, using 8-hydroxyquinoline and sodium oxalate as precipitants. The samples before and after encapsulation were well characterized by means of XRPD, FESEM, FT-IR, TGA-DTG and PL techniques as well as water resistance measurements. The precipitants involved can react with Al 3+ and Sr 2+ (or Ca 2+, Ba 2+) to form complex compounds in aqueous solution, which further convert into porous phosphors by postannealing method under reducing atmosphere. Next, triethanolamine encapsulation at room temperature was conducted onto their surfaces to improve the water resistance. The results reveal that the encapsulation of aluminate phosphors with triethanolamine can effectively enhance the water resistance, and minimally affect on persistent phosphorescence.

  3. SALMO and S3M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies

    PubMed Central

    De Stefano, Concetta

    2015-01-01

    A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium in in vitro equilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, and temperature changes. To simplify equilibrium calculations, a plain approach is also proposed, in order to take into account all the interactions among the major components of saliva, by considering the inorganic components of saliva as a single 1 : 1 salt (MX), whose concentration is cMX = (1/2)∑ci (ci = analytical concentration of all the ions) and z ion charge calculated as z=±(I/cMX)1/2 = ±1.163. The use of the Single Saliva Salt Model (S3M) considerably reduces the complexity of the systems to be investigated. In fact, only four species deriving from internal ionic medium interactions must be considered. PMID:25733975

  4. Tektronix color fiber optic tube for exposure of Mead Imaging's Cycolor and 3M's full-color dry silver media

    NASA Astrophysics Data System (ADS)

    McGlothlan, J. Kirk

    1990-08-01

    The Tektronix CFOT was used to expose Mead Cycolor and 3M dry silver photosensitive media. The results are presented and compared. The color gamut time to complete exposure and discernible resolution for the media are compared. Reciprocity failure and methods of minimizing the problems associated with it are discussed. The interactions between reciprocity failure and exposure time are discussed. The color coordinates attainable on the exposed media were determined by adjusting the paper feed speed and the intensity of the CFOT to obtain a range of exposures up to and beyond complete exposure. The CIELa*b* color coordinates of the media were measured with a Minolta color meter (Chroma Meter II). The discernible resolution was measured by exposing a 32 x 32 dot matrix on the media and then shrinking the dot to dot spacing between subsequent exposures to obtain a range of dot to dot spacings corresponding to resolutions ranging from 150 to 300 DPI. The exposed media was then examined under magnification to determine where uniform color fill was achieved. 1. CATHODE RAY TUBE DESCRIPTION The CFOT is a line scan tube with a fiber optic faceplate designed for producing full color hard copy on optically sensitive media. The tube has 3 stripes of phosphor each approximately . 060 inches wide by 8 inches long. The three phosphors are red green and blue enabling full color hard copy by sequentially

  5. Calculation of design load for the MOD-5A 7.3 mW wind turbine system

    NASA Technical Reports Server (NTRS)

    Mirandy, L.; Strain, J. C.

    1995-01-01

    Design loads are presented for the General Electric MOD-SA wind turbine. The MOD-SA system consists of a 400 ft. diameter, upwind, two-bladed, teetered rotor connected to a 7.3 mW variable-speed generator. Fatigue loads are specified in the form of histograms for the 30 year life of the machine, while limit (or maximum) loads have been derived from transient dynamic analysis at critical operating conditions. Loads prediction was accomplished using state of the art aeroelastic analyses developed at General Electric. Features of the primary predictive tool - the Transient Rotor Analysis Code (TRAC) are described in the paper. Key to the load predictions are the following wind models: (1) yearly mean wind distribution; (2) mean wind variations during operation; (3) number of start/shutdown cycles; (4) spatially large gusts; and (5) spatially small gusts (local turbulence). The methods used to develop statistical distributions from load calculations represent an extension of procedures used in past wind programs and are believed to be a significant contribution to Wind Turbine Generator analysis. Test/theory correlations are presented to demonstrate code load predictive capability and to support the wind models used in the analysis. In addition MOD-5A loads are compared with those of existing machines. The MOD-5A design was performed by the General Electric Company, Advanced Energy Program Department, under Contract DEN3-153 with NASA Lewis Research Center and sponsored by the Department of Energy.

  6. Technical note: Monte Carlo derivation of TG-43 dosimetric parameters for radiation therapy resources and 3M Cs-137 sources.

    PubMed

    Pérez-Calatayud, J; Granero, D; Ballester, F; Casal, E; Cases, R; Agramunt, S

    2005-08-01

    In clinical brachytherapy dosimetry, a detailed dose rate distribution of the radioactive source in water is needed in order to plan for quality treatment. Two Cs-137 sources are considered in this study; the Radiation Therapy Resources 67-800 source (Radiation Therapy Resources Inc., Valencia, CA) and the 3M model 6500/6D6C source. A complete dosimetric dataset for both sources has been obtained by means of the Monte Carlo GEANT4 code. Dose rate distributions are presented in two different ways; following the TG43 formalism and in a 2D rectangular dose rate table. This 2D dose rate table is helpful for the TPS quality control and is fully consistent with the TG43 dose calculation formalism. In this work, several improvements to the previously published data for these sources have been included: the source asymmetries were taken explicitly into account in the MC calculations, TG43 data were derived directly from MC calculations, the data radial range was increased, the angular grid in the anisotropy function was increased, and TG43 data is now consistent with the along and away dose rate table as recommended by the TG43 update. PMID:16193775

  7. Technical note: Monte Carlo derivation of TG-43 dosimetric parameters for radiation therapy resources and 3M Cs-137 sources

    SciTech Connect

    Perez-Calatayud, J.; Granero, D.; Ballester, F.; Casal, E.; Cases, R.; Agramunt, S.

    2005-08-15

    In clinical brachytherapy dosimetry, a detailed dose rate distribution of the radioactive source in water is needed in order to plan for quality treatment. Two Cs-137 sources are considered in this study; the Radiation Therapy Resources 67-800 source (Radiation Therapy Resources Inc., Valencia, CA) and the 3M model 6500/6D6C source. A complete dosimetric dataset for both sources has been obtained by means of the Monte Carlo GEANT4 code. Dose rate distributions are presented in two different ways; following the TG43 formalism and in a 2D rectangular dose rate table. This 2D dose rate table is helpful for the TPS quality control and is fully consistent with the TG43 dose calculation formalism. In this work, several improvements to the previously published data for these sources have been included: the source asymmetries were taken explicitly into account in the MC calculations, TG43 data were derived directly from MC calculations, the data radial range was increased, the angular grid in the anisotropy function was increased, and TG43 data is now consistent with the along and away dose rate table as recommended by the TG43 update.

  8. Criticality calculations for the VR-1 reactor with IRT-3M-HEU fuel and IRT-4MLEU fuel.

    SciTech Connect

    Hanan, N. A.; Matos, J. E.

    2007-01-17

    At The request of the Czech Technical University in Prague, ANL has performed independent verification calculations using the MCNP Monte Carlo code for three core configurations of the VR-1 reactor: a current core configuration B1 with HEU (36%) IRT-3M fuel assemblies and planned core configurations C1 and C2 with LEU (19.7%) IRT-4M fuel assemblies. Details of these configurations were provided to ANL by CTU. For core configuration B1, criticality calculations were performed for two sets of control rod positions provided to ANL by CTU. For core configurations C1 and C2, criticality calculations were done for cases with all control rods at the top positions, all control rods at the bottom positions, and two critical states of the reactor for different control rod positions. In addition, sensitivity studies for variation of the {sup 235}U mass in each fuel assembly and variation of the fuel meat and cladding thicknesses in each of the fuel tubes were done for the C1 core configuration. Finally the reactivity worth of the individual control rods was calculated for the B1, C1, and C2 core configurations.

  9. MPO4:Nd3+ (M=Ca, Gd), Luminomagnetic Nanophosphors with Optical and Magnetic Features for Multimodal Imaging Applications

    NASA Astrophysics Data System (ADS)

    Rightsell, Chris; Mimun, Lawrence C.; Kumar, Ajith G.; Sardar, Dhiraj K.

    2015-03-01

    Nanomaterials with multiple functionalities play a very important role in several high technology applications. A major area of such applications is the biomedical industry, where contrast agents with multiple imaging modalities can provide better results than conventional materials. Many of the contrast agents available now have drawbacks such as toxicity, photobleaching, low contrast, size restrictions, and overall cost of the imaging system. Rare-earth doped inorganic nanophosphors are alternatives to circumvent several of these issues, together with the added advantage of super high resolution imaging due to the excellent near infrared sensitivity of the phosphors. In addition to optical imaging features, by adding a magnetic ion such as Gd3+ at suitable lattice positions, the phosphor can be made magnetic, yielding dual imaging functionalities. In this research, we are presenting the optical and magnetic imaging features of sub-nanometer size MPO4:Nd3+ (M=Ca, Gd) phosphors for the potential application of these nanophosphors as multimodal contrast agents. Cytotoxicity, in vitro and in vivo imaging, penetration depth etc. are studied for various phosphor compositions, and optimized compositions are explored. This research was funded by the National Science Foundation Partnerships for Research and Education in Materials (NSF-PREM) Grant N0-DMR-0934218.

  10. SOLITONS: Dark spatial optical solitons in planar gradient waveguides in the Z-cut of the 3m symmetry crystals

    NASA Astrophysics Data System (ADS)

    Frolova, M. N.; Borodin, M. V.; Shandarov, S. M.; Shandarov, V. M.; Larionov, Yu M.

    2003-11-01

    The propagation of light beams is studied in a planar photorefractive waveguide fabricated by high-temperature diffusion of metal ions in the Z-cut substrate of the 3m symmetry crystal. The wave equations are obtained for single-mode light beams with TE and TM polarisations in planar diffusion waveguides, which take into account the two-dimensional distribution of the optical field. Expressions are found for a nonlinear change in the refractive index when the photovoltaic mechanism makes a dominant contribution to the photorefractive effect. The propagation of single-mode light beams is analysed numerically for a Ti:Fe:LiNbO3 waveguide fabricated by the successive diffusion of titanium and iron into lithium niobate. It is shown that single-mode light beams with a smooth amplitude envelope can propagate without significant changes in the region of a dip in the intensity modelling a dark soliton. The relations between the amplitude and width of a dark spatial soliton are obtained for the TM modes of a photorefractive planar waveguide.

  11. Control system design for the MOD-5A 7.3 mW wind turbine generator

    NASA Technical Reports Server (NTRS)

    Barton, Robert S.; Hosp, Theodore J.; Schanzenbach, George P.

    1995-01-01

    This paper provides descriptions of the requirements analysis, hardware development and software development phases of the Control System design for the MOD-5A 7.3 mW Wind Turbine Generator. The system, designed by General Electric Company, Advanced Energy Programs Department, under contract DEN 3-153 with NASA Lewis Research Center and DOE, provides real time regulation of rotor speed by control of both generator torque and rotor torque. A variable speed generator system is used to provide both airgap torque control and reactive power control. The wind rotor is designed with segmented ailerons which are positioned to control blade torque. The central component of the control system, selected early in the design process, is a programmable controller used for sequencing, alarm monitoring, communication, and real time control. Development of requirements for use of aileron controlled blades and a variable speed generator required an analytical simulation that combined drivetrain, tower and blade elastic modes with wind disturbances and control behavior. An orderly two phase plan was used for controller software development. A microcomputer based turbine simulator was used to facilitate hardware and software integration and test.

  12. An intracellular redox sensor for reactive oxygen species at the M3-M4 linker of GABAAρ1 receptors

    PubMed Central

    Beltrán González, Andrea N; Gasulla, Javier; Calvo, Daniel J

    2014-01-01

    Background and Purpose Reactive oxygen species (ROS) are normally involved in cell oxidative stress but also play a role as cellular messengers in redox signalling; for example, modulating the activity of neurotransmitter receptors and ion channels. However, the direct actions of ROS on GABAA receptors were not previously demonstrated. In the present work, we studied the effects of ROS on GABAAρ1 receptor function. Experimental Approach GABAAρ1 receptors were expressed in oocytes and GABA-evoked responses electrophysiologically recorded in the presence or absence of ROS. Chemical protection of cysteines by selective sulfhydryl reagents and site-directed mutagenesis studies were used to identify protein residues involved in ROS actions. Key Results GABAAρ1 receptor-mediated responses were significantly enhanced in a concentration-dependent and reversible manner by H2O2. Potentiating effects were attenuated by a free radical scavenger, lipoic acid or an inhibitor of the Fenton reaction, deferoxamine. Each ρ1 subunit contains only three cysteine residues, two extracellular at the Cys-loop (C177 and C191) and one intracellular (C364) at the M3-M4 linker. Mutant GABAAρ1 receptors in which C364 was exchanged by alanine were completely insensitive to modulation, implying that this site, rather than a cysteine in the Cys-loop, is essential for ROS modulation. Conclusion and Implications Our results show that the function of GABAAρ1 receptors is enhanced by ROS and that the intracellular C364 is the sensor for ROS actions. PMID:24428763

  13. Steady state hemodynamic and energetic characterization of the Penn State/3M Health Care Total Artificial Heart.

    PubMed

    Weiss, W J; Rosenberg, G; Snyder, A J; Pierce, W S; Pae, W E; Kuroda, H; Rawhouser, M A; Felder, G; Reibson, J D; Cleary, T J; Ford, S K; Marlotte, J A; Nazarian, R A; Hicks, D L

    1999-01-01

    Total Artificial Heart (TAH) development at Penn State University and 3M Health Care has progressed from design improvements and manufacturing documentation to in vitro and in vivo testing to characterize the system's hemodynamic response and energetic performance. The TAH system is completely implantable and intended for use as an alternative to transplantation. It includes a dual pusher plate pump and rollerscrew actuator, welded electronics and battery assembly, transcutaneous energy transmission system, telemetry, and a compliance chamber. In vitro testing was conducted on a Penn State mock circulatory loop with glycerol/water solution at body temperature. Tests were performed to characterize the preload and afterload response, left atrial pressure control, and power consumption. A sensitive preload response was demonstrated with left atrial pressure safely maintained at less than 15 mm Hg for flow rates up to 7.5 L/min. Variations in aortic pressure and pulmonary vascular resistance were found to have minimal effects on the preload sensitivity and left atrial pressure control. In vivo testing of the completely implanted system in its final configuration was carried out in two acute studies using implanted temperature sensors mounted on the electronics, motor, and energy transmission coil in contact with adjacent tissue. The mean temperature at the device-tissue interface was less than 4 degrees C above core temperature. PMID:10360721

  14. Site-preferential design of itinerant ferromagnetic borides: experimental and theoretical investigation of MRh6B3 (M = Fe, Co).

    PubMed

    Misse, Patrick R N; Gillessen, Michael; Fokwa, Boniface P T

    2011-10-17

    Single-phase polycrystalline samples of the compounds MRh(6)B(3) (M = Fe, Co) as well as single crystals of CoRh(6)B(3) have been synthesized by arc-melting the elements under a purified argon atmosphere in a water-cooled copper crucible. The characterization of the new phases was achieved by using single-crystal and powder X-ray diffraction as well as EDX measurements. The two phases are isotypic and crystallize in the hexagonal Th(7)Fe(3) structure type (space group P6(3)mc, no. 186, Z = 2). In this structure, the magnetically active atoms (Fe, Co) are preferentially found on only one of the three available rhodium sites, and together with rhodium they build a three-dimensional network of interconnected (Rh/M)(3) triangles. Magnetic properties investigations show that both phases order ferromagnetically below Curie temperatures of 240 K (for FeRh(6)B(3)) and 150 K (for CoRh(6)B(3)). First-principles DFT calculations correctly reproduce not only the lattice parameters but also the ground state magnetic ordering in the two phases. These calculations also show that the long-range magnetic ordering in both phases occurs via indirect ferromagnetic coupling between the iron atoms mediated by rhodium. This magnetic structural model also predicts the saturation magnetizations to be 4.02 μ(B) for FeRh(6)B(3) (3.60 μ(B) found experimentally) and 2.75 μ(B) for CoRh(6)B(3). Furthermore, both phases are predicted to be metallic conductors as expected for these intermetallic borides. PMID:21905755

  15. Design report for an indirectly cooled 3-m diameter superconducting solenoid for the Fermilab Collider Detector Facility

    SciTech Connect

    Fast, R.; Grimson, J.; Kephart, R.

    1982-10-01

    The Fermilab Collider Detector Facility (CDF) is a large detector system designed to study anti pp collisions at very high center of mass energies. The central detector for the CDF shown employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 3.5 m long an 3 m in diameter. To provide the desired ..delta..p/sub T/p/sub T/ less than or equal to 1.5% at 50 GeV/c using drift chambers with approx. 200..mu.. resolution the field inside this volume should be 1.5 T. The field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 10/sup 6/ A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and the cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe the design for an indirectly cooled superconducting solenoid to meet the requirements of the Fermilab CDF. The components of the magnet system are discussed in the following chapters, with a summary of parameters listed in Appendix A.

  16. Syntheses and characterization of two alkaline and transition metal orthoborates, LiMBO3 (M = Zn, Cd)

    NASA Astrophysics Data System (ADS)

    Chen, Xuean; Wang, Kun; Chang, Xinan; Xiao, Weiqiang

    2016-02-01

    Two alkaline and transition metal orthoborates, LiMBO3 (M = Zn, Cd), have been synthesized and their crystal structures determined by single-crystal XRD methods with the following crystal data: LiZnBO3, P 1 bar (No.2), a = 5.0559 (15) Å, b = 6.097 (2) Å, c = 8.0359 (18) Å, α = 75.75 (2)°, β = 89.86 (2)°, γ = 89.79 (3) °, Z = 4; LiCdBO3, P21/c (No.14), a = 10.4159 (14) Å, b = 9.005 (2) Å, c = 10.756 (2) Å, β = 92.521 (13)°, Z = 16. The crystal structure of LiZnBO3 is composed of edge-sharing ZnO5 trigonal bipyramids which are bound together via ZnO4 tetrahedra and BO3 planar triangles to form a polyanionic framework. LiCdBO3 also features a 3D framework, but constructed by edge-sharing CdO5 trigonal bipyramids and BO3 triangles. Both structures afford open channels that are occupied by Li+ cations. IR spectra further confirm that these two compounds contain the planar triangular BO3 groups. UV-VIS diffuse reflectance spectra show band gaps of about 3.10 and 4.28 eV and solid-state fluorescence spectra demonstrate emission bands at around 542 and 412 nm for LiZnBO3 and LiCdBO3, respectively. Band structure calculations by the density functional theory method indicate that both compounds are direct band-gap insulators.

  17. Characterization and thermal behavior of PrMO{sub 3} (M = Co or Ni) ceramic materials obtained from gelatin

    SciTech Connect

    Aquino, F.M.; Melo, D.M.A.; Pimentel, P.M.; Braga, R.M.; Melo, M.A.F.; Martinelli, A.E.; Costa, A.F.

    2012-09-15

    Graphical abstract: The micrograph in figure shows sample calcined at temperature 900 °C. The sample exhibits morphology with considerable porosity and the formation of agglomerated nanometric particles. Gelatin provides the system with a large amount of organic matter, which is then removed during calcinations, favoring the appearance of pores in the material. Highlights: ► Oxides with PrNiO{sub 3} and PrCoO{sub 3} were prepared by new method synthesis. ► The gelatin, through its carboxylate groups and amine, is an efficient director. ► The obtained materials have magnetic properties and application in catalysis. ► The decomposition kinetic study of bonding groups of gelatin with metallic ions that takes part in the synthesis of PrMO{sub 3}. -- Abstract: Metal oxides with perovskite-type structure have attracted considerable interest in recent years due to their magnetic and electrical properties, as well as their catalytic activity. In this study, oxides with PrNiO{sub 3} and PrCoO{sub 3} composition were prepared by using gelatin powder as a precursor agent for its use as a catalyst. The powders obtained were calcined at 700 °C and 900 °C and characterized using the X-ray diffraction, thermal analysis (thermogravimetry and differential thermal analysis), infrared spectroscopy, temperature programed reduction and scanning electron microscopy techniques. Thermogravimetric data using the non-isothermal kinetic models of Flynn and Wall and “Model-free Kinetics” were used to determine the activation energy to study the decomposition kinetics of the ligand groups with system's metallic ions that takes part in the synthesis of PrMO{sub 3} (M = Ni or Co).

  18. Impaired muscarinic type 3 (M3) receptor/PKC and PKA pathways in islets from MSG-obese rats.

    PubMed

    Ribeiro, Rosane Aparecida; Balbo, Sandra Lucinei; Roma, Letícia Prates; Camargo, Rafael Ludemann; Barella, Luiz Felipe; Vanzela, Emerielle Cristine; de Freitas Mathias, Paulo Cesar; Carneiro, Everardo Magalhães; Boschero, Antonio Carlos; Bonfleur, Maria Lúcia

    2013-07-01

    Monosodium glutamate-obese rats are glucose intolerant and insulin resistant. Their pancreatic islets secrete more insulin at increasing glucose concentrations, despite the possible imbalance in the autonomic nervous system of these rats. Here, we investigate the involvement of the cholinergic/protein kinase (PK)-C and PKA pathways in MSG β-cell function. Male newborn Wistar rats received a subcutaneous injection of MSG (4 g/kg body weight (BW)) or hyperosmotic saline solution during the first 5 days of life. At 90 days of life, plasma parameters, islet static insulin secretion and protein expression were analyzed. Monosodium glutamate rats presented lower body weight and decreased nasoanal length, but had higher body fat depots, glucose intolerance, hyperinsulinemia and hypertrigliceridemia. Their pancreatic islets secreted more insulin in the presence of increasing glucose concentrations with no modifications in the islet-protein content of the glucose-sensing proteins: the glucose transporter (GLUT)-2 and glycokinase. However, MSG islets presented a lower secretory capacity at 40 mM K(+) (P < 0.05). The MSG group also released less insulin in response to 100 μM carbachol, 10 μM forskolin and 1 mM 3-isobutyl-1-methyl-xantine (P < 0.05, P < 0.0001 and P < 0.01). These effects may be associated with a the decrease of 46 % in the acetylcholine muscarinic type 3 (M3) receptor, and a reduction of 64 % in PKCα and 36 % in PKAα protein expressions in MSG islets. Our data suggest that MSG islets, whilst showing a compensatory increase in glucose-induced insulin release, demonstrate decreased islet M3/PKC and adenylate cyclase/PKA activation, possibly predisposing these prediabetic rodents to the early development of β-cell dysfunction. PMID:23652999

  19. Geometry, bonding and magnetism in planar triangulene graphene molecules with D3h symmetry: Zigzag Cm∗∗2+4m+1H3m+3 (m = 2, …, 15)

    NASA Astrophysics Data System (ADS)

    Philpott, Michael R.; Cimpoesu, Fanica; Kawazoe, Yoshiyuki

    2008-12-01

    Ab initio plane wave based all valence electron DFT calculations with geometry optimization are reported for the electronic structure of planar zigzag edged triangular shaped graphene molecules CH where the zigzag ring number m = 2, …, 15. The largest molecule C 286H 48 has a 3.8 nm side length and retains D3h symmetric geometry. The zone in the middle of the molecules, where the geometry and electronic properties resemble infinite single sheet graphite (graphene), expands with increasing ring number m, driving deviations in geometry, charge and spin to the perimeter. If a molecule is viewed as a set of nested triangular rings of carbon, then the zone where the lattice resembles an infinite sheet of graphene with CC = 142 pm, extends to the middle of the penultimate ring. The radial bonds joining the perimeter carbon atoms to the interior are long CC = 144 pm, except near the three apexes where the bonds are shorter. Isometric surfaces of the total charge density show that the two bonds joined at the apex have the highest valence charge. The perimeter CC bonds establish a simple pattern as the zigzag number increases, which shares some features with the zigzag edges in the D2h linear acenes C 4m+2H 2m+4 and the D6h hexangulenes CH6m but not the D6h symmetric annulenes (CH). The two CC bonds forming each apex are short (≈139 pm), next comes one long bond CC ≈ 142 pm and a middle region where all the CC bonds have length ≈141 pm. The homo-lumo gap declines from 0.53 eV at m = 2 to approximately 0.29 V at m = 15, the latter being larger than found for linear or hexagonal shaped graphenes with comparable edge lengths. Across the molecule the charge on the carbon atoms undergoes a small oscillation following the bipartite lattice. The magnitude of the charge in the same nested triangle decreases monotonically with the distance of the row from the center of the molecule. These systems are predicted to have spin polarized ground states with S = ½( m - 1), in

  20. Quantity of Soil Organic Matter in the Upper 3 m of Soil in the Northern Circumpolar Permafrost Region

    NASA Astrophysics Data System (ADS)

    Hugelius, G.; Tarnocai, C.

    2012-12-01

    The current estimate for soil organic carbon (SOC) quantity in the northern circumpolar permafrost region (Tarnocai et al., 2009) is 191 Pg for topsoil (0-30 cm depth), 496 Pg for the upper 100 cm of soil and SOC mass to 300 cm soil depth is estimated to be 1024 Pg. In addition, storage in deeper (> 300 cm) Yedoma deposits (407 Pg) and deltaic deposits (241 Pg) brings the total estimate to 1672 Pg, of which 1466 Pg is stored in perennially frozen ground. The estimate for 0-1 m depth SOC mass is based on the Northern Circumpolar Soil Carbon Database (NCSCD), a geospatial database which links 1647 pedons from the northern permafrost regions to several digitized regional/national soil maps with a combined circumpolar coverage. This database has recently been published online and the data is available in several different file formats, including gridded files with different spatial resolutions. Files adapted for use in GIS or modeling applications (shape-files, TIFF-rasters and NetCDF files) are available for separate regions or with merged circumpolar coverage. Estimates for the 0-30 cm and 0-100 cm depth ranges based on the NCSCD are unlikely to be significantly changed or refined in the coming years. However, the emergence of high quality geospatial datasets with circumpolar coverage as well as applications of spatially distributed regression/kriging techniques in periglacial environments (e.g. Mishra and Riley, 2012) point towards complementary approaches that may significantly increase our knowledge of circumpolar SOC distribution. The present estimates of SOC mass in the 0-300 cm depth range is based on very limited field data (46 Canadian pedons), is accorded low to very low confidence and is not included in the spatially distributed NCSCD (Tarnocai et al., 2009). However, a compilation of additional pedon data is underway and an updated version of the NCSCD will be complemented with spatially distributed estimates of 100-200 cm and 200-300 cm depth SOCM based

  1. The first rubidium rare-earth(III) thiophosphates: Rb 3M3[PS 4] 4 ( M=Pr, Er)

    NASA Astrophysics Data System (ADS)

    Komm, Theresa; Schleid, Thomas

    2005-02-01

    The two non-isotypical rubidium rare-earth(III) thiophosphates Rb 3M3[PS 4] 4 of praseodymium and erbium can easily be obtained by the stoichiometric reaction of the respective rare-earth metal, red phosphorus and sulfur with an excess of rubidium bromide (RbBr) as flux and rubidium source at 950°C for 14 days in evacuated silica tubes. The pale green platelet-shaped single crystals of Rb 3Pr 3[PS 4] 4 as well as the pink rods of Rb 3Er 3[PS 4] 4 are moisture sensitive. Rb 3Pr 3[PS 4] 4 crystallizes triclinically in the space group P1¯ ( a=926.79(5) pm, b=1050.83(5) pm, c=1453.28(7) pm, α=84.329(4)°, β=88.008(4)°, γ=80.704(4)°; Z=2), Rb 3Er 3[PS 4] 4 monoclinically in the space group P21/n ( a=915.97(5) pm, b=1575.86(7) pm, c=1843.32(9) pm, β=95.601(6)°; Z=4). In both structures, there are three crystallographically different rare-earth cations present. ( M1) 3+ is eightfold coordinated in the shape of a square antiprism, ( M2) 3+ and ( M3) 3+ are both surrounded by eight sulfur atoms as bicapped trigonal prisms each with a coordination number of eight as well as for the praseodymium, but better described as CN=7+1 in the case of the erbium compound. These [ MS 8] 13- polyhedra form a layer according to ∞2{[M3[PS]4]} by sharing edges with the isolated [PS 4] 3- tetrahedra ( d(P-S)=200-209 pm, ∢(S-P-S)=102-116°). These layers are stacked with a repetition period of three in the case of the praseodymium compound, but of only two for the erbium analog. The rubidium cation (Rb1) + is located in cavities of these layers and tenfold coordinated in the shape of a tetracapped trigonal antiprism. The also tenfold but more irregularly coordinated rubidium cations (Rb2) + and (Rb3) + reside between the layers.

  2. Spacewatch Astrometry of Asteroids and Comets with the Bok 2.3-m and Mayall 4-m Telescopes.

    NASA Astrophysics Data System (ADS)

    Scotti, James V.; McMillan, Robert S.; Larsen, Jeffrey A.

    2014-11-01

    We use the Bok 2.3-m and Mayall 4-m telescopes on Kitt Peak to improve knowledge of the orbits and magnitudes of high priority classes of Near Earth Objects (NEOs) and other small bodies in need of recovery that cannot be reached with the Spacewatch 0.9-m and 1.8-m telescopes. Targets include NEOs with potential close encounters with Earth (Virtual Impactors; VIs), future targets of radar, NEOs previously detected by NEOWISE with orbits or albedos suggesting potential for cometary activity, potential destinations for spacecraft, returning NEOs with hard-won albedos and diameters determined by NEOWISE, and faint Potentially Hazardous Asteroids (PHAs). Notable targets successfully recovered include the Earth Trojan 2010 TK7 and the faint almost-lost VI 2011 BY24 discovered by NEOWISE. Between 2010 June 6 and 2014 July 23 the MPC accepted 1316 lines of astrometry by us with these telescopes on 207 different NEOs including 84 PHAs. We made 343 observations of PHAs with V>=22. Our average arc extension on large PHAs (with H<=17.75) is 184 days, which is 2x longer than the next most effective observing station. Recently with all four telescopes Spacewatch has made 39% of all the observations of PHAs that were fainter than V=22 at the time of measurement. This count is twice that of the next most productive station in that measure. The faintest V magnitude we have observed so far is 24.4 and the smallest solar elongation angle at which we have observed is 46 degrees. Our work with the Mayall and Bok telescopes has been determined by the Minor Planet Center (MPC) to provide "dramatic improvement" to NEO orbits (T. Spahr, 2014 private communication). Support of Spacewatch was/is from JPL subcontract 100319 (2010-2011), NASA/NEOO grants NNG06GJ42G, NNX11AB52G, NNX12AG11G, NNX13AP99G, NNX14AL13G, and NNX14AL14G, the Lunar and Planetary Laboratory, the Brinson Foundation of Chicago, IL, the estates of R. S. Vail and R. L. Waland, and other private donors. We are also indebted

  3. Overview of the O3M-SAF validation facility for operational GOME-2 NO2 column data

    NASA Astrophysics Data System (ADS)

    Pinardi, Gaia; Lambert, Jean-Christopher; Granville, Jos; van Roozendael, Michel; Delcloo, Andy; Debacker, Hugo; Valks, Pieter; Hao, Nan

    In the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF,) nitrogen dioxide (NO2) total column and tropospheric column data are generated operationally from GOME-2 measurements in near-real-time (within 2:30 hours after sensing). NO2 column data are retrieved from the Earth radiance and solar irradiance spectra by a chain of several modules (currently, the level-0-to-1 processor v4.0 and the level-1-to-2 DOAS retrieval processor GDP v4.3). These intermediate modules calculates the parameters needed to derive the final column data: the slant column density along the optical path, the fractional cover and top pressure of clouds affecting the measurement scene, the geometrical enhancement factor (AMF, needed to convert slant into vertical columns), and the NO2 stratospheric reference to be subtracted from the total column to obtain the tropospheric column. In order to validate the final product (the total and tropospheric NO2 columns) in the best way, and due to the complexity of the GOME-2 retrieval chain and the existing issues related to the set-up of a validation strategy in an operational environment, an end-to-end validation ap-proach has been developed, as recommended by Reference Protocols and Guidelines. To ensure meaningful and continuous quality assessment of GOME-2 NO2 data products, the end-to-end validation approach performs the verification and validation of critical individual components of the level-1-to-2 retrieval chain. Particular interest is given to recurring validation issues, such as the particular way remote sensing samples and smoothes the significant variability of atmospheric NO2, the diurnal cycle of NO2, the poor availability of correlative measure-ments (especially for tropospheric column), as well as the current lack of homogenisation of the validation methods. The end-to-end validation process of GOME-2 NO2 data is based on a set of correlative obser-vations performed by

  4. Dinosaur abundance was not declining in a “3 m gap” at the top of the Hell Creek Formation, Montana and North Dakota

    NASA Astrophysics Data System (ADS)

    Sheehan, Peter M.; Fastovsky, David E.; Barreto, Claudia; Hoffmann, Raymond G.

    2000-06-01

    An ˜3 m stratigraphic interval that entirely lacks dinosaur fossils or has very few fossils has been reported at the top of the Hell Creek Formation in the upper Great Plains of North America. The presence of the “3 m gap” in fossil distribution has been cited as evidence that dinosaurs had either become extinct or were on the verge of extinction prior to the bolide impact at the end of the Cretaceous Period. A survey in two areas of North Dakota and Montana reveals that dinosaur fossils in the upper 3 m of the Hell Creek Formation occur in numbers that are comparable to their abundance in other levels of the formation. Evidence for a gradual extinction is absent, and data are consistent with an abrupt extinction associated with an impact.

  5. COBRA-PI: an extension of the COBRA-3M code dynamically dimensioned to accept pin bundles of any size. [LMFBR

    SciTech Connect

    Froehle, P.H.; Bauer, T.H.

    1983-03-28

    COBRA, in general, performs a thermal-hydraulic analysis of an actual pin bundle by subdividing the bundle cross-section into coolant subchannels, pin sectors, duct wall sectors. Its calculation includes heat convected axially upward through coolant mass flow, heat flow between pin sectors and adjoining subchannels, and heat and mass flow between coolant subchannels. COBRA-3M is a version of COBRA built for LMFBR applications, that includes a sophisticated thermal model of fuel pins and duct wall. COBRA-3M that can explicitly model a wider variety of pin bundle configurations than 3M would allow and includes significant improvements to its thermal modeling. COBRA-PI is currently being used for thermal-hydraulic analysis of hypothetical LMFBR accident transients in both power and flow. Pin bundles currently being analyzed explicitly range from 7 to 37 pins of axial lengths ranging from approx. 0.3-2.0 meters.

  6. Mass Spectrometry Detection of G3m and IGHG3 Alleles and Follow-Up of Differential Mother and Neonate IgG3

    PubMed Central

    Dechavanne, Célia; Guillonneau, François; Chiappetta, Giovanni; Sago, Laïla; Lévy, Prisca; Salnot, Virginie; Guitard, Evelyne; Ehrenmann, François; Broussard, Cédric; Chafey, Philippe; Le Port, Agnès; Vinh, Joëlle; Mayeux, Patrick; Dugoujon, Jean-Michel; Lefranc, Marie-Paule; Migot-Nabias, Florence

    2012-01-01

    Mass spectrometry (MS) analysis for detection of immunoglobulins (IG) of the human IgG3 subclass is described that relies on polymorphic amino acids of the heavy gamma3 chains. IgG3 is the most polymorphic human IgG subclass with thirteen G3m allotypes located on the constant CH2 and CH3 domains of the gamma3 chain, the combination of which leads to six major G3m alleles. Amino acid changes resulting of extensive sequencing previously led to the definition of 19 IGHG3 alleles that have been correlated to the G3m alleles. As a proof of concept, MS proteotypic peptides were defined which encompass discriminatory amino acids for the identification of the G3m and IGHG3 alleles. Plasma samples originating from ten individuals either homozygous or heterozygous for different G3m alleles, and including one mother and her baby (drawn sequentially from birth to 9 months of age), were analyzed. Total IgG3 were purified using affinity chromatography and then digested by a combination of AspN and trypsin proteases, and peptides of interest were detected by mass spectrometry. The sensitivity of the method was assessed by mixing variable amounts of two plasma samples bearing distinct G3m allotypes. A label-free approach using the high-performance liquid chromatography (HPLC) retention time of peptides and their MS mass analyzer peak intensity gave semi-quantitative information. Quantification was realized by selected reaction monitoring (SRM) using synthetic peptides as internal standards. The possibility offered by this new methodology to detect and quantify neo-synthesized IgG in newborns will improve knowledge on the first acquisition of antibodies in infants and constitutes a promising diagnostic tool for vertically-transmitted diseases. PMID:23049948

  7. Dy3+-activated NaM4(VO4)3 (M = Ca, Ba, Sr) phosphor for near-UV solid-state lighting.

    PubMed

    Singh, Roshani; Dhoble, S J

    2011-01-01

    We report the photoluminescence characterization of Dy(3+)-activated NaM(4)(VO(4))(3) (M = Ca, Ba, Sr) phosphors prepared by a solid-state method. The synthesis was confirmed by X-ray diffraction (XRD) characterization and photoluminescence (PL) emission results showed sharp blue and yellow bands for NaM(4)(VO(4))(3) (M = Ca, Ba, Sr):Dy(3+) phosphors at the excitation wavelength of 323 nm, which is near-UV excitation. Thus, these phosphors could be applicable for near-UV excited solid-state lighting devices. PMID:21618681

  8. Trioxorhenium and trioxotechnetium as strong acceptor groups. 3. Charge transfer and bonding energetics in O{sub 3}M-M(CO){sub 5} (M = Re, Tc)

    SciTech Connect

    Costas, M.; Poblet, J.M.; Rohmer, M.M.; Benard, M.

    1995-01-04

    The bonding in O{sub 3}M-M(CO){sub 5} has been studied by ab initio SCF, two-configuration SCF, and CI methods for M = Re and Tc. Calculations indicate that these complexes are highly polar. The nature of the charge transfer in these complexes is considered.

  9. Isothiocyanate-functionalized bifunctional chelates and fac-[MI(CO)3]+ (M = Re, 99mTc) complexes for targeting uPAR in prostate cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developing strategies to rapidly incorporate the fac-[MI(CO)3]+ (M = Re, 99mTc) core into biological targeting vectors is a growing realm in radiopharmaceutical development. This work presents the preparation of a novel isothiocyanate-functionalized bifunctional chelate based on 2,2´-dipicolylamine ...

  10. Full solution, for crystal class 3m, of the Holland-EerNisse complex material-constant theory of lossy piezoelectrics for harmonic time dependence.

    PubMed

    Piquette, Jean C; McLaughlin, Elizabeth A

    2007-06-01

    A complex material-constant theory of lossy piezoelectrics is fully solved for crystal class 3m for harmonic time dependence of the fields and stresses. A new demonstration that the theory's eigen coupling factor equation applies to the lossy alternating current (AC) case also is given. The solution presented for crystal class 3m provides a complete orthonormal set of eigenvectors and eigenvalues for the eigen coupling factor problem, and it also provides a complete orthonormal set of eigenvectors and eigenvalues for the eigen loss tangent problem, for this crystal class. It is shown that two positive coupling factors are sufficient to express an arbitrary 3m crystal state. Despite the complex nature of the material constants, the Holland-EerNisse theory produces fully real expressions for the coupling factors. The loss tangent eigenvalues also are fully real and positive. The loss eigenstates are important because driving a crystal in a loss eigenstate tends to minimize the impact of material losses. Given also is a set of loss inequalities for crystal class 3m. The loss inequalities of crystal class 6mm are recovered from these when d22 and s(E)14 both vanish. PMID:17571823

  11. Influence of Functionalized Pyridine Ligands on the Radio/Chemical Behavior of [MI(CO)3]+ (M = Re and 99mTc) 2 + 1 Complexes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While a number of chelate strategies have been developed for the organometallic precursor fac-[M (OH2)3(CO)3]+ (M = Re, 99mTc), a unique challenge has been to improve the overall function and performance of these complexes for in vivo and in vitro applications. Since its synthesis, the fac-[M (CO)3]...

  12. Developmentally Regulated Expression of HDNF/NT-3 mRNA in Rat Spinal Cord Motoneurons and Expression of BDNF mRNA in Embryonic Dorsal Root Ganglion.

    PubMed

    Ernfors, Patrik; Persson, Håkan

    1991-01-01

    Northern blot analysis was used to demonstrate high levels of hippocampus-derived neurotrophic factor/neurotrophin-3 (HDNF/NT-3) mRNA in the embryonic day (E) 13 - 14 and 15 - 16 spinal cord. The level decreased at E18 - 19 and remained the same until postnatal day (P) 1, after which it decreased further to a level below the detection limit in the adult. In situ hybridization revealed that the NT-3 mRNA detected in the developing spinal cord was derived from motoneurons and the decrease seen at E18 - 19 was caused by a reduction in the number of motoneurons expressing NT-3 mRNA. The distribution of NT-3 mRNA-expressing cells in the E15 spinal cord was very similar to the distribution of cells expressing choline acetyltransferase or nerve growth factor receptor (NGFR) mRNA. Moreover, a striking similarity between the developmentally regulated expression of NT-3 and NGFR mRNA was noted in spinal cord motoneurons. A subpopulation of all neurons in the dorsal root ganglia expressed brain-derived neurotrophic factor (BDNF) mRNA from E13, the earliest time examined, to adulthood. These results are consistent with a trophic role of NT-3 for proprioceptive sensory neurons innervating the ventral horn, and imply a local action of BDNF for developing sensory neurons within the dorsal root ganglia. PMID:12106253

  13. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF MICROBIOLOGICAL & PARTICULATE CONTAMINANTS IN DRINKING WATER: US FILTER 3M10C MICROFILTRATION MEMBRANE SYSTEM AT CHULA VISTA, CALIFORNIA

    EPA Science Inventory

    Verification testing of the US Filter 3M10C membrane system was conducted over a 44-day test period at the Aqua 2000 Research Center in Chula Vista, California. The test period extended from July 24, 2002 to September 5, 2002. The source water was a blend of Colorado River and ...

  14. 29Si attribution of the 1.3 mT hyperfine structure of the E'γ centers in amorphous SiO2

    NASA Astrophysics Data System (ADS)

    Vaccaro, G.; Agnello, S.; Buscarino, G.; Nuccio, L.; Grandi, S.; Mustarelli, P.

    2009-05-01

    We report an experimental investigation by electron paramagnetic resonance of the doublet of lines split by ˜1.3 mT and centered on the E'γ center resonance line in the spectrum of irradiated amorphous SiO2. Commercial and sol-gel materials, some of which subjected to hydrogen-deuterium exchange, were investigated. Exposure to γ or β rays at room temperature of the samples and subsequent thermal treatments were carried out to induce the defects and to study their thermal stability. In all the materials used the ratio between the signal of the E'γ centers and that of the 1.3 mT doublet is constant and independent of the OH and OD contents. Furthermore, the 1.3 mT doublet and the E'γ center feature similar thermal stability. These results support the attribution of the 1.3 mT doublet to the hyperfine interaction between the unpaired electron magnetic moment of the E'γ center and the nuclear magnetic moment of a second near neighboring S29i atom. Our results also suggest that the E'γ site needs an appropriate surrounding of S29i in back-bond configuration to experience this hyperfine interaction.

  15. Possible safety hazards associated with the operation of the 0.3-m transonic cryogenic tunnel at the NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Webster, T. J.

    1982-01-01

    The 0.3 m Transonic Cryogenic Tunnel (TCT) at the NASA Langley Research Center was built in 1973 as a facility intended to be used for no more than 60 hours in order to verify the validity of the cryogenic wind tunnel concept at transonic speeds. The role of the 0.3 m TCT has gradually changed until now, after over 3000 hours of operation, it is classified as a major NASA research facility and, under the administration of the Experimental Techniques Branch, it is used extensively for the testing of airfoils at high Reynolds numbers and for the development of various technologies related to the efficient operation and use of cryogenic wind tunnels. The purpose of this report is to document the results of a recent safety analysis of the 0.3 m TCT facility. This analysis was made as part of an on going program with the Experimental Techniques Branch designed to ensure that the existing equipment and current operating procedures of the 0.3 m TCT facility are acceptable in terms of today's standards of safety for cryogenic systems.

  16. Evaluation of the 3M Rapid Detection Test for Respiratory Syncytial Virus (RSV) in Children during the Early Stages of the 2009 RSV Season▿

    PubMed Central

    Munjal, Iona; Gialanella, Philip; Goss, Cheryl; McKitrick, John C.; Avner, Jeffrey R.; Pan, Qiulu; Litman, Nathan; Levi, Michael H.

    2011-01-01

    We report the results of the 3M rapid detection respiratory syncytial virus (RSV) assay. This study includes pediatric patient results from nasopharyngeal swabs submitted from October to December 2009. There was a sensitivity of 74% and specificity approaching 100% compared to the PCR-based xTAG respiratory viral panel. PMID:21177903

  17. Carbon-carbon cylinder block

    NASA Technical Reports Server (NTRS)

    Ransone, Philip O. (Inventor)

    1998-01-01

    A lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials, such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

  18. Carbon-Carbon Radiator

    NASA Technical Reports Server (NTRS)

    Butler, Dan; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Carbon-Carbon (C-C) Radiator was a success and proved that the technology can work to reduce Spacecraft weight. C-C has a niche, especially for high temperatures. C-C still needs further development: reduction in fabrication time and cost - high conductivity "traditional" composites are more competitive, and CTE interface issues with heat pipes. Redundancy a good idea - we flew the spare panel. CSRP was a success -informal inter-agency partnership. Possible follow-on: C-C foam for low CTE mirrors/optical benches.

  19. METC/3M Cooperative Agreement CRADA 94-024 high temperature high pressure filter materials exposure test program. Volume 1, Final report

    SciTech Connect

    1995-06-01

    In conjunction with shakedown, operation, and desulfurization testing at the Morgantown Energy Technology Center (METC) 10 in. Fluid Bed Gasification and Cleanup facility, a series of tests was completed in cooperation with the Minnesota Mining and Manufacturing Company (3M). This cooperative research and development agreement (CRADA) between METC and 3M was to evaluate exposure of 3M SICONEX{trademark} fiber-reinforced ceramic and NEXTEL{trademark} 312 and 550 ceramic fabric materials to a gasifying environment at high temperatures (1000--1100{degree}F) and high pressure (300 psia). Minnesota Mining and Manufacturing Company (3M) provided two 60 mm I.D. {times} 0.5 m SICONEX{trademark} spools and one each of the NEXTEL{trademark} 312 and 550 ceramic fabrics for exposure to coal gas from the METC gasifier. METC installed the materials in a vessel existing in the METC Cleanup Facility and provided process data in exchange for ceramic filter and ash/char characterization. Details of the CRADA are found in CRADA 94-024. This report contains METC`s contribution to CRADA 94-024. Four gasifier runs were conducted over a five month period to accumulate 483 hours of operation. During this time, 2 LayCer{trademark} 70/3 filters were used for filtering the coal gas while the SICONEX{trademark} and NEXTEL{trademark} were exposed along side of the filters. During one 89 hour test, one Laycer{trademark} 70/3 candle was installed with a 3M ceramic composite filter. The face velocity through the candles was maintained nominally at 2.5 ft/min throughout the testing.

  20. Carbon Smackdown: Carbon Capture

    ScienceCinema

    Jeffrey Long

    2010-09-01

    In this July 9, 2010 Berkeley Lab summer lecture, Lab scientists Jeff Long of the Materials Sciences and Nancy Brown of the Environmental Energy Technologies Division discuss their efforts to fight climate change by capturing carbon from the flue gas of power plants, as well as directly from the air

  1. Carbon Smackdown: Carbon Capture

    SciTech Connect

    Jeffrey Long

    2010-07-12

    In this July 9, 2010 Berkeley Lab summer lecture, Lab scientists Jeff Long of the Materials Sciences and Nancy Brown of the Environmental Energy Technologies Division discuss their efforts to fight climate change by capturing carbon from the flue gas of power plants, as well as directly from the air

  2. EPR study of chromium-doped forsterite crystals: Cr3+( M1) with associated trivalent ions Al3+ and Sc3+

    NASA Astrophysics Data System (ADS)

    Ryabov, I. D.

    2012-10-01

    Electron paramagnetic resonance (EPR) study of single crystals of forsterite co-doped with chromium and scandium has revealed, apart from the known paramagnetic centers Cr3+( M1) and Cr3+( M1)- V_{{{{Mg}}^{2 + } }} ( M2) (Ryabov in Phys Chem Miner 38:177-184, 2011), a new center Cr3+( M1)- V_{{{{Mg}}^{2 + } }} ( M2)-Sc3+ formed by a Cr3+ ion substituting for Mg2+ at the M1 structural position with a nearest-neighbor Mg2+ vacancy at the M2 position and a Sc3+ ion presumably at the nearest-neighbor M1 position. For this center, the conventional zero-field splitting parameters D and E and the principal g values have been determined as follows: D = 33,172(29) MHz, E = 8,482(13) MHz, g = [1.9808(2), 1.9778(2), 1.9739(2)]. The center has been compared with the known ion pair Cr3+( M1)-Al3+ (Bershov et al. in Phys Chem Miner 9:95-101, 1983), for which the refined EPR data have been obtained. Based on these data, the known sharp M1″ line at 13,967 cm-1 (with the splitting of 1.8 cm-1), observed in low-temperature luminescence spectra of chromium-doped forsterite crystals (Glynn et al. in J Lumin 48, 49:541-544, 1991), has been ascribed to the Cr3+( M1)-Al3+ center. It has been found that the concentration of the new center increases from 0 up to 4.4 × 1015 mg-1, whereas that of the Cr3+( M1) and Cr3+( M1)- V_{{{{Mg}}^{2 + } }} ( M2) centers quickly decreases from 7.4 × 1015 mg-1 down to 3 × 1015 mg-1 and from 2.7 × 1015 mg-1 down to 0.5 × 1015 mg-1, i.e., by a factor of 2.5 and 5.4, respectively, with an increase of the Sc content from 0 up to 0.22 wt % (at the same Cr content 0.25 wt %) in the melt. When the Sc content exceeds that of Cr, the concentration of the new center decreases most likely due to the formation of the Sc3+( M1)- V_{{{{Mg}}^{2 + } }} ( M2)-Sc3+ complex instead of the Cr3+( M1)- V_{{{{Mg}}^{2 + } }} ( M2)-Sc3+ center. The formation of such ordered neutral complex is in agreement with the experimental results, concerning the incorporation of Sc

  3. Carbon-carbon piston development

    NASA Technical Reports Server (NTRS)

    Gorton, Mark P.

    1994-01-01

    A new piston concept, made of carbon-carbon refractory-composite material, has been developed that overcomes a number of the shortcomings of aluminum pistons. Carbon-carbon material, developed in the early 1960's, is lighter in weight than aluminum, has higher strength and stiffness than aluminum and maintains these properties at temperatures over 2500 F. In addition, carbon-carbon material has a low coefficient of thermal expansion and excellent resistance to thermal shock. An effort, called the Advanced Carbon-Carbon Piston Program was started in 1986 to develop and test carbon-carbon pistons for use in spark ignition engines. The carbon-carbon pistons were designed to be replacements for existing aluminum pistons, using standard piston pin assemblies and using standard rings. Carbon-carbon pistons can potentially enable engines to be more reliable, more efficient and have greater power output. By utilizing the unique characteristics of carbon-carbon material a piston can: (1) have greater resistance to structural damage caused by overheating, lean air-fuel mixture conditions and detonation; (2) be designed to be lighter than an aluminum piston thus, reducing the reciprocating mass of an engine, and (3) be operated in a higher combustion temperature environment without failure.

  4. Structural investigations of Sb2O3-M2O (M=Li, Na or K) glasses by the mean of thermal and elastics characterization

    NASA Astrophysics Data System (ADS)

    Soltani, M. T.; Haddad, S.; Ouennes, K.; Boulegroun, A.; Poulain, M.

    2012-09-01

    By using classical routes (melting - casting), glasses synthesized in silica crucibles were obtained in the combination of binary systems Sb2O3-M2CO3 (M=Li, Na and K). Ultrasonic's velocities were carried out by pulse echo method to determine the elastics parameters, such as elastic modules (E, G, K, L) and other related parameters (Poisson's ration, acoustic impedance, Debye temperature). Other physical properties were measured, such as density and characteristic temperatures. Influence of composition on these physico-chemical properties is discussed. A quantitative analysis of thermal analysis, free volume, elastic and mechanical measurements have been carried out to obtain more information about the structure of alkali antimonite glasses and the role of alkali oxides in these no-conventional glasses. These measurements have been made for the first time on these glasses.

  5. MicroRNA844-Guided Downregulation of Cytidinephosphate Diacylglycerol Synthase3 (CDS3) mRNA Affects the Response of Arabidopsis thaliana to Bacteria and Fungi.

    PubMed

    Lee, Hwa Jung; Park, Young Ju; Kwak, Kyung Jin; Kim, Donghyun; Park, June Hyun; Lim, Jae Yun; Shin, Chanseok; Yang, Kwang-Yeol; Kang, Hunseung

    2015-08-01

    Despite the fact that a large number of miRNA sequences have been determined in diverse plant species, reports demonstrating the functional roles of miRNAs in the plant response to pathogens are severely limited. Here, Arabidopsis thaliana miRNA844 (miR844) was investigated for its functional role in the defense response to diverse pathogens. Transgenic Arabidopsis plants overexpressing miR844 (35S::miR844) displayed much more severe disease symptoms than the wild-type plants when challenged with the bacterium Pseudomonas syringae pv. tomato DC3000 or the fungus Botrytis cinerea. By contrast, a loss-of-function mir844 mutant showed an enhanced resistance against the pathogens. Although no cleavage was observed at the predicted cleavage site of the putative target mRNA, cytidinephosphate diacylglycerol synthase3 (CDS3), cleavage was observed at 6, 12, 21, or 52 bases upstream of the predicted cleavage site of CDS3 mRNA, and the level of CDS3 mRNA was downregulated by the overexpression of miR844, implying that miR844 influences CDS3 transcript level. To further confirm that the miR844-mediated defense response was due to the decrease in CDS3 mRNA level, the disease response of a CDS3 loss-of-function mutant was analyzed upon pathogen challenge. Increased susceptibility of both cds3 mutant and 35S::miR844 plants to pathogens confirmed that miR844 affected the defense response by downregulating CDS3 mRNA. The expression of miR844 was decreased, and the CDS3 transcript level increased upon pathogen challenge. Taken together, these results provide evidence that downregulation of miR844 and a concomitant increase in CDS3 expression is a defensive response of Arabidopsis to bacteria and fungi. PMID:25775269

  6. Identification of a QTL in Mus musculus for Alcohol Preference, Withdrawal, and Ap3m2 Expression Using Integrative Functional Genomics and Precision Genetics

    PubMed Central

    Bubier, Jason A.; Jay, Jeremy J.; Baker, Christopher L.; Bergeson, Susan E.; Ohno, Hiroshi; Metten, Pamela; Crabbe, John C.; Chesler, Elissa J.

    2014-01-01

    Extensive genetic and genomic studies of the relationship between alcohol drinking preference and withdrawal severity have been performed using animal models. Data from multiple such publications and public data resources have been incorporated in the GeneWeaver database with >60,000 gene sets including 285 alcohol withdrawal and preference-related gene sets. Among these are evidence for positional candidates regulating these behaviors in overlapping quantitative trait loci (QTL) mapped in distinct mouse populations. Combinatorial integration of functional genomics experimental results revealed a single QTL positional candidate gene in one of the loci common to both preference and withdrawal. Functional validation studies in Ap3m2 knockout mice confirmed these relationships. Genetic validation involves confirming the existence of segregating polymorphisms that could account for the phenotypic effect. By exploiting recent advances in mouse genotyping, sequence, epigenetics, and phylogeny resources, we confirmed that Ap3m2 resides in an appropriately segregating genomic region. We have demonstrated genetic and alcohol-induced regulation of Ap3m2 expression. Although sequence analysis revealed no polymorphisms in the Ap3m2-coding region that could account for all phenotypic differences, there are several upstream SNPs that could. We have identified one of these to be an H3K4me3 site that exhibits strain differences in methylation. Thus, by making cross-species functional genomics readily computable we identified a common QTL candidate for two related bio-behavioral processes via functional evidence and demonstrate sufficiency of the genetic locus as a source of variation underlying two traits. PMID:24923803

  7. User's manual for a 0.3-m TCT wall interference assessment/correction procedure: 8- by 24-inch airfoil test section

    NASA Technical Reports Server (NTRS)

    Gumbert, C. R.

    1985-01-01

    A transonic Wall-Interference Assessment/Correction (WIAC) procedure has been developed and verified for the 8- by 24-inch airfoil test section of the Langley 0.3-m Transonic Cryogenic Tunnel. This report is a user's manual for the correction procedure. It includes a listing of the computer procedure file as well as input for and results from a step-by-step sample case.

  8. Assessment of Three Tropospheric Delay Models (IGGtrop, EGNOS and UNB3m) Based on Precise Point Positioning in the Chinese Region.

    PubMed

    Zhang, Hongxing; Yuan, Yunbin; Li, Wei; Li, Ying; Chai, Yanju

    2016-01-01

    Tropospheric delays are one of the main sources of errors in the Global Navigation Satellite System (GNSS). They are usually corrected by using tropospheric delay models, which makes the accuracy of the models rather critical for accurate positioning. To provide references for suitable models to be chosen for GNSS users in China, we conduct herein a comprehensive study of the performances of the IGGtrop, EGNOS and UNB3m models in China. Firstly, we assess the models using 5 years' Global Positioning System (GPS) derived Zenith Tropospheric Delay (ZTD) series from 25 stations of the Crustal Movement Observation Network of China (CMONOC). Then we study the effects of the models on satellite positioning by using various Precise Point Positioning (PPP) cases with different tropospheric delay resolutions, the observation data processed in PPP is from 21 base stations of CMONOC for a whole year of 2012. The results show that: (1) the Root Mean Square (RMS) of the IGGtrop model is about 4.4 cm, which improves the accuracy of ZTD estimations by about 24% for EGNOS and 19% for UNB3m; (2) The positioning error in the vertical component of the PPP solution obtained by using the IGGtrop model is about 15.0 cm, which is about 30% and 21% smaller than those of the EGNOS and UNB3m models, respectively. In summary, the IGGtrop model achieves the best performance among the three models in the Chinese region. PMID:26805834

  9. Measurement of the radiative L3-M vacancy transfer probabilities of some 4f elements and compounds using Indus-2 synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Krishnananda; Mirji, Santosh; Badiger, N. M.; Tiwari, M. K.

    2016-08-01

    The L X-ray intensity ratios (ILα/ILl, ILα/ILβ, ILα/ILγ) and the radiative L3-M vacancy transfer probabilities (ηL3-M) of some 4f elements such as Gd, Tb, Ho and compounds; Pr2O3, Pr2(CO3)3·8H2O, Nd2O3, Sm2O3, Sm2(CO3)3·2.85H2O, Sm2(SO4)3·8H2O, Gd2(CO3)3, Tb2O3, Dy2(SO4)3, Ho2O3 and HoF3 have been measured using Indus-2 synchrotron radiation. The elements and compounds are excited by synchrotron radiation and the emitted characteristic L X-ray photons are measured with high resolution silicon drift detector. The measured intensity ratios of compounds are not influenced by the chemical environment. However, the ηL3-M values of compound targets indicate the effect of crystal structure.

  10. Assessment of Three Tropospheric Delay Models (IGGtrop, EGNOS and UNB3m) Based on Precise Point Positioning in the Chinese Region

    PubMed Central

    Zhang, Hongxing; Yuan, Yunbin; Li, Wei; Li, Ying; Chai, Yanju

    2016-01-01

    Tropospheric delays are one of the main sources of errors in the Global Navigation Satellite System (GNSS). They are usually corrected by using tropospheric delay models, which makes the accuracy of the models rather critical for accurate positioning. To provide references for suitable models to be chosen for GNSS users in China, we conduct herein a comprehensive study of the performances of the IGGtrop, EGNOS and UNB3m models in China. Firstly, we assess the models using 5 years’ Global Positioning System (GPS) derived Zenith Tropospheric Delay (ZTD) series from 25 stations of the Crustal Movement Observation Network of China (CMONOC). Then we study the effects of the models on satellite positioning by using various Precise Point Positioning (PPP) cases with different tropospheric delay resolutions, the observation data processed in PPP is from 21 base stations of CMONOC for a whole year of 2012. The results show that: (1) the Root Mean Square (RMS) of the IGGtrop model is about 4.4 cm, which improves the accuracy of ZTD estimations by about 24% for EGNOS and 19% for UNB3m; (2) The positioning error in the vertical component of the PPP solution obtained by using the IGGtrop model is about 15.0 cm, which is about 30% and 21% smaller than those of the EGNOS and UNB3m models, respectively. In summary, the IGGtrop model achieves the best performance among the three models in the Chinese region. PMID:26805834

  11. Effects of monomethoxypolyethylene glycol-chitosan nanoparticle-mediated dual silencing of livin and survivin genes in prostate cancer PC-3M cells.

    PubMed

    Yang, A Q; Wang, P J; Huang, T; Zhou, W L; Landman, J

    2016-01-01

    Monomethoxypolyethylene glycol-chitosan (mPEG-CS) nanoparticles were used as interfering RNA carriers to transfect human prostate cancer PC-3M cells to evaluate the effects of livin and survivin gene silencing on the proliferation and apoptosis. mPEG-CS nanoparticles with sizes of approximately 60 nm were first synthesized by ionic crosslinking. Through electrostatic adsorption, mPEG-CS-livin short hairpin RNA (shRNA), mPEG-CS-survivin shRNA, and mPEG-CS-(livin shRNA + survivin shRNA) nanoparticles were then prepared to transfect PC-3M cells. The mRNA and protein expression levels of livin and survivin were measured by reverse transcription-PCR and western blotting, respectively. The inhibitory effects of down-regulated livin and survivin gene expression on the cell proliferation were evaluated by MTT assay. Cell apoptosis was assessed visually using Hoechst staining. Livin and survivin expression levels in all shRNA interference groups were effectively down-regulated at both the mRNA and protein levels. Dual silencing of livin and survivin genes markedly inhibited cell proliferation and facilitated apoptosis, with better outcomes than those of individual shRNA treatments. mPEG-CS nanoparticle-mediated dual shRNA interference of livin and survivin genes significantly reduced the expression levels in PC-3M cells, inhibited proliferation, and promoted apoptosis. As these effects were superior to single interference, this method may have synergistic effects. PMID:27173182

  12. Crystal structure and antiferromagnetic spin ordering of L n F e2 /3M o1 /3O3(L n =Nd ,Pr ,Ce ,La ) perovskites

    NASA Astrophysics Data System (ADS)

    Ivanov, S. A.; Beran, P.; Bazuev, G. V.; Ericsson, T.; Tellgren, R.; Anil Kumar, P.; Nordblad, P.; Mathieu, R.

    2015-03-01

    Stoichiometric polycrystalline samples of L n F e2 /3M o1 /3O3(L n =Nd ,Pr ,Ce ,La ) have been prepared by solid-state reaction and studied by means of x-ray and neutron powder diffraction as well as Mössbauer spectroscopy and magnetic measurements. All samples were found to be of single phase and to have Pnma symmetry with valence state +3 of Fe and Mo. It is demonstrated that the B-site cations of L n F e2 /3M o1 /3O3 in accord with L n Fe O3 order in a G-type antiferromagnetic structure with the magnetic moments aligned along the b axis. However, with significantly lower Néel temperatures than their L n Fe O3 parent compounds. The Fe-O-Fe bond lengths and bond angles and thus the magnitude of the antiferromagnetic superexchange interaction are found to systematically change with the ionic radius of Ln such that TN increases with increasing radius. Only the CeF e2 /3M o1 /3O3 compound experiences a low temperature spin reorientation from alignment along the b axis to the a axis.

  13. SRG3/mBAF155 stabilizes the SWI/SNF-like BAF complex by blocking CHFR mediated ubiquitination and degradation of its major components

    SciTech Connect

    Jung, Inkyung; Sohn, Dong H.; Choi, Jinwook; Kim, Joo Mi; Jeon, Shin; Seol, Jae Hong; Seong, Rho Hyun

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer CHFR mediates the ubiquitination of the major components of the SWI/SNF complex. Black-Right-Pointing-Pointer CHFR mediated-ubiquitination induces the degradation of the major components. Black-Right-Pointing-Pointer SRG3 stabilizes the SWI/SNF-like BAF complex by blocking the CHFR activity. -- Abstract: The murine SWI/SNF-like BAF complex is an ATP-dependent chromatin remodeling complex that functions as a transcriptional regulator in cell proliferation, differentiation and development. The SWI/SNF-like BAF complex consists of several components including core subunits such as BRG1, BAF155/SRG3, BAF47/SNF5/INI1, and BAF170. We have previously shown that the interaction between SRG3/mBAF155 and other components of the complex stabilizes them by attenuating their proteasomal degradation. However, it has not been known how the major components of the SWI/SNF-like BAF complex such as BRG1, SNF5, and BAF60a are targeted for the ubiquitination and degradation, and how SRG3/mBAF155 protects them from the degradation process. Here we report that CHFR interacts with BRG1, SNF5, and BAF60a of the SWI/SNF-like BAF complex and ubiquitinates them to target for degradation through a proteasome-mediated pathway, and that SRG3/mBAF155 stabilizes these components by blocking their interaction with CHFR.

  14. Ferroelectric and magnetic properties of Aurivillius Bi{sub m+1}Ti{sub 3}Fe{sub m−3}O{sub 3m+3} thin films

    SciTech Connect

    Jia, Tingting Kimura, Hideo; Cheng, Zhenxiang; Zhao, Hongyang

    2015-11-15

    Aurivillius Bi{sub m+1}Ti{sub 3}Fe{sub m−3}O{sub 3m+3} (m = 4, 5, 6) thin films have been deposited by a pulsed laser deposition system. The x-ray diffraction patterns indicate the formation of orthorhombic phase. The remanent polarization (2P{sub r}) of Bi{sub m+1}Ti{sub 3}Fe{sub m−3}O{sub 3m+3} thin films is decreased with the m-number. Positive-up-negative-down measurements indicate the presence of ferroelectric (FE) polarization in as-obtained thin films. Piezoresponse force microscopy investigations confirm the existence of FE domains and the switchable polarization. Weak magnetic moment is detected in the Aurivillius films at room temperature. The present work suggests the possibility of Aurivillius Bi{sub m+1}Ti{sub 3}Fe{sub m−3}O{sub 3m+3} (m = 4, 5, 6) materials as potential room-temperature multiferroics.

  15. Length and Amino Acid Sequence of Peptides Substituted for the 5-HT3A Receptor M3M4 Loop May Affect Channel Expression and Desensitization

    PubMed Central

    McKinnon, Nicole K.; Bali, Moez; Akabas, Myles H.

    2012-01-01

    5-HT3A receptors are pentameric neurotransmitter-gated ion channels in the Cys-loop receptor family. Each subunit contains an extracellular domain, four transmembrane segments (M1, M2, M3, M4) and a 115 residue intracellular loop between M3 and M4. In contrast, the M3M4 loop in prokaryotic homologues is <15 residues. To investigate the limits of M3M4 loop length and composition on channel function we replaced the 5-HT3A M3M4 loop with two to seven alanine residues (5-HT3A-An = 2–7). Mutants were expressed in Xenopus laevis oocytes and characterized using two electrode voltage clamp recording. All mutants were functional. The 5-HT EC50's were at most 5-fold greater than wild-type (WT). The desensitization rate differed significantly among the mutants. Desensitization rates for 5-HT3A-A2, 5-HT3A-A4, 5-HT3A-A6, and 5-HT3A-A7 were similar to WT. In contrast, 5-HT3A-A3 and 5-HT3A-A5 had desensitization rates at least an order of magnitude faster than WT. The one Ala loop construct, 5-HT3A-A1, entered a non-functional state from which it did not recover after the first 5-HT application. These results suggest that the large M3M4 loop of eukaryotic Cys-loop channels is not required for receptor assembly or function. However, loop length and amino acid composition can effect channel expression and desensitization. We infer that the cytoplasmic ends of the M3 and M4 segments may undergo conformational changes during channel gating and desensitization and/or the loop may influence the position and mobility of these segments as they undergo gating-induced conformational changes. Altering structure or conformational mobility of the cytoplasmic ends of M3 and M4 may be the basis by which phosphorylation or protein binding to the cytoplasmic loop alters channel function. PMID:22539982

  16. [Effect of N+ (N = Li, Na, K) on the spectra of M3 (M = Ca, Sr, Ba) Y2 (BO3)4 : Eu3+ luminescent phosphor].

    PubMed

    Li, Pan-Lai; Wang, Zhi-Jun; Gao, Hui-Ying; Yang, Zhi-Ping

    2008-11-01

    The M3 (M = Ca, Sr, Ba) Y2 (BO3)4 : Eu3+ red phosphor was synthesized by firing twice at 800 and 1 050 degrees C each for 4 h and 4 h in air, respectively. Y2O3 (99.9%), Eu2O3 (99.9%), H3BO3 (99.9%), CaCO3 (99.9%), SrCO3 (99.9%), BaCO3 (99.9%), Li2CO3 (99.9%), Na2CO3 (99.9%) and K2CO3 (99.9%) were used as starting materials, and the doping Eu3+ concentration was 3 mol%. The excitation spectrum was measured by a SHIMADZU RF-540 ultraviolet spectrophotometer. The emission spectrum was measured by a SPEX1404 spectrophotometer. All the luminescence characteristics of the phosphors were investigated at room temperature. The emission spectrum of M3 (M = Ca, Sr, Ba) Y2 (BO3)4 : Eu3+ phosphor exhibited a 613 nm red emission corresponding to the electric dipole 55D0 - 7F2 transition of Eu3+ under 365 nm excitation. The excitation spectrum for 613 nm indicates that the phosphor can be effectively excited by ultraviolet (UV) (254, 365 and 400 nm) and blue (470 nm) light. The effect of Li+ , Na+ and K+ on the excitation and emission spectra of M3 (M = Ca, Sr, Ba)Y2 (BO3)4 : Eu3+ phosphor was studied. The results show that the location of the excitation and emission spectrum of M3 (M = Ca, Sr, Ba) Y2 (BO3)4 : Eu3+ phosphor was not influenced by Li+, Na+ and K+. However, the excitation and emission spectrum intensities were greatly influenced by Li+, Na+ and K+, and the emission peak intensities were all enhanced. Under the condition of the same Li+, Na+ and K+ concentration, the emission peak intensities of M3 (M = Ca, Sr, Ba)Y2 (BO3)4 : Eu3+ phosphor were compared, and the result shows that the accretion effect of doping Li+ is the best. The effect of Li+ concentration on the emission peak intensity of Sr3 Y2 (BO3)4 : Eu3+ phosphor was studied. The results show that the emission peak intensity firstly increased with the increasing Li+ concentration, then decreased, and reached the maximum value at 5 mol% Li+, and the maximum value is about twice as much as the Li-undoped one

  17. Calcium Carbonate

    MedlinePlus

    Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not ... for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve ...

  18. Carbon photonics

    NASA Astrophysics Data System (ADS)

    Konov, V. I.

    2015-11-01

    The properties of new carbon materials (single-crystal and polycrystalline CVD diamond films and wafers, single-wall carbon nanotubes and graphene) and the prospects of their use as optical elements and devices are discussed.

  19. Carbon-carbon composites

    NASA Technical Reports Server (NTRS)

    Maahs, Howard G.

    1992-01-01

    The current applications of C-C composites extend to aircraft brakes, rocket nozzles, missile nosetips, and leading edges of the Space Shuttle. More advanced, secondary and even primary structure applications in cyclic, high-temperature oxidizing environments depend on effective oxidation protection for repeated missions. Accounts are presently given of state-of-the-art methods in substrate fabrication, carbon deposition, and SiC and Si3N4 protective coatings. Attention is given to current levels of high temperature oxidation protection for various mission and vehicle types, as well as to performance projections for C-C composites used by a representative National Aerospace Plane airframe structure. Future technology requirements in C-C composites are projected.

  20. Whole-exome analysis of foetal autopsy tissue reveals a frameshift mutation in OBSL1, consistent with a diagnosis of 3-M Syndrome

    PubMed Central

    2015-01-01

    Background We report a consanguineous couple that has experienced three consecutive pregnancy losses following the foetal ultrasound finding of short limbs. Post-termination examination revealed no skeletal dysplasia, but some subtle proximal limb shortening in two foetuses, and a spectrum of mildly dysmorphic features. Karyotype was normal in all three foetuses (46, XX) and comparative genomic hybridization microarray analysis detected no pathogenic copy number variants. Results Whole-exome sequencing and genome-wide homozygosity mapping revealed a previously reported frameshift mutation in the OBSL1 gene (c.1273insA p.T425nfsX40), consistent with a diagnosis of 3-M Syndrome 2 (OMIM #612921), which had not been anticipated from the clinical findings. Conclusions Our study provides novel insight into the early clinical manifestations of this form of 3-M syndrome, and demonstrates the utility of whole exome sequencing as a tool for prenatal diagnosis in particular when there is a family history suggestive of a recurrent set of clinical symptoms. PMID:25923536

  1. An Essential Pentatricopeptide Repeat Protein Facilitates 5′ Maturation and Translation Initiation of rps3 mRNA in Maize Mitochondria[C][W

    PubMed Central

    Manavski, Nikolay; Guyon, Virginie; Meurer, Jörg; Wienand, Udo; Brettschneider, Reinhold

    2012-01-01

    Pentatricopeptide repeat (PPR) proteins are members of one of the largest nucleus-encoded protein families in plants. Here, we describe the previously uncharacterized maize (Zea mays) PPR gene, MPPR6, which was isolated from a Mutator-induced collection of maize kernel mutants by a cDNA-based forward genetic approach. Identification of a second mutant allele and cosegregation analysis confirmed correlation with the mutant phenotype. Histological investigations revealed that the mutation coincides with abnormities in the transfer cell layer, retardation of embryo development, and a considerable reduction of starch level. The function of MPPR6 is conserved across a wide phylogenetic distance as revealed by heterologous complementation of the Arabidopsis thaliana mutant in the orthologous APPR6 gene. MPPR6 appeared to be exclusively present in mitochondria. RNA coimmunoprecipitation and in vitro binding studies revealed a specific physical interaction of MPPR6 with the 5′ untranslated region of ribosomal protein S3 (rps3) mRNA. Mapping of transcript termini showed specifically extended rps3 5′ ends in the mppr6 mutant. Considerable reduction of mitochondrial translation was observed, indicating loss of RPS3 function. This is consistent with the appearance of truncated RPS3 protein lacking the N terminus in mppr6. Our results suggest that MPPR6 is directly involved in 5′ maturation and translation initiation of rps3 mRNA. PMID:22773745

  2. Y chromosome haplotype diversity in Mongolic-speaking populations and gene conversion at the duplicated STR DYS385a,b in haplogroup C3-M407.

    PubMed

    Malyarchuk, Boris A; Derenko, Miroslava; Denisova, Galina; Woźniak, Marcin; Rogalla, Urszula; Dambueva, Irina; Grzybowski, Tomasz

    2016-06-01

    Y chromosome microsatellite (Y-STR) diversity has been studied in different Mongolic-speaking populations from South Siberia, Mongolia, North-East China and East Europe. The results obtained indicate that the Mongolic-speaking populations clustered into two groups, with one group including populations from eastern part of South Siberia and Central Asia (the Buryats, Barghuts and Khamnigans) and the other group including populations from western part of Central Asia and East Europe (the Mongols and Kalmyks). High frequency of haplogroup C3-M407 (>50%) is present in the Buryats, Barghuts and Khamnigans, whereas in the Mongols and Kalmyks its frequency is much lower. In addition, two allelic combinations in DYS385a,b loci of C3-M407 haplotypes have been observed: the combination 11,18 (as well as 11,17 and 11,19) is frequent in different Mongolic-speaking populations, but the 11,11 branch is present mainly in the Kalmyks and Mongols. Results of locus-specific sequencing suggest that the action of gene conversion is a more likely explanation for origin of homoallelic 11,11 combination. Moreover, analysis of median networks of Y-STR haplotypes demonstrates that at least two gene conversion events can be revealed-one of them has probably occurred among the Mongols, and the other event occurred in the Barghuts. These two events give an average gene conversion rate range of 0.24-7.1 × 10(-3) per generation. PMID:26911356

  3. Electrical resistivity of the heavy-fermion-filled cage compound Ce3M4Sn13(M =Co,Rh,Ru) under high pressure

    NASA Astrophysics Data System (ADS)

    Ślebarski, A.; Goraus, J.; Witas, P.

    2015-10-01

    The effect of pressure on electrical resistivity of heavy-fermion compounds Ce3M4Sn13 , where M =Co , Rh, Ru, and the La3M4Sn13 counterparts is studied in the framework of the fully relativistic full potential local orbital method. The experiment shows that the electrical resistivity of Ce3Co4Sn13 and Ce3Rh4Sn13 increases with pressure, a similar pressure effect is obtained for isostructural La-based reference metals, while opposite behaviors under pressure are documented for Ce3Ru4Sn13 and La3Ru4Sn13 . The contrasting pressure dependent effects of Ce3Co4Sn13 and Ce3Ru4Sn13 are discussed. In order to clarify the various phenomena the band-structure calculations under applied pressure were performed. Here, we show that the resistivity increase with pressure arises from the formation of interband distances at the Fermi level in Ce3Co4Sn13 , this pseudo-gap-like effect is also pressure dependent, while in Ce3Ru4Sn13 the opposite change of resistivity results from the suppression of spin fluctuations under pressure.

  4. Nonautophagic cytoplasmic vacuolation death induction in human PC-3M prostate cancer by curcumin through reactive oxygen species -mediated endoplasmic reticulum stress

    PubMed Central

    Lee, Wei-Jiunn; Chien, Ming-Hsien; Chow, Jyh-Ming; Chang, Junn-Liang; Wen, Yu-Ching; Lin, Yung-Wei; Cheng, Chao-Wen; Lai, Gi-Ming; Hsiao, Michael; Lee, Liang-Ming

    2015-01-01

    The antiapoptotic and antiautophagic abilities of cancer cells constitute a major challenge for anticancer drug treatment. Strategies for triggering nonapoptotic or nonautophagic cell death may improve therapeutic efficacy against cancer. Curcumin has been reported to exhibit cancer chemopreventive properties. Herein, we report that curcumin induced apoptosis in LNCaP, DU145, and PC-3 cells but triggered extensive cytoplasmic vacuolation in PC-3M cells. Electron microscopic images showed that the vacuoles lacked intracellular organelles and were derived from the endoplasmic reticulum (ER). Moreover, curcumin-induced vacuolation was not reversed by an apoptosis- or autophagy-related inhibitor, suggesting that vacuolation-mediated cell death differs from classical apoptotic and autophagic cell death. Mechanistic investigations revealed that curcumin treatment upregulated the ER stress markers CHOP and Bip/GRP78 and the autophagic marker LC3-II. In addition, curcumin induced ER stress by triggering ROS generation, which was supported by the finding that treating cells with the antioxidant NAC alleviated curcumin-mediated ER stress and vacuolation-mediated death. An in vivo PC-3M orthotopic prostate cancer model revealed that curcumin reduced tumor growth by inducing ROS production followed by vacuolation-mediated cell death. Overall, our results indicated that curcumin acts as an inducer of ROS production, which leads to nonapoptotic and nonautophagic cell death via increased ER stress. PMID:26013662

  5. Structural design of a vertical antenna boresight 18.3 by 18.3-m planar near-field antenna measurement system

    NASA Technical Reports Server (NTRS)

    Sharp, G. R.; Trimarchi, P. A.; Wanhainen, J. S.

    1984-01-01

    A large very precise near-field planar scanner was proposed for NASA Lewis Research Center. This scanner would permit near-field measurements over a horizontal scan plane measuring 18.3 m by 18.3 m. Large aperture antennas mounted with antenna boresight vertical could be tested up to 60 GHz. When such a large near field scanner is used for pattern testing, the antenna or antenna system under test does not have to be moved. Hence, such antennas and antenna systems can be positioned and supported to simulate configuration in zero g. Thus, very large and heavy machinery that would be needed to accurately move the antennas are avoided. A preliminary investigation was undertaken to address the mechanical design of such a challenging near-field antenna scanner. The configuration, structural design and results of a parametric NASTRAN structural optimization analysis are contained. Further, the resulting design was dynamically analyzed in order to provide resonant frequency information to the scanner mechanical drive system designers. If other large near field scanners of comparable dimensions are to be constructed, the information can be used for design optimization of these also.

  6. Exploring artificial layered heterostructures of LaM'O3/LaM''O3 (M'M''= NiCr, FeCr and NiV).

    NASA Astrophysics Data System (ADS)

    Liu, J.; Kareev, M.; Freeland, J. W.; Kareev, A.; Lee, H. N.; Chakhalian, J.

    2008-03-01

    Digital synthesis of atomically sharp interfaces between strongly correlated electron systems can provide a template to build completely new materials. Here we present our results on magnetism and electronic structure in LaM'O3/LaM''O3 (M'M''= NiCr, FeCr and NiV) superlattices by using polarized X-ray spectroscopies. Using laser MBE, the (111) and (100) oriented ultra-thin superlattices were grown with alternating layer thicknesses of 1 unit cell. In the bulk, LaMO3 (M=Cr,Fe,V) are antiferromagnetic insulators while LaNiO3 is a paramagnetic metal. The evolution of element specific magnetism and charge at the interface of LFO/LCO, LNO/LVO and LNO/LCO superlattices with temperature and an applied magnetic field will be discussed in detail. The superlattice results will be contrasted to the bulk magnetic properties of the constituent layers. The work has been supported by U.S. DOD-ARO under Contract No. 0402-17291.

  7. Carbon-Carbon Piston Architectures

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    1999-01-01

    An improved structure for carbon-carbon composite piston architectures consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat. No. 4.909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially. the carbon fabric or tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel. to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar. or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U" channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also be accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum-alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

  8. New rock salt-related oxides Li{sub 3}M{sub 2}RuO{sub 6} (M=Co, Ni): Synthesis, structure, magnetism and electrochemistry

    SciTech Connect

    Laha, S.; Morán, E.; Sáez-Puche, R.; Alario-Franco, M.Á.; Dos santos-Garcia, A.J.; Gonzalo, E.; Kuhn, A.; García-Alvarado, F.; Sivakumar, T.; Tamilarasan, S.; Natarajan, S.; Gopalakrishnan, J.

    2013-07-15

    We describe the synthesis, crystal structure, magnetic and electrochemical characterization of new rock salt-related oxides of formula, Li{sub 3}M{sub 2}RuO{sub 6} (M=Co, Ni). The M=Co oxide adopts the LiCoO{sub 2} (R-3m) structure, where sheets of LiO{sub 6} and (Co{sub 2}/Ru)O{sub 6} octahedra are alternately stacked along the c-direction. The M=Ni oxide also adopts a similar layered structure related to Li{sub 2}TiO{sub 3}, where partial mixing of Li and Ni/Ru atoms lowers the symmetry to monoclinic (C2/c). Magnetic susceptibility measurements reveal that in Li{sub 3}Co{sub 2}RuO{sub 6}, the oxidation states of transition metal ions are Co{sup 3+} (S=0), Co{sup 2+} (S=1/2) and Ru{sup 4+} (S=1), all of them in low-spin configuration and at 10 K, the material orders antiferromagnetically. Analogous Li{sub 3}Ni{sub 2}RuO{sub 6} presents a ferrimagnetic behavior with a Curie temperature of 100 K. The differences in the magnetic behavior have been explained in terms of differences in the crystal structure. Electrochemical studies correlate well with both magnetic properties and crystal structure. Li-transition metal intermixing may be at the origin of the more impeded oxidation of Li{sub 3}Ni{sub 2}RuO{sub 6} when compared to Li{sub 3}Co{sub 2}RuO{sub 6}. Interestingly high first charge capacities (between ca. 160 and 180 mAh g{sup −1}) corresponding to ca. 2/3 of theoretical capacity are reached albeit, in both cases, capacity retention and cyclability are not satisfactory enough to consider these materials as alternatives to LiCoO{sub 2}. - Graphical abstract: Two new rock salt related oxides of formula, Li{sub 3}M{sub 2}RuO{sub 6}, (M=Co, Ni) have been prepared. The M=Co oxide adopts the LiCoO{sub 2} (R-3m) structure and the M=Ni oxide adopts a similar layered structure related to Li{sub 2}TiO{sub 3,} monoclinic (C2/c), with partial mixing of Li and Ni/Ru atoms. For Li{sub 3}Co{sub 2}RuO{sub 6}, oxidation state for Ru is 4+ and antiferromagnetic (AFM) order is

  9. Low-Potential Stable NADH Detection at Carbon-Nanotube-Modified Glassy Carbon Electrodes

    SciTech Connect

    Musameh, Mustafa; Wang, Joseph; Merkoci, Arben; Lin, Yuehe )

    2002-11-22

    Carbon-nanotube (CNT) modified glassy-carbon electrodes exhibiting strong and stable electrocatalytic response toward NADH are described. A substantial (490 mV) decrease in the overvoltage of the NADH oxidation reaction (compared to ordinary carbon electrodes) is observed using single-wall and multi-wall carbon-nanotube coatings, with oxidation starting at ca.?0.05V (vs. Ag/AgCl; pH 7.4). Furthermore, the NADH amperometric response of the coated electrodes is extremely stable, with 96 and 90% of the initial activity remaining after 60min stirring of 2x10-4M and 5x10-3M NADH solutions, respectively (compared to 20 and 14% at the bare surface). The CNT-coated electrodes thus allow highly-sensitive, low-potential, stable amperometric sensing. Such ability of carbon-nanotubes to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors.

  10. A comparison of the electrochemical behavior of carbon aerogels and activated carbon fiber cloths

    SciTech Connect

    Tran, T.D.; Alviso, C.T.; Hulsey, S.S.; Nielsen, J.K.; Pekala, R.W.

    1996-05-10

    Electrochemical capacitative behavior of carbon aerogels and commercial carbon fiber cloths was studied in 5M KOH, 3M sulfuric acid, and 0.5M tetrethylammonium tetrafluoroborate/propylene carbonate electrolytes. The resorcinol-formaldehyde based carbon aerogels with a range of denisty (0.2-0.85 g/cc) have open-cell structures with ultrafine pore sizes (5-50 nm), high surface area (400-700 m{sup 2}/g), and a solid matrix composed of interconnected particles or fibers with characteristic diameters of 10 nm. The commercial fiber cloths in the density range 0.2-04g/cc have high surface areas (1000-2500 m{sup 2}/g). The volumetric capacitances of high-density aerogels are shown to be comparable to or exceeding those from activated carbon fibers. Electrochemical behavior of these materials in various electrolytes is compared and related to their physical properties.

  11. Carbonate aquifers

    USGS Publications Warehouse

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  12. Effects of electron correlations application to Ti atoms on physical properties of (LaMnO3)m/(SrTiO3)n superlattices

    NASA Astrophysics Data System (ADS)

    Aezami, A.; Abolhassani, M.; Elahi, M.

    2016-05-01

    Magnetic structures and Curie temperatures of the (LaMnO3)m/(SrTiO3)n superlattices (SLm-n) with m=1, 2, 3 and n=1, 2, 3, 8 were investigated, using density functional theory implemented in Quantum-Espresso open source code. By applying on-site coulomb interaction (Hubbard term U) to Ti atoms for all of these superlattices, using Stoner-Wolfarth model, it was found that the magnetic order of interfacial atoms of these superlattices changed to ferromagnetic by implying U=5 eV on Ti atoms. The inclusion of electron-electron correlation with U=5 eV on the Ti atoms for all of the superlattices made the two dimensional electron gas (2DEG) formed at the interfaces, half-metallic. The obtained values of Curie temperature, calculated within mean field approximation with U=5 eV on the Ti atoms, are in good agreement with the experimental results.

  13. Ab-Initio Study on Plutonium Compounds Pu3M (M=Al, Ga, In), PuNp and Elemental Neptunium

    SciTech Connect

    Kutepov, A L

    2005-09-07

    Using spin-polarized relativistic density functional theory the electronic and magnetic structures for the plutonium compounds Pu{sub 3}M(M = Al; Ga; In) and PuNp have been investigated. For the first group of compounds the enhanced hybridization between Pu 5f and p-states of alloying element, as it has been found in spin-polarized calculations, is believed to be the main reason for the higher formation energies obtained in such kind of studies in comparison with the non-spin-polarized case. Also, comparative analysis of the actinides U, Np, Pu, Am, and Cm has been performed based on their electronic and magnetic structure. Some noticeable difference in the calculated magnetic structure was discovered between the actinide with local magnetic moments (Cm) and the actinides (Pu, Am) in which magnetic moments were found only in the calculations.

  14. Ferroelectricity in (BaTiO3)n/(SrTiO3)m Superlattices Containing as Few as one BaTiO3 Layer (n=1)

    NASA Astrophysics Data System (ADS)

    Schlom, Darrell

    2007-03-01

    The question of how thin a ferroelectric can be and still be ferroelectric has been the source of an intensive research effort over the past decade. Several studies, both theoretical and experimental, have concluded that with appropriate boundary conditions ferroelectricity can exist in superlattices containing BaTiO3 or PbTiO3 layers as thin as one unit cell. In this talk I will show the results of experiment and theory for BaTiO3/SrTiO3 superlattices grown by reactive molecular-beam epitaxy (MBE) on three different substrates: TiO2-terminated (001) SrTiO3, (110) DyScO3, and (110) GdScO3. With the aid of reflection high-energy electron diffraction (RHEED), precise single-monolayer doses of BaO, SrO, and TiO2 were deposited sequentially to create commensurate BaTiO3/SrTiO3 superlattices with a variety of periodicities. The superlattices consist of an n unit-cell-thick slab of BaTiO3 followed by an m unit-cell-thick slab of SrTiO3, which are designated [(BaTiO3)n/(SrTiO3)m]q, where q is the number of times the bilayer is repeated. X-ray diffraction (XRD) measurements exhibit clear superlattice peaks and the narrowest rocking curves ever reported for oxide superlattices. High-resolution transmission electron microscopy reveals nearly atomically abrupt interfaces. UV Raman results show that the BaTiO3 in these [(BaTiO3)n/(SrTiO3)m]q superlattices is tetragonal and the SrTiO3 is polar due to strain. Temperature-dependent UV Raman and XRD reveal the paraelectric-to-ferroelectric transition temperature (TC). Our results* demonstrate (1) that [(BaTiO3)n/(SrTiO3)m]q superlattices containing as few as one strained BaTiO3 layer (n=1) are ferroelectric and (2) the sensitivity of TC to the boundary conditions. Comparisons to ab initio and phase-field modeling of the properties of these [(BaTiO3)n/(SrTiO3)m]q ferroelectric superlattices will be made and the importance of strain demonstrated. In addition to probing finite size effects and the importance of mechanical boundary

  15. 3M Petrifilm Staph Express Count plate method for the enumeration of Staphylococcus aureus in selected types of meat, seafood, and poultry: collaborative study.

    PubMed

    McMahon, Wendy A; Aleo, Victoria A; Schultz, Ann M; Horter, Barbara L; Lindberg, Kathryn G

    2003-01-01

    The 3M Petrifilm Staph Express Count plate method was compared with AOAC Official Method 975.55 for the enumeration of Staphylococcus aureus in selected foods. Four foods--cooked, diced chicken; cured ham; smoked salmon; and pepperoni--were analyzed for S. aureus by 12 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample, a low inoculation level, a medium inoculation level, and a medium inoculation level with background flora, each in duplicate. The mean log10 counts for the methods were comparable for all 4 foods. The repeatability and reproducibility variances of the 24 h Petrifilm Staph Express Count plate method were similar to those of the 72 h standard method. PMID:14632396

  16. Is an arsenic-antisite-defect a constituent of hydrogen-related metastable defects (M3/M4) in GaAs?

    SciTech Connect

    Okumura, T.; Shinagawa, T.

    1998-12-31

    The hydrogen-related metastable defects (M3/M4) in n-GaAs, first found by Buchwald et al., were introduced only in the crystals containing the EL2 center. Off-center oxygen (=EL3), could not be responsible for their formation. A quantitative analysis with the samples exposed to atomic hydrogen showed that the M4 defect consisted of two different configurations. One of them did couple with M3, but is latent in the as-exposed state. It was formed after bias annealing at higher temperatures, such as 420 K. The other part of the M4 defect (M4{sup *}) existed at room temperature and after annealing at 513K, but disappeared and reappeared upon forward- and reverse-bias annealings, respectively.

  17. MeV proton beams generated by 3 mJ ultrafast laser pulses at 0.5 kHz

    SciTech Connect

    Hou Bixue; Nees, John; Easter, James; Thomas, Alexander; Krushelnick, Karl; Davis, Jack; Petrov, George

    2009-09-07

    Well-collimated proton beams are generated from bulk glass along the target normal direction by tightly focused 55 fs, 3 mJ pulses from a laser operating at 0.5 kHz repetition rate. Proton beams with energies of >265 keV have an emission angle of about 16 deg. full width at half maximum. Spectral measurements indicate proton energies exceeding 0.5 MeV with a flux of 3.2x10{sup 9} s{sup -1} sr{sup -1} and the flux of measured protons with energies of greater than 90 keV is 8.5x10{sup 11} s{sup -1} sr{sup -1} on center.

  18. Surface modification of MAl2O4:Eu2+,Dy3+ (M = Sr, Ca, Ba) phosphors to enhance water resistance by combustion method

    NASA Astrophysics Data System (ADS)

    Deng, Suqing; Xue, Zhiping; Yang, Qu; Liu, Yingliang; Lei, Bingfu; Xiao, Yong; Zheng, Mingtao

    2013-10-01

    A facile combustion method was introduced into surface modification of MAl2O4:Eu2+,Dy3+ (M = Sr, Ca, Ba) phosphors to improve their water resistance. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), pH measurements and photoluminescence (PL) spectrophotometry were used to characterize the phosphors before and after modification, respectively. Experimental results showed that compact layer of MAl2B2O7 (M = Sr, Ca, Ba) substance was formed on the surface of aluminate phosphors by direct chemical reaction between aluminate and boracic acid. MAl2B2O7 (M = Sr, Ca, Ba) substance is chemically stable in water and could improve water resistance of aluminate phosphors effectively with little influence of luminescence property. It was considered that the versatility of combustion method for surface modification of aluminate phosphors has been confirmed.

  19. Optical Colors of Centaurs and Kuiper Belt Objects From the Keck I 10-m Telescope and the University of Arizona 2.3-m Telescope

    NASA Astrophysics Data System (ADS)

    Tegler, S. C.; Romanishin, W.

    2002-09-01

    Our ongoing survey of Centaur and Kuiper belt object colors includes accurate B-V and V-R colors for about 50 objects. We find 20 out of 20 classical KBOs on low eccentricity and low inclination orbits with perihelion distances, q, greater than 40 AU exhibit extremely red surface colors (Tegler and Romanishin, 2000, Nature, 407, 979; Tegler and Romanishin, 2002, Icarus, submitted). As a result of three nights on the Keck I telescope during April of 2002 and three nights on the 2.3-m telescope during September of 2001, we report B-V and V-R colors for additional Centaurs and KBOs, all with q < 40 AU. We use these latest measurements to test our controversial claim that objects with q < 40 AU divide into two color populations. We thank the NASA Planetary Astronomy Program for their support and the NASA/Keck and University of Arizona TACs for their consistent allocation of telescope time.

  20. Large magnetocaloric effect in La0.845Sr0.155Mn1-xMxO3 (M = Mn, Cu, Co) perovskites

    NASA Astrophysics Data System (ADS)

    Phan, Manh-Huong; Phan, The-Long; Yu, Seong-Cho; Tho, Nguyen Duc; Chau, Nguyen

    2004-06-01

    We present the results of an investigation on the magnetocaloric effect in the perovskites of La0.845Sr0.155Mn1-xMxO3 (M = Mn, Cu, Co). It is found that there was a large magnetic entropy change, i.e. a large magneto-caloric effect, in all these samples. Among them, the magnetic entropy change reaches a maximum value of 2.67 J/kg K at the applied field of 13.5 kOe for the Cu-doped sample, suggesting that this material would be a suitable candidate for the advanced magnetic refrigeration technology. The large magnetic entropy change produced by the abrupt reduction of magnetization is attributed to the strong coupling between spin and lattice that occurs in the vicinity of the ferromagnetic-paramagnetic transition temperature (TC) - which is experimentally verified by electron paramagnetic resonance study.

  1. Divergence of Pumilio/fem-3 mRNA Binding Factor (PUF) Protein Specificity through Variations in an RNA-binding Pocket*

    PubMed Central

    Qiu, Chen; Kershner, Aaron; Wang, Yeming; Holley, Cynthia P.; Wilinski, Daniel; Keles, Sunduz; Kimble, Judith; Wickens, Marvin; Hall, Traci M. Tanaka

    2012-01-01

    mRNA control networks depend on recognition of specific RNA sequences. Pumilio-fem-3 mRNA binding factor (PUF) RNA-binding proteins achieve that specificity through variations on a conserved scaffold. Saccharomyces cerevisiae Puf3p achieves specificity through an additional binding pocket for a cytosine base upstream of the core RNA recognition site. Here we demonstrate that this chemically simple adaptation is prevalent and contributes to the diversity of RNA specificities among PUF proteins. Bioinformatics analysis shows that mRNAs associated with Caenorhabditis elegans fem-3 mRNA binding factor (FBF)-2 in vivo contain an upstream cytosine required for biological regulation. Crystal structures of FBF-2 and C. elegans PUF-6 reveal binding pockets structurally similar to that of Puf3p, whereas sequence alignments predict a pocket in PUF-11. For Puf3p, FBF-2, PUF-6, and PUF-11, the upstream pockets and a cytosine are required for maximal binding to RNA, but the quantitative impact on binding affinity varies. Furthermore, the position of the upstream cytosine relative to the core PUF recognition site can differ, which in the case of FBF-2 originally masked the identification of this consensus sequence feature. Importantly, other PUF proteins lack the pocket and so do not discriminate upstream bases. A structure-based alignment reveals that these proteins lack key residues that would contact the cytosine, and in some instances, they also present amino acid side chains that interfere with binding. Loss of the pocket requires only substitution of one serine, as appears to have occurred during the evolution of certain fungal species. PMID:22205700

  2. Origin of and tuning the optical and fundamental band gaps in transparent conducting oxides: The case of M2O3(M =Al ,Ga ,In )

    NASA Astrophysics Data System (ADS)

    Sabino, Fernando P.; Besse, Rafael; Oliveira, Luiz Nunes; Wei, Su-Huai; Da Silva, Juarez L. F.

    2015-11-01

    Good transparent conducting oxides (TCOs), such as In2O3 :Sn (ITO), usually combine large optical band gaps, essential for high transparency, with relatively small fundamental band gaps due to low conduction-band minima, which favor n -type doping and enhance the electrical conductivity. It has been understood that the optical band gaps are wider than the fundamental band gaps because optical transitions between the band-edge states are forbidden. The mechanism blocking such transitions, which can play a crucial role in the designing of alternative TCOs, nonetheless remains obscure. Here, based on first-principles density functional theory calculations and symmetry analysis of three oxides, M2O3 (M =Al ,Ga ,In ), we identify the physical origin of the gap disparities. Three conditions are necessary: (1) the crystal structure must have global inversion symmetry; (2) in order to belong to the Ag or A1 g irreducible representations, the states at the conduction-band minimum must have cation and oxygen s character; (3) in order to have g parity, the oxygen p orbitals constituting the states near the valence-band maximum must be strongly coupled to the cation d orbitals. Under these conditions, optical excitations across the fundamental gap will be forbidden. The three criteria explain the trends in the M2O3 (M =Al,Ga,In) sequence, in particular, explaining why In2O3 in the bixbyite structure yields the highest figure of merit. Our study provides guidelines expected to be instrumental in the search for new TCO materials.

  3. Tudor-SN, a component of stress granules, regulates growth under salt stress by modulating GA20ox3 mRNA levels in Arabidopsis

    PubMed Central

    Yan, Chunxia; Yan, Zongyun; Wang, Yizheng; Yan, Xiaoyuan; Han, Yuzhen

    2014-01-01

    The Tudor-SN protein (TSN) is universally expressed and highly conserved in eukaryotes. In Arabidopsis, TSN is reportedly involved in stress adaptation, but the mechanism involved in this adaptation is not understood. Here, we provide evidence that TSN regulates the mRNA levels of GA20ox3, a key enzyme for gibberellin (GA) biosynthesis. The levels of GA20ox3 transcripts decreased in TSN1/TSN2 RNA interference (RNAi) transgenic lines and increased in TSN1 over-expression (OE) transgenic lines. The TSN1 OE lines displayed phenotypes that may be attributed to the overproduction of GA. No obvious defects were observed in the RNAi transgenic lines under normal conditions, but under salt stress conditions these lines displayed slower growth than wild-type (WT) plants. Two mutants of GA20ox3, ga20ox3-1 and -2, also showed slower growth under stress than WT plants. Moreover, a higher accumulation of GA20ox3 transcripts was observed under salt stress. The results of a western blot analysis indicated that higher levels of TSN1 accumulated after salt treatment than under normal conditions. Subcellular localization studies showed that TSN1 was uniformly distributed in the cytoplasm under normal conditions but accumulated in small granules and co-localized with RBP47, a marker protein for stress granules (SGs), in response to salt stress. The results of RNA immunoprecipitation experiments indicated that TSN1 bound GA20ox3 mRNA in vivo. On the basis of these findings, we conclude that TSN is a novel component of plant SGs that regulates growth under salt stress by modulating levels of GA20ox3 mRNA. PMID:25205572

  4. C-Reactive Protein Promotes Diabetic Kidney Disease in db/db Mice via the CD32b-Smad3-mTOR signaling Pathway

    PubMed Central

    You, Yong-Ke; Huang, Xiao-Ru; Chen, Hai-Yong; Lyu, Xia-Fei; Liu, Hua-Feng; Lan, Hui Y.

    2016-01-01

    C-reactive protein (CRP) is associated with progressive diabetic nephropathy in patients with type-2 diabetes (T2DN). However, role of CRP in T2DN remains unclear. We report here that CRP is pathogenic in T2DN in db/db mice that express human CRP (CRPtg-db/db). Compared to the littermate db/db mice, CRPtg-db/db developed more severe T2DN, showing higher levels of fasting blood glucose and microalbuminuria and more progressive renal inflammation and fibrosis. Enhanced T2DN in CRPtg-db/db mice were associated with over-activation of CRP-CD32b, NF-κB, TGF-β/Smad3, and mTOR signaling. Further studies in vitro defined that CRP activated Smad3 directly at 15 mins via the CD32b- ERK/p38 MAP kinase crosstalk pathway and indirectly at 24 hours through a TGF-β1-dependent mechanism. Importantly, CRP also activated mTOR signaling at 30 mins via a Smad3-dependent mechanism as Smad3 bound mTOR physically and CRP-induced mTOR signaling was abolished by a neutralizing CD32b antibody and a specific Smad3 inhibitor. Finally, we also found that CRP induced renal fibrosis through a CD32b-Smad3-mTOR pathway because blocking mTOR signaling with rapamycin inhibited CRP-induced CTGF and collagen I expression. Thus, CRP is pathogenic in T2DN. CRP may promote CD32b- NF-κB signaling to mediate renal inflammation; whereas, CRP may enhance renal fibrosis in T2DN via CD32b-Smad3-mTOR signaling. PMID:27221338

  5. C-Reactive Protein Promotes Diabetic Kidney Disease in db/db Mice via the CD32b-Smad3-mTOR signaling Pathway.

    PubMed

    You, Yong-Ke; Huang, Xiao-Ru; Chen, Hai-Yong; Lyu, Xia-Fei; Liu, Hua-Feng; Lan, Hui Y

    2016-01-01

    C-reactive protein (CRP) is associated with progressive diabetic nephropathy in patients with type-2 diabetes (T2DN). However, role of CRP in T2DN remains unclear. We report here that CRP is pathogenic in T2DN in db/db mice that express human CRP (CRPtg-db/db). Compared to the littermate db/db mice, CRPtg-db/db developed more severe T2DN, showing higher levels of fasting blood glucose and microalbuminuria and more progressive renal inflammation and fibrosis. Enhanced T2DN in CRPtg-db/db mice were associated with over-activation of CRP-CD32b, NF-κB, TGF-β/Smad3, and mTOR signaling. Further studies in vitro defined that CRP activated Smad3 directly at 15 mins via the CD32b- ERK/p38 MAP kinase crosstalk pathway and indirectly at 24 hours through a TGF-β1-dependent mechanism. Importantly, CRP also activated mTOR signaling at 30 mins via a Smad3-dependent mechanism as Smad3 bound mTOR physically and CRP-induced mTOR signaling was abolished by a neutralizing CD32b antibody and a specific Smad3 inhibitor. Finally, we also found that CRP induced renal fibrosis through a CD32b-Smad3-mTOR pathway because blocking mTOR signaling with rapamycin inhibited CRP-induced CTGF and collagen I expression. Thus, CRP is pathogenic in T2DN. CRP may promote CD32b- NF-κB signaling to mediate renal inflammation; whereas, CRP may enhance renal fibrosis in T2DN via CD32b-Smad3-mTOR signaling. PMID:27221338

  6. The Association between Splenocyte Apoptosis and Alterations of Bax, Bcl-2 and Caspase-3 mRNA Expression, and Oxidative Stress Induced by Dietary Nickel Chloride in Broilers

    PubMed Central

    Huang, Jianying; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wu, Bangyuan

    2013-01-01

    Two hundred and forty avian broilers were equally divided into four groups, and raised with a corn-soybean basal diet or the same diet supplemented with 300, 600, 900 mg/kg NiCl2 for 42 days. Numbers or percentages of apoptotic splenocytes by flow cytometry (FCM) and TUNEL were higher (p < 0.05 or p < 0.01) in the 300, 600 and 900 mg/kg groups than those in the control group. Results measured by qRT-PCR and ELISA showed that mRNA expression and contents were significantly higher (p < 0.05 or p < 0.01) in Bax and Caspase-3, and were significantly lower (p < 0.05 or p < 0.01) in Bcl-2 of the 300, 600 and 900 mg/kg groups. Also, the SOD, CAT and GSH-Px activities, and the ability to inhibit hydroxyl radical, and GSH contents were significantly decreased (p < 0.05 or p < 0.01), and MDA contents were increased (p < 0.05 or p < 0.01) in all groups. In conclusion, dietary NiCl2 in excess of 300 mg/kg caused apoptosis, altered Bax, Bcl-2 and Caspase-3 mRNA expression levels and contents, and induced oxidative stress in the spleen. Also, splenocyte apoptosis was closely related to the alternations of Bax, Bcl-2 and Caspase-3 mRNA expression, and oxidative damage. The splenic immunity and blood filtration functions were impaired in broilers. PMID:24351749

  7. Coordinated study of subkilometer and 3-m irregularities in the F region generated by high-power HF heating at Arecibo

    SciTech Connect

    Basu, S.; Ganguly, S.; Gordon, W.E.

    1983-11-01

    High-power high-frequency transmitters near Arecibo were used to generate artificial ionospheric irregularities in the F region. Radio star scintillation observations at 430 MHz were performed at Arecibo Ionospheric Observatory with the 305-m antenna, and radar backscatter measurements at 50 MHz were simultaneously made from Guadeloupe Island to probe the subkilometer and 3-m irregularities in the heated volume. Scintillation studies indicate a low-frequency modulation of the faster intensity fluctuation structure. By the use of plasma drift data this low-frequency modulation of the faster intensity fluctuation structure. By the use of plasma drift data this low-frequency temporal structure translates to spatial dimensions of 1--2 km. The frequency of the modulation envelope is found to be controlled by the heater power and is related to the dominant irregularity wavelength generated by the self-focusing instability. Scintillation spectra imply a steep power law index of approx.5 in the scale length range of about 300 m to 150 m and a shallow index of approx.2 at less than 150 m. The steep power law index may arise from a aperture averaging effect of the large 305-m antenna at Arecibo. Simultaneous measurements of 430-MHz scintillations and 50-MHz radar backscatter from field-aligned striations were performed to show that subkilometer irregularities can be generated by both O and X mode heating whereas the 3-m irregularities are excited only by the O mode heating, as is predicted by the theories of self-focusing and parametric instability.

  8. Operational O3M-SAF trace gas column products: GOME-2 ozone, NO2, BrO, SO2 and CH2O

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Valks, Pieter; Loyola, Diego; de Smedt, Isabelle; van Roozendael, Michel; Theys, Nicolas; Rix, Meike; Koukouli, Mariliza; Balis, Dimitris; Lambert, Jean-Christopher; Pinardi, Gaia; Zimmer, Walter; Emmadi, Sunil

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for ozone, NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.x algorithm and the UPAS system. Total ozone and NO2 are retrieved with the Differential Optical Absorption Spectroscopy (DOAS) method using the UV wavelength region around 330 nm and 435 nm respectively. An additional algorithm is applied to retrieve the tropospheric NO2 column for polluted con-ditions. The operational ozone and NO2 products are available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 ozone, total and tropospheric NO2, SO2, BrO, CH2O and cloud products from DLR have reached the operational EUMETSAT O3M-SAF status. All these products are routinely available to the users via EUMETCast, WMO/GTS and FTP in HDF5 and BUFR format. We present initial validation results for GOME-2 products using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  9. Operational O3M-SAF trace gas column products: GOME-2 NO2, BrO, SO2 and CH2O

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Valks, P.; de Smedt, I.; Emmadi, S.; Lambert, J.-C.; Loyola, D.; Pinardi, G.; Rix, M.; van Roozendael, M.; They, N.

    2010-05-01

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.4 using the Differential Optical Absorption Spectroscopy (DOAS) method in the UV and VIS wavelength regions. Total NO2 is retrieved in the 425-450 nm and an additional algorithm is applied to retrieve the tropospheric NO2 column for polluted conditions. The operational GOME-2 NO2 product is available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 using the UV wavelength region around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 SO2, BrO and CH2O products have reached the operational O3M-SAF status, and are routinely available to the users. More than three years of operational trace gas column measurements are now available from GOME-2. We present initial validation results using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  10. Carbon-Carbon Piston Architectures

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved structure for carbon-carbon composite piston architectures is disclosed. The improvement consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat.No. 4,909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially, the carbon fabric of tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel, to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar, or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U"-channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

  11. Temperature sensitivity (Q10), and dynamics of soil organic matter (SOM) decomposition in permafrost soils with different carbon quality and under experimental warming. R. Bracho1, E.A.G Schuur1, E. Pegoraro1, K.G. Crummer1, S. Natali2, J. Zhou, Y Luo3, J. L. Wu3, M. Tiedje4, K. Konstantinidis5 1Department of Biology, University of Florida, Gainesville, FL. 2Woods Hole Research Center, Falmouth, MA. 3Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, OK, 4Center for Microbial Ecology, Michigan State University, East Lansing, MI; 5Center for Bioinformatics and Computational Genomics and School of Biology, Georgia Institute of Technology, Atlanta, GA

    NASA Astrophysics Data System (ADS)

    Bracho, R. G.; Schuur, E. A.; Pegoraro, E.; Crummer, K. G.; Natali, S.; Zhou, J.; Wu, L.; Luo, Y.; Tiedje, J. M.; Konstantinidis, K.

    2013-12-01

    Permafrost soils contain approximately1700 Pg of carbon (C), twice the amount of C in the atmosphere. Temperatures in higher latitudes are increasing, inducing permafrost thaw and subsequent microbial decomposition of previously frozen C. This process is one of the most likely positive feedbacks to climate change. Understanding the temperature sensitivity (Q10) and dynamics of SOM decomposition under warming is essential to predict the future state of the earth - climate system. Alaskan tundra soils were exposed to two winter warming (WW) seasons in the field, which warmed the soils by 4°C to 40 cm depth. Soils were obtained from three depths (0 - 15, 15 - 25 and 45 - 55 cm) and differed in initial amounts of labile and recalcitrant C. Soils were incubated in the lab under aerobic conditions, at 15 and 25°C over 365 days. Q10 was estimated at 14, 100 & 280 days of incubation (DOI); C fluxes were measured periodically and dynamics of SOM decomposition (C pool sizes and decay rates) were estimated by fitting a two pool C model to cumulative respired C (Ccum, mgC/ginitialC). After two WW seasons, initial C content tended to decrease through the soil profile and C:N ratio was significantly decreased in the top 15 cm. After one year of incubation, Ccum was twice as high at 25°C as at 15°C and significantly decreased with depth. No significant WW field treatment was detected, although Ccum tended to be lower in warmed soils. Labile C accounted for up to 5% of initial soil C content in the top 15 cm and decreased with depth. Soils exposed to WW had smaller labile C pools, and higher labile C decay rates in the top 25 cm. Q10 significantly decreased with time and depth as labile pool decreased, especially for WW. This decrease with time indicates a lower temperature sensitivity of the most recalcitrant C pool. The deepest WW soil layer, where warming was more pronounced, had significantly lower Q10 compared to control soils at the same depth. After two seasons, the

  12. Calcium carbonate budgets for two coral reefs affected by different terrestrial runoff regimes, Rio Bueno, Jamaica

    NASA Astrophysics Data System (ADS)

    Mallela, J.; Perry, C. T.

    2007-03-01

    A process-based carbonate budget was used to compare carbonate framework production at two reef sites subject to varying degrees of fluvial influence in Rio Bueno, Jamaica. The turbid, central embayment was subjected to high rates of fluvial sediment input, framework accretion was restricted to ≤30 m, and net carbonate production was 1,887 g CaCO3 m-2 year-1. Gross carbonate production (GCP) was dominated by scleractinians (97%), particularly by sediment-resistant species, e.g. Diploria strigosa on the reef flat (<2 m). Calcareous encrusters contributed very little carbonate. Total bioerosion removed 265 g CaCO3 m-2 year-1 and was dominated by microborers. At the clear-water site, net carbonate production was 1,236 g CaCO3 m-2 year-1; the most productive zone was on the fore-reef (10 m). Corals accounted for 82% of GCP, and encrusting organisms 16%. Bioerosion removed 126 g CaCO3 m-2 year-1 and was dominated by macroborers. Total fish and urchin grazing was limited throughout (≤20 g CaCO3 m-2 year-1). The study demonstrates that: (1) carbonate production and net reef accretion can occur where environmental conditions approach or exceed perceived threshold levels for coral survival; and (2) although live coral cover (and carbonate production rates) were reduced on reef-front sites along the North Jamaican coast, low population densities of grazing fish and echinoids to some extent offset this, thus maintaining positive carbonate budgets.

  13. Evaluation of a 3M Petrifilm on-farm culture system for the detection of intramammary infection at the end of lactation.

    PubMed

    Cameron, M; Keefe, G P; Roy, J P; Dohoo, I R; MacDonald, K A; McKenna, S L

    2013-08-01

    The purpose of this study was to evaluate a 3M Petrifilm-based on-farm culture system for the detection of intramammary infection (IMI) in low somatic cell count (SCC) cows (<200,000 cells/mL) at drying off. The main objectives were to determine the test characteristics and the predictive values of the Petrifilm on-farm culture system. The ability of dairy producers to correctly classify cows as infected or uninfected based on Petrifilm culture and a set colony count threshold was also assessed. A total of 360 cows originating from 16 low bulk tank SCC (<250,000 cells/mL) dairy herds were enrolled at drying off. Enrolled cows had an expected dry period of 30-90 days, a SCC<200,000 cells/mL on the last 3 tests prior to drying off, no clinical mastitis in the same time period, and no antibiotic treatment in the last 14 days. Quarter milk samples were collected on the day prior to drying off, and a composite milk sample was created by combining 5 mL of milk from each quarter sample. Composite milk samples were cultured on-farm using the Petrifilm culture system, which provided results within 24h. Quarter milk samples were cultured in a reference laboratory, and the results were aggregated to the cow level. On the day of drying off, the Petrifilm was read by the producer and cows were classified as positive if ≥5 colonies (equivalent to 50 colony forming units/mL) were present. When read by the producer, 47.8% of the cows cultured negative on Petrifilm and were infused with only an internal teat sealant at drying off. The test characteristics of the Petrifilm on-farm culture system were calculated by comparing the producer-derived Petrifilm results to those obtained by standard laboratory culture. The sensitivity and specificity of the Petrifilm on-farm culture system were 85.2% (78.5-90.5) and 73.2% (66.4-79.3), respectively. The negative predictive value of the Petrifilm test system was high (86.6%) when estimated using the prevalence of IMI in this data set, and

  14. Deep Soil Carbon: The Insight into Global Carbon Estimation and Deforestation Impacts

    NASA Astrophysics Data System (ADS)

    Sangmanee, Podjanee; Dell, Bernard; Harper, Richard; Henry, David

    2015-04-01

    World carbon stocks have been dramatically changed by deforestation. The current estimation of carbon loss is based on allometric techniques assisted with satellite imagery and the assumption that, 20% of the total biomass carbon stock is below ground. However, the monitoring of soil carbon is limited to 0.3 m despite many soils being much deeper than this. For example, direct measurement of soil carbon demonstrated the occurrence of two to five times more carbon stored in deep soils of south Western Australia (SWA) compared to what would normally be reported, although the land had been deforested for 80 years. This raises important questions about the dynamics of this deeper carbon and whether it will contribute to global climate change. This paper reports the form and variation of carbon in soil at three adjacent areas at three different depths (0-1, 11-12 and 18-19 m). Techniques were developed to quantitatively and qualitatively determine small concentrations of carbon in deep soils. There were marked differences in carbon compounds with depth. Near the surface these were macromolecular organic compounds derived from lignin, polysaccharides, proteins, terpenes, whereas at depth they were low molecular weight compounds, 13-docosenamide, 13-docosenoate, xanthone, benzophenone. The deeper compounds are likely derived from the roots of the previous forest whereas the surface soils are affected by current land use. The in situ decomposition of deep roots was revealed by the pyridine compound. The variation of compounds and location of carbon in clay could imply the state of decomposition. The result demonstrated that carbon is contained in deep soils and should be considered in global carbon accounting, particularly given ongoing deforestation on deep soils.

  15. Developments in carbon materials

    NASA Technical Reports Server (NTRS)

    Burchell, Timothy D.

    1994-01-01

    The following carbon-based materials are reviewed and their applications discussed: fullerenes; graphite (synthetic and manufactured); activated carbon fibers; and carbon-carbon composites. Carbon R&D activities at ORNL are emphasized.

  16. The influence of plasma horizontal position on the neutron rate and flux of neutral atoms in injection heating experiment on the TUMAN-3M tokamak

    NASA Astrophysics Data System (ADS)

    Kornev, V. A.; Chernyshev, F. V.; Melnik, A. D.; Askinazi, L. G.; Wagner, F.; Vildjunas, M. I.; Zhubr, N. A.; Krikunov, S. V.; Lebedev, S. V.; Razumenko, D. V.; Tukachinsky, A. S.

    2013-11-01

    Horizontal displacement of plasma along the major radius has been found to significantly influence the fluxes of 2.45 MeV DD neutrons and high-energy charge-exchange atoms from neutral beam injection (NBI) heated plasma of the TUMAN-3M tokamak. An inward shift by Δ R = 1 cm causes 1.2-fold increase in the neutron flux and 1.9-fold increase in the charge-exchange atom flux. The observed increase in the neutron flux is attributed to joint action of several factors-in particular, improved high-energy ion capture and confinement and, probably, decreased impurity inflow from the walls, which leads to an increase in the density of target ions. A considerable increase in the flux of charge-exchange neutrals in inward-shifted plasma is due to the increased number of captured high-energy ions and, to some extent, the increased density of the neutral target. As a result of the increase in the content of high-energy ions, the central ion temperature T i (0) increased from 250 to 350 eV. The dependence of the neutron rate on major radius R 0 should be taken into account when designing compact tokamak-based neutron sources.

  17. Microwave-assisted synthesis: A fast and efficient route to produce LaMO{sub 3} (M = Al, Cr, Mn, Fe, Co) perovskite materials

    SciTech Connect

    Prado-Gonjal, J.; Arevalo-Lopez, A.M.; Moran, E.

    2011-02-15

    Research highlights: {yields} Lanthanum perovskites can be prepared by microwave irradiation in a domestic set-up. {yields} Microwave-assisted synthesis yields well crystallized and pure materials, sometimes nanosized. {yields} Rietveld analysis has been performed to refine the structures. {yields} Magnetic and electric measurements are similar to those previously reported. {yields} Microwave-assisted synthesis is a fast and efficient method for the synthesis of lanthanum perovskites. -- Abstract: A series of lanthanum perovskites, LaMO{sub 3} (M = Al, Cr, Mn, Fe, Co), having important technological applications, have been successfully prepared by a very fast, inexpensive, reproducible, environment-friendly method: the microwave irradiation of the corresponding mixtures of nitrates. Worth to note, the microwave source is a domestic microwave oven. In some cases the reaction takes place in a single step, while sometimes further annealings are necessary. For doped materials the method has to be combined with others such as sol-gel. Usually, nanopowders are produced which yield high density pellets after sintering. Rietveld analysis, oxygen stoichiometry, microstructure and magnetic measurements are presented.

  18. A feasibility study of using Langley 0.3-m transonic cryogenic tunnel sidewall boundary-layer removal system for heavy gas testing

    NASA Technical Reports Server (NTRS)

    Murthy, A. V.; Balakrishna, S.; Kilgore, W. Allen

    1993-01-01

    This report presents the results of a preliminary study for using the 0.3-m Transonic Cryogenic Tunnel sidewall boundary-layer removal system with heavy gas sulfur hexafluoride as the test medium. It is shown that the drive motor speed/power of the existing system and the additional heat load on the tunnel heat exchanger are the major problems limiting the boundary-layer removal system performance. Overcoming these problems can provide the capability to remove about 1.5 percent of the test section mass flow at Mach number M = 0.8 and about 5 percent at M = 0.25. Previous studies have shown that these boundary-layer mass flow removal rates can reduce the boundary-layer thickness by a factor of two at the model station. Also the effect of upstream boundary-layer removal on the airfoil test data is not likely to be significant under high lifting conditions. Near design conditions, corrections to the test Mach number may be necessary to account for sidewall boundary-layer effects.

  19. Measurements in the flow field of a cylinder with a laser transit anemometer and a drag rake in the Langley 0.3 m transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Honaker, W. C.; Lawing, P. L.

    1985-01-01

    An experiment was conducted at the 0.3 m Transonic Cryogenic Tunnel using a Laser Transit Anemometer (LTA) to probe the flow field around a 3.05 centimeter-diameter circular cylinder. Measurements were made along the stagnation line and determination of particle size was evaluated by their ability to follow the flow field. The LTA system was also used to scan into the boundary layer near the 45 degree point on the model. Results of these scans are presented in graphic and tabular form. Flow field particle seeding was accomplished by inbleeding dry service air. The residual moisture (5-10 ppm) condensed and formed ice particles which served as Mie scattering centers for the LTA detection system. Comparison of data taken along the stagnation streamline with theory indicated that these particles tracked the velocity gradient of the flow. Tunnel operating conditions for the tests were a Mach number of 0.3, a pressure of 1.93 x 100000 n/m squared, and a temperature of 225 degrees K. Free stream Mach number and pressure were varied for the particle size determination.

  20. The Structure of the yFACT Pob3-M Domain, Its Interaction with the DNA Replication Factor RPA, and a Potential Role in Nucleosome Deposition

    SciTech Connect

    VanDemark,A.; Blanksma, M.; Ferris, E.; Heroux, A.; Hill, C.; Formosa, T.

    2006-01-01

    We report the crystal structure of the middle domain of the Pob3 subunit (Pob3-M) of S. cerevisiae FACT (yFACT, facilitates chromatin transcription), which unexpectedly adopts an unusual double pleckstrin homology (PH) architecture. A mutation within a conserved surface cluster in this domain causes a defect in DNA replication that is suppressed by mutation of replication protein A (RPA). The nucleosome reorganizer yFACT therefore interacts in a physiologically important way with the central single-strand DNA (ssDNA) binding factor RPA to promote a step in DNA replication. Purified yFACT and RPA display a weak direct physical interaction, although the genetic suppression is not explained by simple changes in affinity between the purified proteins. Further genetic analysis suggests that coordinated function by yFACT and RPA is important during nucleosome deposition. These results support the model that the FACT family has an essential role in constructing nucleosomes during DNA replication, and suggest that RPA contributes to this process.

  1. Structural and electronic properties of UnOm (n=1-3,m=1-3n) clusters: A theoretical study using screened hybrid density functional theory

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Liu, Haitao; Zhang, Ping

    2016-05-01

    The structural and electronic properties of small uranium oxide clusters UnOm (n=1-3, m=1-3n) are systematically studied within the screened hybrid density functional theory. It is found that the formation of U-O-U bondings and isolated U-O bonds are energetically more stable than U-U bondings. As a result, no uranium cores are observed. Through fragmentation studies, we find that the UnOm clusters with the m/n ratio between 2 and 2.5 are very stable, hinting that UO2+x hyperoxides are energetically stable. Electronically, we find that the O-2p states always distribute in the deep energy range, and the U-5f states always distribute at the two sides of the Fermi level. The U-6d states mainly hybridize with the U-5f states in U-rich clusters, while hybridizing with O-2p states in O-rich clusters. Our work is the first one on the screened hybrid density functional theory level studying the atomic and electronic properties of the actinide oxide clusters.

  2. Multiple Magnetic Transitions and Magnetocaloric Effect in (La,Pr,M)MnO3 (M = Ca, Sr, Ba) Mixed Phase Manganites

    NASA Astrophysics Data System (ADS)

    Lampen, P. J.; Bingham, N. S.; Phan, M. H.; Srikanth, H. S.; Phan, T. L.; Yu, S. C.; Cheong, S. W.

    2012-02-01

    The manganite compound (La,Pr,Ca)MnO3 is a well-studied system that is known to exhibit a complex phase diagram featuring ``strain liquid'' and ``strain glass'' regions in combination with competing ferromagnetic (FM) and charge-ordered antiferromagnetic (CO/AFM) phases. The balance of these phases is sensitive to various perturbations including magnetic and electric field, strain, bandwidth, and A-site cation disorder. The A-site disorder and bandwidth of this compound can be tuned through the replacement of Ca with larger Sr and Ba ions. We report here a systematic study of the influence of cation substitution on the magnetic and magnetocaloric properties of La0.35Pr0.275M0.375MnO3 (M = Ca, Sr, Ba). Structural properties, including lattice parameters and Mn--O--Mn bond angles, were determined from X-ray diffraction patterns. DC magnetometry studies reveal multiple magnetic transitions in each sample which are probed by magnetocaloric effect (MCE) and transverse susceptibility (TS) experiments. Increasing the average A-site cationic radius is found to strongly impact the magnetic properties and phase behavior of the system.

  3. Rapid identification of a novel complex I MT-ND3 m.10134C>A mutation in a Leigh syndrome patient.

    PubMed

    Miller, David K; Menezes, Minal J; Simons, Cas; Riley, Lisa G; Cooper, Sandra T; Grimmond, Sean M; Thorburn, David R; Christodoulou, John; Taft, Ryan J

    2014-01-01

    Leigh syndrome (LS) is a rare progressive multi-system neurodegenerative disorder, the genetics of which is frequently difficult to resolve. Rapid determination of the genetic etiology of LS in a 5-year-old girl facilitated inclusion in Edison Pharmaceutical's phase 2B clinical trial of EPI-743. SNP-arrays and high-coverage whole exome sequencing were performed on the proband, both parents and three unaffected siblings. Subsequent multi-tissue targeted high-depth mitochondrial sequencing was performed using custom long-range PCR amplicons. Tissue-specific mutant load was also assessed by qPCR. Complex I was interrogated by spectrophotometric enzyme assays and Western Blot. No putatively causal mutations were identified in nuclear-encoded genes. Analysis of low-coverage off-target mitochondrial reads revealed a previously unreported mitochondrial mutation in the proband in MT-ND3 (m.10134C>A, p.Q26K), a Complex I mitochondrial gene previously associated with LS. Targeted investigations demonstrated that this mutation was 1% heteroplasmic in the mother's blood and homoplasmic in the proband's blood, fibroblasts, liver and muscle. Enzyme assays revealed decreased Complex I activity. The identification of this novel LS MT-ND3 variant, the genomics of which was accomplished in less than 3.5 weeks, indicates that rapid genomic approaches may prove useful in time-sensitive cases with an unresolved genetic diagnosis. PMID:25118196

  4. Blazar variability studies with the 1.3m Robotically Controlled Telescope and the automated 0.6m Bell Observatory telescope

    NASA Astrophysics Data System (ADS)

    Carini, M. T.; Barnaby, D.; Mattox, J. R.; Walters, R.; Poteet, C.; Wills, W.; Gelderman, R.; Davis, D.; Everett, M.; Guinan, E.; Howell, S.; McGruder, C. H., III

    2004-10-01

    One of the key programs on the 1.3m Robotically Controlled Telescope (RCT) located at Kitt Peak National Observatory and the 0.6m telescope at the Bell Observatory operated by Western Kentucky University is a study of the variability of the class of Active Galactic Nuclei (AGN) known as Blazars. Blazars are highly variable on timescales of minutes to decades and this variability is seen across the electromagnetic spectrum. In addition, they display a featureless spectrum, thus continuum variability provides the only diagnostic of these objects. Variability provides information on the size of the emission region responsible for the observed variations and when observations are obtained at multiple wavelengths, it can be used to discriminate between emission models. However, traditional ground based observations are limited in a variety of ways. We will discuss how an automated facility, with time dedicated to this astrophysically interesting problem, can overcome many of these limitations, and we show results from the Bell Observatory as well as some of the first results of Blazar observations from the RCT.

  5. Structural and electronic properties of UnOm (n=1-3,m=1-3n) clusters: A theoretical study using screened hybrid density functional theory.

    PubMed

    Yang, Yu; Liu, Haitao; Zhang, Ping

    2016-05-14

    The structural and electronic properties of small uranium oxide clusters UnOm (n=1-3, m=1-3n) are systematically studied within the screened hybrid density functional theory. It is found that the formation of U-O-U bondings and isolated U-O bonds are energetically more stable than U-U bondings. As a result, no uranium cores are observed. Through fragmentation studies, we find that the UnOm clusters with the m/n ratio between 2 and 2.5 are very stable, hinting that UO2+x hyperoxides are energetically stable. Electronically, we find that the O-2p states always distribute in the deep energy range, and the U-5f states always distribute at the two sides of the Fermi level. The U-6d states mainly hybridize with the U-5f states in U-rich clusters, while hybridizing with O-2p states in O-rich clusters. Our work is the first one on the screened hybrid density functional theory level studying the atomic and electronic properties of the actinide oxide clusters. PMID:27179481

  6. Understanding the Interplay of Polar, Magnetic, and Electronic Order in Ferroic (LuFeO3)m /LuFe2O4 Superlattices

    NASA Astrophysics Data System (ADS)

    Rebola, Alejandro; Das, Hena; Fennie, Craig

    Multiferroics are not only important from a technological point of view but also because of the rich and complex physics that results from the interplay between spin, charge and structural distortions. Hexagonal LuFeO3 has recently been understood theoretical and experimentally, and shown to be an improper structural ferroelectric directly analogous to the hexagonal manganites. LuFe2O4 is structurally homologous to LuFeO3 -both are characterized by a FeO5 bipyramidal crystal field- but unlike the latter it exhibits a much larger magnetic moment and it is still a matter of debate whether it is ferroelectric. The double Fe-layer in LuFe2O4 is thought to be charge ordered and highly frustrated, resulting in possible polar, non-polar or anti-polar charge arrangements. Here we first investigate the relation between different charge and magnetic orders and structural distortions in bulk LuFe2O4 by DFT and Monte Carlo calculations. Then we concentrate on a system that combines both mechanisms -a structural improper ferroelectric and a charge frustrated polar structure- such as the (LuFeO3)m /LuFe2O4superlattices.

  7. IFNL3 mRNA structure is remodeled by a functional non-coding polymorphism associated with hepatitis C virus clearance

    PubMed Central

    Lu, Yi-Fan; Mauger, David M.; Goldstein, David B.; Urban, Thomas J.; Weeks, Kevin M.; Bradrick, Shelton S.

    2015-01-01

    Polymorphisms near the interferon lambda 3 (IFNL3) gene strongly predict clearance of hepatitis C virus (HCV) infection. We analyzed a variant (rs4803217 G/T) located within the IFNL3 mRNA 3′ untranslated region (UTR); the G allele (protective allele) is associated with elevated therapeutic HCV clearance. We show that the IFNL3 3′ UTR represses mRNA translation and the rs4803217 allele modulates the extent of translational regulation. We analyzed the structures of IFNL3 variant mRNAs at nucleotide resolution by SHAPE-MaP. The rs4803217 G allele mRNA forms well-defined 3′ UTR structure while the T allele mRNA is more dynamic. The observed differences between alleles are among the largest possible RNA structural alterations that can be induced by a single nucleotide change and transform the UTR from a single well-defined conformation to one with multiple dynamic interconverting structures. These data illustrate that non-coding genetic variants can have significant functional effects by impacting RNA structure. PMID:26531896

  8. Chemical vapor deposition and electric characterization of perovskite oxides LaMO{sub 3} (M=Co, Fe, Cr and Mn) thin films

    SciTech Connect

    Ngamou, Patrick Herve Tchoua; Bahlawane, Naoufal

    2009-04-15

    Oxides with a perovskite structure are important functional materials often used for the development of modern devices. In view of extending their applicability, it is necessary to efficiently control their growth as thin films using technologically relevant synthesis methods. Pulsed spray evaporation CVD was used to grow several perovskite-type oxides on planar silicon substrates at temperatures ranging from 500 to 700 deg. C. The optimization of the process control parameters allows the attainment of the perovskite structure as a single phase. The electrical characterization using the temperature-dependent conductivity and thermopower indicates the p-type conduction of the grown films and shows a decreasing concentration of the charge carrier, mobility and band gap energy in the sequence LaCoO{sub 3}>LaMnO{sub 3}>LaCrO{sub 3}>LaFeO{sub 3}. The investigation of the electric properties of the obtained perovskite thin films shows the versatility of CVD as a method for the development of innovative devices. - Graphical abstract: We report a single step deposition of perovskite thin films LaMO{sub 3} (M: Co, Mn, Cr, Fe) using pulsed spray evaporation chemical vapor deposition. Electrical and thermopower properties, similar to these of bulk materials, could promote the development of modern thermoelectric devices based on thin films technology.

  9. METC/3M Cooperative Agreement CRADA 94-024 high temperature high pressure filter materials exposure test program. Volume 2, Final report

    SciTech Connect

    1995-06-01

    This report is a summary of the results of activities of the particulate monitoring group in support of the METC/3M CRADA 94024. Online particulate monitoring began in June 1994 and ended in October, 1994. The particulate monitoring group participated in four MGCR runs (No. 7 through No. 10). The instrument used in measuring the particle loadings (particle counts and size distribution) is the Particle Measuring Systems Classical Scattering Aerosol Spectrometer Probe High Temperature and High Pressure (PMS Model CSASP-100-HTHP). This PMS unit is rated to operate at temperatures up to 540{degree}C and gage pressures up to 2.0 MPa. Gas stream conditions, temperature at 540{degree}C, gage pressure at 2.93 MPa, and gas flowrate at 0.0157 SCM per second, precluded the direct measurement of particulate loadings in the gas stream with the PMS unit. A side stream was extracted from the gas stream after it came over to the MGCR, Modular Gas Cleanup Rig, from the FBG, pressurized Fluidized-Bed Gasifier, but before it entered the filter testing vessel. A sampling probe of 0.635 cm O.D. thin wall stainless steel tubing was used for extracting the sample gas isokinetically based on the expected flowrate. The sample gas stream was further split into two streams; one was directed to the PMS unit and the other to the alkali monitor unit. The alkali monitor unit was not used during runs No. 7 through No. 10.

  10. Influence of functionalized pyridine ligands on the radio/chemical behavior of [M(I)(CO)3](+) (M = Re and (99m)Tc) 2 + 1 complexes.

    PubMed

    Hayes, Thomas R; Lyon, Patrice A; Barnes, Charles L; Trabue, Steven; Benny, Paul D

    2015-02-16

    While a number of chelate strategies have been developed for the organometallic precursor fac-[M(I)(OH2)3(CO)3](+) (M = Re, (99m)Tc), a unique challenge has been to improve the overall function and performance of these complexes for in vivo and in vitro applications. Since its discovery, fac-[M(I)(OH2)3(CO)3](+) has served as an essential scaffold for the development of new targeted (99m)Tc based radiopharmaceuticals due to its labile aquo ligands. However, the lipophilic nature of the fac-[M(I)(CO)3](+) core can influence the in vivo pharmacokinetics and biodistribution of the complexes. In an effort to understand and improve this behavior, monosubstituted pyridine ligands were used to assess the impact of donor nitrogen basicity on binding strength and stability of fac-[M(I)(CO)3](+) in a 2 + 1 labeling strategy. A series of Re and (99m)Tc complexes were synthesized with picolinic acid as a bidentate ligand and 4-substituted pyridine ligands. These complexes were designed to probe the effect of pKa from the monodentate pyridine ligand both at the macro scale and radiochemical concentrations. Comparison of X-ray structural data and radiochemical solution experiments clearly indicate an increase in overall yield and stability as pyridine basicity increased. PMID:25590985

  11. Calcium Carbonate.

    PubMed

    Al Omari, M M H; Rashid, I S; Qinna, N A; Jaber, A M; Badwan, A A

    2016-01-01

    Calcium carbonate is a chemical compound with the formula CaCO3 formed by three main elements: carbon, oxygen, and calcium. It is a common substance found in rocks in all parts of the world (most notably as limestone), and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. CaCO3 exists in different polymorphs, each with specific stability that depends on a diversity of variables. PMID:26940168

  12. Infiltrated carbon foam composites

    NASA Technical Reports Server (NTRS)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  13. Final report for the ORNL/3M CRADA No. ORNL91-0061 for the period January 1, 1992--December 31, 1992

    SciTech Connect

    Weaver, B.L.; Besmann, T.M.; Lowden, R.A.

    1995-10-01

    Oxide fiber-reinforced silicon carbide matrix composites were fabricated employing the forced-flow, thermal gradient chemical vapor infiltration (FCVI) process. Composites using Nextel{trademark} fibers of varying composition were prepared to investigate the effectiveness of each Nextel{trademark} fiber as a reinforcement for the given matrix. A carbon interface coating was used for the baseline materials, however, alternate interlayers with improved oxidation resistance were also explored. Room-temperature flexure strengths of as-fabricated composites and specimens heated in air at 1273 K were measured and compared to results for other SiC-matrix composites.

  14. High Precision Photometry of Variable Stars in Clusters of Different Ages with the 1.3 m Robotically Controlled Telescope (RCT)

    NASA Astrophysics Data System (ADS)

    Guinan, E. F.; McCook, G. P.; DeWarf, L. E.; Gelderman, R. F.; McGruder, C. H.; Walter, D. K.; Howell, S. B.; Davis, D. R.; Everett, M.; Mattox, J. R.

    2003-05-01

    We discuss a new program of carrying out high precision VRI CCD photometry of several star clusters of different ages. The photometry is being carried out using the 1.3 m Robotically Controlled Telescope (RCT), located at KPNO. This program focuses on the study of variable stars in mostly open clusters. Selected astrophysically important eclipsing binaries, pulsating variables, blue stragglers, and chromospherically active variable stars will be studied. Also, searches of new variable stars will be made from the expected large samples of cluster stars. For example, photometry is planned of the several W UMa eclipsing binaries and blue straggler stars in the old open cluster NGC 188. Photometry also will be carried out of the young open cluster NGC 7790. This cluster is unique because has three confirmed classical cepheid members: CE Cas A (V ˜ +10.9 mag; F8 Ib; P = 4.446 d ), CE Cep B (V ˜ +11.0 mag; F9 Ib; 5.128 d), and CF Cas (V ˜ +11.1 mag; F8 Ib; 4.875 d). NGC 7790 also contains the 10th mag eccentric B0+B0 eclipsing binary QX Cas. The observations of QX Cas are being conducted to determine the accurate distance to this star and thus to the cluster and its cepheid members. When complete these observations, combined with spectroscopy, will permit a reliable calibration of the ``zero-point'' of the galactic cepheid Period-Luminosity Law. Another possible project is the search of light variations of PMS stars and chromospherically active stars (from star spot rotational modulations) in young clusters such as the alpha Perseus Cluster, h & χ Per, M34, and the Pleiades. Refurbishment of the RCT has been made possible by NASA grant NAG 58762. The RCT Consortium includes: Western Kentucky Univ., S. Carolina St Univ., Francis Marion Univ., Villanova Univ., and the Planetary Science Institute (PSI).

  15. Synthesis and structure of In(IO{sub 3}){sub 3} and vibrational spectroscopy of M(IO{sub 3}){sub 3} (M=Al, Ga, In)

    SciTech Connect

    Ngo, Nhan; Kalachnikova, Katrina; Assefa, Zerihun; Haire, Richard G.; Sykora, Richard E. . E-mail: rsykora@jaguar1.usouthal.edu

    2006-12-15

    The reaction of Al, Ga, or In metals and H{sub 5}IO{sub 6} in aqueous media at 180{sup o}C leads to the formation of Al(IO{sub 3}){sub 3}, Ga(IO{sub 3}){sub 3,} or In(IO{sub 3}){sub 3}, respectively. Single-crystal X-ray diffraction experiments have shown In(IO{sub 3}){sub 3} contains the Te{sub 4}O{sub 9}-type structure, while both Al(IO{sub 3}){sub 3} and Ga(IO{sub 3}){sub 3} are known to exhibit the polar Fe(IO{sub 3}){sub 3}-type structure. Crystallographic data for In(IO{sub 3}){sub 3}, trigonal, space group R3-bar , a=9.7482(4)A, c=14.1374(6)A, V=1163.45(8) Z=6, R(F)=1.38% for 41 parameters with 644 reflections with I>2{sigma}(I). All three iodate structures contain group 13 metal cations in a distorted octahedral coordination environment. M(IO{sub 3}){sub 3} (M=Al, Ga) contain a three-dimensional network formed by the bridging of Al{sup 3+} or Ga{sup 3+} cations by iodate anions. With In(IO{sub 3}){sub 3}, iodate anions bridge In{sup 3+} cations in two-dimensional layers. Both materials contain distorted octahedral holes in their structures formed by terminal oxygen atoms from the iodate anions. The Raman spectra have been collected for these metal iodates; In(IO{sub 3}){sub 3} was found to display a distinctively different vibrational profile than Al(IO{sub 3}){sub 3} or Ga(IO{sub 3}){sub 3}. Hence, the Raman profile can be used as a rapid diagnostic tool to discern between the different structural motifs.

  16. Na2M2(SO4)3 (M = Fe, Mn, Co and Ni): towards high-voltage sodium battery applications.

    PubMed

    Araujo, Rafael B; Chakraborty, Sudip; Barpanda, Prabeer; Ahuja, Rajeev

    2016-04-14

    Sodium-ion-based batteries have evolved as excellent alternatives to their lithium-ion-based counterparts due to the abundance, uniform geographical distribution and low price of Na resources. In the pursuit of sodium chemistry, recently the alluaudite framework Na2M2(SO4)3 has been unveiled as a high-voltage sodium insertion system. In this context, the framework of density functional theory has been applied to systematically investigate the crystal structure evolution, density of states and charge transfer with sodium ions insertion, and the corresponding average redox potential, for Na2M2(SO4)3 (M = Fe, Mn, Co and Ni). It is shown that full removal of sodium atoms from the Fe-based device is not a favorable process due to the 8% volume shrinkage. The imaginary frequencies obtained in the phonon dispersion also reflect this instability and the possible phase transition. This high volume change has not been observed in the cases of the Co- and Ni-based compounds. This is because the redox reaction assumes a different mechanism for each of the compounds investigated. For the polyanion with Fe, the removal of sodium ions induces a charge reorganization at the Fe centers. For the Mn case, the redox process induces a charge reorganization of the Mn centers with a small participation of the oxygen atoms. The Co and Ni compounds present a distinct trend with the redox reaction occurring with a strong participation of the oxygen sublattice, resulting in a very small volume change upon desodiation. Moreover, the average deintercalation potential for each of the compounds has been computed. The implications of our findings have been discussed both from the scientific perspective and in terms of technological aspects. PMID:26996444

  17. CG3TOOL: an interactive computer program to process Scintrex CG-3/3M gravity data for high-resolution applications

    NASA Astrophysics Data System (ADS)

    Gabalda, G.; Bonvalot, S.; Hipkin, R.

    2003-03-01

    A newly developed interactive computer program, CG3TOOL, has been dedicated to the processing of the gravity data acquired by the Scintrex CG-3/3M automated gravity meter. The aim of CG3TOOL is two fold: to allow for an objective evaluation of Scintrex data and to provide a higher resolution in data reductions than those computed in real time by the microprocessor-controlled instrument. The program reads the gravity data acquired in either field or cycle mode (field surveys and continuous recordings, respectively) and then downloaded from the meter to a PC computer. The processing tasks are divided into two successive levels. Level 1 is dedicated to the reduction of the daily data files by applying standard or accurate corrections (earth tide, instrumental drift, atmospheric pressure). The precise corrections are performed up to the microGal (μGal) level, in accordance with the specifications of high-resolution surveys. Level 2 contains a series of processing tools (including network adjustment, anomaly computation, and gravity meter calibration) that will precisely compute and adjust the gravity values with error estimates. The interactive procedures and the program output (plot and text files) have been designed to ease data handling and archiving as well as to provide useful information for future purposes of data interpretation or modeling. CG3TOOL was developed in a standard C language for Unix Sun workstations and uses the standard graphical and mathematical Generic Mapping Tools (GMT) free library, available from the web. The objectives and principles of the computer program are presented below along with corresponding examples of the main processing tasks applied to observed data.

  18. Alkaline Earth Metal Zirconate Perovskites MZrO3 (M=Ba(2+), Sr(2+), Ca(2+)) Derived from Molecular Precursors and Doped with Eu(3+) Ions.

    PubMed

    Drąg-Jarząbek, Anna; John, Łukasz; Petrus, Rafał; Kosińska-Klähn, Magdalena; Sobota, Piotr

    2016-03-24

    The effect of alkaline earth metal alkoxides on the protonation of zirconocene dichloride was investigated. This approach enabled the design of compounds with preset molecular structures for generating high-purity binary metal oxide perovskites MZrO3 (M=Ba(2+), Sr(2+), Ca(2+)). Single-source molecular precursors [Ba4 Zr2 (μ6 -O)(μ3 ,η(2)-OR)8 (OR)2(η(2) -HOR)2 (HOR)2 Cl4], [Sr4 Zr2 (μ6 -O)(μ3 ,η(2)-OR)8 (OR)2 (HOR)4 Cl4], [Ca4 Zr2 (μ6-O)(μ3 ,η(2)-OR)8 (OR)2 Cl4], and [Ca6 Zr2 (μ2 ,η(2)-OR)12 (μ-Cl)2 (η(2) -HOR)4 Cl6 ]⋅8 CH2 Cl2 were prepared via elimination of the cyclopentadienyl ring from Cp2 ZrCl2 as CpH in the presence of M(OR)2 and alcohol ROH (ROH=CH3OCH2 CH2OH) as a source of protons. The resulting complexes were characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. The compounds were then thermally decomposed to MCl2 /MZrO3 mixtures. Leaching of MCl2 from the raw powder with deionized water produced highly pure perovskite-like oxide particles of 40-80 nm in size. Luminescence studies on Eu(3+)-doped MZrO3 revealed that the perovskites are attractive host lattices for potential applications in display technology. PMID:26891039

  19. Photolabeling of membrane-bound Torpedo nicotinic acetylcholine receptor with the hydrophobic probe 3-trifluoromethyl-3-(m-(/sup 125/I)iodophenyl)diazirine

    SciTech Connect

    White, B.J.; Cohen, J.B.

    1988-11-29

    The hydrophobic, photoactivatable probe 3-trifluoromethyl-3-(m-(/sup 125/I)iodophenyl)diazirine ((/sup 125/I)TID) was used to label acetylcholine receptor rich membranes purified from Torpedo californica electric organ. All four subunits of the acetylcholine receptor (AChR) were found to incorporate label, with the ..gamma..-subunit incorporating approximately 4 times as much as each of the other subunits. Carbamylcholine, an agonist, and histrionicotoxin, a noncompetitive antagonist, both strongly inhibited labeling of all AChR subunits in a specific and dose-dependent manner. In contrast, the competitive antagonist ..cap alpha..-bungarotoxin and the noncompetitive antagonist phencyclidine had only modest effect on (/sup 125/I)TID labeling of the AChR. The regions of the AChR ..cap alpha..-subunit that incorporate (/sup 125/)TID were mapped by Staphylococcus aureus V8 protest digestion. The carbamylcholine-sensitive site of labeling was localized to a 20-kDa V8 cleavage fragment that begins at Ser-173 and is of sufficient length to contain the three hydrophobic regions M1, M2, and M3. A 10-kDa fragment beginning at Asn-339 and containing the hydrophobic region M4 also incorporated (/sup 125/I)TID but in a carbamylcholine-insensitive manner. Two further cleavage fragments, which together span about one-third of the ..cap alpha..-subunit amino terminus, incorporated no detectable (/sup 125/I)TID. The mapping results place constraints on suggested models of AChR subunit topology.

  20. Identifying fecal pollution sources using 3M(™) Petrifilm (™) count plates and antibiotic resistance analysis in the Horse Creek Watershed in Aiken County, SC (USA).

    PubMed

    Harmon, S Michele; West, Ryan T; Yates, James R

    2014-12-01

    Sources of fecal coliform pollution in a small South Carolina (USA) watershed were identified using inexpensive methods and commonly available equipment. Samples from the upper reaches of the watershed were analyzed with 3M(™) Petrifilm(™) count plates. We were able to narrow down the study's focus to one particular tributary, Sand River, that was the major contributor of the coliform pollution (both fecal and total) to a downstream reservoir that is heavily used for recreation purposes. Concentrations of total coliforms ranged from 2,400 to 120,333 cfu/100 mL, with sharp increases in coliform counts observed in samples taken after rain events. Positive correlations between turbidity and fecal coliform counts suggested a relationship between fecal pollution and stormwater runoff. Antibiotic resistance analysis (ARA) compared antibiotic resistance profiles of fecal coliform isolates from the stream to those of a watershed-specific fecal source library (equine, waterfowl, canines, and untreated sewage). Known fecal source isolates and unknown isolates from the stream were exposed to six antibiotics at three concentrations each. Discriminant analysis grouped known isolates with an overall average rate of correct classification (ARCC) of 84.3 %. A total of 401 isolates from the first stream location were classified as equine (45.9 %), sewage (39.4 %), waterfowl (6.2 %), and feline (8.5 %). A similar pattern was observed at the second sampling location, with 42.6 % equine, 45.2 % sewage, 2.8 % waterfowl, 0.6 % canine, and 8.8 % feline. While there were slight weather-dependent differences, the vast majority of the coliform pollution in this stream appeared to be from two sources, equine and sewage. This information will contribute to better land use decisions and further justify implementation of low-impact development practices within this urban watershed. PMID:25139239

  1. Magnetic properties of BaTiO3 and BaTi1-xMxO3 (M=Co, Fe) nanocrystals by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Yang, Lihong; Qiu, Hongmei; Pan, Liqing; Guo, Zhengang; Xu, Mei; Yin, Jinhua; Zhao, Xuedan

    2014-01-01

    BaTiO3 and BaTi1-xMxO3 (M=Co, Fe) nanocrystals were prepared by hydrothermal method. X-ray diffraction analysis indicated that all of the samples were of single-phase with tetragonal perovskite structure. The BaTiO3 prepared exhibited weak ferromagnetism rather than diamagnetism, probably due to the oxygen vacancies at the surface. Paramagnetism was observed for all BaTi1-xCoxO3 samples with 0.05≤x≤0.25. The Curie-Weiss fit revealed the paramagnetic moment per Co ion were 4.09 μB, 4.12 μB, and 4.36 μB for x=0.15, 0.20, and 0.25 respectively. Room temperature hysteresis loops of the Fe-doped BaTiO3 samples were observed at the doping level x between 0.2 and 0.5. The saturation magnetization firstly increased with increasing Fe content, but gradually decreased. The divergence was observed in the temperature dependence of the field cooling (FC) and zero-FC (ZFC) magnetization curves, indicating a spin-glass behavior arising from micromagnetic state, i.e. the mixing of ferromagnetic, and antiferromagnetic phases. The observed ferromagnetism may originate from the coupling between the secondary-nearest Fe ions and the antiferromagnetism may be due to the coupling between the nearest Fe ions. The ferromagnetic coupling competes with the antiferromagnetic coupling. Therefore, the ferromagnetic properties are predominant when the Fe doping level are at a certain range.

  2. Developmental regulation of collagenase-3 mRNA in normal, differentiating osteoblasts through the activator protein-1 and the runt domain binding sites

    NASA Technical Reports Server (NTRS)

    Winchester, S. K.; Selvamurugan, N.; D'Alonzo, R. C.; Partridge, N. C.

    2000-01-01

    Collagenase-3 mRNA is initially detectable when osteoblasts cease proliferation, increasing during differentiation and mineralization. We showed that this developmental expression is due to an increase in collagenase-3 gene transcription. Mutation of either the activator protein-1 or the runt domain binding site decreased collagenase-3 promoter activity, demonstrating that these sites are responsible for collagenase-3 gene transcription. The activator protein-1 and runt domain binding sites bind members of the activator protein-1 and core-binding factor family of transcription factors, respectively. We identified core-binding factor a1 binding to the runt domain binding site and JunD in addition to a Fos-related antigen binding to the activator protein-1 site. Overexpression of both c-Fos and c-Jun in osteoblasts or core-binding factor a1 increased collagenase-3 promoter activity. Furthermore, overexpression of c-Fos, c-Jun, and core-binding factor a1 synergistically increased collagenase-3 promoter activity. Mutation of either the activator protein-1 or the runt domain binding site resulted in the inability of c-Fos and c-Jun or core-binding factor a1 to increase collagenase-3 promoter activity, suggesting that there is cooperative interaction between the sites and the proteins. Overexpression of Fra-2 and JunD repressed core-binding factor a1-induced collagenase-3 promoter activity. Our results suggest that members of the activator protein-1 and core-binding factor families, binding to the activator protein-1 and runt domain binding sites are responsible for the developmental regulation of collagenase-3 gene expression in osteoblasts.

  3. Molten Ga as a solvent for exploratory synthesis. Preparation, structure, and properties of two ternary silicides MNiSi{sub 3} (M = Sm, Y)

    SciTech Connect

    Chen, X.Z.; Larson, P.; Sportouch, S.; Mahanti, S.D.; Kanatzidis, M.G.; Brazis, P.; Kannewurf, C.R.

    1999-01-01

    Two ternary silicides, MNiSi{sub 3} (M = Sm, Y), have been synthesized from Sm, Ni, and Si in molten Ga at 850 C in sealed silica tubes. Both compounds form black shiny crystals and are stable even in aqua regia. The structures, determined by single-crystal X-ray diffraction, are orthorhombic, Cmmm (No. 65) with Z = 4, and have lattice parameters a = 3.965(2) {angstrom}, b = 21.144(2) {angstrom}, c = 4.007(1) {angstrom} for M = Sm and a = 3.930(2) {angstrom}, b = 21.021(2) {angstrom}, c = 3.960(1) {angstrom} for M = Y, respectively. Refinement based on F{sub o}{sup 2} yielded R{sub 1} = 0.0319 and wR{sub 2} = 0.0712 [I > 2 {sigma}(I)] for M = Sm and R{sub 1} = 0.0267 and wR{sub 2} = 0.0688 [I > 2{sigma}(I)] for M = Y. The compounds adopt the SmNiGe{sub 3} structure type with zigzag Si chains and Si dimers and exhibit metallic p-type electrical conductivity. Variable temperature magnetic susceptibility data suggest that Sm is 3+ and Ni has no magnetic moment. SmNiSi{sub 3} has an antiferromagnetic transition at 12 K and follows the modified Curie-Weiss law above 12 K. Band structure calculations using density functional theory, generalized gradient approximation, full potential LAPW method, and also extended Hueckel tight binding theory show that the materials are metallic and suggest that Ni is either neutral or in a reduced oxidation state. Additional insight into the bonding was obtained by extended Hueckel calculations carried out on the [NiSi{sub 3}]{sup 3{minus}} framework under the assumption that Y is mostly 3+. These results suggest that the Si zigzag chain contains single bonds with a partial double bond character.

  4. 1,2-Ethanediol and 1,3-Propanediol Conversions over (MO3)3 (M = Mo, W) Nanoclusters: A Computational Study.

    PubMed

    Fang, Zongtang; Zetterholm, Patrick; Dixon, David A

    2016-03-24

    The dehydration and dehydrogenation reactions of one and two 1,2-ethanediol and 1,3-propanediol molecules on (MO3)3 (M = Mo, W) nanoclusters have been studied computationally using density functional and coupled cluster (CCSD(T)) theory. The reactions are initiated by the formation of a Lewis acid-base complex with an additional hydrogen bond. Dehydration is the dominant reaction proceeding via a metal bisdiolate. Acetaldehyde, the major product for 1,2-ethanediol, is produced by α-hydrogen transfer from one CH2 group to the other. For 1,3-propanediol, the C-C bond breaking pathways to produce C2H4 and HCH═O simultaneously and proton transfer to generate propylene oxide have comparable barrier energies. The barrier to produce propanal from the propylene oxide complex is less than that for epoxide release from the cluster. On the Mo3O9 cluster, a redox reaction channel for 1,2-ethanediol to break the C-C bond to form two formaldehyde molecules and then to produce C2H4 is slightly more favorable than the formation of acetaldehyde. For W(VI), the energy barrier for the reduction pathway is larger due to the lower reducibility of W3O9. Similar reduction on Mo(VI) for 1,3-propanediol to form propene is not a favorable pathway compared with the other pathways as additional C-H bond breaking is required in addition to breaking a C-C bond. The dehydrogenation and dehydration activation energies for the selected glycols are larger than the reactions of ethanol and 1-propanol on the same clusters. The CCSD(T) method is required because density functional theory with the M06 and B3LYP functionals does not predict quantitative energies on the potential energy surface. The M06 functional performs better than does the B3LYP functional. PMID:26901665

  5. Control of orbital reconstruction in (LaAlO3)M/(SrTiO3)N(001) quantum wells by strain and confinement

    PubMed Central

    Doennig, David; Pentcheva, Rossitza

    2015-01-01

    The diverse functionality emerging at oxide interfaces calls for a fundamental understanding of the mechanisms and control parameters of electronic reconstructions. Here, we explore the evolution of electronic phases in (LaAlO3)M/(SrTiO3)N (001) superlattices as a function of strain and confinement of the SrTiO3 quantum well. Density functional theory calculations including a Hubbard U term reveal a charge ordered Ti3+ and Ti4+ state for N = 2 with an unanticipated orbital reconstruction, displaying alternating dxz and dyz character at the Ti3+ sites, unlike the previously reported dxy state, obtained only for reduced c-parameter at aSTO. At aLAO c-compression leads to a Dimer-Mott insulator with alternating dxz, dyz sites and an almost zero band gap. Beyond a critical thickness of N = 3 (aSTO) and N = 4 (aLAO) an insulator-to-metal transition takes place, where the extra e/2 electron at the interface is redistributed throughout the STO slab with a dxy interface orbital occupation and a mixed dxz + dyz occupation in the inner layers. Chemical variation of the SrTiO3 counterpart (LaAlO3 vs. NdGaO3) proves that the significant octahedral tilts and distortions in the SrTiO3 quantum well are induced primarily by the electrostatic doping at the polar interface and not by variation of the SrTiO3 counterpart. PMID:25601648

  6. Ab initio investigation of the oxygen reduction reaction activity on noble metal (Pt, Au, Pd), Pt3M (M = Fe, Co, Ni, Cu) and Pd3M (M = Fe, Co, Ni, Cu) alloy surfaces, for Lisbnd O2 cells

    NASA Astrophysics Data System (ADS)

    Sankarasubramanian, Shrihari; Singh, Nikhilendra; Mizuno, Fuminori; Prakash, Jai

    2016-07-01

    First principles, density functional theory (DFT) modelling of the oxygen reduction reaction (ORR) on noble metal (Pt, Au, Pd), Pt3M (M = Fe, Co, Ni, Cu) and Pd3M (M = Fe, Co, Ni, Cu) alloy surfaces, was carried out. Periodic models of close-packed (111) surfaces were constructed, their geometry was optimized and the most stable geometric surface configuration was identified. The correlation between the intermediate species binding energy and the favored reaction pathway from amongst 1e-, 2e-, and 4e- mechanisms were studied by calculating the binding energies of a 1/4 monolayer of O, O2, LiO, LiO2, Li2O2, and Li2O on various sites and orientations. The reaction free energies (ΔGrxn) were calculated and used to compute the catalytic activity of the surfaces using molecular kinetics theory. Plots of the catalytic activity vs. Oxygen binding energy (EBinding (O)) showed a typical "volcano" profile. The insights gained from this study can be used to guide the choice of cathode catalysts in Lisbnd O2 cells.

  7. Carbon particles

    DOEpatents

    Hunt, Arlon J.

    1984-01-01

    A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

  8. Carbon supercapacitors

    SciTech Connect

    Delnick, F.M.

    1993-11-01

    Carbon supercapacitors are represented as distributed RC networks with transmission line equivalent circuits. At low charge/discharge rates and low frequencies these networks approximate a simple series R{sub ESR}C circuit. The energy efficiency of the supercapacitor is limited by the voltage drop across the ESR. The pore structure of the carbon electrode defines the electrochemically active surface area which in turn establishes the volume specific capacitance of the carbon material. To date, the highest volume specific capacitance reported for a supercapacitor electrode is 220F/cm{sup 3} in aqueous H{sub 2}SO{sub 4} (10) and {approximately}60 F/cm{sup 3} in nonaqueous electrolyte (8).

  9. Manual of carbonate sedimentology

    SciTech Connect

    Reijers, T.J.; Hsu, K.S.

    1986-01-01

    This manual, organised along encycolopaedic/lexicographic lines, summarizes information on the properties and characteristics of carbonates and their environments. Part 1 deals with the elements of carbonates; Part 2 with environments, settings, and carbonate bodies; Part 3 with carbonate diagenesis, and Part 4 with carbonate reservoirs. Contents include: Elements of carbonates; Carbonate Environments, Settings and Bodies; Carbonate diagenesis; Carbonate reservoirs; Alphabetical Indices; English, Dutch, German, Spanish, French Computer Compatible Codes; Commonly Used (Informal) abbreviations.

  10. BTG/Tob family members Tob1 and Tob2 inhibit proliferation of mouse embryonic stem cells via Id3 mRNA degradation

    SciTech Connect

    Chen, Yuanfan; Wang, Chenchen; Wu, Jenny; Li, Lingsong

    2015-07-03

    The mammalian BTG/Tob family is a group of proteins with anti-proliferative ability, and there are six members including BTG1, BTG2/PC3/Tis21, BTG3/ANA, BTG4/PC3B, Tob1/Tob and Tob2. Among them, Tob subfamily members, specifically Tob1/Tob and Tob2, have the most extensive C-terminal regions. As previously reported, overexpression of BTG/Tob proteins is associated with the inhibition of G1 to S-phase cell cycle progression and decreased cell proliferation in a variety of cell types. Tob subfamily proteins have similar anti-proliferative effects on cell cycle progression in cultured tumor cells. An important unresolved question is whether or not they have function in rapidly proliferating cells, such as embryonic stem cells (ESCs). Tob1 and Tob2 were expressed ubiquitously in mouse ESCs (mESCs), suggesting a possible role in early embryonic development and mESCs. To address the above question and explore the possible functions of the Tob subfamily in ESCs, we established ESCs from different genotypic knockout inner cell mass (ICM). We found that Tob1{sup −/−}, Tob2{sup −/−}, and Tob1/2 double knockout (DKO, Tob1{sup −/−} & Tob2{sup −/−}) ESCs grew faster than wild type (WT) ESCs without losing pluripotency, and we provide a possible mechanistic explanation for these observations: Tob1 and Tob2 inhibit the cell cycle via degradation of Id3 mRNA, which is a set of directly targeted genes of BMP4 signaling in mESCs that play critical roles in the maintenance of ESC properties. Together, our data suggest that BTG/Tob family protein Tob1 and Tob2 regulation cell proliferation does not compromise the basic properties of mESCs. - Highlights: • We established mouse Tob1/2 double knockout embryonic stem cells. • Tob1 and Tob2 inhibit the proliferation of ESCs without effect on pluripotency. • Tob1 and Tob2 involved in the degradation of Id3 in mESCs.

  11. Comparison of the Baird-Parker agar and 3M Petrifilm Staph Express Count plate methods for enumeration of Staphylococcus aureus in naturally and artificially contaminated foods.

    PubMed

    Ingham, Steven C; Becker, Katie L; Fanslau, Melody A

    2003-11-01

    The recently developed 3M Petrifilm Staph Express Count plate (PFSE) method was compared with the U.S. Food and Drug Administration Bacteriological Analytical Manual's Baird-Parker agar spread plate (B-P) method for enumeration of Staphylococcus aureus in naturally contaminated, mechanically separated poultry (MSP; n = 92) and raw milk (n = 12). In addition, mozzarella and Parmesan cheeses and hot-smoked rainbow trout and chub were surface inoculated with a three-strain mixture of S. aureus, stored at 5 degrees C, and periodically analyzed with both methods for numbers of S. aureus. For naturally contaminated raw milk and MSP samples, the PFSE method yielded counts that were not significantly different (P > 0.05) from counts obtained using the B-P method. From raw milk and MSP samples, 60% (21 of 35) and 55% (124 of 226), respectively, of confirmed (DNAse-positive) isolates from PFSE plates were identified by further testing as S. aureus. Corresponding S. aureus identification rates for isolates forming typical colonies on B-P plates were 53% (19 of 36) and 50% (125 of 248). For both methods, other staphylococci composed the vast majority of tested isolates that were not identified as S. aureus. For inoculated hot-smoked fish, S. aureus counts from the PFSE method were not significantly different from counts from the B-P method. Compared to the B-P method, significantly lower numbers of inoculated S. aureus were recovered using the PFSE method in analyses of mozzarella cheese stored 28 and 42 days at 4 degrees C. The PFSE and B-P methods were not significantly different for inoculated cheeses at all other sampling times. DNAse-positive isolates from PFSE analyses of inoculated cheeses and smoked fish were identified as S. aureus 98% (51 of 52) and 86% (36 of 42) of the time, respectively, as compared with 100% (58 of 58) and 95% (40 of 42) of the time for typical B-P isolates. Overall, the PFSE and B-P methods appeared to perform similarly in enumeration of S

  12. Elastic relaxations associated with the Pm3m-R3c transition in LaA103 III: superattenuation of acoustic resonances

    SciTech Connect

    Darling, Timothy W; Carpenter, M A; Buckley, A; Taylor, P A; Mcknight, R E A

    2009-01-01

    Resonant Ultrasound Spectroscopy has been used to characterize elastic softening and a variety of new acoustic dissipation processes associated with the Pm{bar 3}m {leftrightarrow} R{bar 3}c transition in single crystal and ceramic samples of LaAlO{sub 3}. Softening of the cubic structure ahead of the transition point is not accompanied by an increase in dissipation but follows different temperature dependences for the bulk modulus, 1/3(C{sub 11} + 2C{sub 12}), and the shear components 1/2(C{sub 11}-C{sub 12}) and C{sub 44} as if the tilting instability contains two slightly different critical temperatures. The transition itself is marked by the complete disappearance of resonance peaks (superattenuation), which then reappear below {approx}700 K in spectra from single crystals. Comparison with low frequency, high stress data from the literature indicate that the dissipation is not due to macroscopic displacement of needle twins. An alternative mechanism, local bowing of twin walls under low dynamic stress, is proposed. Pinning of the walls with respect to this displacement process occurs below {approx}350 K. Anelasticity maps, analogous to plastic deformation mechanism maps, are proposed to display dispersion relations and temperature/frequency/stress fields for different twin wall related dissipation mechanisms. An additional dissipation process, with an activation energy of 43 {+-} 6 kJ.mole{sup -1}, occurs in the vicinity of 250 K. The mechanism for this is not known, but it is associated with C{sub 44} and therefore appears to be related in some way to the cubic {leftrightarrow} rhombohedral transition at {approx}817 K. Slight softening in the temperature interval {approx}220 {yields} 70 K of resonance peaks determined by shear elastic constants hints at an incipient E{sub g} ferroelastic instability in LaAlO{sub 3}. The softening interval ends with a further dissipation peak at {approx} 60 K, the origin of which is discussed in terms of freezing of atomic

  13. The 1.3-m Robotically Controlled Telescope (RCT) at Kitt Peak - A Fifty year old dream Realized: Telescope Characteristics, Current Research and Education Progr

    NASA Astrophysics Data System (ADS)

    Guinan, Edward; Gelderman, Richard; Strolger, Louis-Gregory; Carini, Michael T.; McGruder, Charles, III; Campbell, Rachel; Walter, Donald K.; Davis, Donald R.; Tedesco, Edward F.; Engle, Scott G.

    2011-03-01

    The 1.3 m Robotically Controlled Telescope (RCT) on Kitt Peak has a rich history, including its role as a prototype for remotely controlled telescopes during the 1960s. As such, the RCT could be considered one of the first - Telescopes from Afar. The telescope, originally called the Remotely Controlled Telescope, has been renamed the Robotically Controlled Telescope to reflect the change in operational control and mode of use. The RCT was a conceptual precursor of today's robotic telescopes, but the actual operation of a remotely controlled telescope was technologically premature for its time, and was subsequently manually operated primarily to conduct optical and infrared observations as well being used as a test bed for new spectroscopic and photometric instruments. In 1995 budget constraints forced the closing of the telescope as part of the Kitt Peak National Observatory (KPNO), following nearly 30 years of distinguished service to KPNO. A request for proposals to operate this telescope was issued to the science community. The RCT consortium, lead by Western Kentucky University, was the successful proposer for operation of the telescope. After several difficult years of retrofitting, refurbishing, and automating the telecope and observatory dome, the telescope has returned to routine science operations in November 2009. The RCT has operated smoothly since that time, with no major interruptions. Observations of objects of interest to the consortium partners (including: comets & asteroids, variable & binary stars, exoplanets, supernovae, quasars & blazars) are being routinely obtained and evaluated. One of the distinguishing features of the RCT is that it is an autonomous observatory designed to handle diverse optical imaging and photometry programs. These include being able to automatically deal with a wide range of observing parameters such as -integration time, sky conditions, repetitions, return visits, filters, air mass, non-sidereal objects, transients etc

  14. Operational O3M-SAF trace-gas column products: GOME-2 tropospheric NO2, SO2 and BrO

    NASA Astrophysics Data System (ADS)

    Valks, P.; Hao, N.; Rix, M.; Lambert, J.-C.; Pinardi, G.; van Roozendael, M.; Theys, N.; Loyola, D.

    2009-04-01

    This contribution focuses on the operational GOME-2 trace-gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present the algorithms and exemplary results of tropospheric NO2, total BrO and SO2. These trace-gas column products are retrieved from GOME-2 solar backscattered measurements in the UV/VIS wavelength region, using the Differential Optical Absorption Spectroscopy (DOAS) method. Total NO2 is routinely retrieved with the GOME Data Processor (GDP) version 4.2 using the 425-450 nm wavelength region. An additional algorithm is applied to derive the tropospheric NO2 column for polluted conditions: after subtracting the estimated stratospheric component from the total column, the tropospheric NO2 column is determined using an air mass factor based on monthly climatological NO2 profiles from the MOZART-2 model. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 using the UV wavelength region around 320 nm. With GOME-2, it is possible to detect and track volcanic SO2 in near-real time and on a global scale, which is of particular importance for volcanic early warning services. For the GOME-2 retrieval of the total BrO column, current research focuses on the optimisation of the DOAS fitting window in the UV wavelength region. BrO columns retrieved from the baseline GOME fitting window (344.6-359 nm) show relatively large noise levels. Therefore, the use of an alternative fitting window has been analysed. More than two years of tropospheric NO2, total BrO and SO2 measurements are now available from GOME-2. We present initial validation results using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2 columns for air quality applications will be presented. We will show examples of BrO from volcanic eruptions and under

  15. CARBONATE METHOD OF SEPARATION OF TETRAVALENT PLUTONIUM FROM FISSION PRODUCT VALUES

    DOEpatents

    Duffield, R.B.; Stoughton, R.W.

    1959-02-01

    It has been found that plutonium forms an insoluble precipitate with carbonate ion when the carbonate ion is present in stoichiometric proportions, while an excess of the carbonate ion complexes plutonium and renders it soluble. A method for separating tetravalent plutonium from lanthanum-group rare earths has been based on this discovery, since these rare earths form insoluble carbonates in approximately neutral solutions. According to the process the pH is adjusted to between 5 and 7, and approximately stoichiometric amounts of carbonate ion are added to the solution causing the formation of a precipitate of plutonium carbonate and the lanthanum-group rare earth carbonates. The precipitate is then separated from the solution and contacted with a carbonate solution of a concentration between 1 M and 3 M to complex and redissolve the plutonium precipitate, and thus separate it from the insoluble rare earth precipitate.

  16. Carbon tetrachloride

    Integrated Risk Information System (IRIS)

    Carbon tetrachloride ; CASRN 56 - 23 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  17. Carbon disulfide

    Integrated Risk Information System (IRIS)

    Carbon disulfide ; CASRN 75 - 15 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  18. What Have We Learned About Arctic Carbon Since The First State of the Carbon Cycle Report?

    NASA Astrophysics Data System (ADS)

    Schuur, E.

    2015-12-01

    Large pools of organic carbon were reported in The First State of the Carbon Cycle Report, but measurements from high latitude ecosystems, in particular for deeper soils >1m depth, remained scarce. A newly enlarged soil carbon database with an order of magnitude more numerous deep sampling sites has verified the widespread pattern of large quantities of carbon accumulated deep in permafrost (perennially frozen) soils. The known pool of permafrost carbon across the northern circumpolar permafrost zone is now estimated to be 1330-1580 Pg C, with the potential for an additional ~400 Pg C in deep permafrost sediments. In addition, an uncertainty estimate of plus/minus 15% has now been calculated for the soil carbon pool in the surface 0-3m. Laboratory incubations of these permafrost soils reveal that a significant fraction can be mineralized by microbes upon thaw and converted to carbon dioxide and methane on time scales of years to decades, with decade-long average losses from aerobic incubations ranging from 6-34% of initial carbon. Carbon emissions from the same soils incubated in an anaerobic environment are, on average, 78-85% lower than aerobic soils. But, the more potent greenhouse gas methane released under anaerobic conditions in part increases the climate impact of these emissions. While mean quantities of methane are only 3% to 7% that of carbon dioxide emitted from anaerobic incubations (by weight of C), these mean methane values represent 25% to 45% of the overall potential impact on climate when accounting for the higher global warming potential of methane. Taken together though, in spite of the more potent greenhouse gas methane, a unit of newly thawed permafrost carbon could have a greater impact on climate over a century if it thaws and decomposes within a drier, aerobic soil as compared to an equivalent amount of carbon within a waterlogged soil or sediment. Model projections tend to estimate losses of carbon in line with empirical measurements, but

  19. The effect of additives on the reactivity of palladium surfaces for the chemisorption and hydrogenation of carbon monoxide: A surface science and catalytic study. [LaMO/sub 3/(M = Cr, Mn, Fe, Co, Rh)

    SciTech Connect

    Rucker, T.G.

    1987-06-01

    This research studied the role of surface additives on the catalytic activity and chemisorptive properties of Pd single crystals and foils. Effects of Na, K, Si, P, S, and Cl on the bonding of CO and H and on the cyclotrimerization of acetylene on the (111), (100) and (110) faces of Pd were investigated in addition to role of TiO/sub 2/ and SiO/sub 2/ overlayers deposited on Pd foils in the CO hydrogenation reaction. On Pd, only in the presence of oxide overlayers, are methane or methanol formed from CO and H/sub 2/. The maximum rate of methane formation is attained on Pd foil where 30% of the surface is covered with titania. Methanol formation can be achieved only if the TiO/sub x//Pd surface is pretreated in 50 psi of oxygen at 550/sup 0/C prior to the reaction. The additives (Na, K, Si, P, S, Cl) affect the bonding of CO and hydrogen and the cyclotrimerization of acetylene to benzene by structural and electronic interactions. In general, the electron donating additives increase the desorption temperature of CO and increase the rate of acetylene cyclotrimerization and the electron withdrawing additives decrease the desorption temperature of CO and decrease the rate of benzene formation from acetylene.

  20. A novel, cysteine-modified chelation strategy for the incorporation of [MI(CO)3]+ (M = Re, 99mTc) in an α-MSH peptide

    PubMed Central

    Jiang, Han; Kasten, Benjamin B.; Liu, Hongguang; Qi, Shibo; Liu, Yang; Tian, Mei; Barnes, Charles L.; Zhang, Hong; Cheng, Zhen; Benny, Paul D.

    2012-01-01

    Engineering peptide-based targeting agents with residues for site specific and stable complexation of radionuclides is a highly desirable strategy for producing diagnostic and therapeutic agents for cancer and other diseases. In this report, a model N-S-NPy ligand (3) and a cysteine-derived alpha-melanocyte stimulating hormone (α-MSH) peptide (6) were used as novel demonstrations of a widely applicable chelation strategy for incorporation of the [MI(CO)3]+ (M = Re, 99mTc) core into peptide-based molecules for radiopharmaceutical applications. The structural details of the core ligand-metal complexes as model systems were demonstrated by full chemical characterization of fac-[ReI(CO)3(N,S,NPy-3)]+ (4) and comparative high performance liquid chromatography (HPLC) analysis between 4 and [99mTcI(CO)3(N,S,NPy-3)]+ (4a). The α-MSH analogue bearing the N-S-NPy chelate on a modified cysteine residue (6) was generated and complexed with [MI(CO)3]+ to confirm the chelation strategy’s utility when applied in a peptide-based targeting agent. Characterization of the ReI(CO)3-6 peptide conjugate (7) confirmed the efficient incorporation of the metal center, and the 99mTcI(CO)3-6 analogue (7a) was explored as a potential single photon emission computed tomography (SPECT) compound for imaging the melanocortin 1 receptor (MC1R) in melanoma. Peptide 7a showed excellent radiolabeling yields and in vitro stability during amino acid challenge and serum stability assays. In vitro B16F10 melanoma cell uptake of 7a reached a modest value of 2.3 ± 0.08% of applied activity at 2 h at 37 °C while this uptake was significantly reduced by coincubation with a nonlabeled α-MSH analogue, NAPamide (3.2 µM) (P < 0.05). In vivo SPECT/X-ray computer tomography (SPECT/CT) imaging and biodistribution of 7a were evaluated in a B16F10 melanoma xenografted mouse model. SPECT/CT imaging clearly visualized the tumor at 1 h post injection (p.i.) with high tumor-to-background contrast. Blocking

  1. Clickable, Hydrophilic Ligand for fac-[MI(CO)3]+ (M = Re/99mTc) Applied in an S-Functionalized α-MSH Peptide

    PubMed Central

    2015-01-01

    The copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) click reaction was used to incorporate alkyne-functionalized dipicolylamine (DPA) ligands (1 and 3) for fac-[MI(CO)3]+ (M = Re/99mTc) complexation into an α-melanocyte stimulating hormone (α-MSH) peptide analogue. A novel DPA ligand with carboxylate substitutions on the pyridyl rings (3) was designed to increase the hydrophilicity and to decrease in vivo hepatobiliary retention of fac-[99mTcI(CO)3]+ complexes used in single photon emission computed tomography (SPECT) imaging studies with targeting biomolecules. The fac-[ReI(CO)3(3)] complex (4) was used for chemical characterization and X-ray crystal analysis prior to radiolabeling studies between 3 and fac-[99mTcI(OH2)3(CO)3]+. The corresponding 99mTc complex (4a) was obtained in high radiochemical yields, was stable in vitro for 24 h during amino acid challenge and serum stability assays, and showed increased hydrophilicity by log P analysis compared to an analogous complex with nonfunctionalized pyridine rings (2a). An α-MSH peptide functionalized with an azide was labeled with fac-[MI(CO)3]+ using both click, then chelate (CuAAC reaction with 1 or 3 followed by metal complexation) and chelate, then click (metal complexation of 1 and 3 followed by CuAAC with the peptide) strategies to assess the effects of CuAAC conditions on fac-[MI(CO)3]+ complexation within a peptide framework. The peptides from the click, then chelate strategy had different HPLC tR’s and in vitro stabilities compared to those from the chelate, then click strategy, suggesting nonspecific coordination of fac-[MI(CO)3]+ using this synthetic route. The fac-[MI(CO)3]+-complexed peptides from the chelate, then click strategy showed >90% stability during in vitro challenge conditions for 6 h, demonstrated high affinity and specificity for the melanocortin 1 receptor (MC1R) in IC50 analyses, and led to moderately high uptake in B16F10 melanoma cells. Log P analysis of the 99m

  2. IC Engine Applications of Carbon-Carbon

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton; Rivers, H. Kevin

    2000-01-01

    Many of the properties of carbon-carbon make it an ideal material for reciprocating materials of intermittent combustion (IC) engines. Recent diesel engine tests, shown herein, indicate that the thermal and mechanical properties of carbon-carbon are adequate for piston applications, However, reducing the manufacturing costs and providing long term oxidation protection are still issues that need to be addressed.

  3. Carbon investment funds

    SciTech Connect

    2007-01-15

    The report is a study of the development of funds to invest in the purchase of carbon credits. It takes a look at the growing market for carbon credits, the rise of carbon investment funds, and the current state of carbon investing. Topics covered in the report include: Overview of climate change, greenhouse gases, and the Kyoto Protocols. Analysis of the alternatives for reducing carbon emissions including nitrous oxide reduction, coal mine methane capture and carbon capture and storage; Discussion of the different types of carbon credits; Discussion of the basics of carbon trading; Evaluation of the current status of carbon investing; and Profiles of 37 major carbon investment funds worldwide.

  4. Sequestering ADM ethanol plant carbon dioxide

    USGS Publications Warehouse

    Finley, R.J.; Riddle, D.

    2008-01-01

    Archer Daniels Midland Co. (ADM) and the Illinois State Geological Survey (ISGS) are collaborating on a project in confirming that a rock formation can store carbon dioxide from the plant in its pores. The project aimed to sequester the gas underground permanently to minimize release of the greenhouse gas into the atmosphere. It is also designed to store one million tons of carbon dioxide over a three-year period. The project is worth $84.3M, funded by $66.7M from the US Department Energy, supplemented by co-funding from ADM and other corporate and state resources. The project will start drilling of wells to an expected depth over 6500 feet into the Mount Simon Sandstone formation.

  5. Carbonate diagenesis and porosity

    SciTech Connect

    Moore, C.H. )

    1989-01-01

    Carbonate diagenesis is a subject of enormous complexity because of the basic chemical reactivity of carbonate minerals. These carbonate minerals react quickly with natural waters that either dissolve the carbonates, or precipitate new carbonates to bring the water into equilibrium with the host carbonate sediments and rocks. These rock-water interactions either create porosity by dissolution, or destroy porosity by the precipitation of carbonate cements into pore spaces. This book examines these relationships in detail.

  6. Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt3M (where M = 3d transition metals) alloy catalyst from first-principles

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Eun; Lim, Dong-Hee; Jang, Jong Hyun; Kim, Hyoung Juhn; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo; Hong, Seong-Ahn; Soon, Aloysius; Ham, Hyung Chul

    2015-01-01

    The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt3M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt3M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt3M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt3M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit.

  7. Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt3M (where M = 3d transition metals) alloy catalyst from first-principles.

    PubMed

    Kim, Chang-Eun; Lim, Dong-Hee; Jang, Jong Hyun; Kim, Hyoung Juhn; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo; Hong, Seong-Ahn; Soon, Aloysius; Ham, Hyung Chul

    2015-01-21

    The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt3M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt3M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt3M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt3M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit. PMID:25612725

  8. Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt{sub 3}M (where M = 3d transition metals) alloy catalyst from first-principles

    SciTech Connect

    Kim, Chang-Eun; Lim, Dong-Hee; Jang, Jong Hyun; Kim, Hyoung Juhn; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo; Hong, Seong-Ahn; Soon, Aloysius E-mail: hchahm@kist.re.kr; Ham, Hyung Chul E-mail: hchahm@kist.re.kr

    2015-01-21

    The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt{sub 3}M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt{sub 3}M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt{sub 3}M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt{sub 3}M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit.

  9. {sup 29}Si attribution of the 1.3 mT hyperfine structure of the E{sup '}{sub g}amma centers in amorphous SiO{sub 2}

    SciTech Connect

    Vaccaro, G.; Agnello, S.; Buscarino, G.; Nuccio, L.; Grandi, S.; Mustarelli, P.

    2009-05-01

    We report an experimental investigation by electron paramagnetic resonance of the doublet of lines split by approx1.3 mT and centered on the E{sup '}{sub g}amma center resonance line in the spectrum of irradiated amorphous SiO{sub 2}. Commercial and sol-gel materials, some of which subjected to hydrogen-deuterium exchange, were investigated. Exposure to gamma or beta rays at room temperature of the samples and subsequent thermal treatments were carried out to induce the defects and to study their thermal stability. In all the materials used the ratio between the signal of the E{sup '}{sub g}amma centers and that of the 1.3 mT doublet is constant and independent of the OH and OD contents. Furthermore, the 1.3 mT doublet and the E{sup '}{sub g}amma center feature similar thermal stability. These results support the attribution of the 1.3 mT doublet to the hyperfine interaction between the unpaired electron magnetic moment of the E{sup '}{sub g}amma center and the nuclear magnetic moment of a second near neighboring {sup 29}Si atom. Our results also suggest that the E{sup '}{sub g}amma site needs an appropriate surrounding of {sup 29}Si in back-bond configuration to experience this hyperfine interaction.

  10. Carbon Nanomembranes.

    PubMed

    Turchanin, Andrey; Gölzhäuser, Armin

    2016-08-01

    Carbon nanomembranes (CNMs) are synthetic 2D carbon sheets with tailored physical or chemical properties. These depend on the structure, molecular composition, and surroundings on either side. Due to their molecular thickness, they can be regarded as "interfaces without bulk" separating regions of different gaseous, liquid, or solid components and controlling the materials exchange between them. Here, a universal scheme for the fabrication of 1 nm-thick, mechanically stable, functional CNMs is presented. CNMs can be further modified, for example perforated by ion bombardment or chemically functionalized by the binding of other molecules onto the surfaces. The underlying physical and chemical mechanisms are described, and examples are presented for the engineering of complex surface architectures, e.g., nanopatterns of proteins, fluorescent dyes, or polymer brushes. A simple transfer procedure allows CNMs to be placed on various support structures, which makes them available for diverse applications: supports for electron and X-ray microscopy, nanolithography, nanosieves, Janus nanomembranes, polymer carpets, complex layered structures, functionalization of graphene, novel nanoelectronic and nanomechanical devices. To close, the potential of CNMs in filtration and sensorics is discussed. Based on tests for the separation of gas molecules, it is argued that ballistic membranes may play a prominent role in future efforts of materials separation. PMID:27281234

  11. Reservoirs 3 carbonates

    SciTech Connect

    Beaumont, E.A.; Foster, N.H.

    1988-01-01

    This book covers the topics of Carbonates; Carbonate depositional environments and Carbonate diagenesis. Included are the following papers: pore geometry of carbonate rocks as revealed by pore casts and capillary pressure; a review of carbonate reservoirs; the chemistry of dolomitization and dolomite precipitation.

  12. Trading forest carbon

    EPA Science Inventory

    The nature of carbon in forests is discussed from the perspective of carbon trading. Carbon inventories, specifically in the area of land use and forestry are reviewed for the Pacific Northwest. Carbon turnover in forests is discussed as it relates to carbon sequestration. Scient...

  13. Superhydrophobic amorphous carbon/carbon nanotube nanocomposites

    NASA Astrophysics Data System (ADS)

    Han, Z. J.; Tay, B. K.; Shakerzadeh, M.; Ostrikov, K.

    2009-06-01

    Superhydrophobic amorphous carbon/carbon nanotube nanocomposites are fabricated by plasma immersion ion implantation with carbon nanotube forests as a template. The microstructure of the fabricated nanocomposites shows arrays of carbon nanotubes capped with amorphous carbon nanoparticles. Contact angle measurements show that both advancing and receding angles close to 180° can be achieved on the nanocomposites. The fabrication here does not require patterning of carbon nanotubes or deposition of conformal coatings with low surface energy, which are usually involved in conventional approaches for superhydrophobic surfaces. The relationship between the observed superhydrophobicity and the unique microstructure of the nanocomposites is discussed.

  14. Might eddies dominate carbon export ?

    NASA Astrophysics Data System (ADS)

    Allen, J.; Rixen, M.; Fielding, S.; Mustard, A.; Brown, L.; Sanders, R.

    2003-04-01

    surface mixed layer by nutrient upwelling. In this paper we explore the parameter space for mesoscale vertical velocities (10e-5 to 10e-3 m/s), phytoplankton carbon biomass (1 to 1000 mg/m3) and mesoscale eddy ubiquity (10 to 50%). By considering sensible ranges for an open ocean global mean in each case we show that the potential mesoscale eddy transports are much larger than accepted estimates for carbon export. Thus the determination of a sensible vertical eddy flux is essential if we are to quantify the ocean carbon cycle for prognostic studies. Furthermore, we consider the effect that climatically reduced deep winter mixing might have on the sensible range of values of our parameters.

  15. Carbon Farming as a Carbon Negative Technology

    NASA Astrophysics Data System (ADS)

    Anderson, C.; Laird, D.; Hayes, D. J.

    2015-12-01

    Carbon farms have a pivotal role in national and international efforts to mitigate and adapt to climate change. A carbon farm in its broadest sense is one that reduces greenhouse gas (GHG) emissions or captures and holds carbon in vegetation and soils. Their capacity to remove carbon from the air and store it safely and permanently, while providing additional human and ecosystem benefits, means they could contribute significantly to national efforts to stabilize or reduce GHGs. We examine carbon farms in the context of corn and soybean production agriculture. We illustrate, using Iowa data but with relevance across United States corn and soybean production, the potential for carbon farms to reduce human GHG emissions and sequester carbon permanently at a rate that has meaningful impact on global greenhouse gas concentration. Carbon has been viewed as a next generation cash crop in Iowa for over a decade. The carbon farm perspective, however, goes beyond carbon as cash crop to make carbon the center of an entire farm enterprise. The transformation is possible through slight adjustment crop practices mixed with advances in technology to sequester carbon through biochar. We examine carbon balance of Iowa agriculture given only the combination of slight reduction in fertilizer and sequestration by biochar. We find the following. Iowa carbon farms could turn Iowa agriculture into a carbon sink. The estimated range of GHG reduction by statewide implementation of carbon farms is 19.46 to 90.27 MMt CO2-equivalent (CO2-e), while the current agricultural CO2-e emission estimate is 35.38 MMt CO2-e. Iowa carbon farm GHG reduction would exceed Iowa GHG reduction by wind energy (8.7 MMt CO2-e) and could exceed combined reductions from wind energy and corn grain ethanol (10.7 MMt CO2-e; 19.4 MMt CO2-e combined). In fact, Iowa carbon farms alone could exceed GHG reduction from national corn grain ethanol production (39.6 MMt CO2-e). A carbon price accessible to agricultural

  16. Carbon dioxide concentrator

    NASA Technical Reports Server (NTRS)

    Williams, C. F.; Huebscher, R. G.

    1972-01-01

    Passed exhaled air through electrochemical cell containing alkali metal carbonate aqueous solution, and utilizes platinized electrodes causing reaction of oxygen at cathode with water in electrolyte, producing hydroxyl ions which react with carbon dioxide to form carbonate ions.

  17. Method of making carbon-carbon composites

    DOEpatents

    Engle, Glen B.

    1993-01-01

    A process for making 2D and 3D carbon-carbon composites having a combined high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizible woven cloth are infiltrated with carbon material to form green composites. The carbonized composite is then impregnated several times with pitch by covering the composite with hot pitch under pressure. The composites are given a heat treatment between each impregnant step to crack up the infiltrated carbon and allow additional pitch to enter the microstructure during the next impregnation cycle. The impregnated composites are then given a final heat treatment in the range 2500.degree. to 3100.degree. C. to fully graphitize the fibers and the matrix carbon. The composites are then infiltrated with pyrolytic carbon by chemical vapor deposition in the range 1000.degree. C. to 1300.degree. C. at a reduced. pressure.

  18. Carbon Capture (Carbon Cycle 2.0)

    ScienceCinema

    Smit, Berend

    2011-06-08

    Berend Smit speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  19. Integral Ring Carbon-Carbon Piston

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton (Inventor)

    1999-01-01

    An improved structure for a reciprocating internal combustion engine or compressor piston fabricate from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variations in thermal expansion differences between the piston and cylinder liner.

  20. Carbon-carbon grid for ion engines

    NASA Technical Reports Server (NTRS)

    Garner, Charles E. (Inventor)

    1993-01-01

    A method and apparatus of manufacturing a grid member for use in an ion discharge apparatus provides a woven carbon fiber in a matrix of carbon. The carbon fibers are orientated to provide a negatibe coefficient of thermal expansion for at least a portion of the grid member's operative range of use.

  1. Carbon-carbon grid for ion engines

    NASA Technical Reports Server (NTRS)

    Garner, Charles E. (Inventor)

    1995-01-01

    A method and apparatus of manufacturing a grid member for use in an ion discharge apparatus provides a woven carbon fiber in a matrix of carbon. The carbon fibers are orientated to provide a negatibe coefficient of thermal expansion for at least a portion of the grid member's operative range of use.

  2. Composite carbon foam electrode

    DOEpatents

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.

    1997-05-06

    Carbon aerogels used as a binder for granulated materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  3. Composite carbon foam electrode

    DOEpatents

    Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  4. Heterometallic clusters arising from cubic Ni{sub 3}M'O{sub 4} (M'=K and Na) entity: Solvothermal synthesis with/without the assistance of microwave

    SciTech Connect

    Zhang Shuhua; Zhou Yanling; Sun Xiaojun; Wei, Lian-Qiang; Zeng Minghua; Liang Hong

    2009-11-15

    Solvothermal reaction assisted with microwave leads to the formation of two unique heterometallic cubic clusters [Ni{sub 3}M'(L){sub 3}(OH)(CH{sub 3}CN){sub 3}]{sub 2}.CH{sub 3}CN (M'=K for 1 and M'=Na for 2, where L is an anion of 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate) with higher efficiency, yields and purity than those without it. The 6-metallacrown-3 [Ni{sub 3}(OH)(L){sub 3}]{sup -} groups exhibit interesting ion trapping and self-assembly of size-different Na{sup +} and K{sup +} through form recognition and coordination activity in 1 and 2. The magnetic studies for 1 and 2 suggest that the {l_brace}Ni{sub 3}M'O{sub 4}{r_brace} (M'=K and Na) cores both display dominant ferromagnetic interactions from the nature of the binding modes of mu{sub 3}-O (oxidophenyl) and mu{sub 3}-OH. - Graphical abstract: Solvothermal reaction assisted with microwave leads to two heterometallic cubic clusters with 6-metallacrown-3 structure [Ni{sub 3}O{sub 3}(OH)]{sup -} acting as a host for a K{sup +} or Na{sup +} ion. The {l_brace}Ni{sub 3}M'O{sub 4}{r_brace} (M'=K, Na) cores display dominant ferromagnetic interactions.

  5. Variable Carbon Isotopes in ALH84001 Carbonates

    NASA Astrophysics Data System (ADS)

    Niles, P. B.; Leshin, L. A.; Guan, Y.

    2002-12-01

    The Martian meteorite ALH84001 contains a small amount of carbonate that was deposited from aqueous fluids on the Martian surface approximately 3.9 Ga.. McKay et al. (1996) proposed evidence for the existence of life preserved within the carbonate grains. In order to determine the nature of the ancient Martian aqueous system we have combined previously collected oxygen isotopic data with new carbon isotopic measurements performed on the Cameca 6f ion microprobe at Arizona State University. Isotopic measurements were made at high mass resolution with a spot size of 10 microns. The measured carbon isotopic values range from 29.2‰ to 64.5‰ (PDB) with an average uncertainty of +/-1.6‰ (1σ ). These data agree very well with previous acid dissolution and stepped combustion experiments which range from a δ13C of +32‰ to +41‰ . As observed with the oxygen isotopic data, the carbon isotopic composition is correlated with the chemical composition of the carbonates. This allows us to establish that the earliest (Ca-rich) carbonates had the lightest carbon isotopic composition while the latest forming (Mg-rich) carbonates had the heaviest carbon isotopic composition. The large range of carbon isotopic compositions measured in this study cannot be explained by previously proposed models. Temperature change or a Rayleigh distillation process caused by progressive carbonate precipitation are insufficient to create the observed carbon isotopic compositions. Furthermore, processes such as evaporation or photosynthesis will not produce large carbon isotopic variations due to rapid isotopic equilibration with the atmosphere. We propose two possible models for the formation of the ALH84001 carbonates consistent with the isotopic data collected thus far. Carbonates could have formed from an evolving system where the carbon and oxygen isotopic composition of the carbonates reflects a mixing between magmatic hydrothermal fluids and fluids in equilibrium with an isotopically

  6. Carbon in, Carbon out: Reevaluating Carbon Fluxes in Subduction Zones

    NASA Astrophysics Data System (ADS)

    Manning, C. E.; Kelemen, P. B.

    2015-12-01

    Subduction zones exert a fundamental control on the deep carbon cycle. We reevaluated carbon inputs and outputs in convergent margins considering new estimates of C concentration in subducting mantle peridotites, carbonate solubility in aqueous fluids along subduction geotherms, melting and diapirism of carbon-bearing metasediments, and diffuse degassing from arcs. Our updated estimate of carbon inputs to the global subduction system, which includes estimates for C in altered peridotite, is 40-66 megatons carbon/year (MtC/y). We find that estimates of C lost from slabs (14-66 MtC/y) must take into account the high CaCO3 solubility in aqueous fluids, which contributes significant C that must be added to that derived from mineral decarbonation reactions. When taken together with hydrous silicate and carbonatite melts and metasediment diapirs, nearly all C can be scavenged from subducting lithosphere. The return of C to the atmosphere via arc-volcano degassing is only 18-43 MtC/y, but consideration deep volatile saturation of arc magmas, magma ponding in the middle and deep arc crust, and CO2 venting in forearcs can account for the remaining C lost from the slab. Thus, whereas previous studies concluded that about half the subducting carbon is returned to the convecting mantle, we find that relatively little carbon may be recycled. If so, substantial quantities of carbon are stored in the mantle lithosphere and crust and the carbon content of the mantle lithosphere + crust + ocean + atmosphere must be increasing, at least over the last 5-10 My. This is consistent with inferences from noble gas data. Recycled carbon in diamonds is a small fraction of the global carbon inventory.

  7. Influence of cysteine doping on photoluminescence intensity from semiconducting single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Kurnosov, N. V.; Leontiev, V. S.; Linnik, A. S.; Karachevtsev, V. A.

    2015-03-01

    Photoluminescence (PL) from semiconducting single-walled carbon nanotubes can be applied for detection of cysteine. It is shown that cysteine doping (from 10-8 to 10-3 M) into aqueous suspension of nanotubes with adsorbed DNA leads to increase of PL intensity. The PL intensity was enhanced by 27% at 10-3 M cysteine concentration in suspension. Most likely, the PL intensity increases due to the passivation of p-defects on the nanotube by the cysteine containing reactive thiol group. The effect of doping with other amino acids without this group (methionine, serine, aspartic acid, lysine, proline) on the PL intensity is essentially weaker.

  8. Acetylenic carbon allotrope

    SciTech Connect

    1999-11-16

    A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

  9. Acetylenic carbon allotrope

    DOEpatents

    Lagow, Richard J.

    1999-01-01

    A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

  10. Acetylenic carbon allotrope

    DOEpatents

    Lagow, Richard J.

    1998-01-01

    A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

  11. Acetylenic carbon allotrope

    DOEpatents

    Lagow, R.J.

    1998-02-10

    A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein. 17 figs.

  12. Carbon nanotube composite materials

    DOEpatents

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  13. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  14. Mesoporous carbon materials

    DOEpatents

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  15. A 3M high temperature dielectric film

    NASA Technical Reports Server (NTRS)

    Hampl, Edward, Jr.

    1994-01-01

    The performance characteristics of a dielectric film are summarized. Additionally, the film's environmental and chemical properties are listed: low shrinkage to 300 C; moisture insensitive; low outgassing under vacuum; excellent surface qualities--easy metallization of film; flame retardant; and low smoke generation. A series of graphs that display the performance characteristics of the film are also presented.

  16. Field and computer modeling studies of Appalachian cyclic carbonates

    SciTech Connect

    Read, J.F.

    1988-01-01

    Cyclic carbonates in the Cambrian of the Appalachians have been studied using field data integrated with computer modeling studies. The models incorporate 1 to 3-m.y. and 20,000 to 100,000-year low-amplitude sea level fluctuations, water depth-dependent sedimentation rates, lag time, and subsidence. The 1 to 3-m.y. sea level fluctuations are defined by Fischer plots, which are readily compared to the model output. Cycles decrease in number toward regional highs, because lower subsidence rates only allow 40 to 60% of the Milankovitch sea level fluctuations to affect the highs and highs subside lower than third-order sea levels fall, which truncate 50% of cycles. Furthermore, 2 cycles/100,000 years are deposited on the outer shelf, compared to 1 to 1.4 cycles/100,000 years on inner shelf highs. Consequently, cycles have longer average periods toward the highs.

  17. Properties Of Carbon/Carbon and Carbon/Phenolic Composites

    NASA Technical Reports Server (NTRS)

    Mathis, John R.; Canfield, A. R.

    1993-01-01

    Report presents data on physical properties of carbon-fiber-reinforced carbon-matrix and phenolic-matrix composite materials. Based on tests conducted on panels, cylinders, blocks, and formed parts. Data used by designers to analyze thermal-response and stress levels and develop structural systems ensuring high reliability at minimum weight.

  18. Adding Clays to Sandy Soils to Increase Carbon Storage

    NASA Astrophysics Data System (ADS)

    Harper, R. J.; Sochacki, S. J.

    2011-12-01

    Soil carbon storage is often related to clay content and mineralogy. For example, in a dryland farming area (300 mm/year annual rainfall) of Western Australia, carbon storage increased systematically with increasing clay content. Carbon storage in the surface 0.1 m was 42.5 Mg CO2-e/ha in soils with 1.7% clay compared to 99.1 Mg CO2-e/ha for soils with 9.1% clay. Similar results are evident in other data-sets, with carbon storage being related to site water balance, clay content and soil chemical fertility. We thus investigated whether soil carbon storage could be manipulated in sandy soils by adding clay. Clays are often added to farmed sandy soils to overcome water repellency and to reduce nutrient losses by leaching, but are not considered as a carbon management tool. The combined effects can improve plant productivity and thus carbon inputs to soil carbon pools. Bauxite processing residue (10% clay) had been applied in 1982 to sandy soils at different rates in an area with 760 mm/year annual rainfall. Application of 25 Mg clay/ha resulted in an increase in soil carbon content of 47.7 Mg CO2-e/ha. Soils were sampled to a depth of 0.3 m, with most (65%) of the increase being in the surface 0.1 m. Globally, there are large areas of sandy soils occurring across several soil taxonomic orders. In this presentation we describe the implications of clay amendments for increasing the carbon storage in such soils, and suggest areas of further investigation.

  19. Carbon/Carbon extendible Nozzles

    NASA Astrophysics Data System (ADS)

    Lacoste, M.; Lacombe, A.; Joyez, P.; Ellis, R. A.; Lee, J. C.; Payne, F. M.

    2002-03-01

    For many years, SEP has developed C-C composite materials to lighten architectures of propulsion systems, thanks to their high specific mechanical properties kept up to about 2500°C. The 3D carbon reinforcement the so-called Novoltex ® has emerged, and today more than 150 tons per year of C-C is produced by SEP using it. The advent of these thermostructural composite materials have blazed a trail for innovative solutions applicable to the extreme operating conditions of large rocket engines, to improve their performances. The extendible nozzle concept has been developed to optimize the expansion ratio with regard to size restriction required particularly for the upper stages of launchers. The first two tests of a SEP extendible nozzle extension were carried out in 1979, one on a ring design and one on a panel design. Today, nearly all possible configurations have been tested, from the simple scenario of extending a ring from a fixed nozzle prior to ignition, to the most complex one: nozzle deployment while the motor is operating and when the nozzle is being vectored. In August 1995, Pratt & Whitney have entrusted SEP with the development of the C-C exit cone dedicated to the RL10 B-2 cryotechnic engine, propulsion system of the DELTA III upper stage. One year later, in August 1996, SEP delivered the first development item which is currently under testing. When the entire C-C nozzle is attached to the RL10 B-2 engine and deployed, the nozzle diameter increases from 1.1 to 2.1 m and translates to 2.5 m in length, providing an expansion ratio of 285:1 and 30 s of specific impulse increase to the engine. Finally, the paper will describe the design and manufacturing of this huge exit cone and will report the latest test results.

  20. Fertilization increases paddy soil organic carbon density*

    PubMed Central

    Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

    2012-01-01

    Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC. PMID:22467369

  1. Accelerating Mineral Carbonation Using Carbonic Anhydrase.

    PubMed

    Power, Ian M; Harrison, Anna L; Dipple, Gregory M

    2016-03-01

    Carbonic anhydrase (CA) enzymes have gained considerable attention for their potential use in carbon dioxide (CO2) capture technologies because they are able to catalyze rapidly the interconversion of aqueous CO2 and bicarbonate. However, there are challenges for widespread implementation including the need to develop mineralization process routes for permanent carbon storage. Mineral carbonation of highly reactive feedstocks may be limited by the supply rate of CO2. This rate limitation can be directly addressed by incorporating enzyme-catalyzed CO2 hydration. This study examined the effects of bovine carbonic anhydrase (BCA) and CO2-rich gas streams on the carbonation rate of brucite [Mg(OH)2], a highly reactive mineral. Alkaline brucite slurries were amended with BCA and supplied with 10% CO2 gas while aqueous chemistry and solids were monitored throughout the experiments (hours to days). In comparison to controls, brucite carbonation using BCA was accelerated by up to 240%. Nesquehonite [MgCO3·3H2O] precipitation limited the accumulation of hydrated CO2 species, apparently preventing BCA from catalyzing the dehydration reaction. Geochemical models reproduce observed reaction progress in all experiments, revealing a linear correlation between CO2 uptake and carbonation rate. Data demonstrates that carbonation in BCA-amended reactors remained limited by CO2 supply, implying further acceleration is possible. PMID:26829491

  2. Carbon fuel cells with carbon corrosion suppression

    DOEpatents

    Cooper, John F.

    2012-04-10

    An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

  3. Modern carbonate environments

    SciTech Connect

    Bhattacharyya, A.; Friedman, G.M.

    1983-01-01

    This book offers help in evaluating potential sites for oil and gas accumulations. Pointing the way to discovery of hydrocarbons in carbonate reservoirs, this volume discusses modern carbonate depositional environments in different geomorphic settings. It compiles papers by scientists whose observations have revolutionized current thinking on facies relationships in ancient carbonate rock. Contents include: Selected carbonate regions --The Algal Sediments on Androa Island in the Bahamas, Sedimentary Facies, Interaction of Genetic Processes in Holocene Reefs off North Eleuthera Island in the Bahamas, Recent Anhydrite, Holocene Shallow-Water Carbonate and Evaporite Sediments of Khor al Bazam; Carbonate production--On the Origin of Aragonite in the Dead Sea, Carbonate Production by Coral Reefs; Cold-water carbonates--Contributions on the Geology of the Northwestern Peninsula of Iceland, Evaluation of Cold-Water Carbonates as a Possible Paleoclimatic Indicator.

  4. Plumbagin, a medicinal plant (Plumbago zeylanica) - derived 1,4-naphthoquinone, inhibits growth and metastasis of human prostate cancer PC-3M-luciferase cells in an orthotopic xenograft mouse model

    PubMed Central

    Hafeez, Bilal Bin; Zhong, Weixiong; Fischer, Joseph W.; Mustafa, Ala; Shi, Xudong Daniel; Meske, Louise; Hong, Hao; Cai, Weibo; Havighurst, Thomas; Kim, KyungMann; Verma, Ajit. K

    2012-01-01

    We present here first time that Plumbagin (PL), a medicinal plant-derived 1,4-naphthoquinone, inhibits the growth and metastasis of prostate cancer (PCa) in an orthotopic xenograft mouse model. In this study, human PCa PC-3M-luciferase cells (2X106) were injected into the prostate of athymic nude mice. Three days post cell implantation, mice were treated with PL (2 mg/kg body wt. i.p five days in a week) for 8 weeks. Growth and metastasis of PC-3M-luciferase cells was examined weekly by bioluminescence imaging of live mice. PL-treatment significantly (p=0.0008) inhibited the growth of orthotopic xenograft tumors. PCa metastasis into the liver, lungs and lymph nodes was determined by bioluminescence imaging and histopathology. Results demonstrated a significant inhibition of metastasis into liver (p=0.037), but inhibition of metastasis into the lungs (p=0.60) and liver (p=0.27) was not observed to be significant. These results were further confirmed by histopathology of these organs. Results of histopathology demonstrated a significant inhibition of metastasis into lymph nodes (p=0.034) and lungs (p=0.028), and a trend to significance in liver (p=0.075). None of the mice in the PL-treatment group showed PCa metastasis into the liver, but these mice had small metastasis foci into the lymph nodes and lungs. However, control mice had large metastatic foci into the lymph nodes, lungs, and liver. PL-caused inhibition of the growth and metastasis of PC-3M cells accompanies inhibition of the expression of: 1) PKCε, pStat3Tyr705, and pStat3Ser727, 2) Stat3 downstream target genes (survivin and BclxL), 3) proliferative markers Ki-67 and PCNA, 4) metastatic marker MMP9, MMP2, and uPA, and 5) angiogenesis markers CD31 and VEGF. Taken together, these results suggest that PL inhibits tumor growth and metastasis of human PCa PC3-M-luciferase cells, which could be used as a therapeutic agent for the prevention and treatment of human PCa. PL: Plumbagin, PCa: Prostate cancer. PMID

  5. Nonlinear transonic Wall-Interference Assessment/Correction (WIAC) procedures and application to cast-10 airfoil results from the NASA 0.3-m TCT 8- by 24-inch Slotted Wall Test Section (SWTS)

    NASA Technical Reports Server (NTRS)

    Gumbert, Clyde R.; Green, Lawrence L.; Newman, Perry A.

    1989-01-01

    From the time that wind tunnel wall interference was recognized to be significant, researchers have been developing methods to alleviate or account for it. Despite the best effort so far, it appears that no method is available which completely eliminates the effects due to the wind tunnel walls. This report discusses procedures developed for slotted wall and adaptive wall test sections of the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) to assess and correct for the residual interference by methods consistent with the transonic nature of the tests.

  6. Effect of the A-site cation on methane oxidation of perovskite-type (La{sub 1-x}M{sub x})CoO{sub 3} (M=Ca, Sr, and Ba)

    SciTech Connect

    Taguchi, Hideki; Matsu-ura, Keiko; Takada, Masao; Hirota, Ken

    2012-06-15

    Perovskite-type (La{sub 1-x}M{sub x})CoO{sub 3} (M=Ca, Sr, and Ba) synthesized at 700 Degree-Sign C in air using the polymerizable complex method had a rhombohedral perovskite-type structure in the range of x{<=}0.06. The oxygen content of the samples was 2.98-2.99, and the specific surface area was 3.5-8.3 m{sup 2}/g regardless of the M ion or x. The Rietveld method indicated that the Co-O distance was also constant regardless of the M ion or x, and that the Co-O-Co angle between two CoO{sub 6} octahedra increased with an increase in the ionic radius of the M ion. The temperature corresponding to the 50% conversion (T{sub 1/2}) of CH{sub 4} oxidation was almost constant for the samples with x=0.04, while the T{sub 1/2} of the samples with x=0.06 was linearly lowered with increases in the ionic radius of the M ion. - Graphical abstract: The conversion from CH{sub 4} to CO{sub 2} and H{sub 2}O on (La{sub 0.94}M{sub 0.06})CoO{sub 3} (M=Ca, Sr, and Ba). Highlights: Black-Right-Pointing-Pointer (La{sub 1-x}M{sub x})CoO{sub 3} (M=Ca, Sr, and Ba) was synthesized using the polymerizable complex method. Black-Right-Pointing-Pointer The Co-O distance was constant regardless of the M ion or x. Black-Right-Pointing-Pointer The Co-O-Co angle increased with an increase in the ionic radius of the M ion. Black-Right-Pointing-Pointer CH{sub 4} oxidation started above 300 Degree-Sign C and finished at 700 Degree-Sign C. Black-Right-Pointing-Pointer The catalytic activity increased with increases in the ionic radius of the M ion.

  7. Metallic carbon materials

    DOEpatents

    Cohen, Marvin Lou; Crespi, Vincent Henry; Louie, Steven Gwon Sheng; Zettl, Alexander Karlwalter

    1999-01-01

    Novel metallic forms of planar carbon are described, as well as methods of designing and making them. Nonhexagonal arrangements of carbon are introduced into a graphite carbon network essentially without destroying the planar structure. Specifically a form of carbon comprising primarily pentagons and heptagons, and having a large density of states at the Fermi level is described. Other arrangements of pentagons and heptagons that include some hexagons, and structures incorporating squares and octagons are additionally disclosed. Reducing the bond angle symmetry associated with a hexagonal arrangement of carbons increases the likelihood that the carbon material will have a metallic electron structure.

  8. A Symbiosis: Carbon Monitoring and Carbon Management

    NASA Astrophysics Data System (ADS)

    Macauley, M.

    2015-12-01

    "We measure what we value and value what we measure." This old dictum characterizes the usefulness of carbon monitoring in serving society, both in advancing research on carbon cycles and in applying new scientific knowledge to help carbon management. Many attempts to design policy for carbon management have been limited, ineffective, or otherwise unsuccessful in part due to inadequate capacity to observe carbon sources and sinks with sufficient measurement certainty and at appropriate spatial scale. Too often, policy designers fail to understand the complexities of carbon science and carbon researchers fail to align at least a portion of their science goals with policy requirements. The carbon monitoring systems research and applications activities under the auspices of the US National Aeronautics and Space Administration have significantly advanced both science and applications. To further this necessary symbiosis, this paper will synthesize current and prospective spatial and temporal requirements for emerging policy needs, discuss likely requirements for measurement certainty, and draw lessons from experiences in policies designed to monitor and manage other natural resources for which scientific research necessarily influenced policy design and effectiveness.

  9. Carbon cycle: Hoard of fjord carbon

    NASA Astrophysics Data System (ADS)

    Keil, Richard

    2015-06-01

    Fjords account for less than 0.1% of the surface of Earth's oceans. A global assessment finds that organic carbon is buried in fjords five times faster than other marine systems, accounting for 11% of global marine organic carbon burial.

  10. Method of making carbon-carbon composites

    DOEpatents

    Engle, Glen B.

    1991-01-01

    A process for making a carbon-carbon composite having a combination of high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizable woven cloth are covered with petroleum or coal tar pitch and pressed at a temperature a few degrees above the softening point of the pitch to form a green laminated composite. The green composite is restrained in a suitable fixture and heated slowly to carbonize the pitch binder. The carbonized composite is then impregnated several times with pitch by covering the composite with hot pitch under pressure. The composites are given a heat treatment between each impregnation step to crack up the infiltrated carbon and allow additional pitch to enter the microstructure during the next impregnation cycle. The impregnated composites are then given a final heat treatment in the range 2500.degree. to 3000.degree. C. to fully graphitize the fibers and the matrix carbon. The composites are then infiltrated with pyrolytic carbon by chemical vapor deposition in the range 1000.degree. to 1300.degree. C. at a reduced pressure for approximately one hundred and fifty (150) hours.

  11. Carbon nanotube cathode with capping carbon nanosheet

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhao, Dengchao; Pang, Kaige; Pang, Junchao; Liu, Weihua; Liu, Hongzhong; Wang, Xiaoli

    2013-10-01

    Here, we report a vertically aligned carbon nanotube (VACNT) film capped with a few layer of carbon nanosheet (FLCN) synthesized by chemical vapor deposition using a carbon source from iron phthalocyanine pyrolysis. The square resistance of the VACNT film is significantly reduced from 1500 Ω/□ to 300 Ω/□ when it is capped with carbon nanosheet. The VACNT capped with carbon nanosheet was transferred to an ITO glass substrate in an inverted configuration so that the carbon nanosheet served as a flexible transparent electrode at the bottom and the VACNT roots served as emission tips. Because all of the VACNTs start growing from a flat silicon substrate, the VACNT roots are very neat and uniform in height. A field emission test of the carbon nanosheet-capped VACNT film proved that the CNT roots show better uniformity in field emission and the carbon nanosheet cap could also potentially serve as a flexible transparent electrode, which is highly desired in photo-assisted field emission.

  12. [Zr 0.72Y 0.28]Al 4C 4: A new member of the homologous series ( MC) l( T4C 3) m ( M=Zr, Y and Hf, T=Al, Si and Ge)

    NASA Astrophysics Data System (ADS)

    Sugiura, Keita; Iwata, Tomoyuki; Nakano, Hiromi; Fukuda, Koichiro

    2009-07-01

    A new layered carbide, [Zr 0.72(3)Y 0.28(3)]Al 4C 4, has been synthesized and characterized by X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The atom ratios [Zr:Y] were determined by EDX, and the initial structure model was derived by the direct methods, and further refined by Rietveld method. The crystal is trigonal (space group P3¯m1, Z=1) with lattice dimensions of a=0.333990(5) nm, c=1.09942(1) nm and V=0.106209(2) nm 3. This compound shows an intergrowth structure with [Zr 0.72Y 0.28C 2] thin slabs separated by Al 4C 3-type [Al 4C 4] layers. It is a new member with l=1 and m=1 of the homologous series, the general formula of which is ( MC) l( T4C 3) m ( l=1, 2 and 3, m=1 and 2, M=Zr, Y and Hf, T=Al, Si and Ge).

  13. Ternary Phosphide Ho 2Cu 6- xP 5- y, Its Crystal Structure, and REm+ n(Cu 2P 3) m(Cu 4P 2) n Relationship with Other Rhombohedral Rare-Earth Copper Phosphides

    NASA Astrophysics Data System (ADS)

    Mozharivskyj, Yurij; Kuz'ma, Yurij B.

    2000-04-01

    Crystals of the phosphide Ho2Cu6-xP5-y (x=0.41, y=0.50) have been prepared by annealing pressed powders of the elements at 800°C for 2 weeks. The structure was determined by single-crystal methods: space group Roverline3m (No. 166), Z=3, a=3.976(1) Å, c=40.554(8) Å, R=0.045 for 243 independent reflections [F>4σ(F)]. The unit cell of Ho2Cu6-xP5-y can be built from a close packing of Ho atoms and fragments of Cu3P, with one of the fragments containing additional P atoms. It can be also considered as an intercalation of additional P atoms in the YbCu3-xP2 structure (P. Klüfers, A. Mewis, and H. U. Schuster, Z. Kristallogr. 149, 211 (1979)). The REm+n(Cu2P3)m(Cu4P2)n relationship with other rare-earth copper phosphides, having similar structural characteristics is discussed.

  14. GATA3 mRNA expression, but not mutation, associates with longer progression-free survival in ER-positive breast cancer patients treated with first-line tamoxifen for recurrent disease.

    PubMed

    Liu, Jingjing; Prager-van der Smissen, Wendy J C; Look, Maxime P; Sieuwerts, Anieta M; Smid, Marcel; Meijer-van Gelder, Marion E; Foekens, John A; Hollestelle, Antoinette; Martens, John W M

    2016-06-28

    In breast cancer, GATA3 mutations have been associated with a favorable prognosis and the response to neoadjuvant aromatase inhibitor treatment. Therefore, we investigated whether GATA3 mutations predict the outcome of tamoxifen treatment in the advanced setting. In a retrospective study consisting of 235 hormone-naive patients with ER-positive breast cancer who received tamoxifen as first-line treatment for recurrent disease, GATA3 mutations (in 14.0% of patients) did not significantly associate with either the overall response rate (ORR) or with the length of progression-free survival (PFS) after the start of tamoxifen therapy. Interestingly, among 148 patients for whom both mutation and mRNA expression data were available, GATA3 mutations associated with an increased expression of GATA3. However, only 23.7% of GATA3 high tumors had a mutation. Evaluation of the clinical significance of GATA3 mRNA revealed that it was associated with prolonged PFS, but not with the ORR, also in multivariate analysis. Thus, GATA3 mRNA expression, but not GATA3 mutation, is an independent predictor of prolonged PFS in ER-positive breast cancer patients who received first-line tamoxifen for recurrent disease. Besides GATA3 mutation, other mechanisms must exist that underlie increased GATA3 levels. PMID:27018307

  15. Ternary rare-earth ruthenium and iridium germanides RE{sub 3}M{sub 2}Ge{sub 3} (RE=Y, Gd–Tm, Lu; M=Ru, Ir)

    SciTech Connect

    Oliynyk, Anton O.; Stoyko, Stanislav S.; Mar, Arthur

    2013-06-15

    Through arc-melting reactions of the elements and annealing at 800 °C, the ternary rare-earth germanides RE{sub 3}Ru{sub 2}Ge{sub 3} and RE{sub 3}Ir{sub 2}Ge{sub 3} have been prepared for most of the smaller RE components (RE=Y, Gd–Tm, Lu). In the iridium-containing reactions, the new phases RE{sub 2}IrGe{sub 2} were also generally formed as by-products. Powder X-ray diffraction revealed orthorhombic Hf{sub 3}Ni{sub 2}Si{sub 3}-type structures (space group Cmcm, Z=4) for RE{sub 3}M{sub 2}Ge{sub 3} (M=Ru, Ir) and monoclinic Sc{sub 2}CoSi{sub 2}-type structures (space group C2/m, Z=4) for RE{sub 2}IrGe{sub 2}. Full crystal structures were determined by single-crystal X-ray diffraction for all members of RE{sub 3}Ru{sub 2}Ge{sub 3} (a=4.2477(6) Å, b=10.7672(16) Å, c=13.894(2) Å for RE=Y; a=4.2610(3)–4.2045(8) Å, b=10.9103(8)–10.561(2) Å, c=14.0263(10)–13.639(3) Å in the progression of RE from Gd to Lu) and for Tb{sub 3}Ir{sub 2}Ge{sub 3} (a=4.2937(3) Å, b=10.4868(7) Å, c=14.2373(10) Å). Both structures can be described in terms of CrB- and ThCr{sub 2}Si{sub 2}-type slabs built from Ge-centred trigonal prisms. However, band structure calculations on Y{sub 3}Ru{sub 2}Ge{sub 3} support an alternative description for RE{sub 3}M{sub 2}Ge{sub 3} based on [M{sub 2}Ge{sub 3}] layers built from linked MGe{sub 4} tetrahedra, which emphasizes the strong M–Ge covalent bonds present. The temperature dependence of the electrical resistivity of RE{sub 3}Ru{sub 2}Ge{sub 3} generally indicates metallic behaviour but with low-temperature transitions visible for some members (RE=Gd, Tb, Dy) that are probably associated with magnetic ordering of the RE atoms. Anomalously, Y{sub 3}Ru{sub 2}Ge{sub 3} exhibits semiconductor-like behaviour of uncertain origin. Magnetic measurements on Dy{sub 3}Ru{sub 2}Ge{sub 3} reveal antiferromagnetic ordering at 3 K and several unusual field-dependent transitions suggestive of complex spin reorientation processes. - Graphical abstract

  16. Carbon Based Nanotechnology: Review

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1999-01-01

    This presentation reviews publicly available information related to carbon based nanotechnology. Topics covered include nanomechanics, carbon based electronics, nanodevice/materials applications, nanotube motors, nano-lithography and H2O storage in nanotubes.

  17. Potassium carbonate poisoning

    MedlinePlus

    Potassium carbonate is a white powder used to make soap, glass, and other items. This article discusses poisoning from swallowing or breathing in potassium carbonate. This article is for information only. Do ...

  18. Calcium carbonate overdose

    MedlinePlus

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Some products that contain calcium carbonate are certain: ... and mineral supplements Other products may also contain calcium ...

  19. Trading forest carbon - OSU

    EPA Science Inventory

    Issues associate with trading carbon sequestered in forests are discussed. Scientific uncertainties associated with carbon measurement are discussed with respect to proposed accounting procedures. Major issues include: (1) Establishing baselines. (2) Determining additivity from f...

  20. The global carbon cycle

    SciTech Connect

    Sedjo, R.A. )

    1990-10-01

    The author discusses the global carbon cycle and cites the results of several recently completed research projects, that seem to indicate that the temperate zone forests are a sink for carbon rather than a source, as was previously believed.

  1. Sodium carbonate poisoning

    MedlinePlus

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  2. Carbon nanotube nanoelectrode arrays

    DOEpatents

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  3. Interstellar carbon in meteorites

    NASA Technical Reports Server (NTRS)

    Swart, P. K.; Grady, M. M.; Pillinger, C. T.; Lewis, R. S.; Anders, E.

    1983-01-01

    The Murchison and Allende chondrites contain up to 5 parts per million carbon that is enriched in carbon-13 by up to +1100 per mil (the ratio of carbon-12 to carbon-13 is approximately 42, compared to 88 to 93 for terrestrial carbon). This 'heavy' carbon is associated with neon-22 and with anomalous krypton and xenon showing the signature of the s-process (neutron capture on a slow time scale). It apparently represents interstellar grains ejected from late-type stars. A second anomalous xenon component ('CCFXe') is associated with a distinctive, light carbon (depleted in carbon-13 by 38 per mil), which, however, falls within the terrestrial range and hence may be of either local or exotic origin.

  4. Not just carbon widgets

    NASA Astrophysics Data System (ADS)

    2016-08-01

    Forests are important for the global carbon cycle, and for mitigating greenhouse gas emissions. However, the role forests play in carbon sequestration should not eclipse everything else we value them for.

  5. Metal filled porous carbon

    DOEpatents

    Gross, Adam F.; Vajo, John J.; Cumberland, Robert W.; Liu, Ping; Salguero, Tina T.

    2011-03-22

    A porous carbon scaffold with a surface and pores, the porous carbon scaffold containing a primary metal and a secondary metal, where the primary metal is a metal that does not wet the surface of the pores of the carbon scaffold but wets the surface of the secondary metal, and the secondary metal is interspersed between the surface of the pores of the carbon scaffold and the primary metal.

  6. Intro to Carbon Sequestration

    ScienceCinema

    None

    2010-01-08

    NETL's Carbon Sequestration Program is helping to develop technologies to capture, purify, and store carbon dioxide (CO2) in order to reduce greenhouse gas emissions without adversely influencing energy use or hindering economic growth. Carbon sequestration technologies capture and store CO2 that would otherwise reside in the atmosphere for long periods of time.

  7. Protolytic carbon film technology

    SciTech Connect

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  8. Carbon Goes To…

    ERIC Educational Resources Information Center

    Savasci, Funda

    2014-01-01

    The purposes of this activity are to help middle school students understand the carbon cycle and realize how human activities affect the carbon cycle. This activity consists of two parts. The first part of the activity focuses on the carbon cycle, especially before the Industrial Revolution, while the second part of the activity focuses on how…

  9. Intro to Carbon Sequestration

    SciTech Connect

    2008-03-06

    NETL's Carbon Sequestration Program is helping to develop technologies to capture, purify, and store carbon dioxide (CO2) in order to reduce greenhouse gas emissions without adversely influencing energy use or hindering economic growth. Carbon sequestration technologies capture and store CO2 that would otherwise reside in the atmosphere for long periods of time.

  10. Carbon/Carbon Pistons for Internal Combustion Engines

    NASA Technical Reports Server (NTRS)

    Taylor, A. H.

    1986-01-01

    Carbon/carbon piston performs same function as aluminum pistons in reciprocating internal combustion engines while reducing weight and increasing mechanical and thermal efficiencies of engine. Carbon/carbon piston concept features low piston-to-cylinder wall clearance - so low piston rings and skirts unnecessary. Advantages possible by negligible coefficient of thermal expansion of carbon/carbon.

  11. Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

    PubMed

    Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

    2014-04-01

    Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (< 3 m) were relatively high due to the presence of carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions

  12. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates.

    PubMed

    Wolf, Stephan E; Müller, Lars; Barrea, Raul; Kampf, Christopher J; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten; Emmerling, Franziska; Tremel, Wolfgang

    2011-03-01

    During the mineralisation of metal carbonates MCO3 (M=Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. PMID:21218241

  13. High-efficiency optical parametric chirped-pulse amplifier in BiB₃O₆ for generation of 3 mJ, two-cycle, carrier-envelope-phase-stable pulses at 1.7 μm.

    PubMed

    Yin, Yanchun; Li, Jie; Ren, Xiaoming; Zhao, Kun; Wu, Yi; Cunningham, Eric; Chang, Zenghu

    2016-03-15

    We produce a 3 mJ, two-cycle (11.4 fs), 1 kHz, carrier-envelope phase (CEP)-stable laser source at 1.7 μm via a three-stage Ti:sapphire-pumped optical parametric chirped-pulse amplifier in BiB3O6. We achieve a pump-to-signal conversion efficiency of 18% in the last stage, which is, to the best of our knowledge, the highest yet achieved for near-octave bandwidth amplification. A f-to-2f measurement shows a CEP instability of 165 mrad over 1 h. This is an ideal light source for generating isolated attosecond pulses in the soft x-ray region. PMID:26977654

  14. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, William K.; Dahlin, David C.; Nilsen, David N.; Walters, Richard P.; Turner, Paul C.

    2000-01-01

    The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction

  15. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, W.K.; Dahlin, D.C.; Nilsen, D.N.; Walters, R.P.; Turner, P.C.

    2000-07-01

    The Albany Research Center (ARC) of the US Department of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite and member (mg{sub 2}SiO{sub 4})], or serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}]. This slurry is reacted with supercritical carbon dioxide (CO{sub 2}) to produce magnesite (MgCO{sub 3}). The CO{sub 2} is dissolved in water to form carbonic acid (H{sub 2}CO{sub 3}), which dissociates to H{sup +} and HCO{sub 3}{sup {minus}}. The H{sup +} reacts with the mineral, liberating Mg{sup 2+} cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO{sub 2} pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185 C and a partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine

  16. [Fe(TPT)(2/3){M(I)(CN)2}2]⋅nSolv (M(I) = Ag, Au): new bimetallic porous coordination polymers with spin-crossover properties.

    PubMed

    Arcís-Castillo, Zulema; Muñoz, M Carmen; Molnár, Gábor; Bousseksou, Azzedine; Real, José Antonio

    2013-05-17

    Two new heterobimetallic porous coordination polymers with the formula [Fe(TPT)(2/3){M(I)(CN)2}2]⋅nSolv (TPT = [(2,4,6-tris(4-pyridyl)-1,3,5-triazine]; M(I) = Ag (nSolv = 0, 1 MeOH, 2 CH2Cl2), Au (nSolv = 0, 2CH2Cl2)) have been synthesized and their crystal structures were determined at 120 K and 293 K by single-crystal X-ray analysis. These structures crystallized in the trigonal R-3m space group. The Fe(II) ion resides at an inversion centre that defines a [FeN6] coordination core. Four dicyanometallate groups coordinate at the equatorial positions, whilst the axial positions are occupied by the TPT ligand. Each TPT ligand is centred in a ternary axis and bridges three crystallographically equivalent Fe(II) ions, whilst each dicyanometallate group bridges two crystallographically equivalent Fe(II) ions that define a 3D network with the topology of NbO. There are two such networks, which interpenetrate each other, thereby giving rise to large spaces in which very labile solvent molecules are included (CH2Cl2 or MeOH). Crystallographic analysis confirmed the reversible structural changes that were associated with the occurrence of spin-crossover behaviour at the Fe(II) ions, the most significant structural variation being the change in unit-cell volume (about 59 Å(3) per Fe(II) ion). The spin-crossover behaviour has been monitored by means of thermal dependence of the magnetic properties, Mössbauer spectroscopy, and calorimetry. PMID:23576158

  17. Process of making carbon-carbon composites

    NASA Technical Reports Server (NTRS)

    Withers, James C. (Inventor); Loutfy, Raouf O. (Inventor); Kowbel, Witold (Inventor); Bruce, Calvin (Inventor); Vaidyanathan, Ranji (Inventor)

    2000-01-01

    A carbon composite structure, for example, an automotive engine piston, is made by preparing a matrix including of a mixture of non crystalline carbon particulate soluble in an organic solvent and a binder that has a liquid phase. The non crystalline particulate also contains residual carbon hydrogen bonding. An uncured structure is formed by combining the matrix mixture, for example, carbon fibers such as graphite dispersed in the mixture and/or graphite cloth imbedded in the mixture. The uncured structure is cured by pyrolyzing it in an inert atmosphere such as argon. Advantageously, the graphite reinforcement material is whiskered prior to combining it with the matrix mixture by a novel method involving passing a gaseous metal suboxide over the graphite surface.

  18. Spatially Explicit Full Carbon and Greenhouse Gas Accounting for the Midwestern and Continental US: Modeling and Decision Support for Carbon Management

    NASA Astrophysics Data System (ADS)

    West, T. O.; Brandt, C. C.; Wilson, B. S.; Hellwinckel, C. M.; Mueller, M.; Tyler, D. D.; de La Torre Ugarte, D. G.; Larson, J. A.; Nelson, R. G.; Marland, G.

    2006-12-01

    Full carbon accounting for terrestrial ecosystems is intended to quantify changes in net carbon emissions caused by changes in land management. On agricultural lands, changes in land management can cause changes in CO2 emissions from fossil fuel use, agricultural lime, and decomposition of soil carbon. Changes in off-site emissions can occur from the manufacturing of fertilizers, pesticides, and agricultural lime. We are developing a full carbon accounting framework that can be used for estimates of on-site net carbon flux or for full greenhouse gas accounting at a high spatial resolution. Estimates are based on the assimilation of national inventory data, soil carbon dynamics based on empirical analyses of field data, and Landsat-derived remote sensing products with 30x30m resolution. We applied this framework to a mid-western region of the US that consists of 679 counties approximately centered around Iowa. We estimate the 1990 baseline soil carbon for this region to be 4,099 Tg C to a 3m maximum depth. Soil carbon accumulation of 57.3 Tg C is estimated to have occurred in this region between 1991-2000. Without accounting for soil carbon loss associated with changes to more intense tillage practices, our estimate increases to 66.3 Tg C. This indicates that on-site permanence of soil carbon is approximately 86% with no additional economic incentives provided for soil carbon sequestration practices. Total net carbon flux from the agricultural activities in the Midwestern US in 2000 is estimated at about -5 Tg C. This estimate includes carbon uptake, decomposition, harvested products, and on-site fossil fuel emissions. Therefore, soil carbon accumulation offset on-site emissions in 2000. Our carbon accounting framework offers a method to integrate new inventory and remote sensing data on an annual basis, account for alternating annual trends in land management without the need for model equilibration, and provide a transparent means to monitor changes soil carbon

  19. Field and computer modeling studies of Appalachian cyclic carbonates

    SciTech Connect

    Read, J.F.

    1988-02-01

    Cyclic carbonates in the Cambrian of the Appalachians have been studied using field data integrated with computer modeling studies. The models incorporate 1 to 3-m.y. and 20,000 to 100,000-year low-amplitude sea level fluctuations, water depth-dependent sedimentation rates, lag time, and subsidence. The 1 to 3-m.y. sea level fluctuations are defined by Fischer plots, which are readily compared to the model output. Cycles decrease in number toward regional highs, because (1) lower subsidence rates only allow 40 to 60% of the Milankovitch sea level fluctuations to affect the highs and (2) highs subside lower than third-order sea levels fall, which truncate 50% of cycles. Furthermore, 2 cycles/100,000 years are deposited on the outer shelf, compared to 1 to 1.4 cycles/100,000 years on inner shelf highs. Consequently cycles have longer average periods toward the highs. Furthermore, average thickness shows only a slight decrease landward, even though formation thicknesses may be halved. The field data and modeling constrain amplitudes of 1 to 3-m.y. sea level changes because significant unconformities are absent from the shelf sequence, indicating third-order sea levels fell slower than subsidence rates, thus were considerably less than 50 m.

  20. Mechanical behavior of carbon-carbon composites

    NASA Technical Reports Server (NTRS)

    Rozak, G. A.

    1984-01-01

    A general background, test plan, and some results of preliminary examinations of a carbon-carbon composite material are presented with emphasis on mechanical testing and inspection techniques. Experience with testing and evaluation was gained through tests of a low modulus carbon-carbon material, K-Karb C. The properties examined are the density - 1.55 g/cc; four point flexure strength in the warp - 137 MPa (19,800 psi) and the fill - 95.1 MPa (13,800 psi,) directions; and the warp interlaminar shear strength - 14.5 MPa (2100 psi). Radiographic evaluation revealed thickness variations and the thinner areas of the composite were scrapped. The ultrasonic C-scan showed attenuation variations, but these did not correspond to any of the physical and mechanical properties measured. Based on these initial tests and a survey of the literature, a plan has been devised to examine the effect of stress on the oxidation behavior, and the strength degradation of coated carbon-carbon composites. This plan will focus on static fatigue tests in the four point flexure mode in an elevated temperature, oxidizing environment.

  1. Carbon isotopes in mollusk shell carbonates

    NASA Astrophysics Data System (ADS)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  2. Activated carbon from biomass

    NASA Astrophysics Data System (ADS)

    Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

    2013-06-01

    Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

  3. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K.; Lee, Inhee; Akbar, Sheikh A.

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  4. Electrochemical performance of Si anode modified with carbonized gelatin binder

    NASA Astrophysics Data System (ADS)

    Jiang, Ying; Mu, Daobin; Chen, Shi; Wu, Borong; Cheng, Kailin; Li, Luyu; Wu, Feng

    2016-09-01

    Gelatin is alternatively adopted as the binder to modify Si anode coupling with its carbonization treatment. The binder can provide good bonding and uniform dispersion of the particles besides its environmental benignancy. Importantly, the carbonized binder containing nitrogen will be advantageous to the electrical conductivity of the electrode. In addition, some spaces are formed in the electrode due to the decomposition and shrinkage of the gelatin binder during heat-treatment, which may facilitate electrolyte penetration and accommodate volume change during cycling. All these merits make contribution to the good electrochemical performance of the modified Si electrode. It exhibits a reversible capacity of 990.3 mA h g-1 after 70 cycles at a current density of 100 mA g-1 and 904 mA h g-1 after 100 cycles at 400 mA g-1.

  5. Mesoporous carbon materials

    SciTech Connect

    Dai, Sheng; Wang, Xiqing

    2012-02-14

    The invention is directed to a method for fabricating a mesoporous carbon material, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic compound or material, (iii) a crosslinkable aldehyde component, and (iv) at least 0.5 M concentration of a strong acid having a pKa of or less than -2, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a mesoporous carbon material. The invention is also directed to a mesoporous carbon material having an improved thermal stability, preferably produced according to the above method.

  6. Plumbing carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Jin, Chuanhong; Suenaga, Kazu; Iijima, Sumio

    2008-01-01

    Since their discovery, the possibility of connecting carbon nanotubes together like water pipes has been an intriguing prospect for these hollow nanostructures. The serial joining of carbon nanotubes in a controlled manner offers a promising approach for the bottom-up engineering of nanotube structures-from simply increasing their aspect ratio to making integrated carbon nanotube devices. To date, however, there have been few reports of the joining of two different carbon nanotubes. Here we demonstrate that a Joule heating process, and associated electro-migration effects, can be used to connect two carbon nanotubes that have the same (or similar) diameters. More generally, with the assistance of a tungsten metal particle, this technique can be used to seamlessly join any two carbon nanotubes-regardless of their diameters-to form new nanotube structures.

  7. Mesoporous carbon materials

    DOEpatents

    Dai, Sheng; Wang, Xiqing

    2013-08-20

    The invention is directed to a method for fabricating a mesoporous carbon material, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic compound or material, (iii) a crosslinkable aldehyde component, and (iv) at least 0.5 M concentration of a strong acid having a pKa of or less than -2, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a mesoporous carbon material. The invention is also directed to a mesoporous carbon material having an improved thermal stability, preferably produced according to the above method.

  8. Creating With Carbon

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A subsidiary of SI Diamond Technology, Inc., Applied Nanotech, of Austin, Texas, is creating a buzz among various technology firms and venture capital groups interested in the company s progressive research on carbon-related field emission devices, including carbon nanotubes, filaments of pure carbon less than one ten-thousandth the width of human hair. Since their discovery in 1991, carbon nanotubes have gained considerable attention due to their unique physical properties. For example, a single perfect carbon nanotube can range from 10 to 100 times stronger than steel, per unit weight. Recent studies also indicate that the nanotubes may be the best heat-conducting material in existence. These properties, combined with the ease of growing thin films or nanotubes by a variety of deposition techniques, make the carbon-based material one of the most desirable for cold field emission cathodes.

  9. Mesoporous carbon -Cr2O3 composite as an anode material for lithium ion batteries

    SciTech Connect

    Guo, Bingkun; Chi, Miaofang; Sun, Xiao-Guang; Dai, Sheng

    2012-01-01

    Mesoporous carbon-Cr2O3 (M-C-Cr2O3) composite was prepared by co-assembly of in-situ formed phenolic resin, chromium precursor, and Pluronic block copolymer under acidic conditions, followed by carbonization at 750oC under Argon. The TEM results confirmed that the Cr2O3 nanoparticles, ranging from 10 to 20 nm, were well dispersed in the matrix of mesoporous carbon. The composite exhibited an initial reversible capacity of 710 mAh g-1 and good cycling stability, which is mainly due to the synergic effects of carbons within the composites, i.e. confining the crystal growth of Cr2O3 during the high temperature treatment step and buffering the volume change of Cr2O3 during the cycling step. This composite material is a promising anode material for lithium ion batteries.

  10. Activated carbon derived from waste coffee grounds for stable methane storage

    NASA Astrophysics Data System (ADS)

    Kemp, K. Christian; Baek, Seung Bin; Lee, Wang-Geun; Meyyappan, M.; Kim, Kwang S.

    2015-09-01

    An activated carbon material derived from waste coffee grounds is shown to be an effective and stable medium for methane storage. The sample activated at 900 °C displays a surface area of 1040.3 m2 g-1 and a micropore volume of 0.574 cm3 g-1 and exhibits a stable CH4 adsorption capacity of ˜4.2 mmol g-1 at 3.0 MPa and a temperature range of 298 ± 10 K. The same material exhibits an impressive hydrogen storage capacity of 1.75 wt% as well at 77 K and 100 kPa. Here, we also propose a mechanism for the formation of activated carbon from spent coffee grounds. At low temperatures, the material has two distinct types with low and high surface areas; however, activation at elevated temperatures drives off the low surface area carbon, leaving behind the porous high surface area activated carbon.

  11. The carbon dioxide cycle

    USGS Publications Warehouse

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  12. 40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Carbon oxyfluoride (Carbonic... Specific Chemical Substances § 721.2084 Carbon oxyfluoride (Carbonic difluoride). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance carbon oxyfluoride (CAS...

  13. 40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Carbon oxyfluoride (Carbonic... Specific Chemical Substances § 721.2084 Carbon oxyfluoride (Carbonic difluoride). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance carbon oxyfluoride (CAS...

  14. 40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Carbon oxyfluoride (Carbonic... Specific Chemical Substances § 721.2084 Carbon oxyfluoride (Carbonic difluoride). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance carbon oxyfluoride (CAS...

  15. 40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Carbon oxyfluoride (Carbonic... Specific Chemical Substances § 721.2084 Carbon oxyfluoride (Carbonic difluoride). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance carbon oxyfluoride (CAS...

  16. 40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carbon oxyfluoride (Carbonic... Specific Chemical Substances § 721.2084 Carbon oxyfluoride (Carbonic difluoride). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance carbon oxyfluoride (CAS...

  17. Downsizing the pelagic carbonate factory: Impacts of calcareous nannoplankton evolution on carbonate burial over the past 17 million years

    NASA Astrophysics Data System (ADS)

    Suchéras-Marx, Baptiste; Henderiks, Jorijntje

    2014-12-01

    Cenozoic deep-sea carbonates ("calcareous oozes") are predominantly biogenic in origin and offer detailed records of the evolution of calcifying plankton groups, such as coccolithophores and foraminifera. The size and abundance of calcifying plankton determine the strength of the calcium carbonate "pump" in the open ocean, which acts as a short-term source of CO2, while the burial of pelagic carbonates serves as a long-term sink of carbon. Here, we show how the macroevolutionary size decrease in calcareous nannoplankton (coccoliths and calcareous nannoliths) has affected burial rates of calcareous ooze over the past 17 million years. We quantified nannofossil carbonate burial rates (g CaCO3/m2/yr) at five DSDP/ODP sites in the Atlantic, Indian, and Western Pacific oceans. The proportion of nannofossil-dominated fine fraction carbonate (< 38 μm) and its mass accumulation rates were regionally and temporally variable, but our combined data reveal globally consistent long-term trends. Mean nannofossil carbonate mass decreased about four-fold between 9 and 4 Ma, but this had little or only minor impact on the burial of pelagic carbonate until ~ 4 Ma. After ~ 4 Ma, when small-sized coccolith-bearing species prevailed, nannofossil carbonate burial rates decreased by one order of magnitude to the lowest values during the Pleistocene. In contrast, mass accumulation rates of the foraminifera-dominated > 38 μm fraction remained stable over the past 17 Myr. This suggests that changes in the deposition of calcareous ooze were primarily driven by calcareous nannoplankton, and that foraminifera did not compensate for the lower nannofossil-carbonate accumulation rates since the Pliocene. Despite a deepening of the lysocline over the past 4 Myr, global pelagic carbonate mass accumulation likely decreased. Whether, or how, this may relate to changes in weathering or other components within the long-term carbonate cycle remains unclear. Explanations for the macroevolutionary size

  18. Nanographene reinforced carbon/carbon composites

    NASA Astrophysics Data System (ADS)

    Bansal, Dhruv

    Carbon/Carbon Composites (CCC) are made of carbon reinforcement in carbon matrix and have high thermal stability and fatigue resistance. CCC are used in nose cones, heat shields and disc brakes of aircrafts due to their exceptional mechanical properties at high temperature. The manufacturing process of CCC involves a carbonization stage in which unwanted elements, except carbon, are eliminated from the polymer precursor. Carbonization results in the formation of voids and cracks due to the thermal mismatch between the reinforcement and the matrix and expulsion of volatiles from the polymer matrix. Thermal cracks and voids decrease the density and mechanical properties of the manufactured CCC. In this work, Nanographene Platelets (NGP) were explored as nanofillers to fill the voids/cracks and reduce thermal shrinkage in CCC. They were first compared with Vapor Grown Carbon Nanofibers (VGCNF) by dispersion of different concentrations (0.5wt%, 1.5wt%, 3wt%) in resole-type phenolic resin and were characterized to explore their effect on rheology, heat of reaction and wetting behavior. The dispersions were then cured to form nanocomposites and were characterized for morphology, flexure and thermal properties. Finally, NGP were introduced into the carbon/carboncomposites in two stages, first by spraying in different concentrations (0.5wt%, 1.5wt%, 3wt%, 5wt %) during the prepreg formation and later during densification by directly mixing in the corresponding densification mix. The manufactured NGP reinforced CCC were characterized for microstructure, porosity, bulk density and mechanical properties (Flexure and ILSS) which were further cross-checked by non-destructive techniques (vibration and ultrasonic). In this study, it was further found that at low concentration (≤ 1.5 wt%) NGP were more effective in increasing the heat of reaction and in decreasing the viscosity of the phenolic resin. The decrease in viscosity led to better wetting properties of NGP / phenolic

  19. Carbon Monoxide Toxicity

    PubMed Central

    Aniol, Michael J.

    1992-01-01

    Of all fatal poisonings in the United States, an estimated half are due to carbon monoxide. The number of non-lethal poisonings due to carbon monoxide is difficult to estimate because signs and symptoms of carbon monoxide poisoning cover a wide spectrum and mimic other disorders. Misdiagnosis is serious, as the patient often returns to the contaminated environment. Those not receiving proper treatment are at significant risk, as high as 10% to 12%, of developing late neurological sequelae. The diagnosis of carbon monoxide poisoning depends upon precise history taking, careful physical examination, and a high index of suspicion. ImagesFigure 2 PMID:21221282

  20. Environmental carbon dioxide control

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B.; Gidaspow, D.

    1974-01-01

    A study of environmental carbon dioxide control for NASA EVA missions found solid potassium carbonate to be an effective regenerable absorbent in maintaining low carbon dioxide levels. The supported sorbent was capable of repeated regeneration below 150 C without appreciable degradation. Optimum structures in the form of thin pliable sheets of carbonate, inert support and binder were developed. Interpretation of a new solid-gas pore closing model helped predict the optimum sorbent and analysis of individual sorbent sheet performance in a thin rectangular channel sorber can predict packed bed performance.

  1. Nanoindentation of Carbon Nanostructures.

    PubMed

    Kumar, Dinesh; Singh, Karamjit; Verma, Veena; Bhatti, H S

    2016-06-01

    In the present research paper carbon nanostructures viz. single walled carbon nanotubes, multi-walled carbon nanotubes, single walled carbon nanohorns and graphene nanoplatelets have been synthesized by CVD technique, hydrothermal method, DC arc discharge method in liquid nitrogen and microwave technique respectively. After synthesis 5 mm thick pallets of given nanomaterial are prepared by making a paste in isopropyl alcohol and using polyvinylidene difluoride as a binder and then these pallets were used for nanoindentation measurements. Hardness, reduced modulus, stiffness, contact height and contact area have been measured using nanoindenter. PMID:27427726

  2. Activated carbon material

    DOEpatents

    Evans, A. Gary

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

  3. Reinforced Carbon Nanotubes.

    DOEpatents

    Ren, Zhifen; Wen, Jian Guo; Lao, Jing Y.; Li, Wenzhi

    2005-06-28

    The present invention relates generally to reinforced carbon nanotubes, and more particularly to reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  4. Carbon dioxide sequestration by mineral carbonation

    SciTech Connect

    Gerdemann, Stephen J.; Dahlin David C.; O'Connor William K.; Penner Larry R.

    2003-11-01

    Concerns about global warming caused by the increasing concentration of carbon dioxide and other greenhouse gases in the earth’s atmosphere have resulted in the need for research to reduce or eliminate emissions of these gases. Carbonation of magnesium and calcium silicate minerals is one possible method to achieve this reduction. It is possible to carry out these reactions either in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals) or ex situ (above ground in a more traditional chemical processing plant). Research at the Department of Energy’s Albany Research Center has explored both of these routes. This paper will explore parameters that affect the direct carbonation of magnesium silicate minerals serpentine (Mg3Si2O5(OH)4) and olivine (Mg2SiO4) to produce magnesite (MgCO3), as well as the calcium silicate mineral, wollastonite (CaSiO3), to form calcite (CaCO3). The Columbia River Basalt Group is a multi-layered basaltic lava plateau that has favorable mineralogy and structure for storage of CO2. Up to 25% combined concentration of Ca, Fe2+, and Mg cations could react to form carbonates and thus sequester large quantities of CO2. Core samples from the Columbia River Basalt Group were reacted in an autoclave for up to 2000 hours at temperatures and pressures to simulate in situ conditions. Changes in core porosity, secondary minerals, and solution chemistry were measured.

  5. Oxalate-bridged bimetallic complexes {NH(prol)3}[MCr(ox)3] (M = Mn(II), Fe(II), Co(II); NH(prol)3(+) = tri(3-hydroxypropyl)ammonium) exhibiting coexistent ferromagnetism and proton conduction.

    PubMed

    Okawa, Hisashi; Shigematsu, Akihito; Sadakiyo, Masaaki; Miyagawa, Takuya; Yoneda, Ko; Ohba, Masaaki; Kitagawa, Hiroshi

    2009-09-23

    The oxalate-bridged bimetallic complexes {NH(prol)(3)}[M(II)Cr(III)(ox)(3)] (M(II) = Mn(II), Fe(II), Co(II)) with hydrophilic tri(3-hydroxypropyl)ammonium (NH(prol)(3)(+)) were prepared by a new synthetic procedure, and the effects of the NH(prol)(3)(+) ion upon the structure, magnetism, and electrical conduction were studied. An X-ray crystallographic study of the MnCr dihydrate, {NH(prol)(3)}[MnCr(ox)(3)].2H(2)O, was performed. Crystal data: hexagonal, P6(3), a = b = 9.3808(14) A, c = 15.8006(14) A, Z = 2. The structure comprises oxalate-bridged bimetallic layers interleaved by NH(prol)(3)(+) ions. The ions assume a tripodal configuration and are hydrogen bonded to the bimetallic layers together with water molecules, giving rise to a short interlayer separation (7.90 A) and unsymmetrical faces to the bimetallic layer. Cryomagnetic studies demonstrate ferromagnetic ordering with transition temperature of 5.5 K for the MnCr complex, 9.0 K for the FeCr complex, and 10.0 K for the CoCr complex. The interlayer magnetic interaction is negligibly weak in all of the complexes despite the short interlayer separation. A slow magnetization is observed in all the complexes. This is explained by spin canting associated with the unsymmetrical feature of the bimetallic layer. The complexes show proton conduction of 1.2 x 10(-10) to 4.4 x 10(-10) S cm(-1) under 40% relative humidity (RH) and approximately 1 x 10(-4) S cm(-1) under 75% RH. On the basis of water adsorption/desorption profiles, the conduction under 40% RH is mediated through the hydrogen-bonded network formed by the bimetallic layer, NH(prol)(3)(+) ions, and water molecules (two per MCr). Under 75% RH, additional water molecules (three per MCr) are concerned with the high proton conduction. This is the first example of a metal complex system exhibiting coexistent ferromagnetism and proton conduction. PMID:19715318

  6. Trends in Syntheses, Structures, and Properties for Three Series of Ammine Rare-Earth Metal Borohydrides, M(BH4)3·nNH3 (M = Y, Gd, and Dy).

    PubMed

    Jepsen, Lars H; Ley, Morten B; Černý, Radovan; Lee, Young-Su; Cho, Young Whan; Ravnsbæk, Dorthe; Besenbacher, Flemming; Skibsted, Jørgen; Jensen, Torben R

    2015-08-01

    Fourteen solvent- and halide-free ammine rare-earth metal borohydrides M(BH4)3·nNH3, M = Y, Gd, Dy, n = 7, 6, 5, 4, 2, and 1, have been synthesized by a new approach, and their structures as well as chemical and physical properties are characterized. Extensive series of coordination complexes with systematic variation in the number of ligands are presented, as prepared by combined mechanochemistry, solvent-based methods, solid-gas reactions, and thermal treatment. This new synthesis approach may have a significant impact within inorganic coordination chemistry. Halide-free metal borohydrides have been synthesized by solvent-based metathesis reactions of LiBH4 and MCl3 (3:1), followed by reactions of M(BH4)3 with an excess of NH3 gas, yielding M(BH4)3·7NH3 (M = Y, Gd, and Dy). Crystal structure models for M(BH4)3·nNH3 are derived from a combination of powder X-ray diffraction (PXD), (11)B magic-angle spinning NMR, and density functional theory (DFT) calculations. The structures vary from two-dimensional layers (n = 1), one-dimensional chains (n = 2), molecular compounds (n = 4 and 5), to contain complex ions (n = 6 and 7). NH3 coordinates to the metal in all compounds, while BH4(-) has a flexible coordination, i.e., either as a terminal or bridging ligand or as a counterion. M(BH4)3·7NH3 releases ammonia stepwise by thermal treatment producing M(BH4)3·nNH3 (6, 5, and 4), whereas hydrogen is released for n ≤ 4. Detailed analysis of the dihydrogen bonds reveals new insight about the hydrogen elimination mechanism, which contradicts current hypotheses. Overall, the present work provides new general knowledge toward rational materials design and preparation along with limitations of PXD and DFT for analysis of structures with a significant degree of dynamics in the structures. PMID:26196159

  7. A first-principles density functional theory study of the electronic structural and thermodynamic properties of M2ZrO3 and M2CO3 (M=Na, K) and their capabilities for CO2 capture

    SciTech Connect

    Yuhua Duan

    2012-01-01

    Alkali metal zirconates could be used as solid sorbents for CO{sub 2} capture. The structural, electronic, and phonon properties of Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3} are investigated by combining the density functional theory with lattice phonon dynamics. The thermodynamics of CO{sub 2} absorption/desorption reactions of these two zirconates are analyzed. The calculated results show that their optimized structures are in a good agreement with experimental measurements. The calculated band gaps are 4.339 eV (indirect), 3.641 eV (direct), 3.935 eV (indirect), and 3.697 eV (direct) for Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3}, respectively.The calculated phonon dispersions and phonon density of states for M{sub 2}ZrO{sub 3} and M{sub 2}CO{sub 3} (M = K, Na, Li) revealed that from K to Na to Li, their frequency peaks are shifted to high frequencies due to the molecular weight decreased from K to Li. From the calculated reaction heats and relationships of free energy change versus temperatures and CO{sub 2} pressures of the M{sub 2}ZrO{sub 3} (M = K, Na, Li) reacting with CO{sub 2}, we found that the performance of Na{sub 2}ZrO{sub 3} capturing CO{sub 2} is similar to that of Li{sub 2}ZrO{sub 3} and is better than that of K{sub 2}ZrO{sub 3}. Therefore, Na{sub 2}ZrO{sub 3} and Li{sub 2}ZrO{sub 3} are good candidates of high temperature CO{sub 2} sorbents and could be used for post combustion CO{sub 2} capture technologies.

  8. Randomly oriented carbon/carbon composite

    NASA Astrophysics Data System (ADS)

    Raunija, Thakur Sudesh Kumar; Babu, S.

    2013-06-01

    The main objective of this study is to develop an alternate, rapid and cost effective process for the fabrication of carbon/carbon (C/C) composite. Slurry moulding technique is adopted for the fabrication of C/C composite. Randomly oriented hybrid discrete carbon fiber (CF) reinforced and mesophase pitch (MP) derived matrix C/C composite is fabricated. Process parameters are optimized and repeatability is proved. The electrical conductivity of the composite fabricated through the developed process is found to be better than that fabricated through conventional processes. The other properties are also found to be competent. The randomly oriented C/C composite because of its mouldability is found suitable for various applications which require complex shapes.

  9. Microbially mediated mineral carbonation

    NASA Astrophysics Data System (ADS)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  10. Method for Making a Carbon-Carbon Cylinder Block

    NASA Technical Reports Server (NTRS)

    Ransone, Phillip O. (Inventor)

    1997-01-01

    A method for making a lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials. such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

  11. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    Norby, Richard J; Jastrow, Julie D; Miller, Michael R; Matamala, Roser; Boutton, Thomas W; Rice, Charles W; Owensby, Clenton E

    2005-01-01

    In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine year period. They also measured comparable increases in soil carbon for Tennessee deciduous forest and Kansas grassland after five to eight years of experimental exposure to elevated CO2.

  12. Neutron and magnetic studies of L a0.7S r0.3M n1 -xC rxO3 (x ≤0.7 ) : A homogeneous charge-ordered system

    NASA Astrophysics Data System (ADS)

    Creel, Thomas F.; Yang, Jinbo; Malik, Satish K.; Quezado, S.; Pringle, O. A.; Yelon, William B.; James, William J.

    2016-02-01

    Structural and magnetic properties of L a0.7S r0.3M n1 -xC rxO3(0

  13. Bi3+/M2+ oxyphosphate: a continuous series of polycationic species from the 1D single chain to the 2D planes. Part 1: From HREM images to crystal-structure deduction.

    PubMed

    Huvé, M; Colmont, M; Mentré, O

    2006-08-21

    This work deals with the crystal-structure deduction of new structural types of Bi3+-M2+ oxyphosphates (M is a transition element) from HREM images. Previous studies showed the unequivocal attribution of particular HREM contrasts to the corresponding Bi/M/O-based polycationic species in similar materials. On this basis, the examination of isolated crystallites of polyphased samples led to new HREM contrasts assigned to new polycationic species in three new structural types. This helped us to solve one crystal structure, and the two other forms have been deduced through HREM image decoding. It helped to model the investigated materials from the structural point of view as well as the chemical one. The three assumed crystal structures are formed by polycationic ribbons, n tetrahedra wide, surrounded by PO4 groups, as already encountered in these series of oxyphosphates. However, here we deal with the original n= 4-6 cases, whereas, up to this work, only the n= 1-3 ribbons have been reported. The greater size of ribbons is associated with particular structural modifications responsible for complex HREM contrasts. The validity of the proposed models is verified in Part 2 of this work. PMID:16903714

  14. Y-chromosome Short Tandem Repeat DYS458.2 Non-consensus Alleles Occur Independently in Both Binary Haplogroups J1-M267 and R1b3-M405

    PubMed Central

    Myres, Natalie M.; Ekins, Jayne E.; Lin, Alice A.; Cavalli-Sforza, L. Luca; Woodward, Scott R.; Underhill, Peter A.

    2007-01-01

    Aim To determine the human Y-chromosome haplogroup backgrounds of non-consensus DYS458.2 short tandem repeat alleles and evaluate their phylogenetic substructure and frequency in representative samples from the Middle East, Europe, and Pakistan. Methods Molecular characterization of lineages was achieved using a combination of Y-chromosome haplogroup defining binary polymorphisms and up to 37 short tandem repeat loci, including DYS388 to construct haplotypes. DNA sequencing of the DYS458 locus and median-joining network analyses were used to evaluate Y-chromosome lineages displaying the DYS458.2 motif. Results We showed that the DYS458.2 allelic innovation arose independently on at least two distinctive binary haplogroup backgrounds and possibly a third as well. The partial allele length pattern was fixed in all haplogroup J1 chromosomes examined, including its known rare sub-haplogroups. Within the alternative R1b3 associated M405 defined sub-haplogroup, both DYS458.0 and DYS458.2 allele classes occurred. A single chromosome also allocated to the R1b3-M269*(xM405) classification. The physical position of the partial insertion/deletion occurrence within the normal tetramer tract differed distinctly in each haplogroup context. Conclusions While unusual DYS458.2 alleles are informative, additional information for other linked polymorphic loci is required when using such non-conforming alleles to infer haplogroup background and common ancestry. PMID:17696299

  15. Optical and fluorescence spectroscopy of Eu2O3-doped P2O5-K2O-KF-MO-Al2O3 (M = Mg, Sr and Ba) glasses

    NASA Astrophysics Data System (ADS)

    Kumar, K. Upendra; Babu, S. Surendra; Rao, Ch. Srinivasa; Jayasankar, C. K.

    2011-06-01

    Fluorophosphate glasses of composition, P2O5 + K2O + KF + MO + Al2O3 + xEu2O3 (M = Mg, Sr and Ba; x = 0.01, 0.05, 0.1, 1.0, 2.0, 4.0 and 6.0 mol%) were prepared and characterized their optical properties. Crystal-field (CF) analysis revealed a relatively weak CF strength around Eu3+ ions in the Ba based fluorophosphate glasses. The Judd-Ofelt parameters have been estimated from the oscillator strengths of 7F0 → 5D2, 7F0 → 5D4 and 7F0 → 5L6 absorption transitions of Eu3+ ions and were used to evaluate the radiative properties of the 5D0 → 7FJ (J = 0-4) transitions. Considerable variation has been observed in the relative intensity ratio of 5D0 → 7F2 to 5D0 → 7F1 transitions of Eu3+ ions due to change in the alkaline earth metal ions. The decay of the 5D0 level shows single exponential and less sensitive to Eu3+ ions concentration as well as MgO/SrO/BaO modifiers.

  16. Metal-insulator transition and emergence of spontaneous polarization in (La1-xSrxMnO3)m /(LaNiO3)n superlattices constructed from metallic building blocks

    NASA Astrophysics Data System (ADS)

    Ghosh, Saurabh; Mishra, Rohan; Hoffman, Jason; Bhattacharya, Anand; Borisevich, Albina Y.; Pantelides, Sokrates T.

    La0.7Sr0.3MnO3 and LaNiO3 are metallic oxides. However, short-period superlattices of the form (La0.7Sr0.3MnO3)m /(LaNiO3)n show insulating behavior depending on m and n. In particular, the insulating property is robust when m = n = 2 (SL 2/2). Here, using first-principles density functional theory (DFT) and DFT+U (static d - d Coulomb interaction), we explain the experimental observation and discuss a general mechanism that underlies such metal-insulator transition for different m and n. The general mechanism is based on the finding that disproportionation on Ni sites is the key. Further, we predict that insulating SL 2/2 is ferroelectric with large spontaneous polarization. The ferroelectric distortion persists in the cases where the superlattices are metallic, which leads to the possibility of designing a new family of 'polar metals'. Finally, we discuss the origin of such polar distortion and its coupling with the magnetic properties (by considering spin-phonon coupling) of the material. This work is supported by DOE Grant Number DE-FG02-09ER46554 and DOE BES DMSE.

  17. Hydrogenolysis of cellulose to C4-C7 alcohols over bi-functional CuO-MO/Al2O3 (M=Ce, Mg, Mn, Ni, Zn) catalysts coupled with methanol reforming reaction.

    PubMed

    Wu, Yanhua; Gu, Fangna; Xu, Guangwen; Zhong, Ziyi; Su, Fabing

    2013-06-01

    This work demonstrates the efficient hydrogenolysis of cellulose to C4-C7 alcohols and gas products (reaction 1) by coupling it with the reforming reaction of methanol (reaction 2) over bi-functional CuO-based catalysts. In this process, the CuO-based catalysts catalyze both the reactions 1 and 2, and the in situ regenerated H2 in the reaction 2 is used for the reaction 1. A series of CuO-MO/Al2O3 (M=Ce, Mg, Mn, Ni, Zn) catalysts were prepared by the co-precipitation method. Among these catalysts, CuO-ZnO/Al2O3 exhibited the highest activity to generate a high cellulose conversion of 88% and a high C4-C7 alcohols content above 95% in the liquid products. The CuO-ZnO/Al2O3 catalyst was stable under the reaction conditions and reusable after 4 runs. This work provides a cost-effective route to convert abundant renewable cellulose to liquid fuels. PMID:23591118

  18. Effects of Alloyed Metal on the Catalysis Activity of Pt for Ethanol Partial Oxidation: Adsorption and Dehydrogenation on Pt3M (M=Pt, Ru, Sn, Re, Rh, and Pd)

    PubMed Central

    Xu, Zhen-Feng; Wang, Yixuan

    2011-01-01

    The adsorption and dehydrogenation reactions of ethanol over bimetallic clusters, Pt3M (M = Pt, Ru, Sn, Re, Rh, and Pd), have been extensively investigated with density functional theory. Both the α-hydrogen and hydroxyl adsorptions on Pt as well as on the alloyed transition metal M sites of PtM were considered as initial reaction steps. The adsorptions of ethanol on Pt and M sites of some PtM via the α-hydrogen were well established. Although the α-hydrogen adsorption on Pt site is weaker than the hydroxyl, the potential energy profiles show that the dehydrogenation via the α-hydrogen path has much lower energy barrier than that via the hydroxyl path. Generally for the α-hydrogen path the adsorption is a rate-determining-step because of rather low dehydrogenation barrier for the α-hydrogen adsorption complex (thermodynamic control), while the hydroxyl path is determined by its dehydrogenation step (kinetic control). The effects of alloyed metal on the catalysis activity of Pt for ethanol partial oxidation, including adsorption energy, energy barrier, electronic structure, and eventually rate constant were discussed. Among all of the alloyed metals only Sn enhances the rate constant of the dehydrogenation via the α-hydrogen path on the Pt site of Pt3Sn as compared with Pt alone, which interprets why the PtSn is the most active to the oxidation of ethanol. PMID:22102920

  19. Effects of Alloyed Metal on the Catalysis Activity of Pt for Ethanol Partial Oxidation: Adsorption and Dehydrogenation on Pt(3)M (M=Pt, Ru, Sn, Re, Rh, and Pd).

    PubMed

    Xu, Zhen-Feng; Wang, Yixuan

    2011-10-27

    The adsorption and dehydrogenation reactions of ethanol over bimetallic clusters, Pt(3)M (M = Pt, Ru, Sn, Re, Rh, and Pd), have been extensively investigated with density functional theory. Both the α-hydrogen and hydroxyl adsorptions on Pt as well as on the alloyed transition metal M sites of PtM were considered as initial reaction steps. The adsorptions of ethanol on Pt and M sites of some PtM via the α-hydrogen were well established. Although the α-hydrogen adsorption on Pt site is weaker than the hydroxyl, the potential energy profiles show that the dehydrogenation via the α-hydrogen path has much lower energy barrier than that via the hydroxyl path. Generally for the α-hydrogen path the adsorption is a rate-determining-step because of rather low dehydrogenation barrier for the α-hydrogen adsorption complex (thermodynamic control), while the hydroxyl path is determined by its dehydrogenation step (kinetic control). The effects of alloyed metal on the catalysis activity of Pt for ethanol partial oxidation, including adsorption energy, energy barrier, electronic structure, and eventually rate constant were discussed. Among all of the alloyed metals only Sn enhances the rate constant of the dehydrogenation via the α-hydrogen path on the Pt site of Pt(3)Sn as compared with Pt alone, which interprets why the PtSn is the most active to the oxidation of ethanol. PMID:22102920

  20. Theoretical exploration to second-order nonlinear optical properties of new hybrid complexes via coordination interaction between (metallo)porphyrin and [MSiW11O39](3-) (M=Nb(V) or V(V)) polyoxometalates.

    PubMed

    Zhang, Ting; Ma, Nana; Yan, Likai; Wen, Shizheng; Ma, Tengying; Su, Zhongmin

    2013-11-01

    The second-order nonlinear optical (NLO) properties of hybrid complexes via coordination interaction between porphyrin and Keggin-type polyoxometalates (POMs) α-[MSiW11O39](3-) (M=Nb(V) or V(V)) are investigated by time-dependent density functional theory (TDDFT). The calculated results show that this kind of organic-inorganic hybrid complexes possesses remarkably large molecular second-order NLO polarizability, especially for the ZnP3P-C≡C-4-Py-[VSiW11O39](3-) (complex 4), which has a computed β0 value of 261,410 a.u. and might be an excellent second-order NLO material. The effects of substituted metal atom (M), metalloporphyrin, and π-conjugation on NLO response are analyzed, the substituted metal atom (M) with a large electronegativity, the metalloporphyrin, and the lengthening of π-conjugation are helpful in enhancing the optical nonlinearity of these systems, which reveal the general rules to design the complexes with large optical nonlinearities. Furthermore, the solvent effect largely affects the first-order hyperpolarizability of the complex, it implies that the second-order polarizabilities increased with the increase of the solvent in polarity. PMID:24149319

  1. The carbonate profile and water regime of migrational-mycelial chernozems in different ecosystems of Kursk oblast

    NASA Astrophysics Data System (ADS)

    Ovechkin, S. V.; Bazykina, G. S.

    2011-12-01

    The carbonate profiles of migrational-mycelial (typical) chernozems under regularly mown and absolutely reserved steppes in the V.V. Alekhin Central Chernozemic State Biospheric Reserve and under cropland with cereals (Kursk oblast) were studied in 2007-2009. A comparison of the results of these studies with previous results obtained in the mid-1970s attests to certain changes in the carbonate profiles of the soils. They are conditioned by the activation of the migration of carbonates and the more pronounced manifestation of differently directed processes of the leaching and accumulation of carbonates. The reasons for the observed transformation of the carbonate profiles are related to the increased moistening of the upper 3-m-deep chernozemic layer in different ecosystems because of a general rise in the humidity of the local climate in the recent decades (1973-2006).

  2. Mangroves among the most carbon-rich forests in the tropics

    NASA Astrophysics Data System (ADS)

    Donato, Daniel C.; Kauffman, J. Boone; Murdiyarso, Daniel; Kurnianto, Sofyan; Stidham, Melanie; Kanninen, Markku

    2011-05-01

    Mangrove forests occur along ocean coastlines throughout the tropics, and support numerous ecosystem services, including fisheries production and nutrient cycling. However, the areal extent of mangrove forests has declined by 30-50% over the past half century as a result of coastal development, aquaculture expansion and over-harvesting. Carbon emissions resulting from mangrove loss are uncertain, owing in part to a lack of broad-scale data on the amount of carbon stored in these ecosystems, particularly below ground. Here, we quantified whole-ecosystem carbon storage by measuring tree and dead wood biomass, soil carbon content, and soil depth in 25 mangrove forests across a broad area of the Indo-Pacific region--spanning 30° of latitude and 73° of longitude--where mangrove area and diversity are greatest. These data indicate that mangroves are among the most carbon-rich forests in the tropics, containing on average 1,023Mg carbon per hectare. Organic-rich soils ranged from 0.5m to more than 3m in depth and accounted for 49-98% of carbon storage in these systems. Combining our data with other published information, we estimate that mangrove deforestation generates emissions of 0.02-0.12Pg carbon per year--as much as around 10% of emissions from deforestation globally, despite accounting for just 0.7% of tropical forest area.

  3. Inorganic Carbon Limitation and Chemical Composition of Two Freshwater Green Microalgae †

    PubMed Central

    Goldman, Joel C.; Graham, Stephen J.

    1981-01-01

    Two freshwater chlorophytes, Chlorella vulgaris and Scenedesmus obliquus, were grown in inorganic carbon-limited continuous cultures in which HCO3− was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO2 levels present in atmospheric air and at HCO3− concentrations of 3 mM. No growth was observed at 100% CO2. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells. PMID:16345701

  4. Inorganic carbon limitation and chemical composition of two freshwater green microalgae

    SciTech Connect

    Goldman, J.C.; Graham, S.J.

    1981-01-01

    Two freshwater Chlorophytes, Chlorella vulgaris and Scenedesmus obliquus, were grown in inorganic carbon-limited continuous cultures in which HCO/sub 3//sup -/ was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO/sub 2/ levels present in atmospheric air and at HCO/sub 3//sup -/ concentrations of 3 mM. No growth was observed at 100% CO/sub 2/. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells.

  5. Seeing the Carbon Cycle

    ERIC Educational Resources Information Center

    Drouin, Pamela; Welty, David J.; Repeta, Daniel; Engle-Belknap, Cheryl A.; Cramer, Catherine; Frashure, Kim; Chen, Robert

    2006-01-01

    In this article, the authors present a classroom experiment that was developed to introduce middle school learners to the carbon cycle. The experiment deals with transfer of CO[subscript 2] between liquid reservoirs and the effect CO[subscript 2] has on algae growth. It allows students to observe the influence of the carbon cycle on algae growth,…

  6. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, Stephen E.; Moses, William W.

    1991-01-01

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

  7. Carbon Isotope Ratiometer

    SciTech Connect

    Dr. Anthony O'Keefe

    2001-05-07

    This Report details the design of a optical analyzer capable of measuring and recording the carbon 13/12 isotope ratio in atmospheric carbon dioxide. The system can operate in remote modes for long duration and will transmit real-time data via wireless contact.

  8. Carbon Energy Flows Belowground

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants use photosynthesis to convert carbon dioxide in the atmosphere and energy from sunlight into energy-containing, carbon-based foodstuffs (i.e. carbohydrates such as sugars and starches) that provide the building blocks for all life on Earth. Without photosynthesis, sunlight would not be a goo...

  9. Sustainable carbon materials.

    PubMed

    Titirici, Maria-Magdalena; White, Robin J; Brun, Nicolas; Budarin, Vitaliy L; Su, Dang Sheng; del Monte, Francisco; Clark, James H; MacLachlan, Mark J

    2015-01-01

    Carbon-based structures are the most versatile materials used in the modern field of renewable energy (i.e., in both generation and storage) and environmental science (e.g., purification/remediation). However, there is a need and indeed a desire to develop increasingly more sustainable variants of classical carbon materials (e.g., activated carbons, carbon nanotubes, carbon aerogels, etc.), particularly when the whole life cycle is considered (i.e., from precursor "cradle" to "green" manufacturing and the product end-of-life "grave"). In this regard, and perhaps mimicking in some respects the natural carbon cycles/production, utilization of natural, abundant and more renewable precursors, coupled with simpler, lower energy synthetic processes which can contribute in part to the reduction in greenhouse gas emissions or the use of toxic elements, can be considered as crucial parameters in the development of sustainable materials manufacturing. Therefore, the synthesis and application of sustainable carbon materials are receiving increasing levels of interest, particularly as application benefits in the context of future energy/chemical industry are becoming recognized. This review will introduce to the reader the most recent and important progress regarding the production of sustainable carbon materials, whilst also highlighting their application in important environmental and energy related fields. PMID:25301517

  10. Modeling Carbon Exchange

    NASA Technical Reports Server (NTRS)

    Sellers, Piers

    2012-01-01

    Model results will be reviewed to assess different methods for bounding the terrestrial role in the global carbon cycle. It is proposed that a series of climate model runs could be scoped that would tighten the limits on the "missing sink" of terrestrial carbon and could also direct future satellite image analyses to search for its geographical location and understand its seasonal dynamics.

  11. The carbon cycle revisited

    NASA Technical Reports Server (NTRS)

    Bolin, Bert; Fung, Inez

    1992-01-01

    Discussions during the Global Change Institute indicated a need to present, in some detail and as accurately as possible, our present knowledge about the carbon cycle, the uncertainties in this knowledge, and the reasons for these uncertainties. We discuss basic issues of internal consistency within the carbon cycle, and end by summarizing the key unknowns.

  12. Carbon Dioxide and Climate.

    ERIC Educational Resources Information Center

    Brewer, Peter G.

    1978-01-01

    The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

  13. Carbon dioxide recycling

    EPA Science Inventory

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the “Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  14. 1992 Carbon emissions data

    SciTech Connect

    1995-12-31

    This article reports on the global total of carbon dioxide emissions from fossil-fuel burning and cement manufacture in 1992. The total estimate of 6097 million metric tons of carbon is essentially the same for 1990 and down slightly from 1991, but 7 of 9 geographical regions had increases.

  15. Fly ash carbon passivation

    DOEpatents

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  16. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  17. Activity and stability of immobilized carbonic anhydrase for promoting CO2 absorption into a carbonate solution for post-combustion CO2 capture

    USGS Publications Warehouse

    Zhang, S.; Zhang, Z.; Lu, Y.; Rostam-Abadi, M.; Jones, A.

    2011-01-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto three selected support materials having different pore structures. The thermal stability of the immobilized CA enzymes was significantly greater than their free counterparts. For example, the immobilized enzymes retained at least 60% of their initial activities after 90days at 50??C compared to about 30% for their free counterparts under the same conditions. The immobilized CA also had significantly improved resistance to concentrations of sulfate (0.4M), nitrate (0.05M) and chloride (0.3M) typically found in flue gas scrubbing liquids than their free counterparts. ?? 2011 Elsevier Ltd.

  18. Impacts of Land Cover Change on the Carbon Dynamics in Indonesian Tropical Forested Wetlands- Mangroves and Peat Swamp Forests

    NASA Astrophysics Data System (ADS)

    Kauffman, J. B.; Arifanti, V. B.; Basuki, I.; Kurnianto, S.; Novita, N.; Murdiyarso, D.

    2014-12-01

    Tropical wetland forests including mangroves and lowland peat swamp forests contain among the highest carbon stocks of any ecosystem on the planet. This is largely due to the accumulation of deep organic rich soils which have been sequestering carbon for millennia. Depth of organic layers (peats) can exceed 3 m in mangrove and 10 m in the peat swamp forests. The ecosystem carbon stocks may exceed 2000 Mg/ha in mangroves and 5000 Mg/ha in peat swamp forests. Ironically, rates of deforestation of these tropical forests are among the highest in the tropics. With land cover change comes dramatic shifts in carbon stocks, net ecosystem productivity, and greenhouse gas emissions. Land cover change results in carbon losses of practically all aboveground pools as well as losses arising from soil pools. Based upon studies where we have compared stock changes due to land use the carbon emissions arising from land cover change to shrimp ponds and oil palm have ranged from 800-3000 Mg CO2e/ha. The lowered carbon sequestration rates coupled with increased or similar emissions from decomposition results in an ecosystem shift from a carbon sink to a carbon source. Clearly the large carbon stocks, high rates of deforestation, and large emissions resulting from their degradation suggest that these ecosystems should receive great consideration in climate change mitigation and adaptation strategies.

  19. The Contemporary Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Houghton, R. A.

    2003-12-01

    The global carbon cycle refers to the exchanges of carbon within and between four major reservoirs: the atmosphere, the oceans, land, and fossil fuels. Carbon may be transferred from one reservoir to another in seconds (e.g., the fixation of atmospheric CO2 into sugar through photosynthesis) or over millennia (e.g., the accumulation of fossil carbon (coal, oil, gas) through deposition and diagenesis of organic matter). This chapter emphasizes the exchanges that are important over years to decades and includes those occurring over the scale of months to a few centuries. The focus will be on the years 1980-2000 but our considerations will broadly include the years ˜1850-2100. Chapter 8.09, deals with longer-term processes that involve rates of carbon exchange that are small on an annual timescale (weathering, vulcanism, sedimentation, and diagenesis).The carbon cycle is important for at least three reasons. First, carbon forms the structure of all life on the planet, making up ˜50% of the dry weight of living things. Second, the cycling of carbon approximates the flows of energy around the Earth, the metabolism of natural, human, and industrial systems. Plants transform radiant energy into chemical energy in the form of sugars, starches, and other forms of organic matter; this energy, whether in living organisms or dead organic matter, supports food chains in natural ecosystems as well as human ecosystems, not the least of which are industrial societies habituated (addicted?) to fossil forms of energy for heating, transportation, and generation of electricity. The increased use of fossil fuels has led to a third reason for interest in the carbon cycle. Carbon, in the form of carbon dioxide (CO2) and methane (CH4), forms two of the most important greenhouse gases. These gases contribute to a natural greenhouse effect that has kept the planet warm enough to evolve and support life (without the greenhouse effect the Earth's average temperature would be -33

  20. Composition-driven phase boundary and electrical properties in (Ba0.94Ca0.06)(Ti1-xMx)O3 (M = Sn, Hf, Zr) lead-free ceramics.

    PubMed

    Zhao, Chunlin; Wang, Hui; Xiong, Jie; Wu, Jiagang

    2016-04-12

    In this study, we systematically investigated the composition dependence of the phase structure, microstructure, and electrical properties of (Ba0.94Ca0.06)(Ti1-xMx)O3 (M = Sn, Hf, Zr) ceramics synthesised by the conventional solid-state reaction method. The phase boundary type strongly depends on the composition, and then different electrical properties were exhibited. The addition of Hf and Zr can more quickly shift phase transition temperatures (TR-O and TO-T) to a higher temperature with respect to Sn, leading to the formation of different phase boundaries. In addition, different phase boundaries can also be affected by their doped contents. The R-O and O-T phase boundaries can be shown in the Sn-doped ceramics with x = 0.10, and the R-O phase boundary can exist in the Hf (x = 0.07) or Zr (x = 0.075)-doped ceramics. A high piezoelectric property of d33 = 600 pC N(-1) can be achieved in the Sn-doped ceramics due to the involvement of converging R-O/O-T phase boundaries, an enhanced ferroelectric performance with Pr = 14.54 μC cm(-2) and Ec = 1.82 kV cm(-1) can be attained in the Zr-doped ceramics, and Hf would benefit from obtaining a large strain behaviour (∼0.20%). We believe that the electrical properties and the related physical mechanisms of BaTiO3-based ceramics can be well unveiled by studying their chemical modification behavior. PMID:26952807

  1. Constraints on the Distance Moduli, Helium and Metal Abundances, and Ages of Globular Clusters from their RR Lyrae and Non-variable Horizontal-branch Stars. I. M3, M15, and M92

    NASA Astrophysics Data System (ADS)

    VandenBerg, Don A.; Denissenkov, P. A.; Catelan, Márcio

    2016-08-01

    Up-to-date isochrones, zero-age horizontal-branch (ZAHB) loci, and evolutionary tracks for core He-burning stars are applied to the color–magnitude diagrams of M3, M15, and M92, focusing in particular on their RR Lyrae populations. Periods for the ab- and c-type variables are calculated using the latest theoretical calibrations of {log} {P}{ab} and {log} {P}c as a function of luminosity, mass, effective temperature ({T}{{eff}}), and metallicity. Our models are generally able to reproduce the measured periods to well within the uncertainties implied by the stellar properties on which pulsation periods depend, as well as the mean periods and cluster-to-cluster differences in < {P}{ab}> and < {P}c> , on the assumption of well-supported values of E(B-V), {(m-M)}V, and [Fe/H]. While many of RR Lyrae in M3 lie close to the same ZAHB that fits the faintest horizontal-branch (HB) stars at bluer or redder colors, the M92 variables are all significantly evolved stars from ZAHB locations on the blue side of the instability strip. M15 appears to contain a similar population of HB stars as M92, along with additional helium-enhanced populations not present in the latter which comprise most of its RR Lyrae stars. The large number of variables in M15 and the similarity of the observed values of < {P}{ab}> and < {P}c> in M15 and M92 can be explained by HB models that allow for variations in Y. Similar ages (∼12.5 Gyr) are found for all three clusters, making them significantly younger than the field halo subgiant HD 140283. Our analysis suggests a preference for stellar models that take diffusive processes into account.

  2. Constraints on the Distance Moduli, Helium and Metal Abundances, and Ages of Globular Clusters from their RR Lyrae and Non-variable Horizontal-branch Stars. I. M3, M15, and M92

    NASA Astrophysics Data System (ADS)

    VandenBerg, Don A.; Denissenkov, P. A.; Catelan, Márcio

    2016-08-01

    Up-to-date isochrones, zero-age horizontal-branch (ZAHB) loci, and evolutionary tracks for core He-burning stars are applied to the color–magnitude diagrams of M3, M15, and M92, focusing in particular on their RR Lyrae populations. Periods for the ab- and c-type variables are calculated using the latest theoretical calibrations of {log} {P}{ab} and {log} {P}c as a function of luminosity, mass, effective temperature ({T}{{eff}}), and metallicity. Our models are generally able to reproduce the measured periods to well within the uncertainties implied by the stellar properties on which pulsation periods depend, as well as the mean periods and cluster-to-cluster differences in < {P}{ab}> and < {P}c> , on the assumption of well-supported values of E(B-V), {(m-M)}V, and [Fe/H]. While many of RR Lyrae in M3 lie close to the same ZAHB that fits the faintest horizontal-branch (HB) stars at bluer or redder colors, the M92 variables are all significantly evolved stars from ZAHB locations on the blue side of the instability strip. M15 appears to contain a similar population of HB stars as M92, along with additional helium-enhanced populations not present in the latter which comprise most of its RR Lyrae stars. The large number of variables in M15 and the similarity of the observed values of < {P}{ab}> and < {P}c> in M15 and M92 can be explained by HB models that allow for variations in Y. Similar ages (˜12.5 Gyr) are found for all three clusters, making them significantly younger than the field halo subgiant HD 140283. Our analysis suggests a preference for stellar models that take diffusive processes into account.

  3. Conducting carbonized polyaniline nanotubes

    NASA Astrophysics Data System (ADS)

    Mentus, Slavko; Ćirić-Marjanović, Gordana; Trchová, Miroslava; Stejskal, Jaroslav

    2009-06-01

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 °C min-1 up to a maximum temperature of 800 °C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 µm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 µm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm-1, increased to 0.7 S cm-1 upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  4. Carbon dioxide adsorbent study

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B. S.

    1973-01-01

    A study was initiated on the feasibility of using the alkali metal carbonate - bi-carbonate solid-gas reaction to remove carbon dioxide from the atmosphere of an EVA life support system. The program successfully demonstrates that carbon dioxide concentrations could be maintained below 0.1 mole per cent using this chemistry. Further a practical method for distributing the carbonates in a coherent sheet form capable of repeated regeneration (50 cycles) at modest temperatures (423 K), without loss in activity was also demonstrated. Sufficiently high reaction rates were shown to be possible with the carbonate - bi-carbonate system such that EVA hardware could be readily designed. Experimental and design data were presented on the basis of which two practical units were designed. In addition to conventional thermally regenerative systems very compact units using ambient temperature cyclic vacuum regeneration may also be feasible. For a one man - 8 hour EVA unit regenerated thermally at the base ship a system volume of 14 liters is estimated.

  5. Conducting carbonized polyaniline nanotubes.

    PubMed

    Mentus, Slavko; Cirić-Marjanović, Gordana; Trchová, Miroslava; Stejskal, Jaroslav

    2009-06-17

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 degrees C min(-1) up to a maximum temperature of 800 degrees C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 microm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 microm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm(-1), increased to 0.7 S cm(-1) upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy. PMID:19471087

  6. Small diameter carbon nanopipettes

    NASA Astrophysics Data System (ADS)

    Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

    2010-01-01

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 °C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 °C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  7. Flow injection catalase activity measurement based on gold nanoparticles/carbon nanotubes modified glassy carbon electrode.

    PubMed

    El Nashar, Rasha Mohamed

    2012-07-15

    Amperometric flow injection method of hydrogen peroxide analysis was developed based on catalase enzyme (CAT) immobilization on a glassy carbon electrode (GC) modified with electrochemically deposited gold nanoparticles on a multiwalled carbon nanotubes/chitosan film. The resulting biosensor was applied to detect hydrogen peroxide with a linear response range 1.0×10(-7)-2.5×10(-3)M with a correlation coefficient 0.998 and response time less than 10s. The optimum conditions of film deposition such as potential applied, deposition time and pH were tested and the flow injection conditions were optimized to be: flow rate of 3ml/min, sample volume 75μl and saline phosphate buffer of pH 6.89. Catalase enzyme activity was successfully determined in liver homogenate samples of rats, raised under controlled dietary plan, using a flow injection analysis system involving the developed biosensor simultaneously with spectrophotometric detection, which is the common method of enzymatic assay. PMID:22817944

  8. Carbon-fiber technology

    NASA Technical Reports Server (NTRS)

    Hansen, C. F.; Parker, J. A.

    1980-01-01

    The state of the art of PAN based carbon fiber manufacture and the science of fiber behavior is surveyed. A review is given of the stabilization by oxidation and the subsequent carbonization of fibers, of the apparent structure of fibers deduced from scanning electron microscopy, from X-ray scattering, and from similarities with soft carbons, and of the known relations between fiber properties and heat treatment temperature. A simplified model is invoked to explain the electrical properties of fibers and recent quantum chemical calculations on atomic clusters are used to elucidate some aspects of fiber conductivity. Some effects of intercalation and oxidative modification of finished fibers are summarized.

  9. Improving Carbon Fixation Pathways

    PubMed Central

    Ducat, Daniel C.

    2012-01-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that alternative pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. PMID:22647231

  10. Carbon isotope techniques

    SciTech Connect

    Coleman, D.C. ); Fry, B. )

    1991-01-01

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The {sup 11}C, {sup 12}C, {sup 13}C, and {sup 14}C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations.

  11. IMPACCT: Carbon Capture Technology

    SciTech Connect

    2012-01-01

    IMPACCT Project: IMPACCT’s 15 projects seek to develop technologies for existing coal-fired power plants that will lower the cost of carbon capture. Short for “Innovative Materials and Processes for Advanced Carbon Capture Technologies,” the IMPACCT Project is geared toward minimizing the cost of removing carbon dioxide (CO2) from coal-fired power plant exhaust by developing materials and processes that have never before been considered for this application. Retrofitting coal-fired power plants to capture the CO2 they produce would enable greenhouse gas reductions without forcing these plants to close, shifting away from the inexpensive and abundant U.S. coal supply.

  12. Improving carbon fixation pathways

    SciTech Connect

    Ducat, DC; Silver, PA

    2012-08-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that novel pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials.

  13. Carbon monoxide poisoning

    PubMed Central

    Dolan, Michael C.

    1985-01-01

    Carbon monoxide poisoning is a significant cause of illness and death. Its protean symptoms probably lead to a gross underestimation of its true incidence. Low levels of carbon monoxide aggravate chronic cardiopulmonary problems, and high levels are associated with cardiac arrhythmias and cerebral edema. Patients who survive acute poisoning are at risk of delayed neurologic sequelae. The measurement of carboxyhemoglobin levels does not reveal the tissue levels of carbon monoxide but is useful in determining therapy. Treatment includes the monitoring and management of cardiac arrhythmias and oxygenation. Hyperbaric oxygenation is beneficial, but there are currently no definite criteria for its use. PMID:4027805

  14. Resistivity of Carbon-Carbon Composites Halved

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2004-01-01

    Carbon-carbon composites have become the material of choice for applications requiring strength and stiffness at very high temperatures (above 2000 C). These composites comprise carbon or graphite fibers embedded in a carbonized or graphitized matrix. In some applications, such as shielding sensitive electronics in very high temperature environments, the performance of these materials would be improved by lowering their electrical resistivity. One method to lower the resistivity of the composites is to lower the resistivity of the graphite fibers, and a proven method to accomplish that is intercalation. Intercalation is the insertion of guest atoms or molecules into a host lattice. In this study the host fibers were highly graphitic pitch-based graphite fibers, or vapor-grown carbon fibers (VGCF), and the intercalate was bromine. Intercalation compounds of graphite are generally thought of as being only metastable, but it has been shown that the residual bromine graphite fiber intercalation compound is remarkably stable, resisting decomposition even at temperatures at least as high as 1000 C. The focus of this work was to fabricate composite preforms, determine whether the fibers they were made from were still intercalated with bromine after processing, and determine the effect on composite resistivity. It was not expected that the resistivity would be lowered as dramatically as with graphite polymer composites because the matrix itself would be much more conductive, but it was hoped that the gains would be substantial enough to warrant its use in high-performance applications. In a collaborative effort supporting a Space Act Agreement between the NASA Glenn Research Center and Applied Sciences, Inc. (Cedarville, OH), laminar preforms were fabricated with pristine and bromine-intercalated pitch-based fibers (P100 and P100-Br) and VGCF (Pyro I and Pyro I-Br). The green preforms were carbonized at 1000 C and then heat treated to 3000 C. To determine whether the

  15. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon---carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  16. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  17. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  18. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  19. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  20. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  1. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  2. Tracking the migration of the Indian continent using the carbonate clumped isotope technique on Phanerozoic soil carbonates

    PubMed Central

    Ghosh, Prosenjit; Vasiliev, Mikhail V.; Ghosh, Parthasarathi; Sarkar, Soumen; Ghosh, Sampa; Yamada, Keita; Ueno, Yuichiro; Yoshida, Naohiro; Poulsen, Christopher J.

    2016-01-01

    Approximately 140 million years ago, the Indian plate separated from Gondwana and migrated by almost 90° latitude to its current location, forming the Himalayan-Tibetan system. Large discrepancies exist in the rate of migration of Indian plate during Phanerozoic. Here we describe a new approach to paleo-latitudinal reconstruction based on simultaneous determination of carbonate formation temperature and δ18O of soil carbonates, constrained by the abundances of 13C-18O bonds in palaeosol carbonates. Assuming that the palaeosol carbonates have a strong relationship with the composition of the meteoric water, δ18O carbonate of palaeosol can constrain paleo-latitudinal position. Weighted mean annual rainfall δ18O water values measured at several stations across the southern latitudes are used to derive a polynomial equation: δ18Ow = −0.006 × (LAT)2 − 0.294 × (LAT) − 5.29 which is used for latitudinal reconstruction. We use this approach to show the northward migration of the Indian plate from 46.8 ± 5.8°S during the Permian (269 M.y.) to 30 ± 11°S during the Triassic (248 M.y.), 14.7 ± 8.7°S during the early Cretaceous (135 M.y.), and 28 ± 8.8°S during the late Cretaceous (68 M.y.). Soil carbonate δ18O provides an alternative method for tracing the latitudinal position of Indian plate in the past and the estimates are consistent with the paleo-magnetic records which document the position of Indian plate prior to 135 ± 3 M.y. PMID:26931069

  3. Tracking the migration of the Indian continent using the carbonate clumped isotope technique on Phanerozoic soil carbonates

    NASA Astrophysics Data System (ADS)

    Ghosh, Prosenjit; Vasiliev, Mikhail V.; Ghosh, Parthasarathi; Sarkar, Soumen; Ghosh, Sampa; Yamada, Keita; Ueno, Yuichiro; Yoshida, Naohiro; Poulsen, Christopher J.

    2016-03-01

    Approximately 140 million years ago, the Indian plate separated from Gondwana and migrated by almost 90° latitude to its current location, forming the Himalayan-Tibetan system. Large discrepancies exist in the rate of migration of Indian plate during Phanerozoic. Here we describe a new approach to paleo-latitudinal reconstruction based on simultaneous determination of carbonate formation temperature and δ18O of soil carbonates, constrained by the abundances of 13C-18O bonds in palaeosol carbonates. Assuming that the palaeosol carbonates have a strong relationship with the composition of the meteoric water, δ18O carbonate of palaeosol can constrain paleo-latitudinal position. Weighted mean annual rainfall δ18O water values measured at several stations across the southern latitudes are used to derive a polynomial equation: δ18Ow = -0.006 × (LAT)2 - 0.294 × (LAT) - 5.29 which is used for latitudinal reconstruction. We use this approach to show the northward migration of the Indian plate from 46.8 ± 5.8°S during the Permian (269 M.y.) to 30 ± 11°S during the Triassic (248 M.y.), 14.7 ± 8.7°S during the early Cretaceous (135 M.y.), and 28 ± 8.8°S during the late Cretaceous (68 M.y.). Soil carbonate δ18O provides an alternative method for tracing the latitudinal position of Indian plate in the past and the estimates are consistent with the paleo-magnetic records which document the position of Indian plate prior to 135 ± 3 M.y.

  4. Tracking the migration of the Indian continent using the carbonate clumped isotope technique on Phanerozoic soil carbonates.

    PubMed

    Ghosh, Prosenjit; Vasiliev, Mikhail V; Ghosh, Parthasarathi; Sarkar, Soumen; Ghosh, Sampa; Yamada, Keita; Ueno, Yuichiro; Yoshida, Naohiro; Poulsen, Christopher J

    2016-01-01

    Approximately 140 million years ago, the Indian plate separated from Gondwana and migrated by almost 90° latitude to its current location, forming the Himalayan-Tibetan system. Large discrepancies exist in the rate of migration of Indian plate during Phanerozoic. Here we describe a new approach to paleo-latitudinal reconstruction based on simultaneous determination of carbonate formation temperature and δ(18)O of soil carbonates, constrained by the abundances of (13)C-(18)O bonds in palaeosol carbonates. Assuming that the palaeosol carbonates have a strong relationship with the composition of the meteoric water, δ(18)O carbonate of palaeosol can constrain paleo-latitudinal position. Weighted mean annual rainfall δ(18)O water values measured at several stations across the southern latitudes are used to derive a polynomial equation: δ(18)Ow = -0.006 × (LAT)(2) - 0.294 × (LAT) - 5.29 which is used for latitudinal reconstruction. We use this approach to show the northward migration of the Indian plate from 46.8 ± 5.8°S during the Permian (269 M.y.) to 30 ± 11°S during the Triassic (248 M.y.), 14.7 ± 8.7°S during the early Cretaceous (135 M.y.), and 28 ± 8.8°S during the late Cretaceous (68 M.y.). Soil carbonate δ(18)O provides an alternative method for tracing the latitudinal position of Indian plate in the past and the estimates are consistent with the paleo-magnetic records which document the position of Indian plate prior to 135 ± 3 M.y. PMID:26931069

  5. A novel carbon fiber based porous carbon monolith

    SciTech Connect

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  6. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates

    NASA Astrophysics Data System (ADS)

    Wolf, Stephan E.; Müller, Lars; Barrea, Raul; Kampf, Christopher J.; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten; Emmerling, Franziska; Tremel, Wolfgang

    2011-03-01

    During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed.During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. Electronic supplementary information (ESI) available: (S1 and S5) TEM at higher magnifications and of crystallizations conducted at pH = 6.0, 9.0 and 11.3; (S2) sketch of a spreading liquid particle on a TEM grid; (S3) wide-angle scattering of BaCO3 and CdCO3; (S4 and S6-S9) ESI-MS spectra of a solution of carbon dioxide and of bicarbonates of Sr, Ba, Pb, Mn and Cd. See DOI: 10.1039/c0nr00761g

  7. Carbon Fibers and Composites

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1979-01-01

    The basic nature of composite materials is considered. Carbon fiber composites and their area of current and planned application in civil aircraft are discussed, specifically within the framework of the various aspects of risk analysis.

  8. Carbon monoxide poisoning

    MedlinePlus

    ... a chemical produced from the incomplete burning of natural gas or other products containing carbon. ... indoor and camp stoves) Water heaters that use natural gas Note: This list may not be all inclusive.

  9. Sodium carbonate poisoning

    MedlinePlus

    Sal soda poisoning; Soda ash poisoning; Disodium salt poisoning; Carbonic acid poisoning; Washing soda poisoning ... have symptoms. In this rare situation, long-term effects, even death, are possible if you do not ...

  10. Carbon monoxide poisoning

    MedlinePlus

    ... any major gas-burning appliances (such as a furnace or water heater). Many carbon monoxide poisonings occur in the winter months when furnaces, gas fireplaces, and portable heaters are being used ...

  11. Carbon Monoxide Information Center

    MedlinePlus Videos and Cool Tools

    ... Center The Invisible Killer Carbon monoxide, also known as CO, is called the "Invisible Killer" because it's ... used or incorrectly-vented fuel-burning appliances such as furnaces, stoves, water heaters and fireplaces. Watch This ...

  12. Transport in Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Datta, S.; Xue, Yong-Qinag; Anantram, M. P.; Saini, Subhash (Technical Monitor)

    1999-01-01

    This presentation discusses coupling between carbon nanotubes (CNT), simple metals (FEG) and a graphene sheet. The graphene sheet did not couple well with FEG, but the combination of a graphene strip and CNT did couple well with most simple metals.

  13. Carbon monoxide intoxication

    SciTech Connect

    Kales, S.N. )

    1993-11-01

    Carbon monoxide poisoning usually results from inhalation of exhaust fumes from motor vehicles, smoke from fires or fumes from faulty heating systems. Carbon monoxide has a high affinity for hemoglobin, with which it forms carboxyhemoglobin. The resulting decrease in both oxygen-carrying capacity and oxygen release can lead to end-organ hypoxia. The clinical presentation is nonspecific. Headache, dizziness, fatigue and nausea are common in mild to moderate carbon monoxide poisoning. In more severe cases, tachycardia, tachypnea and central nervous system depression occur. When carbon monoxide intoxication is suspected, empiric treatment with 100 percent oxygen should be initiated immediately. The diagnosis is confirmed by documenting an elevated carboxyhemoglobin level. Hyperbaric oxygen therapy is recommended in patients with neurologic dysfunction, cardiac dysfunction or a history of unconsciousness. 26 refs.

  14. Carbon Monoxide Poisoning

    MedlinePlus

    ... colorless gas created when fuels (such as gasoline, wood, coal, natural gas, propane, oil, and methane) burn incompletely. ** Carbon Monoxide can have different effects on people based on its concentration in the ...

  15. Estimating carbon monoxide exposure

    NASA Technical Reports Server (NTRS)

    Edgerley, R. H.

    1971-01-01

    Method predicts effects of carbon monoxide on astronauts confined in spacecraft cabin atmospheres. Information on need for low toxicity level also applies to confined spaces. Benefits are applicable to industry and public health.

  16. Carbon nanotubes: Fibrillar pharmacology

    NASA Astrophysics Data System (ADS)

    Kostarelos, Kostas

    2010-10-01

    The mechanisms by which chemically functionalized carbon nanotubes flow in blood and are excreted through the kidneys illustrate the unconventional behaviour of these fibrillar nanostructures, and the opportunities they offer as components for the design of advanced delivery vehicles.

  17. Green Carbon, Black Carbon, White Carbon: Simultaneous Differentiation Between Soil Organic Matter, Pyrogenic Carbon and Carbonates Using Thermal Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Plante, A. F.; Peltre, C.; Chan, J.; Baumgartl, T.; Erskine, P.; Apesteguía, M.; Virto, I.

    2014-12-01

    Quantification of soil carbon stocks and fluxes continues to be an important endeavor in assessments of soil quality, and more broadly in assessments of ecosystem functioning. The quantification of soil carbon in alkaline, carbonate-containing soils, such as those found in Mediterranean areas, is complicated by the need to differentiate between organic carbon (OC) and inorganic carbon (IC), which continues to present methodological challenges. Acidification is frequently used to eliminate carbonates prior to soil OC quantification, but when performed in the liquid phase, can promote the dissolution and loss of a portion of the OC. Acid fumigation (AF) is increasingly preferred for carbonate removal, but its effectiveness is difficult to assess using conventional elemental and isotopic analyses. The two-step approach is time, labor and cost intensive, and generates additional uncertainties from the calculations. Quantification of the actively cycling pool of soil organic C (SOC) in many soils is further complicated by the potential presence of more recalcitrant/stable forms such as pyrogenic or black carbon (BC) derived from incomplete combustion of vegetation, or even geogenic carbon such as coal. The wide spectrum of materials currently considered BC makes its quantification challenging. The chemical method using benzene polycarboxylic acids (BPCAs) as markers of condensed aromatic structures indicative of pyrogenic C is highly time, labor and cost intensive, and can generate artifacts. Several research groups are now developing method for the simultaneous identification and quantification of these various forms of soil carbon using thermal analysis techniques such as thermogravimetry, differential scanning calorimetry and evolved gas analysis. The objective of this presentation is to provide a general overview and specific examples of the current progress and technical challenges in this evolving methodology.

  18. Carbon and oxygen isotope microanalysis of carbonate.

    PubMed

    Velivetskaya, Tatiana A; Ignatiev, Alexander V; Gorbarenko, Sergey A

    2009-08-30

    Technical modification of the conventional method for the delta(13)C and delta(18)O analysis of 10-30 microg carbonate samples is described. The CO(2) extraction is carried out in vacuum using 105% phosphoric acid at 95 degrees C, and the isotopic composition of CO(2) is measured in a helium flow by gas chromatography/isotope ratio mass spectrometry (GC/IRMS). The feed-motion of samples to the reaction vessel provides sequential dropping of only the samples (without the sample holder) into the acid, preventing the contamination of acid and allowing us to use the same acid to carry out very large numbers of analyses. The high accuracy and high reproducibility of the delta(13)C and delta(18)O analyses were demonstrated by measurements of international standards and comparison of results obtained by our method and by the conventional method. Our method allows us to analyze 10 microg of the carbonate with a standard deviation of +/-0.05 per thousand for delta(13)C and delta(18)O. The method has been used successfully for the analyses of the oxygen and carbon isotopic composition of the planktonic and benthic foraminifera in detailed palaeotemperature reconstructions of the Okhotsk Sea. PMID:19603476

  19. Late Quaternary strata and carbon burial records in the Yellow River delta, China

    NASA Astrophysics Data System (ADS)

    Zhao, Guangming; Ye, Siyuan; Li, Guangxue; Ding, Xigui; Yuan, Hongming

    2015-06-01

    Sediment carbon sequestration plays an essential role in mitigating atmospheric CO2 increases and the subsequently global greenhouse effect. To clarify the late Quaternary strata and carbon burial records in Yellow River delta (YRD), detailed analysis of benthic foraminifera, total carbon (TC), organic carbon (Corg), sedimentary characteristics and moisture contents of sediments, was performed on core ZK3, 30.3 m in length and obtained from YRD in 2007. Eight depositional units (designated U1-U8 in ascending order) were identified. A comprehensive analysis method of historical geography and sedimentary geology was used to determine the precise depositional ages of the modern Yellow River delta (MYRD), from which pre-MYRD ages were deduced. The results indicates that the maximum burial rates of TC, inorganic carbon (IC) and Corg occurred in the delta front (U5), and the minimum in the shallow sea (U3). Remarkable high sedimentation rates in the MYRD are responsible for burial efficiency of carbon, with an average rate of Corg burial reaching 2087±251 g (m2 yr)-1, and that of IC reaching 13741±808 g (m2 yr)-1, which are much higher than those of other regions with high contents of Corg. Therefore, YRD has a significant burial efficiency for carbon sequestration.

  20. A membraneless air-breathing hydrogen biofuel cell based on direct wiring of thermostable enzymes on carbon nanotube electrodes.

    PubMed

    Lalaoui, Noémie; de Poulpiquet, Anne; Haddad, Raoudha; Le Goff, Alan; Holzinger, Michael; Gounel, Sébastien; Mermoux, Michel; Infossi, Pascale; Mano, Nicolas; Lojou, Elisabeth; Cosnier, Serge

    2015-05-01

    A biocathode was designed by the modification of a carbon nanotube (CNT) gas-diffusion electrode with bilirubin oxidase from Bacillus pumilus, achieving high current densities up to 3 mA cm(-2) for the reduction of O2 from air. A membraneless air-breathing hydrogen biofuel cell was designed by combination of this cathode with a functionalized CNT-based hydrogenase anode. PMID:25845356

  1. Carbon dioxide removal process

    DOEpatents

    Baker, Richard W.; Da Costa, Andre R.; Lokhandwala, Kaaeid A.

    2003-11-18

    A process and apparatus for separating carbon dioxide from gas, especially natural gas, that also contains C.sub.3+ hydrocarbons. The invention uses two or three membrane separation steps, optionally in conjunction with cooling/condensation under pressure, to yield a lighter, sweeter product natural gas stream, and/or a carbon dioxide stream of reinjection quality and/or a natural gas liquids (NGL) stream.

  2. Plant Carbonic Anhydrases

    PubMed Central

    Atkins, C. A.; Patterson, B. D.; Graham, D.

    1972-01-01

    On the basis of polyacrylamide gradient gel electrophoresis of leaf extracts from 24 species of higher plants, two main forms of carbonic anhydrase (EC 4.2.1.1) were recognized; the “dicotyledon” type and the “monocotyledon” type. More than one band of enzyme was found on gels from most species, suggesting the possibility of carbonic anhydrase isoenzymes in higher plants. Images PMID:16658144

  3. Functionalization of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Webber, Stephen E.

    2003-01-01

    These project will explore the functionalization of carbon nanotubes via the formation of molecular complexes with perylene diimide based systems. It is anticipated that these complexes would be soluble in organic solvent and enable the homogenous dispersion of carbon nanotubes in polymer films. Molecular complexes will be prepared and characterized using standard spectroscopic and thermal analytical techniques. Polymer films will be prepared with these complexes and their properties (electrical and thermal conductivity, mechanical properties, stability) evaluated.

  4. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, S.E.; Moses, W.W.

    1991-05-14

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses. 3 figures.

  5. Luminosity and carbon enhancement in N-type carbon stars

    NASA Technical Reports Server (NTRS)

    Johnson, H. R.

    1978-01-01

    Recent observational data indicate the likelihood of a relation between luminosity and carbon enhancement in N-type irregularly variable carbon stars in the sense that the more luminous carbon stars appear to have smaller enhancements of carbon. No relation appears between carbon enhancement and red colors. The observational data are the luminosities of Peery (1975), the colors and CN band indices of Baumert (1972), the CO indices of Fay and Ridgway (1976), and the C2 indices of Gow (1977).

  6. Carbon Characterization Laboratory Report

    SciTech Connect

    David Swank; William Windes; D.C. Haggard; David Rohrbaugh; Karen Moore

    2009-03-01

    The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Lab-C20 of the Idaho National Laboratory Research Center. This laboratory was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite research and development activities. The CCL is designed to characterize and test carbon-based materials such as graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully prepared to measure material properties for nonirradiated carbon-based materials. Plans to establish the laboratory as a radiological facility within the next year are definitive. This laboratory will be modified to accommodate irradiated materials, after which it can be used to perform material property measurements on both irradiated and nonirradiated carbon-based material. Instruments, fixtures, and methods are in place for preirradiation measurements of bulk density, thermal diffusivity, coefficient of thermal expansion, elastic modulus, Young’s modulus, Shear modulus, Poisson ratio, and electrical resistivity. The measurement protocol consists of functional validation, calibration, and automated data acquisition.

  7. Carbon based prosthetic devices

    SciTech Connect

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T.; Klawitter, J.J.; Ogilvie, W.; Strzepa, P.; Cook, S.D.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  8. Soil carbonates and soil water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of soil carbonates occurring as solidified masses or dispersed particles can alter soil water dynamics from what would be expected based on non-carbonate soil properties. Carbonate minerals in the soil can be derived from high carbonate parent material, additions in the form of carbonat...

  9. Method for synthesizing carbon nanotubes

    DOEpatents

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  10. Method of manufacturing carbon nanotubes

    NASA Technical Reports Server (NTRS)

    Benavides, Jeanette M. (Inventor); Leidecker, Henning W. (Inventor); Frazier, Jeffrey (Inventor)

    2004-01-01

    A process for manufacturing carbon nanotubes, including a step of inducing electrical current through a carbon anode and a carbon cathode under conditions effective to produce the carbon nanotubes, wherein the carbon cathode is larger than the carbon anode. Preferably, a welder is used to induce the electrical current via an arc welding process. Preferably, an exhaust hood is placed on the anode, and the process does not require a closed or pressurized chamber. The process provides high-quality, single-walled carbon nanotubes, while eliminating the need for a metal catalyst.

  11. Carbon isotope effects in carbonate systems

    NASA Astrophysics Data System (ADS)

    Deines, Peter

    2004-06-01

    Global carbon cycle models require a complete understanding of the δ 13C variability of the Earth's C reservoirs as well as the C isotope effects in the transfer of the element among them. An assessment of δ 13C changes during CO 2 loss from degassing magmas requires knowledge of the melt-CO 2 carbon isotope fractionation. In order to examine the potential size of this effect for silicate melts of varying composition, 13C reduced partition functions were computed in the temperature range 275 to 4000 K for carbonates of varying bond strengths (Mg, Fe, Mn, Sr, Ba, Pb, Zn, Cd, Li, and Na) and the polymorphs of calcite. For a given cation and a given pressure the 13C content increases with the density of the carbonate structure. For a given structure the tendency to concentrate 13C increases with pressure. The effect of pressure (‰/10 kbar) on the size of the reduced partition function of aragonite varies with temperature; in the pressure range 1 to 10 5 bars the change is given by: Δ 13C p average=-0.01796+0.06635∗ 10 3/T+0.006875∗ 10 6/T2 For calcite III the pressure effect is on average 1.4× larger than that for aragonite at all temperatures. The nature of the cation in a given structure type has a significant effect on the carbon isotope fractionation properties. The tendency to concentrate 13C declines in the series magnesite, aragonite, dolomite, strontianite, siderite, calcite, smithonite, witherite, rhodochrosite, otavite, cerrusite. For divalent cations a general expression for an estimation of the reduced partition function (β) from the reduced mass (μ = [M Cation × M Carbonate]/[M Cation + M Carbonate]) is: 1000 lnβ=(0.032367-0.072563∗ 10 3/T-0.01073∗ 10 6/T2)∗μ-14.003+29.953∗ 10 3/T+9.4610∗ 10 6/T2 For Mg-calcite the 13C content varies with the Mg concentration. The fractionation between Mg-calcite (X = mole fraction of MgCO 3) and calcite is given by: 1000 ln(α MgCalite- Calcite)=[0.013702-0.10957× 10 3/T+1.35940× 10 6/T2

  12. Determination of 210Pb, 210Po, 226Ra, 228Ra and uranium isotopes in drinking water in order to comply with the requirements of the EU ‘Drinking Water Directive.

    PubMed

    Vasile, M; Loots, H; Jacobs, K; Verheyen, L; Sneyers, L; Verrezen, F; Bruggeman, M

    2016-03-01

    The European Union published in 2013 a new Drinking Water Directive with stricter requirements for measuring natural radioactivity. In order to adhere to this, a method for sequential separation of 210Pb, 210Po, 238U and 234U in drinking water was applied using UTEVA® and Sr resins. Polonium-210, 238U and 234U were quantified using alpha-particle spectrometry and 210Pb using liquid scintillation counting. Radium-226 and 228Ra were determined using 3M Empore Radium RAD Disks, and their quantification was done using a Quantulus™ 1220 liquid scintillation counter. PMID:27358946

  13. Thermal oxidation of carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Glebova, N. V.; Nechitailov, A. A.; Kukushkina, Yu. A.; Sokolov, V. V.

    2011-05-01

    The process of the thermal oxidation of various carbon nanomaterials (multiwalled carbon nanotubes, carbon black, nanoporous carbon and graphite) used in the catalytic layers of electrochemical energy converters (electrolyzers, fuel cells) has been studied. The thermal stability of these materials has been determined. Relationships between the structural characteristics of carbon nanomaterials and the parameters of their thermal oxidation in air have determined using the methods of differential thermal analysis and adsorption-structure analysis.

  14. Implications of carbon dust emission for terrestrail carbon cycling and carbon accounting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion preferentially removes the finest carbon- and nutrient-rich soil fractions, and consequently its role may be significant within terrestrial carbon (C) cycles. However, the impacts of wind erosion on soil organic carbon (SOC) redistribution are not considered in most carbon cycle models,...

  15. WESTCARB Carbon Atlas

    DOE Data Explorer

    The West Coast Regional Carbon Sequestration Partnership (known as WESTCARB) was established in Fall 2003. It is one of seven research partnerships co-funded by DOE to characterize regional carbon sequestration opportunities and conduct pilot-scale validation tests. The California Energy Commission manages WESTCARB and is a major co-funder. WESTCARB is characterizing the extent and capacity of geologic formations capable of storing CO2, known as sinks. Results are entered into a geographic information system (GIS) database, along with the location of major CO2-emitting point sources in each of the six WESTCARB states, enabling researchers and the public to gauge the proximity of candidate CO2 storage sites to emission sources and the feasibility of linking them via pipelines. Specifically, the WESTCARB GIS database (also known as the carbon atlas) stores layers of geologic information about potential underground storage sites, such as porosity and nearby fault-lines and aquifers. Researchers use these data, along with interpreted geophysical data and available oil and gas well logs to estimate the region's potential geologic storage capacity. The database also depicts existing pipeline routes and rights-of-way and lands that could be off-limits, which can aid the development of a regional carbon management strategy. The WESTCARB Carbon Atlas, which is accessible to the public, provides a resource for public discourse on practical solutions for regional CO2 management. A key WESTCARB partner, the Utah Automated Geographic Reference Center, has developed data serving procedures to enable the WESTCARB Carbon Atlas to be integrated with those from other regional partnerships, thereby supporting the U.S. Department of Energy's national carbon atlas, NATCARB

  16. Measurement of carbon capture efficiency and stored carbon leakage

    DOEpatents

    Keeling, Ralph F.; Dubey, Manvendra K.

    2013-01-29

    Data representative of a measured carbon dioxide (CO.sub.2) concentration and of a measured oxygen (O.sub.2) concentration at a measurement location can be used to determine whether the measured carbon dioxide concentration at the measurement location is elevated relative to a baseline carbon dioxide concentration due to escape of carbon dioxide from a source associated with a carbon capture and storage process. Optionally, the data can be used to quantify a carbon dioxide concentration increase at the first location that is attributable to escape of carbon dioxide from the source and to calculate a rate of escape of carbon dioxide from the source by executing a model of gas-phase transport using at least the first carbon dioxide concentration increase. Related systems, methods, and articles of manufacture are also described.

  17. Microbially mediated carbon mineralization: Geoengineering a carbon-neutral mine

    NASA Astrophysics Data System (ADS)

    Power, I. M.; McCutcheon, J.; Harrison, A. L.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2013-12-01

    Ultramafic and mafic mine tailings are a potentially valuable feedstock for carbon mineralization, affording the mining industry an opportunity to completely offset their carbon emissions. Passive carbon mineralization has previously been documented at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond mine and Mount Keith nickel mine, yet the majority of tailings remain unreacted. Examples of microbe-carbonate interactions at each mine suggest that biological pathways could be harnessed to promote carbon mineralization. In suitable environmental conditions, microbes can mediate geochemical processes to accelerate mineral dissolution, increase the supply of carbon dioxide (CO2), and induce carbonate precipitation, all of which may accelerate carbon mineralization. Tailings mineralogy and the availability of a CO2 point source are key considerations in designing tailings storage facilities (TSF) for optimizing carbon mineralization. We evaluate the efficacy of acceleration strategies including bioleaching, biologically induced carbonate precipitation, and heterotrophic oxidation of waste organics, as well as abiotic strategies including enhancing passive carbonation through modifying tailings management practices and use of CO2 point sources (Fig. 1). With the aim of developing carbon-neutral mines, implementation of carbon mineralization strategies into TSF design will be driven by economic incentives and public pressure for environmental sustainability in the mining industry. Figure 1. Schematic illustrating geoengineered scenarios for carbon mineralization of ultramafic mine tailings. Scenarios A and B are based on non-point and point sources of CO2, respectively.

  18. Carbon nanotube core graphitic shell hybrid fibers.

    PubMed

    Hahm, Myung Gwan; Lee, Jae-Hwang; Hart, Amelia H C; Song, Sung Moo; Nam, Jaewook; Jung, Hyun Young; Hashim, Daniel Paul; Li, Bo; Narayanan, Tharangattu N; Park, Chi-Dong; Zhao, Yao; Vajtai, Robert; Kim, Yoong Ahm; Hayashi, Takuya; Ku, Bon-Cheol; Endo, Morinobu; Barrera, Enrique; Jung, Yung Joon; Thomas, Edwin L; Ajayan, Pulickel M

    2013-12-23

    A carbon nanotube yarn core graphitic shell hybrid fiber was fabricated via facile heat treatment of epoxy-based negative photoresist (SU-8) on carbon nanotube yarn. The effective encapsulation of carbon nanotube yarn in carbon fiber and a glassy carbon outer shell determines their physical properties. The higher electrical conductivity (than carbon fiber) of the carbon nanotube yarn overcomes the drawbacks of carbon fiber/glassy carbon, and the better properties (than carbon nanotubes) of the carbon fiber/glassy carbon make up for the lower thermal and mechanical properties of the carbon nanotube yarn via synergistic hybridization without any chemical doping and additional processes. PMID:24224730

  19. Carbon copy deaths: carbon monoxide gas chamber.

    PubMed

    Patel, F

    2008-08-01

    The news media can exert a powerful influence over suicidal behaviour. It has been observed that like-minded individuals are able to preplan a group suicide method using modern communication technology in the form of websites and online chatrooms and mobile phone texting. A case of carbon monoxide (CO) poisoning is presented to illustrate the recent phenomenon of cyber suicides by suffocation from a burning barbecue (charcoal burner) in 'gas chamber' conversions. Although barbecues (BBQ) are very popular in Britain and widely available, there have been relatively few reported cases of copycat deaths from CO gas suffocation. PMID:18586213

  20. Big Sky Carbon Atlas

    DOE Data Explorer

    The Big Sky Carbon Atlas is an online geoportal designed for you to discover, interpret, and access geospatial data and maps relevant to decision support and education on carbon sequestration in the Big Sky Region. In serving as the public face of the Partnership's spatial Data Libraries, the Atlas provides a gateway to geographic information characterizing CO2 sources, potential geologic sinks, terrestrial carbon fluxes, civil and energy infrastructure, energy use, and related themes. In addition to directly serving the BSCSP and its stakeholders, the Atlas feeds regional data to the NatCarb Portal, contributing to a national perspective on carbon sequestration. Established components of the Atlas include a gallery of thematic maps and an interactive map that allows you to: • Navigate and explore regional characterization data through a user-friendly interface • Print your map views or publish them as PDFs • Identify technical references relevant to specific areas of interest • Calculate straight-line or pipeline-constrained distances from point sources of CO2 to potential geologic sink features • Download regional data layers (feature under development) (Acknowledgment to the Big Sky Carbon Sequestration Partnership (BSCSP); see home page at http://www.bigskyco2.org/)

  1. Chemically modified carbonic anhydrases useful in carbon capture systems

    SciTech Connect

    Novick, Scott; Alvizo, Oscar

    2013-01-15

    The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

  2. Response of carbon-carbon composites to challenging environments

    NASA Technical Reports Server (NTRS)

    Maahs, Howard G.; Ohlhorst, Craig W.; Barrett, David M.; Ransone, Philip O.; Sawyer, J. Wayne

    1988-01-01

    This paper presents results from material performance evaluations of oxidation-resistant carbon-carbon composites intended for multiuse aerospace applications, which cover the effects of the following environmental parameters: the oxidizing nature of the environments (including both high and low oxygen partial pressures), high temperatures, moisture, cyclic temperature service, and foreign-object impact. Results are presented for the carbon-carbon material currently in use as the thermal-protection-system material on Space Shuttle, as well as for newer and more advanced structural forms of carbon-carbon composites.

  3. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  4. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2012-01-24

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  5. Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2008-10-21

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  6. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2011-08-16

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  7. Design and syntheses of hybrid metal-organic materials based on K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] metallotectons

    NASA Astrophysics Data System (ADS)

    Sun, Yayong; Zong, Yingxia; Ma, Haoran; Zhang, Ao; Liu, Kang; Wang, Debao; Wang, Wenqiang; Wang, Lei

    2016-05-01

    By using K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] (C2O42-=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C2O4)2(H2O)2}2]·(H-L1)2·H2O 1, [Fe(C2O4)Cl2]·(H2-L2)0.5·(L2)0.5·H2O 2, [{Fe(C2O4)1.5Cl2}2]·(H-L3)43, [Fe2(C2O4)Cl8]·(H2-L4)2·2H2O 4, K[Al(C2O4)3]·(H2-L5)·2H2O 5, K[Al(C2O4)3]·(H-L6)2·2H2O 6, K[Cr(C2O4)3]·2H2O 7, Na[Fe(C2O4)3]·(H-L6)2·2H2O 8 (with L1=4-dimethylaminopyridine, L2=2,3,5,6-tetramethylpyrazine, L3=2-aminobenzimidazole, L4=1,4-bis-(1H-imidazol-1-yl)benzene, L5=1,4-bis((2-methylimidazol-1-yl)methyl)benzene, L6=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C2O4)2(H2O)2]- unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C2O4)Cl2]- anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe2(C2O4)3Cl4]4- unit. Compound 4 features distinct [Fe2(C2O4)Cl8]4- units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C2O4)3]3- units and K+ cations. The 1D chains are further extended into 3D antionic H-bonded framework through O-H···O H-bonds. Compounds 6-8 show 2D [KAl(C2O4)3]2- layer, [KCr(C2O4)3]2- layer and [NaFe(C2O4)3]2- layer, respectively.

  8. Measuring black carbon spectral extinction in the visible and infrared

    NASA Astrophysics Data System (ADS)

    Smith, A. J. A.; Peters, D. M.; McPheat, R.; Lukanihins, S.; Grainger, R. G.

    2015-09-01

    This work presents measurements of the spectral extinction of black carbon aerosol from 400 nm to 15 μm. The aerosol was generated using a Miniature Combustion Aerosol Standard soot generator and then allowed to circulate in an aerosol cell where its extinction was measured using a grating spectrometer in the visible and a Fourier transform spectrometer in the infrared. Size distribution, number concentration, and mass extinction cross sections have also been obtained using single-particle aerosol samplers. A mean mass extinction cross section at 550 nm of 8.3 ± 1.6 m2 g-1 is found which, assuming a reasonable single scatter albedo of 0.2, corresponds to a mass absorption cross section of 6.6 ± 1.3 m2 g-1. This compares well with previously reported literature values. Computer analysis of electron microscope images of the particles provides independent confirmation of the size distribution as well as fractal parameters of the black carbon aerosol. The aerosol properties presented in this work are representative of very fresh, uncoated black carbon aerosol. After atmospheric processing of such aerosols (which could include mixing with other constituents and structural changes), different optical properties would be expected.

  9. Tensile Strength of Carbon/Carbon Composites

    NASA Astrophysics Data System (ADS)

    Hatta, Hiroshi; Aoi, Tatsuji; Kawahara, Itaru; Kogo, Yasuo; Shiota, Ichiro

    In order to identify ruling mechanisms of tensile fracture of Carbon/Carbon composites (C/Cs), tensile tests were carried out for various C/Cs as functions of the density, heat treatment temperature, and interfacial strength between fiber and matrix. Three processing routes of preformed yarn, resin char, and HIP processes were adopted to densify C/Cs. These C/Cs were finally heat-treated at temperatures from 2273K to 3300K. The interfacial strength between fiber and matrix was varied by the selection of processing routes. As a result, two ruling failure mechanisms were identified. At density lower than 1.6g/cm3, the tensile fracture was controlled by stress transfer capability from the matrix to reinforcing fibers. However, at higher density than 1.6g/cm3, tensile strength was primarily governed by the interfacial strength between the matrix and fibers. Thus the latter mechanism is nearly same as ceramic matrix composites.

  10. Shrimp-shell derived carbon nanodots as carbon and nitrogen sources to fabricate three-dimensional N-doped porous carbon electrocatalysts for the oxygen reduction reaction.

    PubMed

    Liu, Rongrong; Zhang, Haimin; Liu, Shengwen; Zhang, Xian; Wu, Tianxing; Ge, Xiao; Zang, Yipeng; Zhao, Huijun; Wang, Guozhong

    2016-02-01

    Development of cheap, abundant and metal-free N-doped carbon materials as high efficiency oxygen reduction electrocatalysts is crucial for their practical applications in future fuel cell devices. Here, three-dimensional (3D) N-doped porous carbon (NPC) materials have been successfully developed by a simple template-assisted (e.g., SiO2 spheres) high temperature pyrolysis approach using shrimp-shell derived N-doped carbon nanodots (N-CNs) as carbon and nitrogen sources obtained through a facile hydrothermal method. The shrimp-shell derived N-CNs with a product yield of ∼ 5% possess rich surface O- and N-containing functional groups and small nanodot sizes of 1.5-5.0 nm, which are mixed with surface acidification treated SiO2 spheres with an average diameter of ∼ 200 nm in aqueous solution to form a N-CNs@SiO2 composite subjected to a thermal evaporation treatment. The resultant N-CNs@SiO2 composite is further thermally treated in a N2 atmosphere at different pyrolysis temperatures, followed by acid etching, to obtain 3D N-doped porous carbon (NPC) materials. As electrocatalysts for oxygen reduction reaction (ORR) in alkaline media, the experimental results demonstrate that 3D NPC obtained at 800 °C (NPC-800) with a surface area of 360.2 m(2) g(-1) exhibits the best ORR catalytic activity with an onset potential of -0.06 V, a half wave potential of -0.21 V and a large limiting current density of 5.3 mA cm(-2) (at -0.4 V, vs. Ag/AgCl) among all NPC materials investigated, comparable to that of the commercial Pt/C catalyst with an onset potential of -0.03 V, a half wave potential of -0.17 V and a limiting current density of 5.5 mA cm(-2) at -0.4 V. Such a 3D porous carbon ORR electrocatalyst also displays superior durability and high methanol tolerance in alkaline media, apparently better than the commercial Pt/C catalyst. The findings of this work would be valuable for the development of low-cost and abundant N-doped carbon materials from biomass as high

  11. Carbon-particle generator

    DOEpatents

    Hunt, A.J.

    1982-09-29

    A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

  12. Pyrolyzed carbon film diodes.

    PubMed

    Morton, Kirstin C; Tokuhisa, Hideo; Baker, Lane A

    2013-11-13

    We have previously reported pyrolyzed parylene C (PPC) as a conductive carbon electrode material for use with micropipets, atomic force microscopy probes, and planar electrodes. Advantages of carbon electrode fabrication from PPC include conformal coating of high-aspect ratio micro/nanoscale features and the benefits afforded by chemical vapor deposition of carbon polymers. In this work, we demonstrate chemical surface doping of PPC through the use of previously reported methods. Chemically treated PPC films are characterized by multiple spectroscopic and electronic measurements. Pyrolyzed parylene C and doped PPC are used to construct diodes that are examined as both p-n heterojunction and Schottky barrier diodes. Half-wave rectification is achieved with PPC diodes and demonstrates the applicability of PPC as a conductive and semiconductive material in device fabrication. PMID:24090451

  13. The Pyrogenic Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Bird, Michael I.; Wynn, Jonathan G.; Saiz, Gustavo; Wurster, Christopher M.; McBeath, Anna

    2015-05-01

    Pyrogenic carbon (PyC; includes soot, char, black carbon, and biochar) is produced by the incomplete combustion of organic matter accompanying biomass burning and fossil fuel consumption. PyC is pervasive in the environment, distributed throughout the atmosphere as well as soils, sediments, and water in both the marine and terrestrial environment. The physicochemical characteristics of PyC are complex and highly variable, dependent on the organic precursor and the conditions of formation. A component of PyC is highly recalcitrant and persists in the environment for millennia. However, it is now clear that a significant proportion of PyC undergoes transformation, translocation, and remineralization by a range of biotic and abiotic processes on comparatively short timescales. Here we synthesize current knowledge of the production, stocks, and fluxes of PyC as well as the physical and chemical processes through which it interacts as a dynamic component of the global carbon cycle.

  14. Carbon Fibers Conductivity Studies

    NASA Technical Reports Server (NTRS)

    Yang, C. Y.; Butkus, A. M.

    1980-01-01

    In an attempt to understand the process of electrical conduction in polyacrylonitrile (PAN)-based carbon fibers, calculations were carried out on cluster models of the fiber consisting of carbon, nitrogen, and hydrogen atoms using the modified intermediate neglect of differential overlap (MINDO) molecular orbital (MO) method. The models were developed based on the assumption that PAN carbon fibers obtained with heat treatment temperatures (HTT) below 1000 C retain nitrogen in a graphite-like lattice. For clusters modeling an edge nitrogen site, analysis of the occupied MO's indicated an electron distribution similar to that of graphite. A similar analysis for the somewhat less stable interior nitrogen site revealed a partially localized II electron distribution around the nitrogen atom. The differences in bonding trends and structural stability between edge and interior nitrogen clusters led to a two-step process proposed for nitrogen evolution with increasing HTT.

  15. Polymeric Carbon Dioxide

    SciTech Connect

    Yoo, C-S.

    1999-11-02

    Synthesis of polymeric carbon dioxide has long been of interest to many chemists and materials scientists. Very recently we discovered the polymeric phase of carbon dioxide (called CO{sub 2}-V) at high pressures and temperatures. Our optical and x-ray results indicate that CO{sub 2}-V is optically non-linear, generating the second harmonic of Nd: YLF laser at 527 nm and is also likely superhard similar to cubic-boron nitride or diamond. CO{sub 2}-V is made of CO{sub 4} tetrahedra, analogous to SiO{sub 2} polymorphs, and is quenchable at ambient temperature at pressures above 1 GPa. In this paper, we describe the pressure-induced polymerization of carbon dioxide together with the stability, structure, and mechanical and optical properties of polymeric CO{sub 2}-V. We also present some implications of polymeric CO{sub 2} for high-pressure chemistry and new materials synthesis.

  16. Carbon Nanotubes for Supercapacitor

    PubMed Central

    2010-01-01

    As an electrical energy storage device, supercapacitor finds attractive applications in consumer electronic products and alternative power source due to its higher energy density, fast discharge/charge time, low level of heating, safety, long-term operation stability, and no disposable parts. This work reviews the recent development of supercapacitor based on carbon nanotubes (CNTs) and their composites. The purpose is to give a comprehensive understanding of the advantages and disadvantages of carbon nanotubes-related supercapacitor materials and to find ways for the improvement in the performance of supercapacitor. We first discussed the effects of physical and chemical properties of pure carbon nanotubes, including size, purity, defect, shape, functionalization, and annealing, on the supercapacitance. The composites, including CNTs/oxide and CNTs/polymer, were further discussed to enhance the supercapacitance and keep the stability of the supercapacitor by optimally engineering the composition, particle size, and coverage. PMID:20672061

  17. Orbiting Carbon Observatory

    NASA Technical Reports Server (NTRS)

    Miller, Charles E.

    2005-01-01

    Human impact on the environment has produced measurable changes in the geological record since the late 1700s. Anthropogenic emissions of CO2 today may cause the global climate to depart for its natural behavior for many millenia. CO2 is the primary anthropogenic driver of climate change. The Orbiting Carbon Observatory goals are to help collect measurements of atmospheric CO2, answering questions such as why the atmospheric CO2 buildup varies annually, the roles of the oceans and land ecosystems in absorbing CO2, the roles of North American and Eurasian sinks and how these carbon sinks respond to climate change. The present carbon cycle, CO2 variability, and climate uncertainties due atmospheric CO2 uncertainties are highlighted in this presentation.

  18. HOLLOW CARBON ARC DISCHARGE

    DOEpatents

    Luce, J.S.

    1960-10-11

    A device is described for producing an energetic, direct current, hollow, carbon-arc discharge in an evacuated container and within a strong magnetic field. Such discharges are particularly useful not only in dissociation and ionization of high energy molecular ion beams, but also in acting as a shield or barrier against the instreaming of lowenergy neutral particles into a plasma formed within the hollow discharge when it is used as a dissociating mechanism for forming the plasma. There is maintained a predetermined ratio of gas particles to carbon particles released from the arc electrodes during operation of the discharge. The carbon particles absorb some of the gas particles and are pumped along and by the discharge out of the device, with the result that smaller diffusion pumps are required than would otherwise be necessary to dispose of the excess gas.

  19. Superconductivity in carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Dlugon, Katarzyna

    The purpose of this thesis is to explain the phenomenon of superconductivity in carbon nanomaterials such as graphene, fullerenes and carbon nanotubes. In the introductory chapter, there is a description of superconductivity and how it occurs at critical temperature (Tc) that is characteristic and different to every superconducting material. The discovery of superconductivity in mercury in 1911 by Dutch physicist Heike Kamerlingh Onnes is also mentioned. Different types of superconductors, type I and type II, low and high temperatures superconductors, as well as the BCS theory that was developed in 1957 by Bardeen, Cooper, and Schrieffer, are also described in detail. The BCS theory explains how Cooper's pairs are formed and how they are responsible for the superconducting properties of many materials. The following chapters explain superconductivity in doped fullerenes, graphene and carbon nanotubes, respectively. There is a thorough explanation followed by many examples of different types of carbon nanomaterials in which small changes in chemical structure cause significant changes in superconducting properties. The goal of this research was not only to take into consideration well known carbon based superconductors but also to search for the newest available materials such as the fullerene nanowhiskers discovered quite recently. There is also a presentation of fairly new ideas about inducing superconductivity in a monolayer of graphene which is more challenging than inducing superconductivity in graphite by simply intercalating metal atoms between its graphene sheets. An effort has been taken to look for any available information about carbon nanomaterials that have the potential to superconduct at room temperature, mainly because discovery of such materials would be a real revolution in the modern world, although no such materials have been discovered yet.

  20. Nanotube composite carbon fibers

    NASA Astrophysics Data System (ADS)

    Andrews, R.; Jacques, D.; Rao, A. M.; Rantell, T.; Derbyshire, F.; Chen, Y.; Chen, J.; Haddon, R. C.

    1999-08-01

    Single walled carbon nanotubes (SWNTs) were dispersed in isotropic petroleum pitch matrices to form nanotube composite carbon fibers with enhanced mechanical and electrical properties. We find that the tensile strength, modulus, and electrical conductivity of a pitch composite fiber with 5 wt % loading of purified SWNTs are enhanced by ˜90%, ˜150%, and 340% respectively, as compared to the corresponding values in unmodified isotropic pitch fibers. These results serve to highlight the potential that exits for developing a spectrum of material properties through the selection of the matrix, nanotube dispersion, alignment, and interfacial bonding.